GEOSC 10 All

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1. Human population continues to grow. Looking at many of the things we use on Earth (farmland and land for wood and other things, fish in the sea, etc.): A) We use almost everything, 99% or more, so we're in deep doo-doo for the future. B) Our use is large but not everything; we are approaching use of half of all that is available. C) We use less than 1% or so, the tiniest bit, with vast amounts out there in the wilderness somewhere. D) We use almost all of the Diet Pepsi springs but with huge natural reserves of Diet Coke. E) We use almost all of the dilithium crystals for our warp drives. A nighttime picture of Earth shows human-controlled lights spread across most of the land surface, and a few out in the ocean on ships. In round numbers, humans (and the things we grow, or the pets we live with): A) Still use much less than 10% of everything the world makes available and that we find useful. B) Use much more than 90% of everything the world makes available and that we find useful. C) Use almost all of the fireflies in the world to generate all of that light. D) Use almost 50% of everything the world makes available and that we find useful. E) Use almost all of the bioluminescent algae in the oceans to generate all of that light.

1. B) Our use is large but not everything; we are approaching use of half of all that is available. 2. D) Use almost 50% of everything the world makes available and that we find useful. Notes: We have removed perhaps 90% of the large fish in the ocean, and we raise crops or cut trees on much of the land surface. In very round numbers, we are approaching use of half of everything available on the planet, with the likelihood that we will greatly increase our population in the future.

1. Before they can be published, scientific papers must be peer-reviewed. This means that: ( A) Some other scientific experts read the papers and guarantee that they are True. B) Some other scientific experts read the papers and provide quality control by eliminating many mistakes. C) An editor reads the papers, to make sure that all the semicolons are in the correct places. D) Everyone in the world is given the opportunity to comment on the papers through a specially maintained blog. E) Government bureaucrats read the papers, to be sure that the papers do not insult the political positions of the current officeholders. 2. What is accurate about peer review of scientific papers? A) It is why we call scientific papers "primary sources". B) It insures that they are True. C) It provides quality control by eliminating many mistakes. D) It is primarily done by government bureaucrats hired for that purpose. E) It almost always leads to the recommendation that the papers be published without changes.

1. B) Some other scientific experts read the papers and provide quality control by eliminating many mistakes. 2. C) It provides quality control by eliminating many mistakes. Notes: Reviewers work hard to identify errors of any sort, almost always identify many, and then the reviewers and editors insist that those errors be fixed before publication. Review is done voluntarily by scientists; this is part of the cost of being a member of this great human undertaking. Science doesn't claim Truth; although science strives to be as accurate as humanly possible, that is often well short of Truth. Asking grandpa what school was like in his childhood gives you a primary source (grandpa), even if he insists that he walked 20 miles through neck-deep snow, uphill both ways. Some primary sources have selective memories.

1. Air moves in from the Pacific, over the Sierra Nevada (a mountain range), and down towards Death Valley. What happens? A) As the air rises up the Sierra, the air expands, making rain and snow, and cooling by 5 degrees F per thousand feet upward. B) As the air rises up the Sierra, the air is compressed, making rain and snow, and warming by 5 degrees F per thousand feet upward. C) As the air rises up the Sierra, the air expands, making rain and snow, and cooling by 3 degrees F per thousand feet upward. D) As the air rises up the Sierra, the air is compressed, evaporating clouds and warming by 5 degrees F per thousand feet upward. E) As the air rises up the Sierra, the air cools, making clouds that rain Diet Pepsi on unsuspecting marmots beneath. 2. Rising air expands and cools; sinking air is compressed and warms. Typically, the size of the temperature change is: A) 5oF/1000 ft change in elevation going up, and 3oF/1000 ft coming down B) 5 F/1000 ft change in elevation if condensation or evaporation are not occurring; 3 F/1000 ft change in elevation if condensation or evaporation are occurring C) Zero if cooling of the air is causing vapor to condense and form rain clouds, and 5 F/1000 ft change in elevation if clouds are not forming D) 5oF/1000 ft change in elevation E) No temperature change occurs when air moves vertically

1. C) As the air rises up the Sierra, the air expands, making rain and snow, and cooling by 3 degrees F per thousand feet upward. Feedback: If clouds and rain are not forming, rising air cools by about 5 degrees F per thousand feet upward. But, condensing water to make clouds and rain releases the heat that was stored when the water evaporated, so air that is making clouds and rain doesn't cool as much as dry air. The cooling of air making clouds and rain is about 3 degrees F per thousand feet upward. 2. B) 5 F/1000 ft change in elevation if condensation or evaporation are not occurring; 3 F/1000 ft change in elevation if condensation or evaporation are occurring Notes: The expansion of air on rising takes work, which cools air, at about 5 F/1000 ft, and the compression on sinking reverses this. But, if rising air cools enough, further cooling causes water to condense, the heat given off by the condensation partially offsets the cooling, leaving about 3 F/1000. If there are clouds in the air as it sinks again, the air will warm about 3 F/1000 ft, with some energy being used to evaporate the cloud water rather than to warm the air; once the clouds are gone, then the full 5 F/1000 ft warming occurs.

1. The law that established Yellowstone as the first national park: A) Was written by socialists, because it mentions the word "society". B) Clearly was written by politicians running for reelection, because it required that the parks make people happy today even if things are damaged for the future. C) Was written by communists, because park rangers have installed commodes in commodious outhouses. D) Was written to help people today and in the future, by requiring that the parks provide enjoyment today while preserving the parks for the future. E) Clearly was written by political conservatives, because it required conservation of the parks even if that means locking people out today. 2. One of the big problems faced by National Parks is that: A) They must preserve valuable things for the future, and not allow people to enjoy those things today, but people want to enjoy them now. B) They must provide marriage counseling for their moose, so that the mommy and daddy moose have lots of baby moose that can be sold on the export market to raise money to pay the rangers. C) They must allow people to enjoy things today even if that destroys things that many people would like to save for future generations. D) They must allow people to enjoy things today, and preserve those things for the future, but achieving both of these is not easy. E) They must cure the chipmunks of their cappuccino habit or Congress will cut funding, and getting chipmunks off caffeine isn't easy.

1. D) Was written to help people today and in the future, by requiring that the parks provide enjoyment today while preserving the parks for the future. 2. D) They must allow people to enjoy things today, and preserve those things for the future, but achieving both of these is not easy. Notes: The law that established Yellowstone as the first national park required "conservation... unimpaired for...future generations" and "to provide for the enjoyment" of the parks. But what if so many people want to visit that they scare the wolves, or trample the soil and kill the roots of the big trees? Enjoying and preserving at the same time isn't easy! Fortunately, caffeinated chipmunks and maritally distressed moose are not big problems.

1. The jobs of geologists include: A) Supervising taste-tests between Coke and Pepsi. B) Writing new computer viruses, to make people really depressed. C) Cloning new organisms to sabotage competing companies. D) Supervising taste-tests between Coke and Pepsi, and not telling anyone that the geologists drink coffee at home. E) Finding valuable things in the Earth, warning about hazards, learning how the Earth works, and educating and entertaining people. 2. Geology departments are seeing a lot of recruiters recently, because geology is an in-demand major. Which of the following is NOT a job that geologists commonly end up doing? A) Packaging substandard mortgages into "securities" and trying to sell them to unsuspecting people. 2) Educator or teacher. 3) Exploring for oil, coal, gas, diamonds, gold, or other valuable things. 4) Helping people avoid landslides, tsunamis, volcanic eruptions, and other natural disasters. 5) Helping people use knowledge of the Earth to make wise decisions.

1. E) Finding valuable things in the Earth, warning about hazards, learning how the Earth works, and educating and entertaining people. 2. A) Packaging substandard mortgages into "securities" and trying to sell them to unsuspecting people. Notes: Most jobs in geology involve finding valuable things: oil, clean water, ores, and more. But, geologists also teach and communicate in other interesting and entertaining ways, warn about hazards, and help understand the Earth system.

Pictures 1 and 2 [See image: UNIT 6.12] show two very different looking rivers. What can you say about them? A) 1 is a meandering stream with clay-rich banks, and 2 is a braided stream with sandy or gravelly banks. B) 1 is a meandering stream with sandy or gravelly banks, and 2 is a braided stream with clay-rich banks. C) 1 is a braided stream with clay-rich banks, and 2 is a meandering stream with sandy or gravelly banks. D) 1 is a braided stream with sandy or gravelly banks, and 2 is a meandering stream with clay-rich banks. E) Both are anastamosing streams with concrete banks.

A) 1 is a meandering stream with clay-rich banks, and 2 is a braided stream with sandy or gravelly banks.

Near Aaronsburg, PA, a company wanted to start a limestone quarry, and planned to pump lots of water out of the ground to make things fairly dry near the quarry so it wouldn't fill with water. Concern was raised—would this affect the nearby trout streams? So, a little harmless dye was placed in a sinkhole next to the proposed quarry, and a fire-engine pumper added a lot of water to the sinkhole. How long did it take, or will take, for the dye to reach the trout stream? A) A few hours to days. B) A few centuries. C) A few thousand years. D) Never, because sinkholes don't drain to trout streams. E) Never, because all sinkholes drain to Michigan.

A) A few hours to days. Feedback: The dye showed up in a few hours, and the quarry was not excavated. Sinkholes often connect directly and quickly to underground caves or big cracks, and thus to streams, allowing rapid drainage. There are rock units that would hold their water for centuries or millennia, but such units have small spaces, not caves and sinkholes. Local sinkholes do drain to trout streams, and Michigan has to make their own water pollution because water pollution from Pennsylvania does not reach them. (Fun thing to do if you're bored: fit this question into the Michigan fight song.)

Which is more likely to contain reliable information? A) A refereed article in a learned journal. B) A cola commercial. C) A magazine article summarizing recent newspaper and television reports. D) A web page posted by an independent "think-tank". E) The views of public figures reported in a newspaper article.

A) A refereed article in a learned journal. Notes: No source of information is perfect, but the refereed articles in learned journals put immense effort into "getting it right". The web has reliable information, of course, but probably most of the information on the web is not especially reliable. The web is very inexpensive, and lots of people put junk on it. Think tanks also often are pushing an agenda, and try to "spin" information their way. Most newspapers are around for the long haul, and try to make the news fairly accurate, although some newspapers do have agendas, and the editorial pages are not especially accurate. But, if the report is on the views of a public figure, the newspaper may accurately report what the public figure said, but what the public figure said may be less than completely accurate. Some magazines are quite good and careful, but many are pushing a belief or just overhyping things to tease you into buying the magazine. And while you are welcome to believe that drinking a particular cola makes you sexy... don't count on it.

[See image: UNIT 8.11] The pink arrows point to a barrier beach, formed when waves fromthe ocean (on the left) washed away mud and piled up sand, after themud and sand were delivered by the stream flowing in from the upperright. The yellow arrows point to interesting features. How did they form? A) A storm broke through the barrier beach and pushed sand farther inland. B) The beach used to be where the yellow arrows are, but was moved seaward by the river, which flowed over the old beach. C) A sinkhole opened behind the barrier beach, and the yellow-arrowed material slumped into it. D) The stream flowing from the upper right is a braided stream, and the yellow arrows point to levees that keep the stream from flooding. E) Beavers dug through the barrier beach and threw the material behind them, forming the yellow-arrowed deposits.

A) A storm broke through the barrier beach and pushed sand farther inland. Feedback: Barrier beaches are piled up by waves, but especially strong storms often break through the beaches. Some of the sand at such new inlets is moved toward the land, often forming new beach-like deposits such as those indicated by the yellow arrows. Some sand is also often moved offshore into deeper water. The river would have buried or reworked the yellow-arrowed features if the river flowed over them, there is no sign of a sinkhole, and bars in the river can be seen to be lower and elongated, not on top and transverse as the yellow-arrowed features are.

An unconformity is: A) A time gap in a sequence of sedimentary rocks caused by a period of erosion or nondeposition. B) The principle that younger sedimentary rocks normally occur on top of older rocks, unless they are turned upside-down by mountain building. C) A clast of some other, older rock in a sedimentary rock, showing that the clast is older than the sedimentary rock. D) An igneous rock intrusion cutting a sedimentary rock, showing that the igneous rock is younger than the sedimentary rock. E) The principle that younger fossils look more like living types than do older fossils.

A) A time gap in a sequence of sedimentary rocks caused by a period of erosion or nondeposition. Notes: Most of the land is eroding most of the time. Streams carry rocks and mud away from the mountains, lowering the mountains. Eventually, if mountains are lowered enough, by erosion or by Death-Valley-type faulting or some other process, new sediments may be deposited on top, but there will be a surface separating older rocks from younger rocks, and no rocks from the in-between time. This surface is called an unconformity. One can see older clasts in younger rocks, but these are usually called "older clasts in younger rocks", not unconformities. Whatever events made the old rocks, broke them up, and transported them to the site where the new rock formed must have happened before the new rock formed. A rock must exist before it can be cut, so an igneous rock cutting a sedimentary rock is younger than the sedimentary rock, and geologists do study such cross-cutting relationships, but they aren't unconformities. Younger sedimentary rocks do occur on top of older rocks unless turned upside-down by mountain building, but this goes by the fancy name of the "principle of superposition", not "unconformity". And younger fossils looking more like living things than do older fossils is William Smith's "law" of faunal succession, not an unconformity.

Look at the picture above [See image: UNIT 9.3] which shows a region just less than a foot across, of a stream deposit from the base of the same pile of rocks that show up in Bryce Canyon. This picture was taken in the face of a cliff in Red Canyon, just west of Bryce Canyon National Park. A indicates a piece of limestone that has been rounded off in a stream; B indicates a mass of sand glued together by hard-water deposits, and C indicates another such mass of sand glued together by hard-water deposits . In order of time of formation, they are: A) A was formed first, then B was glued together by hard-water deposits, then C was glued together by hard-water deposits. B) B was glued together by hard-water deposits, then C was glued together by hard-water deposits, then A was formed. C) C was glued together by hard-water deposits, then B was glued together by hard-water deposits, then A was formed. D) C was glued together by hard-water deposits, then A was formed, then B was glued together by hard-water deposits. E) B was glued together by hard-water deposits, then A was formed, then C was glued together by hard-water deposits.

A) A was formed first, then B was glued together by hard-water deposits, then C was glued together by hard-water deposits.

We now know a lot about the big processes that shape the Earth's geology. Which of the following is NOT correct about that knowledge? A) Almost all of the motion of lithospheric plates is vertical, with almost no horizontal motion. B) The lithosphere is broken into a few large plates plus a few smaller ones. C) Most formation of mountains occurs near the edges of the lithospheric plates. D) The upper layer of the Earth, called the lithosphere, is made of plates that float on softer material below. E) Convection occurs in the hot, soft rocks below the lithosphere.

A) Almost all of the motion of lithospheric plates is vertical, with almost no horizontal motion. Feedback: Although there surely is vertical motion, making mountains and subduction zones, most of the motion is horizontal, with plates moving hundreds or thousands of miles.

Chemists recognize many different elements, such as gold, or oxygen, or carbon, or iron. Suppose you got some iron, and started splitting it into smaller pieces. The smallest piece that would still be called "iron" would be: A) An atom B) A proton C) A quark D) An electron E) A neutron

A) An atom

A) An atom Notes: We can break matter down into atoms (Greek for "not cuttable" because the Greeks didn't have atom smashers or other exotic tools that would allow cutting atoms into smaller pieces). All of the wrong answers here are smaller pieces of atoms, but they wouldn't be gold any more; you can make any of the elements out of these pieces.

The picture above shows: [See image: UNIT 11.13] A) An upside-down dinosaur track. B) A right-side-up dinosaur track. C) A sideways dinosaur track; the picture should be rotated ninety degrees clockwise to be right-side-up. D) A sideways dinosaur track; the picture should be rotated ninety degrees counterclockwise to be right-side-up. E) Mud cracks.

A) An upside-down dinosaur track. Feedback: This is a dinosaur track, from Dinosaur Ridge, and the dinosaur stomped down into the mud, so the track is upside-down; the instructional team used the power of modern computers to invert the picture.

Tsunamis: A) Are like tornadoes; they can be predicted with some accuracy seconds to hours before they strike in most cases, allowing quick warnings to save many lives. B) Are completely unpredictable on all time scales. C) Are like the weather; they can be predicted fairly accurately days in advance, allowing wise planning. D) Are like the seasons; they can be predicted accurately months in advance, allowing wise planning. E) Always are huge and destructive.

A) Are like tornadoes; they can be predicted with some accuracy seconds to hours before they strike in most cases, allowing quick warnings to save many lives. Feedback: Because tsunamis are triggered by earthquakes, among other things, and we cannot predict earthquakes accurately, we cannot make months-in-advance predictions of tsunamis. The p-waves from the earthquakes that cause the most common tsunamis move much more rapidly than the tsunamis do, allowing timely warnings; however, because the tsunamis get where they are going in hours or less typically, not much time is available. Water does go out before rushing in along some coasts, but comes in before going out along other coasts, waves have "up" and "down" parts, and some coasts get an "up" first while other coasts get a "down" first. Little earthquakes make little tsunamis; big earthquakes make big tsunamis.

What geological processes have caused the Grand Canyon to be wider at the top than at the bottom? A) As the river cuts down, the steep walls of the canyon experience mass movement (rocks fall, slump, creep or otherwise move off the walls and down to the river), so the top of the canyon is widening as the river deepens the bottom. B) The bulldozer that made the canyon was wearing out its blade as it dug down. C) Uplift of the Rockies split the canyon, and the sides fell away to leave the top wider than the bottom. D) The river once was several miles wide, but has gotten narrower as it cut down through the rocks. E) The canyon really isn't wider at the top; that's just an optical illusion.

A) As the river cuts down, the steep walls of the canyon experience mass movement (rocks fall, slump, creep or otherwise move off the walls and down to the river), so the top of the canyon is widening as the river deepens the bottom.

Regions with mountain glaciers that experience much surface melting in the summer typically are eroded: A) At a faster rate than regions with streams but no glaciers. B) At the same rate as regions with streams but no glaciers. C) At a slower rate than regions with streams but no glaciers. D) At the same rate that natural rainfall dissolves granite. E) Not at all; no erosion occurs in typical regions with melting glaciers.

A) At a faster rate than regions with streams but no glaciers. Feedback: Yosemite Valley, Glacier National Park and other glaciated regions still bear the unmistakable marks of glaciers despite more than 10,000 years of modification by streams. Glaciers experiencing melting change the landscape faster than streams do.

What do we know about the effects of humans on extinction of plant and animal species on Earth? A) Both prehistoric and modern humans have been responsible for extinctions. B) Extinction did not exist anywhere at any time until humans showed up and trashed the joint. C) Prehistoric humans lived in harmony with nature, but modern humans don't, so prehistoric humans didn't cause extinctions but modern humans do. D) Neither prehistoric nor modern humans have contributed to any extinctions. E) Prehistoric hunter-gatherers gathered up lots of species, but modern humans have national parks, so prehistoric humans caused extinctions but modern humans don't.

A) Both prehistoric and modern humans have been responsible for extinctions. Feedback: Extinction has happened naturally, but humans have greatly accelerated the rate. Early humans caused extinctions, and so have modern humans, with real worries that the rate of extinction will accelerate a lot more in the near future.

If you went swimming in the single channel of this river, and grabbed a sample of the river bank, what would you likely come up with? A) Clay, that sticks together and can hold up steep slopes. B) Sand, that can make really steep slopes such as are seen in sand castles. C) Boulders, that pile together to hold up river banks. D) A mixture of clay, sand and boulders, called till. E) Sand, that collapses to plug channels .

A) Clay, that sticks together and can hold up steep slopes. Notes: This is a meandering channel, and these normally are fairly deep and narrow, so the materials of the banks should be able to stick together and support a steep slope. Sand can be steep when damp, but slumps to nearly flat when wet, and boulders or too much sand plug streams and make a braided pattern, whereas clay can make very steep slopes.

Among fossil fuels: A) Coal is made by heating of woody plant material, and oil is made by heating of algae. B) Oil is made by heating of woody plant material, and coal is made by heating of algae. C) Coal is made by heating of plant material deposited on land, and oil is made by heating of plant material deposited in water. D) Oil is made by heating of plant material deposited on land, and coal is made by heating of plant material deposited in water. E) Oil is made by spraying WD-40 on duct tape, and coal is made by being bad so Santa delivers it to your stocking.

A) Coal is made by heating of woody plant material, and oil is made by heating of algae. Feedback: Slimy algae gives slimy oil; chunky wood gives chunky coal. Works great. Duct tape and WD-40 are the quick-fix tool kit; if something moves but it shouldn't, apply duct tape, and if something doesn't move but it should, apply WD-40. None of you would be so bad as to merit coal in your stocking, but we presume Santa gets it from a mine somewhere.

Heat is moved around by convection, conduction and radiation (and by lemmings carrying space heaters, if lemmings ever carry space heaters). Which statement is more nearly correct? A) Convection moves heat efficiently through the soft, hot rocks of the Earth's mantle, but is not efficient at moving heat through the space between the Sun and the Earth. B) No matter where you are, lemmings carrying space heaters are always moving more heat than convection is moving. C) No matter where you are, radiation always moves heat more efficiently than does convection. D) No matter where you are, conduction always moves heat more efficiently than does convection. E) Convection moves heat efficiently through the space between the Sun and the Earth, but not through the soft, hot rocks of the mantle.

A) Convection moves heat efficiently through the soft, hot rocks of the Earth's mantle, but is not efficient at moving heat through the space between the Sun and the Earth. Feedback: Heat from deep in the Earth is moved up through the soft bulk of the planet primarily by convection, but convection of rocks certainly does not continue beyond the planet, where radiation becomes dominant. In the shallowest, uppermost layers of the Earth, most of the heat transfer is by conduction. And the poor lemmings deserve a rest and a snack.

Two neutral atoms have the same number of protons in the nucleus, but different numbers of neutrons. These are: A) Different isotopes of the same element. Different ions of the same element. B) Different packaging of the same cola. C) Different isopleths of the same element. D) Different elements.

A) Different isotopes of the same element. Different ions of the same element. Notes: The element is determined by the number of protons, so if each atom has the same number of protons, the atoms are the same element. Changing the number of neutrons primarily affects the weight, giving a different isotope of the same element. (Changing the number of neutrons too much can introduce radioactivity, so the isotope won't hang around forever.) Ions are made by gaining or losing electrons. Isopleths are lines on a map connecting places with the same concentration of something that someone has measured, not exactly relevant here. And cola requires making atoms into molecules, and then mixing molecules of several sorts (water, sweetener, coloring agent, flavoring agent, perhaps caffeine) to make cola.

Some eruptions come out of volcanoes really rapidly and shoot really high because: A) Dropping pressure as the melt rises allows volatiles including water vapor and carbon dioxide to make bubbles that lower the density and make the melt rise even faster. B) As the melt nears the surface in subduction-zone volcanoes, the higher pressure near the surface squeezes the melt out faster. C) Hot spots shove the melt out faster. D) Giant marmots named George suck the melt out. E) The suction from the pull of spreading ridges makes the melt come out really rapidly.

A) Dropping pressure as the melt rises allows volatiles including water vapor and carbon dioxide to make bubbles that lower the density and make the melt rise even faster.

In the picture above, the ice that modified the rock moved: A) From left to right, striating the surfaces the ice reached first and plucking blocks loose from the far sides of bumps. B) From top to bottom; ice flows downhill, and this is the downhill direction. C) From bottom to top; ice often is forced uphill, as seen here. D) From right to left, smashing the front of the rock and then sandpapering the back of the rock smooth. E) Directly from the rock toward the camera.

A) From left to right, striating the surfaces the ice reached first and plucking blocks loose from the far sides of bumps. Notes: Indeed, ice sandpapers and striates the rocks it hits first, and then plucks blocks loose from the other side. And the striae go in the direction that the ice moved.

Yellowstone is in some ways similar to Hawaii. This is because both are: A) Hot spot volcanic regions B) Pull-apart plate boundaries C) Push-together subduction zones D) Slide-past plate boundaries E) Push-together obduction zones

A) Hot spot volcanic regions

Lithospheric plates move on the surface of the planet. Plates meet at long plate boundaries. The types of interactions at these boundaries are very important. Which is NOT an interaction type commonly observed along the length of one of these boundaries? A) Hot spot. B) Push-together obduction. C) Push-together subduction. D) Pull-apart. E) Slide past.

A) Hot spot.

The interactions at the edges of plates are very important. Which is NOT an interaction that is commonly observed all along the length of one of the edges where two plates meet? A) Hot spot. B) Push-together obduction. C) Push-together subduction. D) Pull-apart. E) Slide past.

A) Hot spot. Feedback: A hot spot pokes through a plate from below, in some small region. All of the others happen at the long edges of plates.

Examine the two pictures above, [See image: UNIT 11.12] labeled I and II. They are from the same sediment core collected in sea-floor muds from beneath the Atlantic Ocean off the coast of South Carolina. (The pictures are scanning electron micrographs by Brian Huber of the Smithsonian Institution, and the scale is the same on both, as shown at the bottom of each.) One picture shows a sample from just below the unique layer marking the extinction that killed the dinosaurs, and the other picture shows a sample from just above that unique layer. Which is which? A) I is from below the unique layer, and II is from above the unique layer. B) I is from above the unique layer, and II is from below the unique layer.

A) I is from below the unique layer, and II is from above the unique layer. Feedback: Before the impact, biodiversity was high, as shown in I, which includes fossils from below the unique layer and thus deposited before the meteorite hit. After the impact, most of the living types were killed, giving rise to the limited diversity seen in II from above the unique layer after the impact.

A University of Michigan student visiting Penn State's University Park campus drinks too much Diet Pepsi, wanders out in a pouring rainstorm, and takes a leak in a sinkhole behind the nearby Nittany Mall. The trout in the stream to which the sinkhole drains will notice the dastardly deed: A) In a few hours to days. B) In a few centuries. C) In a few thousand years. D) Never, because sinkholes don't drain to trout streams. E) Never, because all sinkholes drain to Michigan.

A) In a few hours to days.

Given the materials presented in this class about the formation of caves, it is likely that most large caves are formed: A) In limestone in moist climates. B) In limestone in dry climates. C) In sandstone in moist climates. D) In sandstone in dry climates. E) In granites under Diet Pepsi.

A) In limestone in moist climates. Notes: Caves require easily dissolved rock, and water to dissolve that rock. In really dry climates, limestone is a resistant rock that stands in huge cliffs. In wet climates, limestone dissolves to yield caves. Sandstone is not a good cave-former because sandstone does not dissolve easily. (Yes, there are very shallow rock-shelter caves in sandstone, which is why the question specifically notes "large caves".) And while Diet Pepsi actually would be marvelous at dissolving limestone, Diet Pepsi attacks granite rather slowly and won't make caves well.

Calcium released by chemical weathering is transported by streams to the ocean, where much of it: A) Is used by clams, corals, etc. to make their shells B) Builds up in the water, making the ocean saltier C) Evaporates from the ocean and rains back out on the land D) Is subducted back into the mantle at the mid-ocean ridges E) Is extracted from the water by marine dairy cows to add to milk

A) Is used by clams, corals, etc. to make their shells

Silica released by chemical weathering is transported by streams to the ocean, where much of it: A) Is used by sea creatures to make their shells B) Builds up in the water, making the ocean saltier C) Reacts with hot sea-floor rocks to make different minerals there D) Is subducted back into the mantle at the mid-ocean ridges E) Is extracted from the water by marine dairy cows to add to milk

A) Is used by sea creatures to make their shells

Most U.S. beaches are shrinking or encroaching on the land rather than growing or moving seaward, so the land of the U.S. is getting smaller, not bigger. Which of the following is a likely cause for loss of at least some of our beaches: A) Land is sinking in some places as it recovers from being bulged up beyond the edge of the ice-age ice sheets. B) Global sea level is falling, exposing more land. C) Dams have greatly increased the sediment supply to deltas that feed longshore drift to grow beaches. D) Water, oil and gas are being pumped into the ground in some places, causing the land to rise. E) Sea-level rise as the last ice age drained river valleys to get rid of bays, and sediment now is transported to the coast rather than being trapped in bays.

A) Land is sinking in some places as it recovers from being bulged up beyond the edge of the ice-age ice sheets. Feedback: As sea level rises, beaches are pushed landward unless something happens to offset this tendency. Dams keep sediment away from beaches, as do the bays formed by post-glacial sea-level rise, and human-caused subsidence of the land is an important problem. But land rising would make for more land, not less.

In the map above, blue shows the Mississippi River, and the Gulf of Mexico, around the Birdfoot Delta of the river. The USGS image uses different colors to indicate changes in the delta. Orange and red both indicate change in one direction, whereas yellow and green indicate change in the other direction. Based on the material presented in this class: A) Orange and red indicate loss of wetlands over time, whereas yellow and green indicate gain of wetlands over time. B) Orange and red indicate gain of wetlands over time, whereas yellow and green indicate loss of wetlands over time.

A) Orange and red indicate loss of wetlands over time, whereas yellow and green indicate gain of wetlands over time.

The arrows point to an interesting feature, high in a road cut in the folded Appalachians of western Maryland. [See image: UNIT 4.10] What happened here? A) Push-together forces broke a layer during folding and shoved one side over the other side. B) Pull-apart forces broke a rock layer, and earthquakes happened as one side slid past the other as they were pulled apart. C) The sediments in the rock layer near the arrows were deposited this way; muds and sands normally form overlapping shingle-type patterns such as this. D) Slide-past forces caused one side of the rock to slide past the other side. E) High-temperature metamorphism caused the rocks to soften and flow, with one side "dripping" under the other

A) Push-together forces broke a layer during folding and shoved one side over the other side. Feedback: It is always shorter around the inside of a curve than around the outside, a fact well-known to NASCAR drivers and wannabees. The rocks above were folded in the great collision that made the Appalachians, which tends to stretch the rocks on the outside of the curve (near and below the bottom of the picture) and squeeze the rocks on the inside. If the rocks are brittle and don't "want" to flow, they may break, giving patterns such as that shown by the arrows. You can see similar things in many places; if you happen to visit Penn State's University Park campus, such features are exposed in the road cut along the Rt. 322 expressway just southeast of East College Avenue.

What tectonic setting is primarily responsible for producing Crater Lake? A) Push-together subduction. B) Hot-spot. C) Slide-past. D) Pull-apart. E) Push-together obduction.

A) Push-together subduction.

In age dating, geologists use: A) Radiometric techniques and layer-counting for absolute dating of events that happened in the last 100,000 years, and other radiometric techniques for absolute dating of much older events. Correct! B) Radiometric techniques for absolute dating of events that happened in the last 100,000 years, and other radiometric techniques and layer-counting for absolute dating of much older events. C) Radiometric techniques and layer-counting for relative dating of events that happened in the last 100,000 years, and other radiometric techniques for relative dating of much older events. D) Cross-cutting relationships for absolute ages, and uniformitarianism for relative ages. E) Radiometric techniques for relative dating of events that happened in the last 100,000 years, and layer-counting for relative dating of events that happened billions of years ago.

A) Radiometric techniques and layer-counting for absolute dating of events that happened in the last 100,000 years, and other radiometric techniques for absolute dating of much older events. Notes: If you want an absolute date (number of years) rather than older/younger, you can count layers for young things, or use radiometric techniques for young things or for old ones.

The picture above [See image: UNIT 9.2] shows a muddy limestone that was deposited in shallow water of a lake. The pocket knife is sitting on a high region of the rock. The pink arrow points along a low trough or groove in the rock, and several other such grooves are evident. The rock is: A) Right-side-up; you are looking at the side that was facing up toward the sky when the rock was deposited. B) Upside-down; you are looking at the side that was facing down toward the center of the Earth when the rock was deposited. C) Edge-on; the side that was facing up toward the sky when the rock was deposited is now facing toward the upper-right-hand-corner of the picture. D) Edge-on; the side that was facing up toward the sky when the rock was deposited is now facing toward the lower-right-hand-corner of the picture. E) Edge-on; the side that was facing up toward the sky when the rock was deposited is now facing toward the lower-left-hand-corner of the picture

A) Right-side-up; you are looking at the side that was facing up toward the sky when the rock was deposited. Feedback: These are mud cracks, and they go down into the mud, so the rock is right-side up.

You drill through the muds at the bottom of the sea floor and sample the rocks beneath, and you then determine the ages of those rocks, using standard scientific techniques. As described in the course materials, you will find that: A) Rocks farthest from spreading ridges are oldest, with ages decreasing as you move toward a ridge. B) Rocks of many different ages occur, but there is no sensible pattern to the ages. C) Rocks near spreading ridges are oldest, and ages decrease as you move away from a spreading ridge in either direction. D) All sea-floor rocks have the same age, made by sudden volcanic eruptions. E) The rocks are older west of a spreading ridge and younger east of the ridge, controlled by the Earth's rotation.

A) Rocks farthest from spreading ridges are oldest, with ages decreasing as you move toward a ridge.

Most earthquakes in the upper part of the Earth's crust are caused by elastic rebound, according to geologists. What do those geologists mean when they say this? A) Rocks moving in opposite directions on opposite sides of a fault get stuck for a while and bend, then "snap back" when something breaks along the fault. B) High-pressure water in faults allows the rocks on opposite sides of a fault to move smoothly in opposite directions all the time, carrying halves of houses built on the faults in opposite directions and so slowly tearing the houses in half. C) All rocks on a continent move in the same direction at the same speed, even if there is a fault splitting the continent. D) Rocks compressed by volcanic eruptions "bounce back", shaking their surroundings. E) Rocks stretched by implosion of subducted slabs then "bounce back", shaking their surroundings.

A) Rocks moving in opposite directions on opposite sides of a fault get stuck for a while and bend, then "snap back" when something breaks along the fault. Feedback: Try sliding a boulder over the ground, and you'll find the boulder gets stuck for a while. Lean harder, the boulder jerks forward suddenly, and you just had a tiny earthquake. Implosion earthquakes probably exist, but the rocks don't bounce back to their original size, and such quakes only can happen deep.

In the two pictures above, I and II, [See image: UNIT 10.13] show traces of former life in rocks from the Grand Canyon. Each is "typical";the rocks near sample I contain fossils similar to those shown in sample I, and the rocks near sample II contain fossils similar to those shown in sample II. It is likely that: A) Sample I is from higher in the cliffs of the Grand Canyon, and sample II is from much lower, nearer to the river. B) Sample I is from lower, nearer the river, and sample II is from higher in the cliffs of the Grand Canyon. C) Sample I is from low in the cliffs, near the river, and sample II is also from low in the cliffs, near the river. D) Sample I is from high in the cliffs of the Canyon, and sample II is also from high in the cliffs of the Canyon. E) Sample I shows the President's desk, and sample II is the sole of the Speaker of the House's shoe.

A) Sample I is from higher in the cliffs of the Grand Canyon, and sample II is from much lower, nearer to the river. Feedback: Sample I shows reptile tracks from the fossil sand dunes of the Coconino far up the side of the Canyon, and thus shows the presence of complex creatures. Sample II includes algal-mat deposits (stromatolites) from the Precambrian Chuar Group of the Grand Canyon Supergroup, deep in the Canyon near the river, from a time when biology was not a whole lot more diverse than algal mats. Notes: Sample I is a wonderful shell hash, or coquina, from the Supai Rocks well up the side of the Canyon, and contains shells from a great diversity of different creatures. Sample II includes algal-mat deposits (stromatolites) from the Precambrian Chuar Group of the Grand Canyon Supergroup, deep in the Canyon near the river, from a time when biology was not a whole lot more diverse than algal mats. Lake Winna-Bango featured in the gripping Dr. Suess tale of Thidwick, the Big-Hearted Moose, but is not pictured here.

In the picture above, [See image: UNIT 8.6] the big W is in ocean water, while the little w is in water in a bay cut off from the ocean by the bar indicated by the pink dashed arrow. A stream flows toward the bay along the blue arrow, and coastal bluffs are indicated by the dashed yellow arrow. What probably happened here? A) Sediment has been eroded from the land by waves crashing against the bluffs, and the sediment has been transported along the shore by longshore drift to build the bar. B) Sediment has been delivered from deep water to the land, building the bar and piling up to form the low bluffs. C) Sediment supplied by the stream has piled up to build the bar that separates the stream from the ocean. D) A sinkhole opened behind the beach, and the stream slumped into the hole, leaving the bar. E) The navy dammed the stream valley to keep enemy submarines from sneaking in and launching missile attacks on the secret underground base under the stream.

A) Sediment has been eroded from the land by waves crashing against the bluffs, and the sediment has been transported along the shore by longshore drift to build the bar. Feedback: Longshore drift is important, and moves much sediment. The greater width of the beach across the mouth of the stream than nearby shows how far waves can go; adjacent to the stream, the waves must cross the beach during storms and batter the bluffs, making sediment that feeds the longshore drift. Submarines are not a big worry in such shallow, near-shore settings, and sinkholes tend to be round, not elongated as seen here.

In the picture above, the pink and yellow arrows in front of Dr. Alley point to two rather different deposits from an eruption of the Hawaiian Volcano Kilauea. As described in the class materials, these materials are: A) Small pieces thrown through the air, and frozen "waterfalls" of lava that flowed quietly before freezing. B) Giant bus-sized bombs thrown through the air by the violent eruptions, and interleaved thick lava flows that followed the violent eruptions. C) Materials that were raised along faults, as we saw last week near Bryce, and materials that were shoved under the faulted materials as melted intrusions. D) Materials that were lowered along faults, as we saw last week near Bryce, and materials shoved under the faulted materials as melted intrusions. E) Materials washed into place by giant waves when the side of the island fell off.

A) Small pieces thrown through the air, and frozen "waterfalls" of lava that flowed quietly before freezing.

What happens to most of the water that falls as rain on central Pennsylvania's Happy Valley each year (or any similar place, such as Washington, DC or other places with trees)? A) The biggest amount is re-evaporated, mostly through trees, and most of the remainder soaks into the ground and then flows through the ground to streams. B) The biggest amount is re-evaporated, mostly through trees, and most of the remainder flows directly over the surface to streams. C) The biggest amount soaks into the ground and then flows through the ground to streams, and most of the remainder flows directly over the surface to streams. D) The biggest amount falls directly on streams, with mosts of the remainder evaporated especially from trees. E) It is used in soft-drink bottling plants.

A) The biggest amount is re-evaporated, mostly through trees, and most of the remainder soaks into the ground and then flows through the ground to streams. Feedback: Water gives life, and life is very good at using water. When their leaves are out, trees use almost all the rain that falls, and tree roots reach down into the ground and pull up some of the water from cold-season rain and snowmelt. An important amount of water does soak into the ground and flow to streams (maybe 1/3 of the total), but plants still get the majority. The amount of water that flows across the surface is increasing as we pave the landscape, but most of the land is not paved, and flow across natural surfaces to streams is small. Streams are tiny, so direct rainfall into them is small. And soft-drink plants use only a tiny bit of water compared to total rainfall.

On the Richter scale of earthquake intensity: A) The ground is shaken 10 times less by a magnitude-4 quake than by a magnitude-5 quake. B) The ground is shaken twice as much by a magnitude-5 quake as by a magnitude-2.5 quake. C) The ground is shaken 10 times less by a magnitude-3 quake than by a magnitude-2 quake. D) The ground is shaken 3 times more by a magnitude-3 quake than by a magnitude-1 quake. E) A magnitude-8.5 quake is impossible; nothing that big can occur.

A) The ground is shaken 10 times less by a magnitude-4 quake than by a magnitude-5 quake. Feedback: One problem in describing earthquakes is that the ground shaking in the smallest one you can feel is 1,000,000,000 times smaller than the ground shaking in the largest quakes. We usually dislike having a scale that requires us to talk about an event of, say, size 100,000,000; instead, if a magnitude-1 quake moves the ground 10 units (say, 10 nanometers at some specified distance from the quake), than we say that a magnitude-2 quake moves the ground 100 units, and a magnitude-3 quake moves the ground 1000 units, and so on. You'll notice that the magnitude is just the number of zeros after the 1; this is a logarithmic scale.

In chemistry, the type of an atom (what element it is) is determined by: A) The number of protons it contains in its nucleus. B) The number of neutrons it contains in its nucleus. C) The number of protons it has in a cloud around the nucleus. D) The number of neutrons it has in a cloud around the nucleus. E) The number of electrons it exchanges with its neighbors.

A) The number of protons it contains in its nucleus.

A) The number of protons it contains in its nucleus. Notes: Physicists change the name when the number of charged, massive protons in the nucleus changes. Adding one proton makes a HUGE difference to how an atom behaves, and so deserves a new name. The neutrons hang around in the nucleus to keep the protons from kicking each other out. Exchanging electrons is important, but doesn't change the element type.

What is an accurate description of the job of a scientist? A) The scientist invents new ideas, and goes on to show that some of those Correct! ideas are false. B) The scientist does only things that show how sexy being a scientist really is, causing downtrodden non-scientists to lose control of themselves with carnal lust for the scientist. C) The scientist Invents new ideas, and then goes on to prove that some of those ideas are True. D) The scientist learns the Truth through careful application of the scientific method. E) The scientist does only things that require high-tech equipment.

A) The scientist invents new ideas, and goes on to show that some of those Correct! ideas are false.

Dave Janesko is explaining the great Sevier Fault to Dr. Alley and the CAUSE class. [See image: UNIT 2.1] Dave has just informed everyone that the black rocks, which formed by cooling of a very hot lava flow, are much younger than the red rocks, which formed from sediments deposited in a lake. He has examined the red rocks and found that they have not been "cooked" by heat from the black rocks, so the red and black rocks must have been placed together after the black rocks cooled. And, he has examined the contact between red and black rocks and found that it is a fault that has been scratched by the motion of the rocks along the fault. It is likely that: A) The scratches are nearly vertical, because the black rocks were dropped down along a pull-apart fault to lie next to the red rock. B) The scratches are nearly vertical, because the black rocks were pushed up from below along a push-together fault to lie next to the red rocks. C) The scratches make little curlicues, because motion on the fault screwed the two sides together. D) The scratches are nearly horizontal, because the black rocks were slid in from the side along a slide-past fault. E) The scratches are all horizontal, because the red rocks moved over the black rocks in a landslide.

A) The scratches are nearly vertical, because the black rocks were dropped down along a pull-apart fault to lie next to the red rock. Feedback: The spreading that opened Death Valley affected a lot of the west, all the way over to Bryce Canyon in Utah. The Sevier Fault, just west of Bryce, formed as pull-apart action broke the rocks, allowing younger rocks including the black lava flow to drop down next to older rocks including the red lake sediments. The scratches are not too far from vertical, made as the rocks dropped down.

Chemical reactions involve: A) The sharing or trading of electrons. B) The sharing or trading of quarks. C) The sharing or trading of partons. D) The sharing or trading of neutrons. E) The sharing or trading of protons.

A) The sharing or trading of electrons. Notes: The clouds of electrons around the nuclei of atoms serve as the Velcro of the universe. Atoms gain or lose electrons and then stick together by static electricity, or else share electrons and stick together inside the shared cloud. The nuclei with their protons and neutrons (which are themselves composed of quarks, which also were called partons at one time) are the things held together by the electronic Velcro of chemistry.

If you could jump in a time machine and zoom back to when the Earth was only half its current age, you would probably find: A) The total area of continents then was smaller than now; continents have grown over time as material scraped off downgoing slabs of subduction zones has been added to the continents. B) There were no continents at all then. C) The total area of continents then was larger than now; continents have shrunk over time. D) The total area of continents then was the same as now; continents have neither grown nor shrunk over time. E) All of the continents then were covered in plants producing Diet Pepsi and Duff Beer.

A) The total area of continents then was smaller than now; continents have grown over time as material scraped off downgoing slabs of subduction zones has been added to the continents.

The picture above shows river gravels in the bottom of Death Valley. [See image: UNIT 2.3] Based on the lesson materials for this unit, a likely explanation for this occurrence of river gravels in the valley bottom is: A) The valley was dropped relative to the mountains by faulting, and rivers now are carrying gravels down from the mountains into the valley. B) The valley was made by folding, which ground up the rocks into little pieces to make the gravel. C) The valley was paved with gravels by a movie company for a really spectacular stunt in the Dukes of Hazzard movie, involving long-distance car chases and Daisy leaping the boys' car across the entire park. D) The valley is deep because it was carved by a river, which later dried up when the desert formed, leaving the gravels behind. E) The valley was raised by faulting, bringing up gravels from subterranean caves.

A) The valley was dropped relative to the mountains by faulting, and rivers now are carrying gravels down from the mountains into the valley. Feedback: Faulting dropped the valley (or raised the mountains, or more likely both), and the melting snows of the mountains feed rivers that carry rocks down into the valley, slowly filling it up while lowering the mountains. There really are deep canyons that were carved by rivers, but as we saw in class and online, Death Valley is not one of them. Rivers don't run on the tops of mountains to deposit gravels. And Daisy was more into shorts than into long jumps.

What happens to most living things, after they die? A) They are recycled, usually by being "burned" with oxygen to provide energy for other living things, or to provide energy to fires. B) They are recycled, usually by being "burned" with Diet Pepsi to provide energy for other living things, or to provide energy to fires. C) They are fossilized. D) They are buried in regions with much oxygen, and turned into fossil fuel. E) They are buried in regions with little oxygen, and turned into fossil fuel.

A) They are recycled, usually by being "burned" with oxygen to provide energy for other living things, or to provide energy to fires. Feedback: Nature is a very efficient recycler, so almost everything that lives is recycled. The recycling is usually achieved through slow "fires" in other living things (including you!), using oxygen. However, sometimes a "real" fire such as a forest fire will do the job.

A dam is built on a river, forming a reservoir. Over time, this likely will cause the fields of some farmers along the river just upstream of the reservoir: A) To be buried by sediment. B) To be washed away as the river cuts downward while the extra sediment is deposited below the dam. C) To dry out as the water table falls. D) To become saturated with Pepsi. E) To experience no changes.

A) To be buried by sediment. Feedback: The stream will slow where it enters the new lake, and so will deposit sediment to form a delta rather than cutting downward or having no change. As the delta builds out into the lake, the upstream end of the delta must build up so that the stream still slopes downward, and this will tend to bury fields upstream. The water table will rise as the lake floods formerly dry regions, but the lake is highly unlikely to contain Pepsi, which has a carefully guarded formula.

Much melting in the mantle occurs near subducting slabs primarily because: A) Water taken down subduction zones lowers the melting temperature in and near the slabs. B) Convection cells from the deep mantle rise along subduction zones. C) Slabs are the hottest things in the mantle because of friction from the subduction. D) Sediments scraped off downgoing slabs pile up, trapping heat and causing the rocks below to be warmer than elsewhere in the mantle. E) Hot spots come up subduction zones.

A) Water taken down subduction zones lowers the melting temperature in and near the slabs.

If you could drill a hole straight to the center of the Earth, and keep track of what the hole is going through, you would find: A) You would go through one sort of material, and then a different, denser material, and then a still-different, still-denser material, because the planet is made of concentric layers, sort of like an onion. B) You would go through one sort of material all the way to the center, because the planet is all mixed up. C) If your hole started at the North Pole, you would go through different layers of different materials, but if your hole started at the equator, you would go through one sort of material all the way to the center. D) If your hole started at the equator, you would go through different layers of different materials, but if your hole started at the North Pole, you would go through one sort of material all the way to the center. E) You would strike Diet Pepsi when you got to the center.

A) You would go through one sort of material, and then a different, denser material, and then a still-different, still-denser material, because the planet is made of concentric layers, sort of like an onion. Notes: The planet is onion-like, with an inner core, then an outer core, a mantle (which has several sub-layers), and a crust. The core is waaaaay too hot and high-pressure for Diet Pepsi.

The picture above is from Alaska, which is well-known for its huge rivers, dynamic glaciers, and towering mountains made by tectonic processes including faulting. The view is across an arm of the sea and up a side valley. The shape of the side valley suggests that it was primarily formed by: A). Glacier erosion B). Stream erosion C). Push-together folding D). Pull-apart folding

A). Glacier erosion Notes: The fact that this is in Alaska may have been a tip-off that a glacier did this, and the snow in the picture may help. But, Alaska does have streams and push-together folding, and even a bit of pull-apart action in places (although that is not a big cause of folding). Glaciers are wide, and tend to widen and deepen their valleys during erosion, making a "U" shaped valley—one that looks like a U when you peer along it. When streams are eroding downward, the narrow stream tends to cut a narrow slot, and then mass-wasting processes widen it to make a "V". Once streams quit eroding down, they may migrate laterally, and deposit mud during floods, making large, flat floodplains. But, streams by themselves rarely make a "U" shape, so if you see a "U", think glacier.

How about this one (above picture)? What is it? A. Algal-mat deposits in Precambrian rocks of the Grand Canyon. B. Debris-flow deposits in Paleozoic rocks of the Grand Canyon. C. Cross-sections of fossil bones in Mesozoic rocks of the Grand Canyon. D. Moose doots in Cenozoic rocks of the Grand Canyon.

A. Algal-mat deposits in Precambrian rocks of the Grand Canyon. Notes: Step on a rock in a pond or stream, and you're likely to slip on the algae "slime" on the rock, and you might fall in and get wet. During a flood, the "slime" can be buried in a layer of silt and clay, and then the algae may grow up through the little mud pieces and spread across the surface above them. In the modern world, by the time a few layers are laid down, there almost always are some snails that come by and eat up almost everything, and the algae have to start over. But, in places that are too salty for snails but not for certain algae, you get layered deposits almost identical to the ones featured in this picture, which shows Precambrian rocks deep in the Grand Canyon. In the Precambrian, before the appearance of snails, such deposits were much more common than they are now, because the algae weren't eaten nearly as much. So, A is correct. There isn't a scale in this picture, which actually shows rocks about a foot high, and there isn't any reason that you should have known this before, but you know it now, and if you see it on a quiz, you'll be ready.

Look at the picture above, which shows a small section of a "fossil" sand dune (a sand dune in which the grains have been "glued" together by hard water deposits). When the dune was first deposited, which was up (which letter is closest to the arrow that is pointing in the direction you would have looked to see the sky when the dune was deposited)? D C Correct! B A

B Notes: Just to the left of the letter B there is a small unconformity. The layers farther to the left are cut along that surface. Layers must exist to be cut, so the left-hand layers are older, the right-hand layers are younger, and up was to the right.

You start with 200 parent atoms of a particular radioactive type, which decays in a single step to give a stable offspring, and you start with none of those stable offspring. You wait just long enough for two half lives to pass. You should expect to have how many offspring atoms (on average)(remember that the number of parents and the number of offspring add up to 200, so if you have 10 parents, you have 190 offspring because 10 and 190 add up to 200, and if you have 20 parents you have 180 offspring, and so on): A) 200. B) 150. C) 100. D) 50. E) 25.

B) 150. Feedback: After one half-life, you've gone from 200 parents to 100, and 100 offspring have been made. In the second half-life, you go from 100 to 50 parents, and that makes another 50 offspring. Adding the additional 50 to the 100 from the previous half-life gives 150 offspring. (Typical studies of radioactive decay use many more atoms, to avoid statistical fluctuations, but the question says "on average", so we asked you about 200 rather than 200,000,000,000,000 to make the math easier.)

[See image: UNIT 8.8] Acadia National Park has a long, rich and varied geologic history. The large island marked "I" in the middle of the above picture is composed of resistant granite from the long-ago closure of the proto-Atlantic. However, the shape of the island was formed by much more geologically recent processes (within the last 100,000 years or so). What is primarily responsible for the beautiful shape of the island? A) A glacier flowed over the island, moving from right to left, grinding off the rock first encountered and smoothing the long tail. B) A glacier flowed over the island, moving from left to right, smoothing the rocks encountered first and plucking rocks free from the other side. C) Strong winds blowing from left to right shaped the rocks. D) Huge storms pounded the island from the right, breaking the rocks to make the bluff facing the sea. E) Sculpting of the rocks by stone masons hired by the Rockefellers, followed by donation of the sculpture to the people of Maine.

B) A glacier flowed over the island, moving from left to right, smoothing the rocks encountered first and plucking rocks free from the other side. Feedback: The side of the rock that a glacier reaches first is sandpapered and rounded by the ice; the side of a rock that the flowing glacier pulls away from is plucked rough as blocks are removed. The ice thus flowed from left to right, streamlining and smoothing the island. Wind and waves do not make such distinctive forms, and while Rockefeller stonemasons might have done so, they probably would have carved a huge likeness of a fabled ancestor instead.

The above picture [See image: UNIT 7.14] shows: A) A glacier, which is generally flowing away from you, carrying rocks to smear them against the ridges as the glacier makes the mountains bigger; you can see where the black stripe under the yellow arrow curves around to smash against the rock. B) A glacier, which is generally flowing toward you, carrying rocks picked up from the ridges; the yellow arrow points up one of the stripes of rock, and you can follow the stripe to the ridge where the rocks started. C) A glacier, which has quit flowing and is wasting away in response to global warming. D) A permafrost soil-creep lobe, which is generally coming toward you, moving in the opposite direction indicated by the arrow. E) A permafrost soil-creep lobe, which is generally moving away from you, moving in the direction indicated by the arrow.

B) A glacier, which is generally flowing toward you, carrying rocks picked up from the ridges; the yellow arrow points up one of the stripes of rock, and you can follow the stripe to the ridge where the rocks started. Feedback: The glacier picks up rocks from ridges, and carries those rocks along to eventually dump those rocks in moraines. The ice is flowing down its surface slope toward you.

This rock in the picture above [See image: UNIT 7.15] was modified by: A) A glacier, which scratched and polished the rock at A and plucked blocks loose at B, as the ice moved from B to A. B) A glacier, which scratched and polished the rock at A and plucked blocks loose at B, as the ice moved from A to B. C) A glacier, which scratched and polished the rock at B and plucked blocks loose at A, as the ice moved from B to A. D) A glacier, which scratched and polished the rock at B and plucked blocks loose at A, as the ice moved from A to

B) A glacier, which scratched and polished the rock at A and plucked blocks loose at B, as the ice moved from A to B. Feedback: Indeed, ice sandpapers and striates the rocks it hits first, and then plucks blocks loose from the other side. And the striae go in the direction that the ice moved.

In the photo above, [See image: UNIT 7.13] the letters A and B are in bowl-shaped features in east Greenland. The yellow arrow in the far upper right points to a peak between bowl B and two other bowls, one on the far side of the peak, and one on the right of the peak. What name should be applied to the peak between the three bowls? A) A moraine, bulldozed up by the glaciers that hollowed out the bowls. B) A horn, left between the bowls that gnawed into the mountain. C) A cirque, left by the one glacier that gnawed into the mountain. D) An arête, left by the two glaciers that gnawed into the mountain. E) A giant alien toilet, proof that we are visited by beings from another planet, but only evident from the air such as seen here.

B) A horn, left between the bowls that gnawed into the mountain. Feedback: This is indeed a horn between three cirques. The strong layering of the rock material is suggestive of bedrock, not loose pieces as seen in moraines. (This is basaltic bedrock from the breakup that formed the Atlantic.) And whoooo, what would the alien use for TP???

The picture above [See image: UNIT 7.12] shows a glacier in eastern Greenland, in the world's largest national park, flowing from mountains at the top of Jameson Land (at the top of the picture) toward the lowlands of Kong Oskar Fjord (just out of the picture at the bottom). The yellow arrow from the letter C is pointing at a geological feature. What is that feature? A) A moraine, left behind when the glacier retreated because of an increase in melting of the accumulation zone or a decrease in snowfall in the ablation zone. B) A moraine, left behind when the glacier retreated because of an increase in melting of the ablation zone or a decrease in snowfall in the accumulation zone. C) An arete, left behind when the glacier retreated because of an increase in melting of the accumulation zone or a decrease in snowfall in the ablation zone. D) An arete, left behind when the glacier retreated because of an increase in melting of the ablation zone or a decrease in snowfall in the accumulation zone. E) A dirty ring, left behind when the ice worms used the wrong soap in the tub.

B) A moraine, left behind when the glacier retreated because of an increase in melting of the ablation zone or a decrease in snowfall in the accumulation zone. Feedback: Most of the glaciers of the world, including this one, have retreated over the last century. Many had "bulldozed" ridges around them, and the arrow points to one such ridge, a moraine. Retreat may be caused by increase in melting or decrease in snowfall; in this case (and for most of the worlds' glaciers), warming has been responsible.

When scientists agree that a particular scientific theory is a good one, and the scientists use that theory to help make new things, cure diseases, etc., that "agreement" came about because: A) A single experiment had an outcome that was well-predicted by that theory. B) A number of different experiments by different people all had outcomes that were well-predicted by the theory. C) That's what it says in all the books. D) A single, well-respected scientist put forward the idea. E) The Nobel prize committee gave the inventor of the idea a lot of money.

B) A number of different experiments by different people all had outcomes that were well-predicted by the theory.

B) A number of different experiments by different people all had outcomes that were well-predicted by the theory. Notes: Agreement on scientific theories is a contentious, drawn-out, and sometimes acrimonious business. Scientists are no better (and no worse!) than everybody else: we think we are right and those who disagree with us are dunderheads! I put forward my idea, and the experiments that I did that show the idea is a good one... then everybody else piles on and pooh-poohs my idea. BUT, they go out and do experiments that try and show my ideas are wrong... and they can't do it! So eventually all those experiments accumulate, and finally people agree that my idea is a good one. (Sometimes accompanied by a sneer: "...but of course I knew that all along. I just didn't bother to publicize it..." I told you, scientists are no better and no worse than the rest of the world.)

When we speak of the Mississippi Delta, most people mean some interesting region in Louisiana with good music and seafood. Geologically, however, the Mississippi Delta is: A) A river-built deposit that is almost a mile thick at its thickest point, and extends from near Baton Rouge, Louisiana to the Gulf of Mexico. B) A river-built deposit that is several miles thick at its thickest point, and extends from near St. Louis, Missouri to the Gulf of Mexico. C) A great trench eroded by the Mississippi River from near St. Louis, Missouri to the Gulf of Mexico, causing earthquakes to occur at the tip of this trench near St. Louis, Missouri. D) A small trench eroded by the Mississippi River from near Baton Rouge, Louisiana to the Gulf of Mexico. E) A giant pile of spit-up Yoo Hoo.

B) A river-built deposit that is several miles thick at its thickest point, and extends from near St. Louis, Missouri to the Gulf of Mexico.

Suppose that tomorrow someone bulldozed all the rocks in the Appalachians, right down to sea level, and shipped all of those bulldozed rocks to Uzbekistan to build ski slopes. A few thousand years from now, we probably would find that the surface of the Earth exposed by the bulldozers was: A) Higher than the Appalachians are today, because of volcanic eruptions triggered by the bulldozers. B) Almost, but not quite, as high as the Appalachians are today, because the roots of the mountains bobbed up. C) At sea level. D) As high as the Appalachians are today, because of obduction. E) As high as the Appalachians are today, because the roots of the mountains bobbed up.

B) Almost, but not quite, as high as the Appalachians are today, because the roots of the mountains bobbed up.

[See image: UNIT 8.10] Dr. Alley is pointing to a brownish zone exposed in the low bluff along Coast Guard Beach, Cape Cod National Seashore. The brown zone is rounded on the bottom, flat on the top, rests on sand and gravel, and has sand dunes on top. In the lower picture, Dr. Alley is showing that the brown zone contains twigs and other organic material. What is the brown zone doing here? A) A sinkhole opened here, forming a lake that was then filled with organic material. B) An ice block from the glacier was buried in sand and gravel, then melted to make a lake that filled with organic material. C) Humans dammed a nearby river, forming a lake that then filled with organic material. D) The brown zone is mostly the carcass of a dead whale, which washed up on the beach and was buried. E) The brown zone is mostly the carcass of a dead whale, which was propelled here when highway-department workers dynamited it to get it off the beach.

B) An ice block from the glacier was buried in sand and gravel, then melted to make a lake that filled with organic material. Feedback: Cape Cod is a creature of the glaciers, and most of the Cape's lakes started by melting of buried ice blocks. Sinkholes and human-made lakes do fill with organic material sometimes, but this is the wrong setting. A whale carcass wouldn't be twigs, etc. In Oregon, the highway department did once try dynamiting a whale carcass to speed natural decay, and succeeded in splattering bystanders and even denting some car roofs with large flying whale parts. (One has to wonder whether there exists a rock band somewhere named "Large Flying Whale Parts".)

Which of the following is commonly expected near a "textbook" subduction zone (that is, near a subduction zone that is so perfect and free of confusing complications that you would use it in a textbook to teach students)? A) Basaltic hot-spot-type volcanoes, such as at Hawaii Volcanoes. B) Andesitic stratovolcanoes, such as Mt. St. Helens, fed by melt from the slab being subducted. C) Slide-past (or transform, with horizontal but not vertical movement) earthquakes and faults, such as occur along the San Andreas Fault. D) Pull-apart earthquakes and faults, such as occur in Death Valley. E) Basaltic mid-ocean-ridge-type volcanoes, such as are found at undersea spreading ridges.

B) Andesitic stratovolcanoes, such as Mt. St. Helens, fed by melt from the slab being subducted.

Continents: A) Can sink all the way to the core-mantle boundary in subduction zones. B) Are the "unsinkable" part of the solid Earth; although a little of a continent might go down, most continental material stays near the surface. C) Can sink into sea floor but not into denser mantle. D) Often sink into giant subterranean lakes of Pepsi One. E) Won't sink when young and warm, but will sink when old and cold.

B) Are the "unsinkable" part of the solid Earth; although a little of a continent might go down, most continental material stays near the surface.

Continents: A) Won't sink when young and warm, but will sink when old and cold. B) Are the "unsinkable" part of the solid Earth; although a little of a continent might go down, most continental material stays near the surface. C) Often sink into giant subterranean lakes of Pepsi One. D) Can sink into sea floor but not into denser mantle. E) Can sink all the way to the core-mantle boundary in subduction zones.

B) Are the "unsinkable" part of the solid Earth; although a little of a continent might go down, most continental material stays near the surface. Feedback: "The Unsinkable North America" might not make it as a vehicle for show tunes, but continents have floated around for 4 billion years and are unlikely to sink in the near future. Old, cold sea floor can sink into the mantle, but continents are lower in density than sea floor and cannot follow. A continent could sink into a subterranean lake of Pepsi One if such a thing existed, but no such thing exists.

The deepest earthquakes are rare, and differ in some ways from the more-common type of quakes. These deepest earthquakes probably: A) Are caused by Coke drinkers kicking Pepsi machines and then jumping back when Gatorade squirts out. B) Are the shaking of the ground caused by "implosion" as minerals rearrange to denser forms as the pressure on them rises in downgoing slabs. C) Are caused by Pepsi machines exploding after being kicked by Coke drinkers to cause Gatorade to squirt out. D) Are the shaking of the ground caused by elastic rebound of bent rocks when a fault breaks. E) Are caused by atomic-bomb testing.

B) Are the shaking of the ground caused by "implosion" as minerals rearrange to denser forms as the pressure on them rises in downgoing slabs.

Convection occurs: A) Because hotter things are more dense and tend to sink. B) Because hotter things are less dense and tend to rise. C) In solids only. D) Because hotter things are more dense and tend to rise. E) In liquids only.

B) Because hotter things are less dense and tend to rise. Feedback: Almost everything expands from heating, taking up more space with the same weight and so becoming less dense. Gases, liquids, and sufficiently soft solids can convect if heated from below, with warming of the lower layer causing it to rise.

[See image: UNIT 11.11] The Petrified Forest of Arizona includes a great diversity of fossils. In the picture above, paleontologist Randall Irmis excavates a plate from a specimen of Buettneria. Based on the discussions of evolution in the class materials, it is likely that: A) Buettneria is essentially identical to species still alive today. B) Buettneria is related to, but recognizably different from, species still alive today. C) Buettneria is completely unrelated to species still alive today.

B) Buettneria is related to, but recognizably different from, species still alive today. Feedback: Evolutionary theory indicates that living things change from generation to generation, but that all living things are related. Consistent with this, Buettneria is recognizably similar to, yet different from, amphibians still alive today.

You are the chief biodiversity officer for the National Park Service in the eastern US, responsible for maintaining as much diversity as possible, and your boss has told you to focus on maintaining biodiversity of things big enough to see with the naked eye (so you don't need to worry about microorganisms). You have two parks, and enough money to buy 10,000 acres of land. You may add the 10,000 acres to one of the parks, add 5,000 acres to each park while leaving them as isolated parks, or buy a 10,000-acre corridor connecting the two parks. All of the land for sale is now wilderness, but the land you do not buy is going to be paved for a super-mega-mall. You would be wise to: A) Don't worry, the key is how much area you have in wilderness, so each of the plans is equally valuable. B) Buy the corridor connecting the two parks; this keeps one big "island" rather than two smaller ones, and so keeps more species. C) Enlarge one park a good bit; bigger islands have more species, so you want to make a big "island". D) Enlarge both parks some; each park has some diversity, and you want to enhance both. E) Don't worry; malls are highly biodiverse, so you'll succeed no matter what you do.

B) Buy the corridor connecting the two parks; this keeps one big "island" rather than two smaller ones, and so keeps more species. Notes: Remember the terrarium—you will have more diversity in an undivided terrarium than in a divided one. Your park area is your terrarium; keep it undivided. Malls have low biodiversity.

The above diagram is from one of the Geomations in the unit. [See image: UNIT 2.15] It shows three possible fault styles. A and B are cross-sections, with a collapsed building on top to show you which way is up—the yellow band is a distinctive layer of rock that was broken by the earthquake that also knocked down the building. C is viewed from a helicopter, looking down on a road with a dashed yellow line down the middle; the road was broken by an earthquake along the green fault, and the earthquake knocked down a building to make the funky-looking brown pile in the upper right.What is accurate about the different earthquake styles? A) C is pull-apart, B is push-together, and A is slide-past. B) C is slide-past, B is pull-apart, and A is push-together. C) C is slide-past, B is push-together, and A is pull-apart. D) C is push-together, B is slide-past, and A is pull-apart. E) C is push-together, B is pull-apart, and A is slide-past.

B) C is slide-past, B is pull-apart, and A is push-together. Feedback: Imagine putting the image on paper, cutting out the blocks (one block on each side of the fault), and then sliding them back together to make the original, unbroken features. A and B stand up from the table, C lies down on the table. Now, slide them to make the picture as seen here. In A, you'll be moving the right-hand block up and toward the other block, so it is push-together. In B, you'll be moving the right-hand block down and away from the other block, so it is pull-apart. And in C, you'll slide one past the other (geologists distinguish right-lateral and left-lateral motion for C, but you don't have to worry about that much detail).

Sediment is changed to sedimentary rock by: A) Cementation by oil. B) Cementation by hard-water deposits, intergrowth of new minerals, and squeezing under the weight of additional sediment. C) Chemical weathering of mineral surfaces. D) Cementation by hard-water deposits only. E) Compaction under the weight of additional sediments only.

B) Cementation by hard-water deposits, intergrowth of new minerals, and squeezing under the weight of additional sediment. Feedback: Hard-water deposits are especially important in hardening coarse clastic deposits, especially sandstone and coarser. The finer-grained deposits are more controlled by compaction under additional weight, and intergrowth of new minerals. But all of these processes can contribute.

What cause probably was not important in contributing to extinction of most species on Earth, including the dinosaurs, in a very short interval of time at the end of the Mesozoic Era? A) Wildfires caused by great heat from rocks warmed by atmospheric friction while falling back to Earth after being blasted high in the atmosphere by the impact. B) Cold from the change in Earth's orbit caused when the meteorite shoved the planet farther from the sun. C) "Impact winter" caused when tiny pieces of dust or other materials, which were put in the air by a meteorite impact, blocked incoming sunshine for months or years, after larger pieces had fallen back to Earth. D) Acid rain, from sulfuric acid from the meteorite hitting sulfur-bearing rocks, and nitric acid from the heat of the meteorite burning the air.

B) Cold from the change in Earth's orbit caused when the meteorite shoved the planet farther from the sun. Note: Robert Frost once wrote "Some say the world will end in fire, some say in ice". For the dinosaurs, both were probably true, with acid thrown in. But the meteorite was not nearly big enough to change the planet's orbit noticeably. Frost went on "From what I've tasted of desire, I hold with those who favor fire, But if it had to perish twice, I think that for destruction ice, Is also great, and would suffice."

The North Pole sticks up out of Dr. Alley's bald spot, and the equator crosses his nose and cheeks. The sun shines on this odd globe, and on the real globe, the most likely thing that would happen here is: A) Dr. Alley may get a sunburned nose, and the equator is hotter than the pole on the real Earth, primarily because the equator is so much closer to the sun than the pole is. B) Dr. Alley may get a sunburned nose, and the equator is hotter than the pole on the real Earth, primarily because the sun hits the equator directly but the sun hits the pole a glancing blow. C) Dr. Alley may get a sunburned nose, and the equator is hotter than the pole on the real Earth, primarily because the wind heats the surface as it rotates by, just as Dr. Alley can turn his head rapidly and cause heat by friction. D) Dr. Alley may get a sunburned nose, and the equator is hotter than the pole on the real Earth, primarily because most volcanoes are located near the equator, forced there by the centrifugal force of Earth's rotation, and Dr. Alley exhales hot air from his equatorial nose. E) Dr. Alley is undoubtedly the sexiest human being on Earth.

B) Dr. Alley may get a sunburned nose, and the equator is hotter than the pole on the real Earth, primarily because the sun hits the equator directly but the sun hits the pole a glancing blow.

You get in your Magic School Bus, drive down the throat of a volcano, and find that you are driving through melted rock that flows with much greater difficulty than does most melted rock, because the melted rock you are driving through is lumpier than typical for melted rock. It is likely that the melted rock you are driving through is: A) Especially warm compared to most melted rocks. B) Especially low in water and carbon dioxide compared to most melted rocks. C) Especially rich in water and carbon dioxide compared to most melted rocks. D) Especially rich in iron and other things that would get between silicon-oxygen tetrahedra, compared to most melted rocks. E) Especially rich in Diet Pepsi compared to most melted rocks.

B) Especially low in water and carbon dioxide compared to most melted rocks.

Which of the following is not a scientifically accepted statement about the occurrence of transitional forms in the fossil record? A) Transitions between some older and younger fossil types have not been found because evolution occurred in small populations, and fossilization is less likely in smaller populations. B) Evolutionary theory shows that many lineages should have developed by "Ford Mustang" evolution without transitions. C) Transitional forms are known from many lineages, and especially from commonly fossilized lineages. D) Transitional forms are missing from many lineages, and especially from rarely fossilized lineages. E) Evolutionary theory shows that transitional forms should have occurred, and so should be found in the fossil record if they were fossilized.

B) Evolutionary theory shows that many lineages should have developed by "Ford Mustang" evolution without transitions.

What probably happened to create the two rocks with the orange surfaces, seen in the center of the above picture from Greenland? [See image: UNIT 5.10] A) A tree root cracked the rock, which killed the tree, so we don't see the tree anymore B) Expansion from water freezing in the crack wedged the rock apart C) A performance artist painted the rock orange, to signify the coming of deer-hunting season D) The rock was recently erupted from a volcano, thrown high in the air, and broke when it hit the surface, as shown by the orange caused by heat from the volcano E) The two pieces of rock with the orange are completely unrelated, and just happened to wind up next to each other

B) Expansion from water freezing in the crack wedged the rock apart Feedback: Frost-wedging is probably the most important process in breaking rocks. Tree roots do crack rocks, but in this case, the root almost certainly would have shoved the rocks farther apart, and breaking rocks doesn't kill trees. The broken surface is colored by lichen, which doesn't look much like paint. And if a volcano made the orange, the orange would be on the outside as well.

As water from rain soaks through the soil, the water typically: A) Loses carbon dioxide (CO2) to the air and then to plant roots, becoming more basic. B) Gains carbon dioxide (CO2) from the air and then gains more carbon dioxide in the soil, becoming more acidic. C) Neither gains nor loses carbon dioxide (CO2) in the air or the soil. D) Gains humic compounds from the air and more from the soil, becoming a strong base. E) Gains Diet Pepsi from the air and loses it in the soil, becoming a strong electrolyte.

B) Gains carbon dioxide (CO2) from the air and then gains more carbon dioxide in the soil, becoming more acidic. Feedback: CO2 is fairly soluble in water. Rain picks up some in the air, becoming slightly acidic. Lots of things living in the soil emit carbon dioxide, and soils contain a lot of carbon dioxide that helps make water more acidic. Humic compounds are picked up from soil by water, and make the water more acidic.

As rain falls through air, the water typically: A) Loses carbon dioxide (CO2) to the air, becoming a strong base B) Gains carbon dioxide (CO2) from the air, becoming a weak acid C) Neither gains nor loses carbon dioxide (CO2) D) Gains humic compounds from the air, becoming a strong base E) None of the options

B) Gains carbon dioxide (CO2) from the air, becoming a weak acid

The Mississippi River: A) Has built a delta, which is almost a mile thick at its thickest point, from near Baton Rouge, LA to the Gulf of Mexico over millions of years. B) Has built a delta, which is several miles thick at its thickest point, from near St. Louis, MO to the Gulf of Mexico over millions of years. C) Has split the continent by eroding a great trench from near St. Louis, MO to the Gulf of Mexico, causing earthquakes to occur at the tip of this trench near St. Louis, MO. D) Is colored brown because of people spitting up massive quantities of Yoo Hoo. E) Has split the southern part of the continent by eroding a small trench from near Baton Rouge, LA to the Gulf of Mexico over millions of years.

B) Has built a delta, which is several miles thick at its thickest point, from near St. Louis, MO to the Gulf of Mexico over millions of years. Feedback: Amazing as it may seem, the Mississippi has been taking the debris from the vast area from the Rockies to the Appalachians, and dumping that debris into the Gulf of Mexico, building a pile of sediment that is miles thick in places and extends from St. Louis to the Gulf. The mud has filled an old crack in the continent from when the Atlantic and Gulf of Mexico opened, but the mud doesn't stop the earthquakes that occasionally occur near the tip of the crack. And as for the Yoo Hoo, Yuck!

Which of the following is not part of the evidence that the odd layer marking the extinction of the dinosaurs was caused by a large meteorite impact? A) The common occurrence in the layer of otherwise-rare "shocked" quartz and other mineral types known to be formed only by quickly applied high pressures. B) High concentrations of silica found in the layer. C) Abundant soot found in the layer. D) High concentrations of iridium found in the layer. E) Large torn-up rock blocks from a tsunami (giant wave), found in the layer near the Caribbean Sea.

B) High concentrations of silica found in the layer. Feedback: We have seen several times that silica is very common, so its presence in a layer would not indicate much of anything. Features really observed in the layer that are associated with meteorites but not common elsewhere in rocks include shocked quartz from the impact, soot from wildfires, iridium from the meteorite, and a giant-wave deposit because the meteorite hit water as well as land at the edge of the Yucatan Peninsula.

During the most recent ice age: A) Ice from Canada advanced down the Mississippi to near the Gulf of Mexico, helping build the Mississippi Delta. B) Ice from Canada advanced across the Great Lakes and into the northern states of the US, but not farther. C) Ice from Canada advanced to the southern edge of the Great Lakes, hollowing them out, but didn't go any farther. D) Ice from Canada advanced to the northern shore of the Great Lakes, but not farther. E) Ice from Canada advanced into Mexico. During the most recent ice age: A) Central Pennsylvania was overrun by ice from the south. B) We have no idea what central Pennsylvania was like. C) Central Pennsylvania was just beyond the edge of the Canadian ice. D) Central Pennsylvania was far from the nearest ice. E) Central Pennsylvania was overrun by ice from Canada.

B) Ice from Canada advanced across the Great Lakes and into the northern states of the US, but not farther. Feedback: This is just a fact of geography; the ice came out of the Great Lakes and somewhat farther, but not greatly so. C) Central Pennsylvania was just beyond the edge of the Canadian ice. Notes: This is just a fact of geography as described in the text; central Pennsylvania was near but beyond the edge of ice coming from the north. The last option, "no one knows", is the last refuge of lazy minds, and not at all correct.

What is accurate about the scientific theory of evolution today? A) It is one of those "academic" things, made up so professors feel good, with no applications to the real world. B) It is being applied successfully in the real world in many ways, including helping fight new disease organisms, and even guiding the thinking of computer scientists. C) It is not being used anywhere for anything. D) It is being used successfully to fight new diseases, but that is the only possible use for evolutionary theory in the real world. E) It is one of those "academic" things, made up so professors feel good, and it always fails when the professors try to apply it to the real world.

B) It is being applied successfully in the real world in many ways, including helping fight new disease organisms, and even guiding the thinking of computer scientists. Feedback: As antibiotic resistance appears in disease organisms, evolutionary biologists are helping doctors find better strategies to keep us healthy. The processes behind evolution—try new things, keep the ones that work, repeat—has been used intentionally for guidance in many human endeavors, including "evolutionary computing" in computer science. Ecologists trying to rescue ecosystems are informed by understanding of the evolutionary processes that made, and are changing, those ecosystems. Even regulations for sport fishing are guided by our understanding of evolution. In the same way as other successful ideas in science, evolution is useful in many practical ways in the real world.

What sort of rock is pictured above? [See image: UNIT 4.7] A) Igneous; The layers were caused by flow processes during the eruption that released this. B) Metamorphic; The rock separated into layers as it was cooked and squeezed deep in a mountain range. C) Marmot #2 D) Sedimentary; The layering was caused by changes in the flow velocity of the river that deposited the material E) Sediment that isn't rock yet. The layers are alternating silt and sand from deposition from landslides off the Olympic Peninsula into the trench offshore.

B) Metamorphic; The rock separated into layers as it was cooked and squeezed deep in a mountain range. Feedback: The large crystals, intergrown nature, and separate dark and light layers all point to metamorphism, deep inside a mountain range. Rapid cooling in volcanic eruptions gives tiny crystals, not the big, pretty ones here. You can see the former sand grains or other-sized pieces in sediment and sedimentary rocks. And marmot doo-doo consists of small, dark pellets, akin to big rabbit doots, and usually isn't considered to be rock.

Which is not part of our modern view of geology? A) Lithospheric plates float on soft material deeper in the mantle. B) Most mountain building occurs in the centers of lithospheric plates. C) The Earth's lithosphere is broken into a few major plates plus a few smaller ones. D) Lithospheric plates move mainly horizontally on the soft, deeper material. E) Convection occurs below the lithosphere in the deeper mantle.

B) Most mountain building occurs in the centers of lithospheric plates.

Bigger earthquakes occur less frequently, but a bigger quake releases more energy and does more damage. An interesting question to ask about earthquakes (and about almost anything else!) is whether the increase in energy release and damage done is larger or smaller than the decrease in frequency as one looks at bigger earthquakes. Asked a different way, is most of the damage done by the many little earthquakes or by the few big earthquakes? A) The drop-off in frequency just balances the rise in energy, so all earthquake sizes contribute equally to global earthquake damages. B) Most of the damage is done by the few, big earthquakes. C) Earthquakes only damage Coke machines, under an exclusive contract with Pepsi. D) Most of the damage is done by the many, little earthquakes. E) Earthquakes don't do any damage, so this is a silly question.

B) Most of the damage is done by the few, big earthquakes.

Newton's ideas on physics "won", and Aristotle's ideas were kicked out of science and over into history. Why? A) Newton won the Nobel prize. B) Newton's ideas did a better job of predicting how nature would behave. C) Newton's ideas appealed to dead white European males, whereas Aristotle's didn't because Aristotle wore a toga all the time. D) Newton's ideas appealed to dead white European males, whereas Aristotle's didn't. E) Newton's ideas were more elegant, and so were intellectually favored.

B) Newton's ideas did a better job of predicting how nature would behave. Notes: Unlike painting or literature, scientific inquiry has a well-defined procedure for figuring out if Newton's ideas are better or if Aristotle had it right all along. In looking at a painting, we can ask different people what they think, or we can make up our own mind on whether we like it or not, and that is perfectly valid. In science, we have to ask: does the idea fit with the way the world works? Can I predict the speed of a falling object better using Newton's ideas or Aristotle's? As it turns out, Aristotle's ideas didn't predict things very well, and Newton's did.

Human population continues to grow. Looking at many of the things we use on Earth (farmland and land for wood and other things, fish in the sea, etc.): A) We use almost everything, 99% or more, so we're in deep doo-doo for the future. B) Our use is large but not everything; we are approaching use of half of all that is available. C) We use less than 1% or so, the tiniest bit, with vast amounts out there in the wilderness somewhere. D) We use almost all of the Diet Pepsi springs but with huge natural reserves of Diet Coke. E) We use almost all of the dilithium crystals for our warp drives.

B) Our use is large but not everything; we are approaching use of half of all that is available.

What is accurate about seismic waves moving through the Earth? A) Neither S-waves (also called shear-waves) nor p-waves (also called push-waves or sound waves) move through liquids. B) P-waves (also called push-waves or sound waves) move through liquids, but s-waves (also called shear waves) don't. C) P-waves (also called push-waves or sound waves) move through all liquids except Diet Pepsi, and s-waves (also called shear-waves) move through no liquids except Diet Pepsi. D) S-waves (also called shear-waves) and p-waves (also called push-waves or sound waves) both move through both liquids and solids. E) P-waves (also called push-waves or sound waves) move through solids, but s-waves (also called shear waves) don't.

B) P-waves (also called push-waves or sound waves) move through liquids, but s-waves (also called shear waves) don't. Feedback: P-waves go through liquids and solids, because you can squeeze and release a liquid or a solid—push hear and it squeezes a bit, which squeezes what is next to you... and on in a wave. S-waves are a bit like waves on a rope—grab an end and move it sideways, which moves the neighboring part sideways... This works with solids, but not liquids, which cannot "grab" and move the neighboring part.

The geologic time scale is, starting with the oldest and ending with the youngest: A) Precambrian, Cenozoic, Mesozoic, Paleozoic. B) Precambrian, Paleozoic, Mesozoic, Cenozoic. C) Paleozoic, Precambrian, Cenozoic, Mesozoic. D) Paleozoic, Mesozoic, Cenozoic, Precambrian. E) Precambrian, Paleozoic, Cenozoic, Mesozoic.

B) Precambrian, Paleozoic, Mesozoic, Cenozoic. Notes: You could probably reason this out if you remember some Greek roots, or else just memorize it—Precambrian is oldest, then Paleozoic, Mesozoic and Cenozoic.

Ignoring good manners, you start rooting around in the nucleus of a poor, unsuspecting atom, to see what is in there. What are you most likely to find? A) Only protons. B) Protons, usually with some neutrons hanging around among the protons. C) Protons, usually with some electrons hanging around among the protons. D) Neutrons, usually with some electrons hanging around among the neutrons. E) Only neutrons.

B) Protons, usually with some neutrons hanging around among the protons.

This is a photo of a road cut through a mountain called Sideling Hill, in Western Maryland. What happened here? A) Slide-past forces moved the rocks from Tennessee to Maryland, where the rocks piled up at a bend in a San-Andreas-type fault to form the Appalachians of Maryland. B) Push-together forces when Africa and Europe ran into the Americas bent the rocks, which later were exposed at the surface by erosion. C) Graffiti artists painted the roadcut to look like a bunch of bent rocks. D) Bulldozers bent the rocks during the excavation of the road cut. E) Pull-apart forces acting in geologically recent times caused fault-block faulting, forming the mountain.

B) Push-together forces when Africa and Europe ran into the Americas bent the rocks, which later were exposed at the surface by erosion.

What tectonic setting is primarily responsible for producing Olympic National Park as well as the hills on which San Francisco is built? A) Hot-spot. B) Push-together subduction. C) Pull-apart. D) Push-together obduction. E) Slide-past.

B) Push-together subduction.

What tectonic setting is primarily responsible for producing Olympic National Park as well as the hills on which San Francisco is built? A) Slide-past. B) Push-together subduction. C) Push-together obduction. D) Pull-apart. E) Hot-spot.

B) Push-together subduction. Feedback: The rocks of Olympic and San Francisco were scraped off the downgoing slab of the subduction zone.

What is accurate about the scientific results learned by counting tree rings and other annual layers? A) No known records have more than 5000 layers. B) Records in tree rings, lakes and ice all reach beyond 12,000 years, and some of them reach beyond 40,000 years. C) No known records have more than 6000 layers. D) The longest record of annual layers goes back 12,429 years, but there is no way to check this because there are no other records that long. E) Records in trees, lakes and ice all go back 12,429 years, but none of them are longer than that, so that must be the age of the Earth.

B) Records in tree rings, lakes and ice all reach beyond 12,000 years, and some of them reach beyond 40,000 years. Feedback: There is a continuous record of overlapping tree rings from north Germany with 12,429 years in trees (and that was published a few years ago). The longest lake-sediment record of annual layers is over 40,000 years, and there are over 100,000 years sin the longest ice-core record that preserves annual layers. And, various lake, tree and ice records agree on the history of volcanoes, climate changes, etc.

Sometimes, people with scientific backgrounds say bad things about religion, and sometimes people with religious backgrounds say bad things about science. This is because: A) Religion and science must disagree. B) Religion and science do not need to disagree, but sometimes science-background and religion-background people choose to disagree.

B) Religion and science do not need to disagree, but sometimes science-background and religion-background people choose to disagree.

Hot spots: A) Are found only under oceans. B) Rise from as deep in the mantle as the core-mantle boundary to the surface of the Earth, bringing up heat and feeding volcanoes. C) Bring caffeine up beneath the Capitol Building to stir up trouble in Congress. D) Are found only under continents. E) Move around rapidly under the plates while the plates sit still.

B) Rise from as deep in the mantle as the core-mantle boundary to the surface of the Earth, bringing up heat and feeding volcanoes.

Geologically speaking, the water table: A) Rises in elevation during times of drought as trees suck it up, and sinks during rainstorms as trees quit pulling up water because they are well-watered. B) Rises during or soon after rainstorms as spaces fill up, and sinks during droughts as water drains away. C) Never changes its elevation, because it is pinned by the creeks. D) Changes elevation randomly. E) Sits next to the coffee table in the Capitol Building.

B) Rises during or soon after rainstorms as spaces fill up, and sinks during droughts as water drains away. Notes: As trees suck up water during droughts, air enters spaces where water once was, so the water table (which is the bottom of the region with some air in spaces) must sink in elevation. Creeks do change in elevation between rain and drought (floods happen...), and while there are random elements in the world, this is surely not one of them. (Whenever someone claims something is random, at least suspect that the person is really saying "I don't know what I'm talking about, and I'm too lazy to find out.") And while there might be bottled water in the Capitol, geologically speaking, that is not the right answer.

The US government, and most other governments of the world provide support for scientists but not for astrologers, palm readers, or telephone "psychics". Why do governments support scientists? A) Scientists learn the Truth, and governments are always deeply committed to learning the truth. B) Scientists help humans do useful things, which makes the humans healthier, wealthier, etc., and governments often like to support health and wealth. C) Scientists are amazingly sexy, and government functionaries simply cannot control themselves in the presence of such overwhelming sexiness and throw money at the scientists (sometimes tucking tens and twenties into the pockets of the scientists' lab coats). D) Scientists all drink Diet Pepsi because they think it makes them look sexy, and governments are all controlled by the powerful Pepsi Corporation and so the governments support the Diet-Pepsi-drinking scientists. E) Scientists use a careful method, and governments are always committed to supporting the use of careful methods.

B) Scientists help humans do useful things, which makes the humans healthier, wealthier, etc., and governments often like to support health and wealth. Notes: The government is often interested in seeing people live longer, or improving the economy, or having better and more-accurate explosive devices for the military, or in many other things that improve our lives, and science plus engineering and scientific medicine are better than any other human activity at delivering these. A cynic might say that politicians are often not all that interested in finding the Truth. And a realist would note that science is being improved all the time, and because you cannot improve on the Truth, science has not (yet?) learned the Truth. There are many methods in the world, some of them are careful, and many of them are not funded by the government. Some of our spouses or significant others may think that some scientists are sexy, but many other sexy persons are not funded by the government. One of the professors has been known to drink a competitor of Pepsi on occasion, and some scientists refrain from soft drinks entirely.

Geologically speaking, the water table: A) Separates the water-filled region near the Earth's surface from the deeper region with some air in the spaces. B) Separates the water-filled region below the Earth's surface from the region closer to the surface in which some air exists in the spaces. C) Rises during droughts, and sinks during rainy times. D) Never changes its elevation, because it is pinned by the creeks. E) Sits next to the coffee table in the Capitol Building.

B) Separates the water-filled region below the Earth's surface from the region closer to the surface in which some air exists in the spaces. Feedback: The water table is the surface below which all the spaces are full of water, but above which there is generally some air in the spaces. During droughts, water drains away from the ground to the creeks, so air enters spaces previously occupied by water, and the water table drops in elevation. Creeks do change in elevation between rain and drought (floods happen...). And while there might be bottled water in the Capitol, geologically speaking, that is not the right answer.

Before they can be published, scientific papers must be peer-reviewed. This means that: A) Some other scientific experts read the papers and guarantee that they are True. B) Some other scientific experts read the papers and provide quality control by eliminating many mistakes. C) An editor reads the papers, to make sure that all the semicolons are in the correct places. D) Everyone in the world is given the opportunity to comment on the papers through a specially maintained blog. E) Government bureaucrats read the papers, to be sure that the papers do not insult the political positions of the current officeholders.

B) Some other scientific experts read the papers and provide quality control by eliminating many mistakes.

Geologists get to play with chemistry, physics, biology... and history! And what a history you will meet as you work your way through the course. Starting at the beginning, the textbook provides the scientifically accepted start of the story... and promises that you'll get to explore some of the evidence for that scientific view, later in the semester. Meanwhile, which is more nearly correct of the scientifically accepted view? A) The Earth formed when the Big Bang caused older materials to fall together, about 14 billion years ago. B) The Earth formed from the falling together of older materials, about 4.6 billion years ago. C) The Earth formed in the Big Bang, about 6000 years ago. D) The Earth is eternal, having been here forever and promising to be here forever. E) The Earth was assembled by gigantic space beavers, which gnawed down the primordial tree of life and piled its branches together to form the planet.

B) The Earth formed from the falling together of older materials, about 4.6 billion years ago.

B) The Earth formed from the falling together of older materials, about 4.6 billion years ago. Notes: The Big Bang is estimated as having occurred about 14 billion years ago. Stars that eventually formed in the wake of the Big Bang led to production of elements such as iron and silicon that are common in the Earth—we are formed from second-generation stardust, which "got it together" to make the planet about 4.6 billion years ago.

In the picture above, when Dr. Alley slices his finger through the sand, he is recreating on a smaller scale what type of geologic process? [See image: UNIT 5.13] A) The action of waves making a beach in Hawaii. B) The action of mass wasting, as soil and rock collapses off of newly steep canyon walls initially carved out by water. C) The action of an earthquake tearing apart continents. D) The action of Chuck Norris karate chopping someone. E) The action of earthworms burrowing in loose soil.

B) The action of mass wasting, as soil and rock collapses off of newly steep canyon walls initially carved out by water. Feedback: Despite any passing resemblance, Dr. Alley is not using martial-arts techniques to extract money from sand. Instead, he is showing how a river carves a canyon, which then widens as mass wasting occurs on the steep new walls.

The picture above illustrates what scientific principle? [See imagine: UNIT 5.3 A) The equator is hotter than the pole because the equator is closer to the sun than the pole B) The equator is hotter than the pole because the sun hits the equator directly but the sun hits the pole a glancing blow C) The equator is hotter because it rotates faster, and the wind heats the surface as it rotates by, just as Dr. Alley can turn his head rapidly and cause heat by friction D) The equator is hotter than the poles because most volcanoes are located near the equator, forced there by the centrifugal force of Earth's rotation, and Dr. Alley exhales hot air from his equatorial nose E) Dr. Alley is undoubtedly the sexiest human being on Earth

B) The equator is hotter than the pole because the sun hits the equator directly but the sun hits the pole a glancing blow Feedback: Geometry is the main control on equatorial heating. Although the equator is closer to the sun than the pole, the difference is tiny and matters little to the temperature difference between equator and pole. The rotation of the Earth causes winds to turn as they blow over the surface, but does not heat the air. There is no clustering of volcanoes at the equator, and the heat from volcanoes is tiny compared to the heat from the sun. And we are quite confident that several celebrities and politicians believe that they are the world's sexiest human being, so Dr. Alley's standing cannot be "undoubtedly" claimed.

Often, landowners along eroding beaches will build groins, which are walls or dams sticking out into the ocean or lake from the beach. Why are these built, and what happens? A) The landowners are trying to catch sediment from the longshore drift to add to the beach; this almost always works well. B) The landowners are trying to catch sediment from the longshore drift to add to the beach; this can work, but often erosion on the "downstream" side of the groin makes the neighbors mad. C) The landowners are trying to block the energy of the waves, which usually turn to move almost parallel to the beach; this almost always works well. D) The landowners are trying to block the energy of the waves, which usually turn to move almost parallel to the beach; this can work, but often increases energy on the "upstream" side of the groin and makes the neighbors mad. E) The landowners are trying to make a nice photographic platform from which to take pictures of their houses falling apart during the next storm.

B) The landowners are trying to catch sediment from the longshore drift to add to the beach; this can work, but often erosion on the "downstream" side of the groin makes the neighbors mad. Feedback: The "river of sand" that is the longshore drift along the beach is similar to a river in many ways. "Damming" the flow with a groin will trap sand upstream, on the side from which water and sand are coming, but that will allow water with less sand to attack the downstream side, causing erosion there. Dense groin networks may actually so roughen the coast that they hold sand overall, but the erode-the-downstream-neighbors problem is real and often dominates. The waves typically turn so they are coming almost straight in and out, not moving along the beach. And groins are not the best places on which to stand during storms, nor do many landowners actually plan ahead to get good pictures of their houses falling apart in the waves.

It is almost always interesting to ask whether most of the "action" comes from the few, rare events, or the many common events. For earthquakes, we saw that most of the energy is released by the few, big events. For mass movement, averaged over the land surface and over thousands of years, which moves the most material: A) The rare, large events (such as the Gros Ventre slide in the Tetons or the Hebgen Lake slide just outside of Yellowstone) move the most material. B) The many, small events (often lumped together as soil creep) move the most material. C) Landslides move material downhill, but soil creep moves the material back uphill, so that nothing is accomplished. D) No material is moved downhill by mass movement, which actually refers to the process by which marmot #2 is produced, and may happen uphill or downhill.

B) The many, small events (often lumped together as soil creep) move the most material.

What type of mass movement moves the most material, averaged over the Earth's land and over long times? A) The rare, large events move the most material. B) The many, small events move the most material. C) The many, small events and the few, large events move exactly the same amount of material. D) The landslides are lubricated by marmot number 2, while soil creep is greased by bird droppings, and marmot number 2 is more slippery so landslides go faster.

B) The many, small events move the most material. Feedback: As rocks move to streams in many places, such as Pennsylvania, the slow and steady motions are more important than the few dramatic events. Specific places may be dominated by the few, dramatic events, especially in steep mountains, but across the Earth soil creep probably dominates.

The picture above [See image: UNIT 10.12] shows a very hard piece of rock about six inches across, in the Grand Canyon. The surface of the rock looks rather different from the surfaces of many other rocks. What made this odd-looking surface? A) A glacier; the high plateaus adjacent to the canyon had ice-age glaciers that helped carve the canyon. B) The river, which blasted the rock with sand- and silt-laden water during floods; this shows that even hard rocks can be eroded by rivers. C) The wind, which has been primarily responsible for carrying away sand bars, and which sand-blasts rocks with the sand. D) A fault, which dropped old rocks so that they were preserved in Death-Valley-type valleys and so were not eroded away. E) The river; because the rocks are still there, this shows that rivers cannot really erode hard rocks and thus that the river could not have carved the canyon.

B) The river, which blasted the rock with sand- and silt-laden water during floods; this shows that even hard rocks can be eroded by rivers. Feedback: The Canyon was carved by the Colorado River. Glaciers have not been there, and while wind and faults can change the appearance of rocks, none makes something like this river-polished rock, as you saw in one of the Grand Canyon V-Trips.

Dust and shells and fish poop and all sorts of things fall to the sea bed to make sediment. Across broad central regions of the ocean, the sediment accumulates at a uniform rate—piling up about as rapidly here as it does over there. And, in most places, the currents don't move the sediment around much, so that it stays where it falls. Thus, the thickness of the sediment is related to the age of the rocks beneath the sediment. If you go around an ocean and measure the thickness of the sediment in lots of places, you are likely to find: A) The sediment thickness varies a lot from place to place, but the pattern is totally random. B) The sediment is thin near spreading ridges, and thicker away from the ridges. C) The sediment thickness forms waves, thicker thinner thicker thinner thicker thinner, as you cross the ocean, but with no influence from spreading ridges. D) The sediment is thick near spreading ridges, and thinner away from the ridges. E) The sediment is the same thickness everywhere.

B) The sediment is thin near spreading ridges, and thicker away from the ridges. Feedback: Sea floor is made at the spreading ridges, and moves away on both sides. Sediment piles up over time, and while there are variations in sedimentation rate, the huge difference in age of the sea-floor rocks (140 million years near the edges of some ocean basins, to essentially zero at the ridges) is the main controlling factor on sediment thickness. Fish actually poop wherever they travel, and tend to go all over the oceans.

The concentration of CO in the atmosphere rose as the last ice age ended, and then stabilized for thousands of years, until humans became serious about changing the atmosphere with the start of the industrial revolution. Suppose that we succeed in raising the CO concentration in the atmosphere to a level twice as high as occurred for the thousands of years after the ice age and before the industrial revolution, and then we hold the concentration constant at that new, higher level for the next thousand years. What would happen to the average temperature of the planet? A) The temperature would drop a lot, causing a new ice age. B) The temperature would increase to a few degrees above the pre-industrial revolution level, and then stabilize at that new, warmer level. C) The temperature would increase 30 or 40 degrees, and then stabilize at that new, warmer level. D) The temperature would drop a few degrees and then stabilize, not cold enough to cause a new ice age, but cold enough to be unpleasant. E) The temperature would remain the same as it is now, which is about the same as it was before the industrial revolution.

B) The temperature would increase to a few degrees above the pre-industrial revolution level, and then stabilize at that new, warmer level. Doubling CO is estimated to warm the Earth by between 1.5 and 4.5 C, or 2.7 to 8.1 F, with some chance of slightly larger change and very little chance of smaller change. The physical basis of warming from CO is quite well understood, and cooling or no response is very unlikely. You might compare the expected warming from CO to getting up to put another blanket on the bed in the night if you are cold. True, you might spill a glass of water into the bed, or your significant other might steal the other blankets while you're up, so getting the extra blanket might make you colder, but common sense says that getting the extra blanket warms you. Warming from CO is about as certain as warming from the extra blanket—maybe a huge number of volcanoes will explode in the near future and offset the effects of the CO , but don't count on it.

What probably happened in the above picture? A) The tree initially sprouted on another stump, which was removed by the Park Service after new growth had occurred for a while, leaving the tree we see now perched on roots that encircled the original stump. B) The tree started with its roots underground, but erosion washed the dirt away from them, so now they stick out. C) Jeffrey pines such as this are known as multi-leader trees, and typically grow such a trunk for extra support. D) The Park Service hired an expert in topiary, the growth of interesting trees, to make sculptures such as this along the rim of Bryce Canyon. E) Nothing

B) The tree started with its roots underground, but erosion washed the dirt away from them, so now they stick out.

[See image: UNIT 8.12] Above is a "beach" at Acadia National Park. The pieces are granite. A) There is no sand here, so this must be a place where sand is not produced. B) There is no sand here, so sand must be lost to deep water fast enough in comparison to sand supply that sandy beaches have not formed. C) There is no sand here, because Acadia and the surrounding coast of Maine get huge storms, and sandy beaches cannot exist where such huge storms occur. D) There is no sand here, because the Park Service mines the sand to pave park roads. E) There is sand under the rocks; the Park Service places the rocks on top to protect the beach, and takes the rocks off on sunny days.

B) There is no sand here, so sand must be lost to deep water fast enough in comparison to sand supply that sandy beaches have not formed. Feedback: Granite does weather to make sand, so some sand must be produced, but this is not a sand deposit, so sand loss must be fast enough to prevent large accumulations. The Park Service neither mines sand from beaches, nor hides sand on beaches. And huge storms hit Florida and the Gulf Coast, but they have sandy beaches

The photograph above shows some rocks in Great Smoky Mountains National Park. From looking at the rocks, and what you know about the park, a likely story is that: A) These rocks are really marmot #2. B) These rocks were buried deeply and squeezed in a continent-continent collision, and then brought to the surface as overlying rocks were eroded. C) These rocks were sheared in the great slide-past fault that slid rocks from Florida up to the North- Carolina/Tennessee border to form the Smokies. D) These rocks were stretched and then snapped back, bending as they did so and making an earthquake. E) These rocks were buried deeply and squeezed in a continent-continent collision, and then brought to the surface in one of the giant volcanic eruptions that built the Smokies.

B) These rocks were buried deeply and squeezed in a continent-continent collision, and then brought to the surface as overlying rocks were eroded.

In the picture above, Dr. Alley is discussing events that are happening outside of Grand Canyon National Park, which may impact the park. What are the issues he is discussing? A) Water spread on golf courses is causing flooding in the park. B) Water pumped out of the ground for golf courses and other uses evaporates, so less water flows through the ground to the springs of the canyon. C) A terrible shortage of Pepsi has alarmed the Park Service. D) Plastic pieces, such as the straw he is holding in the picture to your right, are littered outside the park, and will break down and release toxins that pollute the waters of the park. E) Water spread on golf courses is introducing nitrates into the park.

B) Water pumped out of the ground for golf courses and other uses evaporates, so less water flows through the ground to the springs of the canyon.

The great scientist Alfred Wegener proposed that continents have moved, while other scientists such as T.C. Chamberlin argued against Wegener. Wegener's ideas eventually won, and are now widely accepted, because: A) Wegener's ideas were more beautiful, and so were favored by the intellectual elite. B) Wegener's ideas did a better job of predicting the results of new observations and experiments. C) Wegener's ideas appealed to dead white European males, whereas Chamberlin's didn't. D) Wegener's ideas appalled dead white European males, and we all know that in this politically correct era, dead white European males cannot get a fair shake. E) Wegener won the Nobel prize.

B) Wegener's ideas did a better job of predicting the results of new observations and experiments.

You develop a new idea, which is in conflict with a widely accepted scientific idea. For your new idea to gain widespread acceptance, you probably will need to show that: A) Your new idea does a better job than the previously accepted idea in predicting the outcome of one experiment that you conducted. B) Your new idea does a better job than the previously accepted idea in predicting the outcomes of an interlocking web of important experiments or observations. C) The development of the old idea was influenced by the socially conditioned ideas of the scientists involved. D) Your new idea is consistent with your interpretation of received wisdom from sacred books. E) Your new idea is informed by Diet Pepsi ads.

B) Your new idea does a better job than the previously accepted idea in predicting the outcomes of an interlocking web of important experiments or observations. Feedback: At last observation, Pepsi commercials were not highly scientific, even if science is involved in figuring out what sells. It is a romantic notion that you could overturn great knowledge with a single observation; however, observing nature is not easy, and nature occasionally fools us (you can, rarely, flip an honest coin twenty times and get twenty heads), so if a single observation disagrees with a lot of other information, that single observation will be checked in various ways to see if the new result "stands up" before the older body of knowledge is discarded. Before an idea gains wide currency, that idea is tried in various ways, in many labs, in many places in nature, while models are run and theory is developed. The interlocking of all of these provides the confidence that scientists can use in doing things successfully. Although received wisdom from sacred books can be used for inspiration, scientific ideas must be tested against nature. Social scientists have quite rightly learned that scientists are affected by their prejudices, their funding sources, their mating habits, and other things, and that the path of science is not nearly the straight-ahead road to understanding presented in some textbooks. Unfortunately, some of those social scientists have then gone off the deep end and claimed that science is no more useful than any other human story—claiming that astrology and astronomy are equally valid, for example, or palm-reading and modern medicine. These same social scientists seem to know where to find a real doctor when they get in trouble, however. Science is appealed to nature, and builds on the learning of people from around the world. Airplanes that fly, computers that calculate, small devices that make big explosions, etc. are not socially conditioned ideas but instead are demonstrations of the success of science coupled to engineering.

The fulmar shown above is soaring across the mouth of Scoresby Sound, off the coast of east Greenland. Behind the fulmar you can see some blurry white areas, which are ice about 3 feet (1 m) thick, and some blurry blue areas, which are open ocean water. The white areas likely are: A). Icebergs, which calved off the outlet glaciers of the Greenland ice sheet and floated down the Sound to the open ocean B). Sea ice, which is frozen ocean water C). River ice, which formed along the main rivers that drain into Scoresby Sound and then was washed out to sea in the spring flood D). Glacier ice, which formed from snowfall and is building up to flow back inland

B). Sea ice, which is frozen ocean water Notes: A fulmar is more-or-less a small, northern albatross. Fulmars are truly marine birds—the bumps at the base of the beak are glands that allow the fulmar to excrete salt, so that the bird does not need to go find fresh water on land. Behind the fulmar is sea ice, frozen ocean water. The saltiness of typical ocean water lowers the freezing point to about 28oF (about -2oC), but with temperatures that plunge below -40 oF (which is where the scales cross, so is -40 oC) in the cold Arctic winter, the weather is cold enough to freeze the sea. Cooling causes sea water to become denser, hence more sink-able. So, as water cools, there is a competition—will the water sink before it freezes, allowing warmer waters to flow in along the surface to fill the space left by the sinking? Or, will the waters freeze before they sink? Where sea water is slightly fresher than typical (more rain or snow melt), freezing occurs. The slightly saltier sea water sinks. (Say that five times fast!) Here, you see some open water and some sea ice. Sea ice is important in many ways in the Arctic, insulating the warmer ocean from the colder air in winter, providing a platform for polar bears to hunt from, reflecting sunlight to keep the air cold, and more.

Scientific evidence indicates that the Earth is about how old? A. 5 thousand to 10 thousand years 13% B. 4.6 billion years 86%

B. 4.6 billion years Notes: Questions about the age of the Earth were discussed by scientists and nonscientists alike in the 1700s and into the 1800s. Early geologists were usually churchgoers—many still are—and often were members of the clergy. Many early geologists started with a "literal" interpretation of the first of the accounts of creation in Genesis of the Christian Bible, and initially these early geologists interpreted the rocks in accord with the worldview that the Earth is no older than the written records of people. However, the more the early geologists looked and studied, the less sense they could make of a young Earth, and virtually all the scientists and the non-scientists who were paying attention came to accept the scientific evidence that the Earth is far, far older than the written histories. Most Christian groups came to accept the overwhelming scientific evidence while still maintaining their beliefs, although some Christian groups have continued to reject the scientific evidence. (In many other religious traditions, there is no objection to the scientific evidence, so this is just not an issue.) Scientifically, there is a correct answer to this question, and it is B, as we will see in the instructional materials. Science has rules, the rules have been followed, and the old Earth "won" while the young Earth was falsified and so set aside as incorrect 200 or more years ago.

There are many greenhouse gases, including carbon dioxide (CO2), methane (CH4). and vaporized water (H2O). These and other greenhouse gases warm the Earth primarily by: A) Raising the atmospheric pressure, because squeezing air warms it, as we saw at the Redwoods. B) Making more clouds, because clouds block the radiation from the planet, which is why cold, frosty nights are rare during cloudy weather. C) Absorbing some of the infrared radiation emitted from the Earth. D) Preventing convection currents that take heat aloft, in the same way that the glass of a greenhouse stops convection currents and so makes the air in the greenhouse warmer. E) Making politicians mad, so they give speeches that heat the air. Carbon dioxide, CO2, is an important greenhouse gas. Greenhouse gases warm the Earth primarily by: A) Absorbing some of the infrared radiation emitted from the Earth. B) Making politicians mad, so they give speeches that heat the air. C) Absorbing the sunlight reflected from snow, clouds, and reflective desert sands. D) Breaking down the methane emitted by flatulent cows. E) Breaking down the ozone layer that cools the planet.

C) Absorbing some of the infrared radiation emitted from the Earth. Feedback: Although it is true that squeezing air warms it, the pressure does not set the temperature (change in pressure brings change in temperature), and, the greenhouse gases are really very rare and don't affect pressure much. Clouds are not caused by greenhouse gases, and while clouds warm nights, clouds cool days, and the net effect of clouds is probably slight cooling of the planet. Convection currents are blocked by the glass of greenhouses, but not by greenhouse gases. But CO2 does absorb some of the infrared radiation emitted from the planet. Absorbing an infrared photon puts a CO2 molecule into an excited state, and fairly quickly the molecule returns to its unexcited state by emitting a photon of the same energy. Some of those photons emitted by excited CO2 molecules head back toward Earth (the emission direction is random). So, the CO2 serves to trap energy in the Earth system, warming the planet so that it glows more brightly to shove infrared radiation past the CO2, achieving a new balance. A) Absorbing some of the infrared radiation emitted from the Earth. Notes: CO2 has very little interaction with the ozone, which is not big on cooling the planet anyway, and CO2 does little to the sunlight reflected from the Earth. But CO2 does absorb some of the infrared radiation emitted from the planet. Absorbing an infrared photon puts a CO2 molecule into an excited state, and fairly quickly the molecule returns to its unexcited state by emitting a photon of the same energy. Some of those photons emitted by excited CO2 molecules head back toward Earth (the emission direction is random). So, the CO2 serves to trap energy in the Earth system, warming the planet so that it glows more brightly to shove infrared radiation past the CO2, achieving a new balance.

What is accurate about the planet's climate system? A) Much more energy is received from the sun than is sent back to space, because high-energy shortwave radiation is received but low-energy longwave radiation is sent back. B) Much more energy is received from the sun than is sent back to space, because high-energy longwave radiation is received but low-energy shortwave radiation is sent back. C) Almost the same amount of energy is received from the sun as is sent back to space, but shortwave radiation is received and longwave radiation is sent back to space. D) Almost the same amount of energy is received from the sun as is sent back to space, but longwave radiation is received and only energy stored by evaporation is sent back to space. E) Much more energy is sent back to space than is received from the sun, because the planet emits longwave radiation but the sun emits shortwave.

C) Almost the same amount of energy is received from the sun as is sent back to space, but shortwave radiation is received and longwave radiation is sent back to space.

In 2005, Hurricane Katrina brought a storm surge that overtopped the levees and flooded New Orleans, causing over 1400 deaths and perhaps $100 billion in damages. This flooding of New Orleans from a big storm was: A) An "act of nature" that no one could have foreseen; these things just happen. B) A disaster that humans made much worse by causing massive sedimentation that raised the whole Mississippi Delta above the surface of the Gulf of Mexico, so that the storm waves could use the Delta as a ramp to jump easily into the city. C) An event that scientists had warned about for decades, based on the known size of hurricanes, and the sinking of the city and the Delta. D) An event proving that if you drive your Chevy to the levee, it causes a hurricane to form. E) An event that proves that civil authorities are so good at planning that you never need to worry about dangers from any weather events in the future.

C) An event that scientists had warned about for decades, based on the known size of hurricanes, and the sinking of the city and the Delta. Feedback: Scientists and planners did not know exactly when a big hurricane would hit New Orleans and threaten the city, but serious assessments had consistently highlighted the possibility for decades. The failures at New Orleans happened despite the fact that Katrina was NOT the "Big One"—on a scale of 1-5, Katrina was a 3 when it made landfall

The age of the Earth can be estimated in many ways. Which statement below is most accurate (remember that uniformitarian calculations involve looking at the thickness and type of sedimentary rocks, and similar things, but do NOT include radiometric dating or counting of annual layers)? A) Annual-layer counting shows that the Earth is more than about 100 million years old. B) Annual-layer counting shows that the Earth is more than about 100 thousand years old, uniformitarian calculations show that the Earth is more than about 100 million years old, but we don't know how to estimate how much more than 100 million years the Earth is. C) Annual-layer counting shows that the Earth is more than about 100 thousand years old, uniformitarian calculations show that the Earth is more than about 100 million years old, and radiometric techniques tell us how old the Earth is. D) Annual-layer counting shows that the Earth is 4.6 billion years old. E) Uniformitarian calculations show that the Earth is 4.6 billion years old.

C) Annual-layer counting shows that the Earth is more than about 100 thousand years old, uniformitarian calculations show that the Earth is more than about 100 million years old, and radiometric techniques tell us how old the Earth is.

Transitional forms between distinct types (species) of different ages in the fossil record: a) Are known for all types. B) Are never referred to in the debate about evolution. C) Are common for commonly fossilized types, but rare for rarely fossilized types. Correct! D) Do not occur. E) Prove that the theory of evolution is wrong.

C) Are common for commonly fossilized types, but rare for rarely fossilized types. Notes: Most living things are recycled, not fossilized. Most of the world is eroding, so no fossils are made in most places. Where fossils are being made, only a few percent of living types typically end up producing fossils. And in those few types, new species often appear in small, isolated populations. But careful search has shown many, many transitions in commonly fossilized types. In rarely fossilized types, transitions are much rarer. Lots of people refer to transitional forms in debating evolution. Anti-evolutionists often claim that transitional forms are unknown. When transitional forms are demonstrated, the anti-evolutionists usually argue that all known transitions are "microevolution" which somehow is not "real" or "macro-evolution". Because some transitions will always be missing, there is no way to show every possible transition in the fossil record, so this anti-evolutionist argument can't be totally disproven. But that does not make this argument a good one.

The recent changes in the amount of ice on Earth over time occurred: A) At random times, in response to very large changes in the total sunshine received by the Earth in response to features of Earth's orbit. B) At regular and repeating times, controlled by the very large changes in total sunshine received by the Earth in response to features of Earth's orbit. C) At regular and repeating times, controlled by redistribution of sunlight on the surface of the Earth in response to features of Earth's orbit, even though total sunshine received by the planet didn't change much. D) At random times, controlled by redistribution of sunlight on the surface of the Earth in response to features of Earth's orbit, even though total sunshine received by the planet didn't change much. E) Because flocks of giant ptarmigan and herds of giant marmots clustered on the edges of the ice sheets, which melted the ice.

C) At regular and repeating times, controlled by redistribution of sunlight on the surface of the Earth in response to features of Earth's orbit, even though total sunshine received by the planet didn't change much. Feedback: The orbital changes have little effect on the total sunshine, but do move that sunshine around, with important consequences. And the orbital changes are far from random, having very strong regularities. We'd love to have seen flocks of ptarmigan and herds of marmots, but no one has found their bones, so it is highly likely that they did not exist.

The above picture [See image: UNIT 8.7] shows ocean in the upper right, a beach, andland (lower left). The red dashes trace the crest of a wave. Wavesmove perpendicular to their crests. What principle is illustrated by the picture? A) The rotation of the Earth causes wave crests to be curved as they approach the beach. B) Because waves go faster in shallower water, waves move primarily along the beach, causing longshore motion of sediment. C) Because waves go slower in shallower water, waves turn and move almost directly towards the beach, but the little bit of along-beach motion remaining drives longshore transport. D) Because waves go faster in shallower water, waves turn and move almost directly towards the beach, but the little bit of along-beach motion remaining drives longshore transport. E) Because waves move slower in shallower water, waves turn and move exactly toward the beach.

C) Because waves go slower in shallower water, waves turn and move almost directly towards the beach, but the little bit of along-beach motion remaining drives longshore transport. Feedback: The rotation of the Earth has only miniscule effect at scales this small. Waves do go slower in shallower water, so as one end nears the coast, that end "waits" for the other end to catch up, causing waves to be going almost straight toward the shore when they run up the beach, but with just a little along-beach motion driving longshore drift.

Some natural resources are renewable—nature produces them fast enough that humans can obtain valuable and useful supplies of a resource without depleting it. Other natural resources are nonrenewable—if we use the resource at a rate fast enough to matter to our economy, the resource will run out because use is much faster than natural production. What do we know about oil and coal? A) Both oil and coal are renewable resources; they are being made rapidly by natural processes in places such as the Mississippi and Mekong Deltas. B) Oil is a nonrenewable resource, but coal is made more rapidly and so is a renewable resource. C) Both oil and coal are nonrenewable resources, and at current usage rates and prices similar to today, oil will run out in about a century and coal will run out in a few centuries. D) Coal is a nonrenewable resource, but oil is made more rapidly and so is a renewable resource. E) Both oil and coal are nonrenewable resources, and at current usage rates and prices similar to today, both will last a few hundred years before running out.

C) Both oil and coal are nonrenewable resources, and at current usage rates and prices similar to today, oil will run out in about a century and coal will run out in a few centuries. Feedback: There is lots more coal than oil; oil has this habit of floating on water, thus rising through rocks and escaping to the sea floor where the oil is "burned" for energy by bacteria or other creatures. The size of the resource, in coal, oil, or anything else, depends on the price, and how long the resource lasts depends on rate of use, which is increasing rapidly for fossil fuels. The idea that immense pools of oil are out there, undiscovered but easy to get, is pretty silly—oil companies are really smart, drilled the easy stuff early on, and are now running out of oil that can be drilled and produced at prices close to modern.

Hawaiian volcanoes, where they emerge above sea level, are: A) Steep, narrow stratovolcanoes, much steeper than shield volcanoes such as Mt. St. Helens. B) Especially silica-rich, unlike the lower-silica rocks of Mt. St. Helens. C) Broad, gentle shield volcanoes, much flatter than stratovolcanoes such as Mt. St. Helens. D) All clinkery-looking lava called aa, very different from the pahoehoe flows of Mt. St. Helens. E) All ropy-looking lava called pahoehoe, very different from the aa of Mt. St. Helens.

C) Broad, gentle shield volcanoes, much flatter than stratovolcanoes such as Mt. St. Helens.

Chemical weathering of a continental rock such as granite in a climate such as that of Pennsylvania or other places where a good bit of rain falls, produces: A) Feldspar and dark-mineral grains, that do not wash away easily, and dissolved quartz that does wash away easily B) Clays that dissolve and wash away easily C) Clays and rust, that do not wash away easily, and soluble ions, that do wash away easily D) Soluble ions that do not wash away easily, and clays and rust that wash away easily E) Salt-laden soils (also called pedocals)

C) Clays and rust, that do not wash away easily, and soluble ions, that do wash away easily Feedback: Weathering of granite in Pennsylvania makes some things (clay, rust, and quartz sand) that stay behind to contribute to soil, and other things (soluble ions) that dissolve and wash away very quickly. In dry climates, not very much rainwater percolates downward and through rocks to streams; most rain soaks in a little bit, but is evaporated back to the atmosphere before soaking way down in soil. Very soluble things (sodium ions, for example) may wash away in the little water that reaches streams, but slightly less soluble things (which would wash away in Pennsylvania) such as calcium will be released from rocks but then accumulate in spaces in the soil as water evaporates. These give rise to pedocals, calcium-laden soils. But these are not expected in rainy places such as Pennsylvania, and this isn't a subject introduced in the course, so you really shouldn't worry about it.

Air can be heated in many different ways. At night, if air moves up one side of a mountain range such as the Sierra Nevada, raining or snowing on the way, and then down the other side, the air is hotter after moving over than it was before. What is the main reason, as discussed in the class materials? A) Moonlight is so bright that it heats the air a lot. B) Moving air is always heated a lot by friction with the trees beneath. C) Condensation of water vapor to form clouds and rain releases heat that was stored when the water evaporated. D) The Earth's rotation turns air into tornadoes and hurricanes by the Coriolis effect, and this turning makes the air warmer. E) Forest fires that are always burning in the Sierra make the air a whole lot hotter.

C) Condensation of water vapor to form clouds and rain releases heat that was stored when the water evaporated.

Glaciers move by: A) Deformation within the ice. B) Deformation within the ice, and sometimes sliding over materials beneath. C) Deformation within the ice, and sometimes sliding over materials beneath or deformation within materials beneath. D) Deformation within materials beneath and sliding over those materials, and sometimes by deformation within the ice. E) Deformation within materials beneath, and sometimes by sliding over those materials or by deformation within the ice.

C) Deformation within the ice, and sometimes sliding over materials beneath or deformation within materials beneath. Feedback: Deformation within the ice is essentially the definition of a glacier, so that is always present. When the bed is warmed by heat from the Earth, the ice can slide over materials beneath, and may also deform till beneath.

In the photo above, Dave and Kym are discussing a model of the Waterpocket Fold in Capitol Reef National Park. The Waterpocket probably formed in the same way as the Front Range of the Rockies. This involved: A) The spreading of Death Valley pinched Utah into Colorado. B) The low region, in Dave's left hand, dropped relative to the high region, in Dave's right hand, along a Death-Valley-type fault, and something similar happened in dropping Denver relative to the Front Range. C) Especially warm sea floor in the subduction zone off the west coast rubbed along under western North America and squeezed or wrinkled the rocks, folding them (probably with a push-together fault somewhat deeper under the fold). D) A subduction zone in western Utah squeezed eastern Utah (Capitol Reef) and Colorado (Front Range). E) An obduction zone in western Utah squeezed eastern Utah (Capitol Reef) and Colorado (Front Range).

C) Especially warm sea floor in the subduction zone off the west coast rubbed along under western North America and squeezed or wrinkled the rocks, folding them (probably with a push-together fault somewhat deeper under the fold).

If you are drilling a well to reach water, you usually will have to drill: A) To the same depth, wherever you were. B) Farther into the ground to make a deeper well in a valley than on a ridge. C) Farther into the ground to make a deeper well on a ridge than in a valley. D) To a random and unpredictable depth unrelated to where you are drilling E) Into a cave, because only caves contain water underground.

C) Farther into the ground to make a deeper well on a ridge than in a valley.

If humans change the composition of the atmosphere in a way that would warm the world by one degree if everything else in the Earth system remained unchanged, most studies indicate that over the next years to decades: A) Feedback processes will enhance this warming a lot, causing the total warming to be many tens of degrees. B) Feedback processes will oppose this warming a little and cause the total warming of the world to be less than a degree. C) Feedback processes will enhance this warming a little, causing the total warming to be a few degrees. D) Feedback processes will oppose this warming a lot and cause the world to cool. E) No feedback processes will act, and the total warming of the world will be one degree.

C) Feedback processes will enhance this warming a little, causing the total warming to be a few degrees. Notes: Negative feedbacks stabilize the climate over long times of hundreds of thousands or millions of years or more, but feedbacks over years to millennia are mostly positive, amplifying changes. If there is a change in the sun, or CO2, or something else sufficient by itself to raise the temperature by one degree, this will be amplified to a few degrees by feedbacks.

The above picture [See image: UNIT 9.5] is from the Escalante-Grand Staircase National Monument. The pink arrows point along some interesting features. What are they? A) Faults, where rocks were moved in earthquakes. B) Mud cracks, formed when a flash flood roared down the road (which is under the lower-right pink arrow), spread mud onto the desert surface, and then the mud dried. C) Joints, formed when the sedimentary rocks were broken by physical-weathering or other processes. D) Unconformities, formed by erosion in the past. E) Sand-dune cross beds, formed when the wind deposited sand.

C) Joints, formed when the sedimentary rocks were broken by physical-weathering or other processes. Feedback: This is the Navajo Sandstone, and it is a sand-dune deposit, but you can't really see that in this picture. Almost all rocks have joints. Joints channel water, and make space for roots, so plants often grow along joints, as you see here. The change from red to white along the upper-left arrow is probably a record of places in the past where fluids carrying oil met fluids carrying water—the water rusted the iron and made red; the oil left the iron reduced and carried it away.

It would be really nice to know whether an earthquake is coming, so we could prepare for it. At this time, we are able to: A) Predict where earthquakes will occur, but not when; however, we're positive that in the near future we'll be able to predict the "when" with high accuracy as well. B) Say with absolute certainty that no earthquake will ever occur in central Pennsylvania, where the author of the course textbook lives. C) Make reasonably accurate estimates of where earthquake damage is likely, and how bad earthquake damage is likely to be, but not exactly when an earthquake will occur. D) Say nothing; scientists have supplied no useful information on earthquake occurrence. E) Watch animals and water levels in wells, and whenever the water levels bounce in the wells and the animals act strangely, an earthquake is coming.

C) Make reasonably accurate estimates of where earthquake damage is likely, and how bad earthquake damage is likely to be, but not exactly when an earthquake will occur.

During chemical weathering, sodium is released as dissolved ions and transported to the ocean, where: A) Most of it is used in shells of such creatures as clams, corals and coccolithss. B) Most of it is used in shells of such creatures as diatoms, radiolarians and sponges. C) Most of it stays in the water for a while, making the water salty. D) Most of it reacts with hot sea-floor rocks to make new minerals. E) Most of it vaporizes to cause intense air pollution.

C) Most of it stays in the water for a while, making the water salty. Feedback: The "saltiness" of the ocean is primarily sodium chloride, table salt. Most of the sodium goes to make this salt. But, eventually salt beds forming by evaporation of water in marginal basins, or subduction of muds with salty water in the spaces between the grains, does remove sodium from the sea.

The above photograph was taken in the Grand Canyon, and shows a cliff that is approximately 30 feet high. What are the rocks in the cliff? A) Precambrian sedimentary rocks, preserved in blocks dropped down by Death-Valley-Type faulting; the folding was caused by the drag along the faults. B) Paleozoic sedimentary rocks that form the main walls of the canyon; the folding was caused by mass-movement processes before the rocks were hardened by hard-water deposits. C) Precambrian metamorphic rocks with some igneous rocks intruded; the folding was caused by mountain-building processes when the rocks were very hot deep in a mountain range. D) Recent lava flows from pull-apart faults near the west end of the canyon; the folding happened as the lava cascaded over the canyon walls and flowed toward the river. E) Cement poured to make the walls of the new gift shop that sits above the canyon, painted to look like something more interesting.

C) Precambrian metamorphic rocks with some igneous rocks intruded; the folding was caused by mountain-building processes when the rocks were very hot deep in a mountain range. Feedback: This is the Vishnu Schist and Zoroaster Granite, rocks from the heart of a mountain range. The river is just barely out of the picture to the bottom.

What tectonic setting is primarily responsible for producing the Appalachian Mountains and Great Smoky Mountains National Park? A) Hot Spot B) Push-together Subduction C) Push-together Obduction D) Pull-Apart E) Slide Past

C) Push-together Obduction Feedback: A proto-Atlantic Ocean once separated Africa and Europe from the Americas, and subduction occurred as the ocean slowly closed. Then, a great collision—obduction—raised the Appalachians, bending and breaking the rocks. Later, the mountain range fell apart in Death-Valley-type faulting to start the present Atlantic.

National Parks are: A) Regions containing key biological resources that have been set aside for the enjoyment of the present generation. B) Regions containing key geological resources that have been set aside for the enjoyment of future generations. C) Regions containing key biological, geological or cultural resources that have been set aside for the enjoyment of the present generation and future generations. D) Regions containing key cultural resources that have been set aside for the enjoyment of the present generation. E) Regions containing key bumper-cars games that have been set aside for the enjoyment of the current presidential administration.

C) Regions containing key biological, geological or cultural resources that have been set aside for the enjoyment of the present generation and future generations.

C) Regions containing key biological, geological or cultural resources that have been set aside for the enjoyment of the present generation and future generations. Notes: Old Faithful, the giant sequoias, and Mesa Verde's cliff dwellings are waiting for you, and your grandchildren.

What happened in the picture above? A) Turbulence where the rivers enter the sea has caused suspended sediment in the seawater to flocculate and settle, forming the deposits seen on the right. B) Rivers have delivered sediment to the sea, forming flat-topped deposits called deltas. C) Rivers have delivered sediment to the sea, forming deltas that built up as they built out so that they still slope slightly downhill toward the sea. D) Divers have built the mud piles to slow down the river water and protect endangered clams that live along the coast. E) A certain financially ailing airline that flies to Cincinnati and then Atlanta built this from thrown-out beverage cups as an advertisement.

C) Rivers have delivered sediment to the sea, forming deltas that built up as they built out so that they still slope slightly downhill toward the sea.

What is accurate about the land surface today, that you can observe in places such as Pennsylvania? A) Sediment is being deposited in most places, but a few places are eroding. B) Sediment is being deposited everywhere, covering the land surface deeper and deeper. C) Sediment is being deposited in a few places, but most places are eroding. D) Sediment is not being deposited anywhere, and it never has been. E) Sediment is not being deposited anywhere, so everywhere is eroding.

C) Sediment is being deposited in a few places, but most places are eroding. Feedback: Today in Pennsylvania (and across most of the land surface of the planet), sediments are accumulating in a few human-made lakes, a few natural wetlands or natural lakes, along some streams and in some caves, but almost everywhere else is eroding. This is the typical state of affairs, so you need to correlate events across large regions to get a good geologic record

In the picture above, the yellow arrow points at a jetty, a sort of sea wall or groin or dam, that was constructed along the coast of Washington. A likely interpretation of what you see here is: A) Sediment transport is typically from the upper left, and the sediment falls into the lee of the jetty on the right and piles up, while the left side is unaffected B) Sediment transport is typically from the right, causing deposition to the right of the jetty but no change to the left C) Sediment transport is typically from the right, causing deposition to the right of the jetty but erosion to the left D) Sediment transport is typically from the upper left, and the sediment falls into the lee of the jetty on the right and piles up, while erosion happens on the left E) Sediment transport is typically directly from the ocean to the land, piling up sediment on both sides of the jetty.

C) Sediment transport is typically from the right, causing deposition to the right of the jetty but erosion to the left Feedback: A jetty works like a dam, trapping sediment on the "upstream" side and letting clean water pass to the other side, where the clean water erodes. So, the transport is typically from the right. A large beach has been formed there, but erosion "downstream" is cutting around the end of the jetty.

There is a deep trench in the sea floor off the Marianas volcanic arc of explosive, andesitic, Ring of Fire volcanoes in the South Pacific, but the water is not deep off the coast of Oregon and Washington near Mt. St. Helens and the Olympic, because: A) The Marianas, Oregon and Washington have trenches, but the trench off Oregon and Washington is filled by discarded Microsoft Windows CDs that are obsolete because of all the virus problems. B) Oregon and Washington are near a subduction zone, but the Marianas are not. C) The Marianas, Oregon and Washington have had the sea floor bent downward by subduction to make trenches, the trench off Oregon and Washington is filled by sediment eroded from the nearby continent, but the Marianas don't have a nearby continent and so the trench there is not filled with sediment. D) The trench off Oregon and Washington is filled with great basaltic lava flows from the hot spot that feeds the Cascades volcanoes. E) The Marianas are near a subduction zone, but Oregon and Washington are not.

C) The Marianas, Oregon and Washington have had the sea floor bent downward by subduction to make trenches, the trench off Oregon and Washington is filled by sediment eroded from the nearby continent, but the Marianas don't have a nearby continent and so the trench there is not filled with sediment.

Your boss has assigned you to get the low-down on the latest wonder-drug, and to be darn sure to get it right. You would be wise to consult: A) The Wikipedia; everything they publish is up-to-date. B) The web site of the manufacturer of the wonder drug; they know more about it than anyone else does. C) The article in the Journal of the American Medical Society, a peer-reviewed scientific journal, reporting on the discovery and testing of the drug. D) The New York Times article quoting the discoverer of the drug on how wonderful it is. E) The web site in the email you received with the subject line "Grow your ***** naturally with new wonder drug

C) The article in the Journal of the American Medical Society, a peer-reviewed scientific journal, reporting on the discovery and testing of the drug.

Which is accurate about the Earth? A) The asthenosphere is a layer containing both the uppermost part of the mantle and the crust, where breaking is more common than flowing. B) The lithosphere is the very center of the Earth. C) The asthenosphere is the soft part of the mantle below the lithosphere. The lithosphere is a layer containing both the uppermost part of the mantle and the crust, where breaking is more common than flowing. D) The asthenosphere is a layer containing both the uppermost part of the mantle and the crust, where flowing is more common than breaking. E) The asthenosphere is the soft part of the mantle below the lithosphere. The lithosphere is a layer containing both the hottest part of the mantle and the crust, where flowing is more common than breaking.

C) The asthenosphere is the soft part of the mantle below the lithosphere. The lithosphere is a layer containing both the uppermost part of the mantle and the crust, where breaking is more common than flowing.

The size of a typical sandy beach, averaged over a few decades, is usually controlled by: A) The balance between loss of sand blown away to make sand dunes, and gain of quartz sand from weathering of the granite bluffs just behind the beach. B) The balance between net transport of sand to the beach by wintertime storms, and removal of sand from the beach by smaller summertime waves. C) The balance between sand supply from rivers or from coastal erosion, and sand loss to deep water. D) The balance between sand supply from glaciers and sand loss to the wind. E) The balance between sand dug up from below by crabs, and sand taken inland in the shorts of small beach-goers.

C) The balance between sand supply from rivers or from coastal erosion, and sand loss to deep water. Feedback: On average, beaches lose sand to deep water, and will shrink unless that sand is replaced. Glaciers contributed some of the sand in places, but are not important now for typical beaches. Wind matters a bit, but not too much. Only a little sand is supplied from weathering of the bluffs behind a beach (if the beach has bluffs...); most is brought in from elsewhere. Winter waves tend to remove sand from the beach, with summer waves returning the sand. And while any parent can comment eloquently on the volume of sand brought home by the offspring, the amount is not large in the grand scheme of things.

Large rivers have many interesting features, including: A) The flood plain, that flat area above where any floods reach. B) The natural levees, high regions left behind when compaction of mud occurs beneath the river. C) The flood plain, the nearly flat region farther from the river than the natural levees and composed of mud deposited by the river's floods. D) The natural levees, formed when beavers build dams along the river. E) The flood plain, the region dragged flat by beaver tails while they're building their dams.

C) The flood plain, the nearly flat region farther from the river than the natural levees and composed of mud deposited by the river's floods.

In the photo above, [See image: UNIT 5.14] Sam Ascah is standing on sand and gravel in a pothole, where a stream swirls during the short but intense thunderstorms of Zion National Park. And next to that stream, the other picture shows the sandstone and the hang-on-so-you-don't-fall-over-the-cliff chain along the trail. A likely interpretation of these features is: A) The Park Service carefully cut little grooves behind the chain before they hung it, so that it would look cute and slide well, and they cut the potholes so that hikers would have something to look at. B) The stream swirled rocks around and cut the potholes, and even bounced up the cliff to cut the notches behind the chain. C) The grooves behind the chain have been cut over decades by motion of the chain as hikers grabbed it, and the potholes were cut by water swirling rocks around during the rare floods over much longer times. D) The potholes and the grooves behind the chain were gnawed by giant beavers. E) The potholes and the grooves behind the chain were gnawed by giant marmots.

C) The grooves behind the chain have been cut over decades by motion of the chain as hikers grabbed it, and the potholes were cut by water swirling rocks around during the rare floods over much longer times. Feedback: The chain really has hung there for decades, and has been scraped against the cliff dozens of times per day each summer, slowly wearing into the easily broken sandstone. The stream does swirl rocks around and slowly wear down the potholes. The potholes were there beside the cliff when the trail was established, and haven't changed too much over decades.

Air that passes over the Sierra Nevada from the Redwoods to Death Valley is warmed by roughly 30oF, even if the air goes over at night. Where does the energy come from? A) Friction as the air moves over the rocks beneath, driven by pressure differences between the Pacific and Death Valley. B) Friction as the air moves over the rocks beneath, driven by the rotation of the Earth, which causes winds to curve as they blow over the surface. C) The heat that had been stored during evaporation of water from the ocean and was released when condensation made clouds and rain over the Redwoods. D) Cooling of the air during expansion, by 5oF/1000 ft change in elevation. E) Gas-passing marmots, such as George, seen here.

C) The heat that had been stored during evaporation of water from the ocean and was released when condensation made clouds and rain over the Redwoods. Feedback: Much of the sun's energy that falls on the tropics is stored by evaporating water, and only later made so you can feel it (called sensible heat) when condensation reverses the evaporation. Winds are driven by pressure differences, and do curve in response to the Earth's rotation, and there is a little bit of heat generation from friction, but you should probably know that standing outside in the wind does not make you hot as the frictional heating occurs around your body—the frictional heat is very small. (If the air were moving past you at many times the speed of sound, the frictional heat would become large, as shown by meteorites "burning up" in the atmosphere, and the need for heat shields on spacecraft re-entering the atmosphere. And while marmots do produce a little methane, and a bit of heat, they don't produc

If you went to Greenland and drilled a hole in the ice sheet, then came back later and surveyed the hole, you would find that the shape of the hole had changed. If you asked Dr. Anandakrishnan why the shape changed, he would tell you that the ice sheet was flowing. He would be correct. What does he mean by this? A) Your drill has melted the ice, the water flowed away and refroze. B) Your drill has shaken the ice, which settled downward, changing the shape of the hole. C) The ice is not too much colder than its melting point, and deforms something like hot rocks in the mantle or a chocolate bar in your pocket. D) Your drill compresses the ice, turning it into a denser type in an implosion-style earthquake that deforms the hole. E) Your drill woke up the ice from a nice nap, but the ice then settled back down to "going with the flow".

C) The ice is not too much colder than its melting point, and deforms something like hot rocks in the mantle or a chocolate bar in your pocket. Feedback: Materials warmed almost but not quite to their melting point can deform without breaking or melting. We saw this with the great convection cells in the mantle, back in unit 2, and we meet it again with ice. If you list the temperature of the ice in degrees F, it is a lot colder than the mantle, or iron heated by a blacksmith, or a chocolate bar in your pocket. But, the ice has been warmed from absolute zero almost to the melting temperature, just like the mantle and the iron and the chocolate, so the stress from gravity can cause the ice to deform or flow.

Which is accurate about the Earth? A) The lithosphere usually breaks rather than flows, and the asthenosphere usually breaks rather than flows. B) The lithosphere usually flows rather than breaks, and the asthenosphere usually breaks rather than flows. C) The lithosphere usually breaks rather than flows, and the asthenosphere usually flows rather than breaks. D) The lithosphere and the asthenosphere freeze in the winter to make Pepsi slushees. E) The lithosphere usually flows rather than breaks, and the asthenosphere usually flows rather than breaks.

C) The lithosphere usually breaks rather than flows, and the asthenosphere usually flows rather than breaks. Feedback: "Litho" means stone, and the lithosphere is the hard breakable layer, above the softer asthenosphere.

The picture above [See image: UNIT 7.10] shows a hillslope in Greenland that is about ½ mile across. The hill slope towards you, so the lowest part of the hill is at the bottom of the picture, and the highest part is at the top of the picture. What is likely to be true? A) The materials on the hillside are moving toward you at many miles per hour. B) The materials on the hillside are moving toward you at a few miles per year. C) The materials on the hillside are moving toward you at an inch or so per year. D) The materials on the hillside are not moving, but moved toward you at a few miles per year during the ice age when such motion was common. E) The materials on the hillside have never moved.

C) The materials on the hillside are moving toward you at an inch or so per year. Feedback: The hillslope in Greenland bears the unmistakable signs of creep on permafrost, carrying streams of rocks and bits of tundra downhill at an inch or so per year. Such processes used to occur in Pennsylvania and elsewhere during the ice age, but are still active in Greenland.

Large rivers have many interesting features, including: A) The flood plain, that flat area above where any floods reach. B) The natural levees, high regions left behind when compaction of mud occurs beneath the river. C) The natural levees, formed when flood waters leaving the channel slow down and drop much of their load near the channel; beyond the natural levees is the flood plain, where much of the rest of the mud in a flood is deposited in a thin layer. D) The natural levees, formed when water rushing back into the river channel after floods erodes troughs away from the river. E) The flood plain, the flat region left behind when the river cuts downward to make a valley and leave uplands.

C) The natural levees, formed when flood waters leaving the channel slow down and drop much of their load near the channel; beyond the natural levees is the flood plain, where much of the rest of the mud in a flood is deposited in a thin layer. Feedback: Many processes contribute to the formation of flood plains, but deposition of mud to smooth the surface is the most important one. Flood plains often occur beyond natural levees. The initial slowdown as floodwater spreads from a river channel into the trees deposits sediment to form natural levees.

The United Nations-sponsored Intergovernmental Panel on Climate Change shared the 2007 Nobel Peace Prize. The information that the Panel has supplied to policymakers includes: A) The observed rise in atmospheric CO levels has been caused primarily by a sudden increase in explosive volcanism, and is causing the climate to warm. B) The observed rise in atmospheric CO levels has been caused primarily by human fossil-fuel burning, and is having no effect on the climate. C) The observed rise in atmospheric CO levels has been caused primarily by human fossil-fuel burning, and very likely is causing warming of the climate that is likely to become much larger if we continue our current behavior. d) The observed rise in atmospheric CO levels has been caused primarily by a sudden increase in explosive volcanism, and is having no effect on the climate. E) The observed rise in atmospheric CO levels has been caused primarily by human fossil-fuel burning, and very likely is causing warming of the climate that is unlikely to become much larger.

C) The observed rise in atmospheric CO levels has been caused primarily by human fossil-fuel burning, and very likely is causing warming of the climate that is likely to become much larger if we continue our current behavior. Notes:

The above Landsat image [See image: UNIT 8.5] from NASA shows Cape Cod, Massachusetts. The short yellow arrow indicates new sand deposits, which have formed over the last decades. The long pink arrow indicates underwater sand deposits. The dotted blue arrow points to the great Outer Beach of the Cape. Based on material presented in this class, what is going on? A) The ocean is eroding the outer beach, but the ocean is also taking sand from the pink-arrowed underwater deposits to add to the yellow-arrowed regions where the Cape is growing. B) The ocean is eroding the blue-arrowed outer beach, and all of that sand is transferred to the yellow-arrowed end, while nothing happens to the pink-arrowed underwater sand, so the Cape as a whole is holding its own. C) The ocean is eroding the blue-arrowed outer beach, and the yellow-arrowed end is growing more slowly, with some sand falling off to the pink-arrowed deposits and then off into deeper water, so the Cape as a whole is shrinking. D) The ocean is "mining" material from the pink-arrowed region, and adding that material to the yellow-arrowed and blue-arrowed places, so the Cape is getting longer as well as wider. E) The yellow and pink arrows actually indicate piles of peripherals lost by wintertime nudists sunbathing on the Cape's beaches.

C) The ocean is eroding the blue-arrowed outer beach, and the yellow-arrowed end is growing more slowly, with some sand falling off to the pink-arrowed deposits and then off into deeper water, so the Cape as a whole is shrinking. Feedback: The blue-arrowed Outer Beach is eroding, losing some sand to the yellow-arrowed Monomoy Island—a remarkable birding spot—and some sand to the pink-arrowed underwater bars, which lose sand to deeper water—the Cape is losing ground. Furthermore, the Cape is losing ground much faster than nudists are losing peripherals.

Pieces of bedrock from Canada are spread across large areas of northwestern Pennsylvania, even though the Great Lakes are between Pennsylvania and Canada. How do geologists explain this? A) The rocks floated into Pennsylvania in icebergs during a great flood. B) The rocks were "splashed" into Pennsylvania by a meteorite impact that formed Hudson Bay. C) The rocks were carried into Pennsylvania by a glacier flowing from Canada; the base of the ice was able to flow uphill from Lake Ontario into Pennsylvania because the top of the ice sloped down toward Pennsylvania. D) The rocks were carried into Pennsylvania by ice but before the Great Lakes formed, because ice cannot flow uphill. E) The rocks were carried into Pennsylvania in the gizzards of migrating geese.

C) The rocks were carried into Pennsylvania by a glacier flowing from Canada; the base of the ice was able to flow uphill from Lake Ontario into Pennsylvania because the top of the ice sloped down toward Pennsylvania. Feedback: Ice, or pancake batter, or any pile, tends to spread from where its upper surface is high to where its upper surface is low. The Great Lakes are old features, but the base of the ice really did flow up out of the Great Lakes into Pennsylvania because the top of the ice sloped down from Canada into Pennsylvania.

A scientist successfully predicts the outcome of an experiment. You watch carefully and know he didn't cheat. The scientist's success shows that: A) The scientist knows absolute Truth about this experiment; success is not possible unless you know the Truth B) The scientist was just lucky; no one ever knows what's going on, so successful predictions require luck C) The scientist may know the truth, or at least know something that is close to the truth, or the scientist may have gotten lucky this time; you can't be absolutely sure D) The scientist really was cheating, even though you didn't see the cheating; no one can get things right, except by cheating E) The scientist spent the night at a particular hotel chain and go a free breakfast, giving the scientist the ability to do amazing things

C) The scientist may know the truth, or at least know something that is close to the truth, or the scientist may have gotten lucky this time; you can't be absolutely sure

In the image above, [See image: UNIT 6.11] a stream from the land on the right enters the ocean on the left in the lower part of the picture, and another does the same near the top of the picture. What happened where the streams met the ocean? A) The calcium carbonate carried by the rivers precipitated out to form cave-formation-like deposits. B) The sediment carried by the streams settled out in the slower-moving ocean water, forming flat-topped deposits called deltas. C) The sediment carried by the streams settled out in the slower-moving ocean water, forming deltas that built up as they built out so that they still slope slightly downhill toward the sea. D) Tsunamis rushing from the ocean into the streams pushed up mud to make the deposits. E) Earthquakes shook the sea floor and pushed up mud to form the deposits.

C) The sediment carried by the streams settled out in the slower-moving ocean water, forming deltas that built up as they built out so that they still slope slightly downhill toward the sea. Feedback: These deltas in a fjord in Greenland are like any other deltas; the deposits cannot be purely flat-topped, or the rivers would not flow across to get to the sea water in the fjord.

Most landslides happen when: A) The unconsolidated materials on hillslopes are dry, so the grains roll easily downhill. B) The unconsolidated materials on hillslopes are damp, so the grains are made slippery by the water. C) The unconsolidated materials on hillslopes are very wet and thus heavy and slippery, and the water doesn't have to "break" as the grains move. D) The unconsolidated materials on hillslopes are paved with blacktop. E) The unconsolidated materials on hillslopes are paved with concrete.

C) The unconsolidated materials on hillslopes are very wet and thus heavy and slippery, and the water doesn't have to "break" as the grains move.

You build and maintain two biologically diverse terrariums that are identical in every way at the beginning, except that one is divided in half by an unbreachable glass wall. After some time (long enough for many generations to pass, but not long enough for much evolution to occur), it is most likely that: A) The total number of species in each terrarium will be the same. B) The divided terrarium will have more species than the undivided one. C) The undivided terrarium will have more species than the divided one. D) The Pepsi Corporation will buy advertising in your terrariums. E) The Pepsi Corporation will buy advertising in your terrariums, and then "water" them with Pepsi, killing them.

C) The undivided terrarium will have more species than the divided one. Feedback: The Pepsi Corporation is more likely to advertise at the Super Bowl. Dividing the terrarium makes two smaller populations. A species that dies out on one side cannot be replaced from the other side as in the undivided terrarium; then, loss of that species on the other side will be total loss from your terrarium.

What is accurate about the planet's climate system? A) The wind blows because heating of the poles drives convection cells in the atmosphere, and the winds appear to curve to the left or right over the surface of the planet because of the planet's the planet is spherical shape. B) The wind blows because heating near the equator drives convection cells in the atmosphere, and the winds appear to curve to the left or right over the surface of the planet because of the planet's spherical shape. C) The wind blows because heating near the equator drives convection cells in the atmosphere, and the winds appears to curve to the left or right over the surface of the planet because of friction produced by the spherical planet's rotation beneath the atmosphere. D) The wind blows because heating near the poles drives convection cells in the atmosphere, and the winds appear to curve to the left or right over the surface of the planet because of friction produced by the spherical planet's rotation beneath the atmosphere. E) The wind blows because of marmot flatulence.

C) The wind blows because heating near the equator drives convection cells in the atmosphere, and the winds appears to curve to the left or right over the surface of the planet because of friction produced by the spherical planet's rotation beneath the atmosphere. Feedback: Heating near the equator causes pressure differences that drive the winds. On a rotating body, whether a flat merry-go-round or a spherical Earth, the rotation causes flows to curve. And very very very little of the wind is traceable to marmots.

Your friend wants to see some real Pennsylvania coals. Where should you send your friend to see coal in the rocks of Pennsylvania (if you honestly are being helpful), and what coals would your friend see? A) To the metamorphic rocks of eastern Pennsylvania to see bituminous, and to the sedimentary rocks of western Pennsylvania to see anthracite. B) To Ohio; there is no coal in Pennsylvania, but some Ohio coal is shipped through Pennsylvania. C) To the sedimentary rocks of western Pennsylvania to see bituminous, and to the metamorphic rocks of eastern Pennsylvania to see anthracite. Correct! D) To the metamorphic rocks of eastern Pennsylvania to see bituminous, and to the sedimentary rocks of western Pennsylvania to see more bituminous. E) To the metamorphic rocks of eastern Pennsylvania to see lignite, and to the sedimentary rocks of western Pennsylvania to see more lignite.

C) To the sedimentary rocks of western Pennsylvania to see bituminous, and to the metamorphic rocks of eastern Pennsylvania to see anthracite. Notes: Bituminous is found with sedimentary rocks, but ones that have been squeezed and heated a bit so they are held together well and are not much like loose sediment; such rocks are common in western Pennsylvania. Anthracite is the most-cooked coal, and is found with metamorphic rocks in eastern Pennsylvania. Pennsylvania has lots of coal, but not much lignite, which would not be found in metamorphic rocks anyway.

At the beach, you can build really good sand castles: A) When the sand is dry. B) When the sand is damp, because the water in the sand makes it heavier so the grains cohere better. C) When the sand is damp, because water is attracted to sand grains and to other water; thus, pulling sand grains apart when damp requires "breaking" the water, which is not easy. D) When the sand is damp, because gelatinous material in the water from seaweed gives an agar glue that holds the sand grains together. E) When the sand is fully saturated with water.

C) When the sand is damp, because water is attracted to sand grains and to other water; thus, pulling sand grains apart when damp requires "breaking" the water, which is not easy. Feedback: Any good glue must stick to other things and to itself. If it doesn't stick to other things, the glue just peels off. If it doesn't stick to itself, you can break the glue in the middle easily, separating the things that you just glued, although leaving a little glue on those things. Water works the same way—it sticks to sand grains well, and water molecules are attracted to each other, so that it takes some "oomph" to break apart damp sand grains. Make them fully wet, and the grains can move without "breaking" the water, so the material becomes weak.

The close end of the glacier pictured above is outlined by a zone of sediment that lacks the reddish tinge of the tundra in autumn, whereas that faint reddish tinge is evident on the rest of the land surface in the picture. This suggests that the glacier is now shorter than it was in the past. A likely interpretation is: A). The glacier has changed its flow direction and moved back up the valley, revealing the tundra-free rocks B). The glacier stopped moving and has been melting away, revealing the tundra-free rocks C). The glacier has continued to flow downhill toward the camera, but an increase in melting has caused the glacier to become shorter anyway

C). The glacier has continued to flow downhill toward the camera, but an increase in melting has caused the glacier to become shorter anyway Notes: Glaciers flow downhill. Interestingly, the "hill" is the slope of the upper surface. If you were skiing on top of the glacier, the way you'd go most steeply downhill is the direction the ice flows. The same is true for a pile of pancake batter—pour it on a waffle iron, and the batter will flow up over some of the bumps, spreading from the high center of your batter pile. Snow accumulates at high elevation, and flows to low elevation to melt. If the temperature rises, the ice is still flowing downhill, but ice at low elevation melts faster than more ice is supplied by the flow, so the glacier shrinks.

This picture above shows a small island in Kong Oscar Fjord of east Greenland. A likely explanation of the odd lines forming the bulls-eye pattern on the island is that: A). Greenlandic farmers practice contour plowing, and this is a field ready for planting B). Horizontal sedimentary strata have been eroded by the brief, heavy rains of summer to reveal the layering seen C). The land has rebounded after former ice sheets melted, raising beaches above sea level D). The ocean has been falling as glaciers grew, leaving beaches stranded on the sides of the island

C). The land has rebounded after former ice sheets melted, raising beaches above sea level Not sure how you could possibly have known this one, but the answer is "C", and now you know it, in case you see it again. Remember that the weight of a mountain range pushes the land down beneath it. An ice sheet, such as the one on Antarctica or Greenland, or the one that used to sit on Canada, is an odd mountain range almost as wide as a continent and two miles thick in the middle. The weight of the ice pushes the land down. Grow an ice sheet, and sea level falls as the water evaporated from the ocean piles up as snow on the ice. But, the most recent ice age lowered the elevation of the ocean surface only about 400 feet (just over 120 m), while the weight of the ice pushed the land down well over 1000 feet (300 m). When the ice melted, the ocean rose rapidly, while the land bobbed back up more slowly (the hot, soft rocks down below take a while to flow). As the land bobbed up through the sea, beaches were formed and then rose while new beaches formed. The beach on top is the oldest, and the beach at the coast is the modern one.

The ptarmigan shown above is walking on rocks of Danmark Island, east Greenland. The rocks record: A). Tracks of a thrust fault from the closing of the proto-Atlantic, with motion along the fault running away from the camera B). Tracks of a pull-apart fault from the opening of the Atlantic, with the motion along the fault running away from the camera C). Tracks of a glacier, with the motion running away from the camera D). Tracks of a glacier, with the motion from left to right in the picture

C). Tracks of a glacier, with the motion running away from the camera Notes: Ptarmigan are essentially alpine or arctic grouse, the most cold-hardy of the chicken-like birds. Notice the feathers down the ptarmigan's feet—insulation and snowshoes. The glacier moved over this rock during the ice age, and the moving ice picked up rocks and used them to "sandpaper" the rock beneath, scratching and polishing as the ice moved away from the camera. Weathering has removed a bit of the polish, but you can probably see some of the scratches, including one running directly away from the camera that just seems to touch the bird's beak in the picture.

Suppose we didn't burn fossil fuels, and you had to get the energy you now use from the labor of a bunch of people who work for you. How many people would you need to replace the fossil fuels? A. 1 8% B. 10 28% C. 100 64%

C. 100 64% Notes: Most of you got this one—our energy use per person in the U.S. is a bit over 100 times larger than what we personally burn inside of us. If you tried to ride a bicycle hitched to a generator to run a TV, you could more-or-less handle a small picture but not a big screen. If you think of all the trucks and tractors and heating and cooling and more... and how would you ever get enough willing workers to pick up your car and carry it down I-80 at 70 mph??? The great majority of the energy used in the U.S. is from fossil fuels—about 83%.

And here's another (above). What do you suppose this is? A. Sedimentary rocks that slumped downhill when they were soft, folding the rocks; now found near the top of the Grand Canyon. B. Rocks folded by drag along a large fault, about halfway between the top and the river in the Grand Canyon. C. Rocks that were cooked, squeezed and partially melted in the heart of an old mountain range, now found near the river in the Grand Canyon. D. Old lava flows that came up pull-apart faults near the west end of the Grand Canyon, and folded before they hardened. E. A wall in the gift shop at the Grand Canyon, painted by artists to look like real rocks. In the photograph above, a portion of cliff about 30 feet high is shown. From what location in the Grand Canyon did Dr. Alley take this image? A) About halfway between the top and the river, where a large fault has dragged the rocks and caused the fold. B) In the gift shop, where artists have painted the cliff to look like real rocks. C) Near the bottom, where the river has cut through rocks that were cooked, squeezed, and partially melted deep in an old mountain range. D) Near the top, in sedimentary rocks that slumped downhill when they were soft, folding the rocks. E) Near the west end, where lava that came up pull-apart faults folded while flowing before hardening fully.

C. Rocks that were cooked, squeezed and partially melted in the heart of an old mountain range, now found near the river in the Grand Canyon. Notes: We saw rocks like these back at Rocky Mountain, and in the Smokies—rocks that had been metamorphosed, cooked deep in a mountain range, squeezed and even partially melted. The pink is granite that melted, and the black is a rock (called schist) that didn't quite melt. This is along the river in the heart of the Grand Canyon, and C is correct. C) Near the bottom, where the river has cut through rocks that were cooked, squeezed, and partially melted deep in an old mountain range. Notes: This is the Vishnu Schist and Zoroaster Granite, rocks from the heart of a mountain range. The river is just barely out of the picture to the bottom.

Scientists receive govt funding primarily bc: A) They learn the truth B. They use a careful method C. They help humans do useful things D. They are all sexy E. They all drink diet pepsi bc they think it makes them look sexy

C. They help humans do useful things

Both of the above pictures are along the Colorado River. [See image: UNIT 6.14] The clear water of picture 1 and the muddy water of picture 2 appear quite different. What's going on? A) 1 is upstream of the Glen Canyon Dam, and 2 is downstream. B) 1 is 7-UP, and 2 is Yoo-Hoo. C) 2 is downstream of the Glen Canyon Dam, and 1 is also downstream of the dam. D) 2 is upstream of the Glen Canyon Dam, and 1 is downstream of the dam. E) 1 is upstream of the Glen Canyon Dam, and 2 is also upstream of the dam.

D) 2 is upstream of the Glen Canyon Dam, and 1 is downstream of the dam. Feedback: The naturally muddy river is seen clearly in Canyonlands in 2. The river dumps its sedimentary load in the reservoir above the dam, so downstream of the dam the water is clear, as shown in 1.

If all the water that falls on central Pennsylvania's Happy Valley in a year as snow or rain stayed here as water without being used or evaporated, if spread uniformly over the land, it would make a layer about how thick? (Pennsylvania gets about the same amount of precipitation as the average for the world.) A) 0.003 feet. B) 0.03 feet. C) 0.3 feet. D) 3 feet. E) 30 feet.

D) 3 feet. Feedback: A typical rainfall supplies about an inch of water, or just under 0.1 foot. 30 feet of rain would be a big storm every day, about equal to the wettest place on Earth, and while sometimes it may seem the rain in Pennsylvania will never end, there really are clear days. 0.3 feet is a mere 3 or 4 rainfalls per year, and is a dry desert. 0.03 feet would be the driest place on Earth, and 0.003 doesn't occur on Earth. 3 feet is a nice number, and is correct.

The extinction of many types of dinosaurs occurred about: A) 65,000 years ago. B) 650,000 years ago. C) 6,500,000 years ago. D) 65,000,000 years ago. E) 650,000,000 years ago.

D) 65,000,000 years ago. Feedback: Humans were trotting around 65,000 years ago, and met dinosaurs only in The Flintstones. 650,000 years is barely enough time for evolution to have changed large animals a bit, and although 6,500,000 years is enough time for noticeable change of large animals—increase in maximum size of members of the horse family, for example—the huge changes since the dinosaurs needed 65,000,000 years. 650,000,000 years goes back before any land creatures, and before all but the simplest of multi-celled organisms.

[See image: UNIT 10.10] Two yellow lines have been drawn on the picture by the instructional team. These lines follow an interesting surface, which separate flat-lying sedimentary rocks, on top, from slanting sedimentary rocks beneath. This surface is: A) A great fault, where push-together action shoved the upper rocks over the lower ones. B) A great fault, where pull-apart Death-Valley-type faulting dropped rocks so that they could be preserved from erosion and seen today. C) A great unconformity, with sedimentary rocks above resting on igneous and metamorphic rocks below. D) A great unconformity, with sedimentary rocks above resting on older sedimentary rocks below. E) A great unconformity, with sedimentary rocks above resting on younger sedimentary rocks below.

D) A great unconformity, with sedimentary rocks above resting on older sedimentary rocks below. Feedback: John Wesley Powell, of the United States Geological Survey, and the leader of the first boat trip through the Grand Canyon, called the feature marked by the yellow lines "The Great Unconformity". It separates horizontal Paleozoic sedimentary rocks, above, from inclined Precambrian sedimentary rocks, below. Notes: This is often called the great unconformity, and is seen here in the eastern end of Grand Canyon National Park. The layered sedimentary rocks below were deposited, hardened, tipped a bit, eroded on top, and then the sea rose (or the rocks fell) and younger sediments were deposited on top. Those younger sediments have also been hardened, and are exposed above the Colorado River, which you can see at the bottom of the picture. So, C is the correct answer here.

Look at the picture above. What happened here? A) An immense marmot named George, shown here, dug the hole. B) A giant glacier used to sit here, and water flowing into a hole on the surface fell to the bed and hollowed out a great pothole, seen here. C) Death-Valley-type faulting dropped the bottom, making space for the lake; during the Ice Age, Death Valley looked like this, too. D) A great volcanic explosion occurred, spreading material across the landscape, and the hole left behind after the eruption later filled with water. E) A sharp bend in a river created a whirlpool that carved the hole now filled by a lake.

D) A great volcanic explosion occurred, spreading material across the landscape, and the hole left behind after the eruption later filled with water.

Which of these materials is "hottest" in the sense that it is most likely to flow rather than to break (note that K stands for Kelvin, an absolute temperature scale in which zero is absolute zero and higher numbers mean warmer temperatures): A) A material at 1001oK that melts at 12000oK. B) A material at 100oK that melts at 200oK. C) All are the same temperature. D) A material at 250oK that melts at 300oK. E) A material at 1000oK that melts at 2000oK.

D) A material at 250oK that melts at 300oK. Notes: Flowing rather than breaking becomes likely when a material is warmed more than halfway from absolute zero to the melting temperature. The case with 250oK here is warmed five-sixths of the way from absolute zero toward the melting point, and the others are only halfway or less. They are not all at the same temperature.

Which formula describes the chemical changes that occur and release energy when you start with plant material and then burn it in a fire or "burn" it in a stomach? A) CaCO3 + H2CO3 → Ca+2 + 2HCO3- B) Ca+2 + 2HCO3- → CaCO3 + H2CO3 C) CO2 + H2O → CH2O + O2 D) CH2O + O2 → CO2 + H2O E) Diet_Coke + Mentos → Boom Which formula most closely describes the process by which plants make more of themselves: A) CH2O + O2 → CO2 + H2O + energy B) Diet_Coke + Mentos → Boom C) Ca+2 + 2HCO → CaCO + H CO D) CaCO3 + H2CO3 → Ca + 2HCO E) CO + H O + energy → CH O + O

D) CH2O + O2 → CO2 + H2O Feedback: CaCO3 is shell or cave-rock; the equation with CaCO3 on the left is dissolution of rock to make caves, and the equation with CaCO3 on the right is formation of shells. CH2O is a pretty good estimate of average plant composition; the equation with CH2O on the left is burning of plant material for energy, and with CH2O on the right is how plant material is made. Diet Coke plus Mentos does produce an interesting effect, but this is not the way plants grow. E) CO + H O + energy → CH O + O

The idea that human activities will cause global warming is well over a century old now. The United Nations has been sponsoring studies of this idea for almost two decades. The assembled scientists have concluded, with high confidence, that: A) CO2 levels in the atmosphere have been rising because of natural causes, and this has been the primary cause of the ozone hole. B) CO2 levels in the atmosphere have been rising, with no effect on the climate. C) CO2 levels in the atmosphere have been rising, warming the planet a small fraction of a degree, and if we burn all the remaining fossil fuels, we may raise the temperature another small fraction of a degree. D) CO2 levels in the atmosphere have been rising, warming the planet a degree or so, and burning all the remaining fossil fuels likely will raise the Earth's temperature many degrees or more. E) Human activities have lowered methane levels in the atmosphere, causing cows to become more flatulent to achieve balance.

D) CO2 levels in the atmosphere have been rising, warming the planet a degree or so, and burning all the remaining fossil fuels likely will raise the Earth's temperature many degrees or more. Feedback: Human activities have raised CO2 in the atmosphere, causing warming of a degree or so. But if we continue with business as usual, we haven't seen anything yet—we haven't even doubled CO2, but a quadrupling or even octupling seems possible. Cow flatulence is not greatly affected by external methane levels, which are rising in any case. Besides, bovine belching is a larger methane source than is outlet through the other orifice.

You watched online as Dr. Alley carved a sand canyon with his finger. Based on what you saw, and on what you know about slopes, stability, mass movement, etc., if a landslide happened someplace last week, you would tell the neighbors: A) Run for your lives! Landslides are always followed by floods and more landslides. B) Special care is required; landslides invariably trigger earthquakes. C) Run for your video cameras! Landslides are invariably followed by professors sticking out fingers, and you can get footage to win megabucks on America's Funniest Classroom Videos. D) Care is required; landslides are removing instabilities and moving things towards stability, but a second landslide, or a flood, or other problems are real possibilities. D) All is safe now; nature relieves stress and removes instabilities, and that is what the landslide did.

D) Care is required; landslides are removing instabilities and moving things towards stability, but a second landslide, or a flood, or other problems are real possibilities. Notes: When Dr. Alley made a "landslide", others often followed, but not always. Similar behavior is often observed in nature. The Gros Ventre slide near the Tetons dammed a river, with dam failure later releasing a flood, but a flood was avoided at Hebgen Lake outside of Yellowstone. And so far, we don't think that America's Funniest Classroom Videos is handing out megabucks. But let us know if they start.

Clay consists of new minerals commonly formed by: A) Chemical weathering of quartz (quartz is pure silica) B) Evaporation of water leaving the salts it was carrying C) Combination of iron with water and oxygen D) Chemical weathering of feldspar (feldspar contains silica, aluminum, potassium and other things) E) Combination of acid rain with limestone.

D) Chemical weathering of feldspar (feldspar contains silica, aluminum, potassium and other things) Feedback: When weathering attacks feldspar, some things are washed away, water is added, there is a little rearrangement of the chemicals, and clay results. Quartz, which is pure silica, mostly just sits around not doing much. Weathering usually dissolves a little bit of quartz, but this leaves a smaller piece of quartz and doesn't make anything new. Hence, when weathering attacks granite, the quartz pieces in the granite become quartz sand in the soil that is formed.

Regarding global warming, most scientists (including those who have advised the United Nations through the Intergovernmental Panel on Climate Change) agree that if we continue to burn fossil fuels at an accelerating rate: A) Climate changes will primarily hurt poor people who live in warm places and who are the major contributors to climate change through cutting of tropical rain forests and other activities. B) Climate changes will primarily hurt wealthy people in cold places. C) Climate changes will hurt everyone, equally. D) Climate changes will primarily hurt poor people in warm places, but the climate changes are primarily being caused by wealthier people in colder places. E) Climate changes will help everyone.

D) Climate changes will primarily hurt poor people in warm places, but the climate changes are primarily being caused by wealthier people in colder places. Notes: Blizzards play havoc with airline travel, which hurts the economy in the mid- and high-latitude wealthier countries. If you have winter (so that warming reduces blizzards), air conditioners (so you can keep the economy humming when the weather is otherwise too hot for office work), and bulldozers (so you can build sea walls or haul things out of the way as the ocean rises), a little warming might even help your economy, although too much warming will be bad. If you are missing any of winter, air conditioning, or bulldozers, all warming is likely to be bad. Most of the world's people are missing all three, and will be hurt by warming, but the warming is being caused primarily by people who have all three.

The United Nations, under the auspices of the Intergovernmental Panel on Climate Change, has attempted to assess the scientific understanding of how greenhouse-gas emissions will affect the climate, and thus people. The UN reports show that if we continue on our present path, burning fossil fuels at a faster and faster rate: A) Climate will change, primarily getting warmer, and these changes will hurt everyone, equally. B) Climate will change, with cooling at high latitudes that primarily will hurt wealthy people living in those cold places. C) Climate will change, primarily getting warmer, and those changes will primarily hurt the poor people in warm places who are the main causes of the climate changes through deforestation and other actions. D) Climate will change, primarily getting warmer, and those changes will primarily hurt poor people in warm places, but the climate changes are primarily being caused by wealthier people in colder places. E) Climate will change, primarily getting colder, and those changes will especially hurt those people living in northwestern Europe. Regarding global warming, most scientists (including those who have advised the United Nations through the Intergovernmental Panel on Climate Change) agree that if we continue to burn fossil fuels at an accelerating rate: A) Climate changes will primarily hurt poor people in warm places, but the climate changes are primarily being caused by wealthier people in colder places. Correct! B) Climate changes will help everyone. C) Climate changes will primarily hurt poor people who live in warm places and who are the major contributors to climate change through cutting of tropical rain forests and other activities. D) Climate changes will hurt everyone, equally. E) Climate changes will primarily hurt wealthy people in cold places.

D) Climate will change, primarily getting warmer, and those changes will primarily hurt poor people in warm places, but the climate changes are primarily being caused by wealthier people in colder places. Feedback: Blizzards play havoc with airline travel, which hurts the economy in the mid- and high-latitude wealthier countries. If you have winter (so that warming reduces blizzards), air conditioners (so you can keep the economy humming when the weather is otherwise too hot), and bulldozers (so you can build sea walls or haul things out of the way as the ocean rises), a little warming might even help your economy, although too much warming will be bad. If you are missing any of winter, air conditioning, or bulldozers, all warming is likely to be bad. Most of the world's people are missing all three, and will be hurt by warming, but the warming is being caused primarily by people who have all three. A) Climate changes will primarily hurt poor people in warm places, but the climate changes are primarily being caused by wealthier people in colder places.

The processes that made Death Valley continue to operate today. For this question, ignore the sand and gravel moved by water and wind, and think about the big motions of the rocks beneath. Choose the best answer: what are they doing to the valley? A) Death Valley is not changing. B) Death Valley is getting narrower C) Death Valley is getting shallower. D) Death Valley is getting wider and deeper. E) Death Valley is getting narrower and shallower.

D) Death Valley is getting wider and deeper. Feedback: The pull-apart action that is spreading Death Valley and surroundings also involves uplift of mountains or downdrop of valleys, and Death Valley has dropped as its flanking mountains have moved apart.

You are asked to assign as accurate a numerical age as possible (how many years old) to a sedimentary deposit. You would be wise to use: A) Uniformitarian techniques. B) Counting of annual layers if the deposit is old (more than about 100,000 years), and radiometric techniques if the deposit is young (less than about 100,000 years). C) Either counting of annual layers or radiometric techniques if the deposit is old (more than about 100,000 years), and radiometric techniques if the deposit is young (less than about 100,000 years). D) Either counting of annual layers or radiometric techniques if the deposit is young (less than about 100,000 years), and radiometric techniques if the deposit is old (more than about 100,000 years). E) Uniformitarian techniques if the deposit is old, and counting of annual layers if the deposit is young.

D) Either counting of annual layers or radiometric techniques if the deposit is young (less than about 100,000 years), and radiometric techniques if the deposit is old (more than about 100,000 years). Feedback: If you want an absolute date (number of years) rather than older/younger, you can count layers for young things, or use radiometric techniques for young things or for old ones. Uniformitarian calculations aren't very accurate.

[See image: UNIT 4.12] In the photo above, Dave and Kym are discussing a model of the Waterpocket Fold in Capitol Reef National Park. The Waterpocket probably formed in the same way as the Front Range of the Rockies. This involved: A) An obduction zone in western Utah squeezed eastern Utah (Capitol Reef) and Colorado (Front Range). B) The low region, in Dave's left hand, dropped relative to the high region, in Dave's right hand, along a Death-Valley-type fault, and something similar happened in dropping Denver relative to the Front Range. C) The spreading of Death Valley pinched Utah into Colorado. D) Especially warm sea floor in the subduction zone off the west coast rubbed along under western North America and squeezed or wrinkled the rocks, folding them (probably with a push-together fault somewhat deeper under the fold). E) A subduction zone in western Utah squeezed eastern Utah (Capitol Reef) and Colorado (Front Range).

D) Especially warm sea floor in the subduction zone off the west coast rubbed along under western North America and squeezed or wrinkled the rocks, folding them (probably with a push-together fault somewhat deeper under the fold). Feedback: We're still arguing about the West, but it is clear that the west-coast subduction zone, which started with old, cold sea floor going down, slowly warmed as the subduction zone and the spreading ridge came closer together. Warmer sea floor would be more buoyant, and so would sink more slowly, or float better. And that would create more friction, squeezing and rumpling with the overlying continent. As the sea floor warmed, squeezed-up/rumpled-up features developed in the West. So we think this makes sense.

When humans build or raise levees along big rivers such as the lower part of the Mississippi, we are likely to cause: A) The surface of the water in the river to become slanted to the side, as mud compaction beneath the river increases meandering. B) Land to emerge from the sea at the mouth of the river, because the levees stop compaction of sediment downstream. C) Fields and roads on the flood plain to rise above the surface of the river, because compaction of flood-plain mud will no longer be balanced by sediment accumulation during floods. D) Fields and roads on the flood plain to drop below the surface of the river, because compaction of flood-plain mud will no longer be balanced by sediment accumulation during floods. E) Madonna and Don McLean to drive their Chevys to the levees, but the levees will be dissolving rapidly in Pepsi.

D) Fields and roads on the flood plain to drop below the surface of the river, because compaction of flood-plain mud will no longer be balanced by sediment accumulation during floods. Feedback: "Long, long, time ago, I can still remember how the river used to mend with mud..." The continuing compaction of the sediment along the lower Mississippi should be balanced by new deposits on top; stopping the new deposits does not stop the compaction, so the surface of the flood plain sinks. Even racing around curves, rivers don't tilt much, and mud compaction doesn't do much to meandering. "With a pink carnation and a pickup truck..."

Which statement is true about the physical conditions required for convection to occur? A) Melting; convection can occur only in liquids. B) Freezing; convection can occur only in solids. C) Heating from below, which raises density and causes a tendency for the heated material to rise. D) Heating from below, which reduces density and causes a tendency for the heated material to rise. E) Heating from below, which raises density and causes a tendency for that deep, heated material to sink.

D) Heating from below, which reduces density and causes a tendency for the heated material to rise.

Yellowstone is in some ways similar to Hawaii. This is because both are: A) Push-together subduction zones B) Push-together obduction zones C) Slide-past plate boundaries D) Hot spot volcanic regions E) Pull-apart plate boundaries

D) Hot spot volcanic regions Feedback: Hot-spots rise from deep in the mantle, with some melting on the way up to feed volcanoes such as Hawaii and Yellowstone.

Which of the following is not a part of the modern theory of evolution? A) Diversity exists within a species, and "experiments" that tend to promote diversity sometimes occur during reproduction. B) A "successful experiment" during reproduction is one that increases the ability of an individual to have children who survive to have children. C) Children are more similar to their parents than to other individuals from their parents' generation. D) If the body of an adult living thing is changed by its environment, those changes usually are passed on biologically to children. E) If a reproductive "experiment" is successful, it will be passed to more and more children in successive generations until all members of a population have it.

D) If the body of an adult living thing is changed by its environment, those changes usually are passed on biologically to children. Feedback: You can get a tattoo without worry that your children will be born with that same tattoo, but all the rest of these contribute to evolution.

Which is accurate about the history of the Grand Canyon: A) The Kaibab limestone that forms the upper rim of the canyon is the youngest rock layer known from Arizona and surrounding states. B) The rock record of the canyon contains exactly one unconformity. C) The canyon is wider at the top and narrower at the bottom because the river was wider when the region was wetter, and has narrowed as deserts spread recently. D) In the deepest part of the canyon, the river cuts through rocks formed by metamorphism of older sedimentary rocks in the heart of a mountain range. E) The oldest rocks are on top, with younger ones beneath, as shown by all of the footprints being upside-down in the rocks of the canyon walls.

D) In the deepest part of the canyon, the river cuts through rocks formed by metamorphism of older sedimentary rocks in the heart of a mountain range. Feedback: The Colorado River is cutting through the metamorphic rocks from the heart of an old mountain range. The sedimentary rocks above are right-side up, and the Kaibab Limestone slants down to the north beneath the rocks of Zion, which are older than the rocks of Bryce, among others. Many unconformities exist in the walls of the Canyon, including the one below the Precambrian sediments and the one above those sediments. The idea of the river narrowing over time was the hypothesis that an interested tourist presented to one of the professors and a ranger at the Canyon a few years ago. When the professor asked whether the tourist would want to go out on a narrow point with a jackhammer, the tourist said no, because the rocks might fall off and slide down into the Canyon. When the professor pointed out the many places that rocks had fallen off and slid down, the quick-witted tourist figured out that the Canyon has been widened by such rockfalls as the river has cut downward.

Most commonly, a hot-spot volcano: A) Is richer in silica than andesite. B) Is mostly andesitic in composition. C) Is andesitic in composition, and shaped like a Pepsi can, with vertical sides below sea level. D) Is basaltic in composition. E) Is lower in silica than basalt, more like the mantle from which the hot-spot lava comes.

D) Is basaltic in composition.

The gas from the Marcellus shale: A) Is produced by "fracking", which is an illegal "infraction" against Pennsylvania laws forbidding gas production, so all the "fracking" is done at night. B) Is produced by "fracking", which employs special "diffraction" lenses to separate valuable fossil fuels from the almost-worthless shale. C) Is produced by "fracking", which heats the rocks greatly to drive the gas to wells. D) Is produced by "fracking", which uses high-pressure water and chemicals to make new "fractures" in the shale that allow the gas to escape to wells. E) Is produced by "fracking", the prehistoric technique of sucking gas out of rocks using a straw, so-named because someone once said "What the frac...". To get gas from the Marcellus shale, drillers: A) Core vertically through the rocks, and then use powerful vacuum pumps to suck, or "frac", the gas out of the rocks. B) Drill into and then along the shale, and then pump in high-pressure fluids to fracture the rock and release the gas. C) Drill diagonally through the rocks, and then use powerful compression pumps to blow the gas out the other end of the holes. D) Deepen existing water wells that have flammable methane in them, blowing up people's houses so the gas companies can then buy the land cheaply. E) Put machines into the ground the crawl along the shale layer, grinding up the rock to release the gas.

D) Is produced by "fracking", which uses high-pressure water and chemicals to make new "fractures" in the shale that allow the gas to escape to wells. Feedback: Water containing special chemicals is pressurized in holes bored through the Marcellus Shale, breaking the rocks to make pathways that allow the gas in the rock to escape through the holes to the surface, where it can be sold. B) Drill into and then along the shale, and then pump in high-pressure fluids to fracture the rock and release the gas. Notes: Fracking involves raising the pressure in holes drilled into and along the shale layer, by pumping in water with special chemicals, and this breaks the rock to release the gas. It is still possible that some water wells have been contaminated by leaking gas, but this is not part of the gas-recovery plan.

One way to treat a dying beach is to dig up sand somewhere and dump it on the beach. What is this likely to accomplish? A) It causes the sand to pile up under the boardwalk, forcing all the people hiding under there to run up into the sun and do song-and-dance numbers to music from the 1950s. B) It causes growth of the beach for the next century, because the sand attracts more sand from the longshore drift. C) It causes the beach to lose the new sand, but only after many centuries, as the extra sand is very, very slowly washed back to deep water by waves and currents. D) It causes the beach to lose the new sand over the next year or years, as the extra sand is washed back to deep water by waves and currents. E) It causes growth of the beach for the next millennia, because the sand attracts more sand from the longshore drift.

D) It causes the beach to lose the new sand over the next year or years, as the extra sand is washed back to deep water by waves and currents. Feedback: Waves and currents move lots of sand. If we want to offset this, we need to move a lot of sand, too. Building beaches from mined sand can work, but the sand heads back to deep water quickly, so in most cases the activity must be repeated every year or every few years to keep the beaches large and sandy.

Geological evidence based on several radiometric techniques has provided a scientifically well-accepted age for the Earth. Represent that age of the Earth as the 100-yard length of a football field, and any time interval can be represented as some distance on the field. (So something that lasted one-tenth of the age of the Earth would be ten yards, and something that lasted one-half of the age of the Earth would be fifty yards.) On this scale, how far on the football field would represent the time between the first appearance of abundant shelly creatures and today? A) Over 80 yards. B) 60 yards. C) 50 yards. D) Just over 10 yards. E) Over 90 yards.

D) Just over 10 yards. Feedback: If the 4.6 billion years of Earth history are 100 yards, then the 570 million years since the widespread appearance of shelly creatures is a bit over 10 yards. Most of our fossil record is limited to the last 10% of the planet's history. The shells appeared "suddenly"—in a few million years, or a few inches on the football field of time.

Any region of limestone bedrock containing caves, sinkholes, springs, etc. is called: A) Slovenian (former Yugoslavian). B) cavaranoidal C) Scruty. D) Karst. E) Pepsoidal.

D) Karst. Feedback: Karst is the region of Slovenia (formerly in Yugoslavia) that has given its name to places with cave-related features. Many, many geological terms have been borrowed from other languages or places, including "geyser" from Icelandic and "tsunami" from Japanese. Permafrost is permanently frozen ground, Pepsoidal is a neologism for "of or pertaining to Pepsi", and scruty is just a word we made up so we wouldn't have to use Pepsi again. Sounds like some bizarre disease, anyway. "Stay back. I have scruty."

You wander around the world for a while and take pictures of many typical living things. If you then were to follow those living things to see what would happen to them after they die, and they behaved naturally, it is likely that: A) Most of the living things would be heated and squeezed in oxygen-poor regions to make coal, oil and natural gas. B) Most of the living things would be "burned", combining with Diet Pepsi to fuel other living things, or would be burned in a real fire. C) Most of the living things would be heated and squeezed in oxygen-rich regions to make coal. D) Most of the living things would be "burned", combining with oxygen to fuel some other living thing, or would be burned in a real fire. E) Most of the living things would combine with dissolved minerals in groundwaters to be petrified. Nature is a very efficient recycler, so almost everything that lives is recycled. The recycling is usually achieved through slow "fires" in other living things (including you!), using oxygen. However, sometimes a "real" fire such as a forest fire will do the job.

D) Most of the living things would be "burned", combining with oxygen to fuel some other living thing, or would be burned in a real fire. Notes: Nature is a very efficient recycler, so almost everything that lives is recycled. The recycling is usually achieved through slow "fires" in other living things (including you!), using oxygen. However, sometimes a "real" fire such as a forest fire will do the job.

Weathering attacks a granite in Pennsylvania or Washington, DC, or a similarly rainy place. The feldspar grains in the granite primarily: A) Dissolve and wash away quickly and completely, helping grow shells in the ocean while leaving nothing behind in the soil. B) Dissolve and wash away quickly and completely, to react with sea-floor rocks in the ocean, while leaving nothing behind in the soil. C) Are loosened from the rock but don't change much, which is where we get quartz sand. D) Mostly make clay that stays in the soil for a while, although some chemicals also dissolve and wash away to the ocean. E) Are loosened from the rock but don't change much, staying in the soil as diamonds, rubies and emeralds.

D) Mostly make clay that stays in the soil for a while, although some chemicals also dissolve and wash away to the ocean.

Soil is produced by weathering of rocks, and moved to streams by mass-movement. Our understanding of nature and humans shows: A) Naturally, soil thickens over time, and human activities have caused soil to thicken more rapidly than the natural rate. B) Naturally, soil thins over time, and human activities have caused soil to thin more rapidly than the natural rate. C) Naturally, soil thickness reaches an approximate balance, with soil production and loss about equal if averaged over an appropriate time, but human activities have upset this balance and caused soil to thicken. D) Naturally, soil thickness reaches an approximate balance, with soil production and loss about equal if averaged over an appropriate time, but human activities have upset this balance and caused soil to thin. E) Naturally, soil was primarily marmot #2, but human pets are now the major source. The soil is mainly produced by human pets.

D) Naturally, soil thickness reaches an approximate balance, with soil production and loss about equal if averaged over an appropriate time, but human activities have upset this balance and caused soil to thin. Notes: Naturally, there is a balance between production and removal of soil over large areas and long times, although over short times the thickness may change. Humans have greatly increased loss of soil through burning, plowing, etc., which is not good for our long-term ability to grow crops. Human pets (including orange-and-white Coral and gray Prancer Alley, seen here in a group hug with Eeyore), do affect things but are not major sources of soil.

The final arbitrator between two alternate theories (for example Aristotle's and Newton's ideas) is: A) A committee of "wise men" who gather twice a year to arbitrate such disputes. B) A public opinion poll conducted by Gallup, ABC News, and Fox News. C) The Nobel Prize Committee in Stockholm, Sweden. D) Nature, and experiments conducted to test each idea.

D) Nature, and experiments conducted to test each idea. Notes: This has feedback for all three options

At current rates of use, and at prices not greatly higher than those of today: A) Oil will run out in a few centuries, and coal will run out in a few centuries. B) Oil and coal will last much longer than a few centuries. C) Coal will run out in a century or so, and oil will run out in a few centuries. D) Oil will run out in a century or so, and coal will run out in a few centuries. E) Coal will run out in a century or so, and oil will run out in a century or so.

D) Oil will run out in a century or so, and coal will run out in a few centuries. Notes: There is lots more coal than oil; oil has this habit of floating on water, thus rising through rocks and escaping to the sea floor where the oil is "burned" for energy by bacteria or other creatures. The size of the resource, in coal, oil, or anything else, depends on the price, and how long the resource lasts depends on rate of use, which is increasing rapidly for fossil fuels. The idea that immense pools of oil are out there, undiscovered but easy to get, is pretty silly—oil companies are really smart, drilled the easy stuff early on, and are now running out of oil that can be drilled and produced at prices close to modern.

Rocks in continents are on average much older than sea-floor rocks. The likely explanation is: A) For a long time the Earth had continents but no sea floor; only recently, Death-Valley-type spreading has split continents to make sea floor. B) So much undersea mining has been conducted to get valuable metals from old sea-floor rocks that all of the old ones have been ground up by people. C) Techniques used to estimate the age of the rocks all yield perfect ages for continental rocks but wild errors for sea-floor rocks, and sea-floor rocks are really as old as the continents. D) Old sea floor is recycled back into the deep mantle at subduction zones at the same rate that new sea floor is produced, but continents are not taken into the mantle and so remain on the surface for a long time. E) For a long time the Earth had continents but no sea floor; only recently, continents sank and allowed lakes to grow into oceans.

D) Old sea floor is recycled back into the deep mantle at subduction zones at the same rate that new sea floor is produced, but continents are not taken into the mantle and so remain on the surface for a long time.

You start with some of the right kind of dead material, and heat this material in the right way, perhaps with a little squeezing. As the material changes, you end up with coal, and the name scientists give to the material changes. In order, from COOLEST (first) to WARMEST (last) the names given are: A) Bituminous, peat, lignite, anthracite. B) Bituminous, lignite, anthracite, peat. C) Bituminous, anthracite, peat, lignite. D) Peat, lignite, bituminous, anthracite. E) Bituminous, anthracite, lignite, peat. Heating of some materials produces coal. The most-heated is the most valuable. In order, from the MOST-VALUABLE/MOST-HEATED (FIRST) to the least-valuable/least-heated (LAST), the coals (and material that gives coal) are: A) Peat, lignite, anthracite, bituminous. B) Anthracite, lignite, bituminous, peat. C) Peat, lignite, bituminous, anthracite. D) Anthracite, bituminous, lignite, peat. E) Peat, anthracite, lignite, bituminous.

D) Peat, lignite, bituminous, anthracite. Feedback: This is mostly memorization. But the names hide a lot of history, the peat-bog cutters of Ireland, the brown lignites now being mined in Wyoming, the deep-mines and strip-mines of the bituminous coals of western Pennsylvania, West Virginia and elsewhere, and the hard-coal anthracite of the Scranton and Wilkes-Barre region. If you don't know any of this history, you might consider reading up on it a bit; it is fascinating. D) Anthracite, bituminous, lignite, peat.

Pictures I and II show famous volcanoes. What is accurate about these? A) Picture I shows a subduction-zone-type cinder cone, and picture II shows a head-of-hot-spot-type shield volcano. B) Picture I shows a hot-spot-type shield volcano, and picture II shows a pile dug up by a big marmot named George. C) Picture I shows a hot-spot-type shield volcano, and picture II shows a subduction-zone-type stratovolcano. D) Picture I shows a subduction-zone-type stratovolcano, and picture II shows a hot-spot-type shield volcano. E) Picture I shows a hot-spot-type cinder cone, and picture II shows a subduction-zone-type shield volcano.

D) Picture I shows a subduction-zone-type stratovolcano, and picture II shows a hot-spot-type shield volcano.

The picture above [See image: UNIT 12.13] shows the stem of devil's club, a plant of the northwestern coast of North America. The native people use devil's club for medicinal purposes. We now know that: A) Most plants protect themselves primarily through thorns, hairs, etc., such as shown here. B) Plants protect themselves in many ways, including thorns but also through chemicals that are poisonous to many things that would eat the plants; those chemicals are always harmful to humans (poison ivy, for example). C) Plants protect themselves in many ways, including thorns but also through chemicals that are poisonous to many things that would eat the plants; those chemicals are always beneficial to humans, and are the basis for all of our medicines. D) Plants protect themselves in many ways, including thorns but also through chemicals that are poisonous to many things that would eat the plants; those chemicals are sometimes harmful to humans (poison ivy, for example) but sometimes beneficial to humans, and have given us many of our medicines. E) This is a device developed by Pepsi to keep people away from Coke machines.

D) Plants protect themselves in many ways, including thorns but also through chemicals that are poisonous to many things that would eat the plants; those chemicals are sometimes harmful to humans (poison ivy, for example) but sometimes beneficial to humans, and have given us many of our medicines. Feedback: Most plants have physical protections of some sort (hairs, thorns, hardened parts, bark, etc.), but almost all plants have chemical defenses. Those chemical defenses may kill us if we eat too much, but they also may kill microbes that would kill us before the chemicals kill us. A whole lot of our medicines have come from plants, and there undoubtedly are more to be discovered. There is a race on to find those new medicines before we exterminate the plants containing the medicines. Devil's club has been around longer than Pepsi has.

The picture above shows a view in the Earthquake Lake region just northwest of Yellowstone. The ramp or slope (often called a scarp) formed in an earthquake.What likely happened? A) Pull-apart forces shoved one side up over the other, making the break. B) Slide-past forces pulled the rocks apart, making the break, and allowing one side to drop relative to the other. C) Slide-past forces shoved one side up over the other, making the break. D) Pull-apart forces pulled the rocks apart, making the break, and allowing one side to drop relative to the other. E) An earthquake agitated a great underground lake of Pepsi until "kablam" the top blew off, making this feature.

D) Pull-apart forces pulled the rocks apart, making the break, and allowing one side to drop relative to the other.

What tectonic setting is primarily responsible for producing Mt. St Helens? A) Pull-Apart B) Push-together Obduction C) Hot Spot D) Push-together Subduction E) Slide Past

D) Push-together Subduction

Soil thickness: A) Reaches a natural balance between production by weathering and loss by mass movement, and humans have not affected that balance. B) Reaches a natural balance between loss by weathering and production by mass movement, and humans have not affected that balance. C) Reaches a natural balance between production by weathering and loss by mass movement, and humans have upset this balance, primarily by increasing weathering so that soils are thickening. D) Reaches a natural balance between production by weathering and loss by mass movement, and humans have upset this balance, primarily by increasing mass movement so that soils are thinning. E) Reaches a natural balance between loss by weathering and production by mass movement, and humans have upset this balance, primarily by increasing weathering so that soils are thickening.

D) Reaches a natural balance between production by weathering and loss by mass movement, and humans have upset this balance, primarily by increasing mass movement so that soils are thinning.

When discussing earthquakes that happen in the upper part of the Earth's crust, geologists believe that most are caused by elastic rebound. This means: A) Rocks taken down into the Earth by subduction are squeezed until they implode, and then they elastically rebound to their former size, shaking their surroundings. B) The Speaker of the House wears support hose. C) Rocks on opposite sides of a break, or fault, move in the same direction at the same speed. D) Rocks on opposite sides of a break, or fault, move in opposite directions, get stuck against each other for a while, bend, then "snap back" when something breaks or gives along the fault. E) Rocks on opposite sides of a break, or fault, move in opposite directions, and move freely all the time because high-pressure groundwater lubricates motion.

D) Rocks on opposite sides of a break, or fault, move in opposite directions, get stuck against each other for a while, bend, then "snap back" when something breaks or gives along the fault.

On average around the world: A) Sea level is rising, because the ocean is expanding as it cools off. B) Sea level is rising, because glaciers and ice sheets are getting bigger as warmer air carries more moisture to snow on them. C) Sea level is rising, as humans store more water on the land surface behind big dams. D) Sea level is rising, as warming causes ocean water to expand, and glaciers to melt. E) Sea level is rising, as humans store more water as Pepsi in machines and bottling plants.

D) Sea level is rising, as warming causes ocean water to expand, and glaciers to melt. Feedback: Indeed, sea level is rising, by almost an inch per decade. The biggest reasons are melting of ice on land that releases water that flows into the ocean, and expansion of ocean water as it warms up.

Evidence that there was much more land ice about 20,000 years ago than there is now includes: A) Land bearing the unique marks of glaciers is sinking today, while regions just around that land are rising as deep hot rock flows back after being displaced by the glaciers. B) River valleys have cut down rapidly over the last 20,000 years, draining coastal embayments. C) 20,000-year-old deceased shallow-water corals occur in growth position far above modern sea level on the sides of oceanic islands. D) Shells of creatures that lived in the ocean about 20,000 years ago indicate that the ocean water was especially isotopically heavy then. E) Immense volumes of Diet Pepsi were forced into subglacial aquifers by the weight of the overlying ice, serving as the modern source of all the Diet Pepsi sold.

D) Shells of creatures that lived in the ocean about 20,000 years ago indicate that the ocean water was especially isotopically heavy then. Feedback: The land with the unique glacier marks was pushed down by the ice and now is bobbing back up, water returned to the oceans from the melting ice caused sea level to rise so that river valleys were drowned and are filling up with sediment, and so that shallow-water corals were left far below sea level, but taking light water out of the oceans to grow ice sheets causes the remaining waters, and the shells, to be isotopically heavy.

The dominant large animals on Earth today are mammals. Before the giant meteorite impact 65 million years ago: A) Mammals also were the dominant large animals. B) Very large mammals coexisted with the dinosaurs; those very large mammals have gotten smaller after the meteorite impact because the mammals don't have to be big to compete with the dinosaurs any more. C) Small mammals coexisted with dinosaurs, and after the dinosaurs were killed by the meteorite, the small animals wanted to become bigger and so made themselves bigger. D) Small mammals coexisting with the dinosaurs were not able to outcompete the dinosaurs for big-animal jobs, but after the dinosaurs were killed, some large mammals evolved from small mammals to fill the large-animal jobs. E) Moose were the dominant large animals.

D) Small mammals coexisting with the dinosaurs were not able to outcompete the dinosaurs for big-animal jobs, but after the dinosaurs were killed, some large mammals evolved from small mammals to fill the large-animal jobs. Feedback: There are "big-animal" jobs—eating tall trees, eating smaller animals, etc. But the total number of big-animal jobs is limited. The dinosaurs filled the big-animal jobs before mammals really got going, and mammals were not able to displace the dinosaurs. Some small mammals survived the meteorite that killed the dinosaurs, and then evolved to give big mammals over millions of years and longer. There were almost no big mammals before the dinosaurs were killed off. Volition has nothing to do with evolution.

We humans are changing the composition of the atmosphere in many ways. Those changes will directly affect the planet's temperature, but the resulting change in temperature will affect other things on the planet that also affect the planet's temperature. Suppose that we could magically change the composition of the atmosphere enough to raise the temperature one degree if all other parts of the Earth system were held fixed, and after the warming, we allowed the other parts of the Earth system to react for a few years or decades. At the end of that time, what would be the total change in the Earth's temperature? A) The Earth would end up cooler than before the human influence, as feedback processes oppose the tiny warming caused by the change in atmospheric composition. B) The Earth would end up warmer than before the human influence but by less than one degree, because feedback processes would oppose the initial warming. C) The Earth would end up one degree warmer than before the human influence, because positive and negative feedback processes would offset each other. D) The Earth would end up a few degrees warmer than before the human influence, because positive feedbacks would amplify the original change. E) The Earth would end up a few tens of degrees warmer than before the human influence, because positive feedbacks would amplify the original changes a whole lot.

D) The Earth would end up a few degrees warmer than before the human influence, because positive feedbacks would amplify the original change. Feedback: Negative feedbacks stabilize the climate over long times of hundreds of thousands or millions of years or more, but feedbacks over years to millennia are mostly positive, amplifying changes. If there is a change in the sun, or CO2, or something else sufficient by itself to raise the temperature by one degree, this will be amplified to a few degrees by feedbacks.

We humans are on track to increase the amount of CO2 in the atmosphere so that the concentration in the future more than double the atmospheric CO2 concentration that existed for the few millennia before the industrial revolution. If we could cause just a doubling and then hold the CO2 level constant at that doubled level for the next thousand years, we very likely would see: A) The Earth would cool and cool, eventually causing a new ice age. B) The Earth would cool a few degrees, and then the temperature would stabilize at that new, cooler level. C) The Earth's temperature would remain the same as it was before the start of the industrial revolution. D) The Earth would warm a few degrees, and then the temperature would stabilize at that new, warmer level. E) The Earth would warm many tens of degrees, and then the temperature would stabilize at that new, warmer level.

D) The Earth would warm a few degrees, and then the temperature would stabilize at that new, warmer level. Feedback: Doubling CO2 is estimated to warm the Earth by between 1.5 and 4.5oC, or 2.7 to 8.1oF, with some chance of slightly larger change and very little chance of smaller change. The physical basis of warming from CO2 is quite well understood, and cooling or no response is very unlikely. You might compare the expected warming from CO2 to getting up to put another blanket on the bed in the night if you are cold. True, you might spill a glass of water into the bed, or your significant other might steal the other blankets while you're up, so getting the extra blanket might make you colder, but common sense says that getting the extra blanket warms you. Warming from CO2 is about as certain as warming from the extra blanket—maybe a huge number of volcanoes will explode in the near future and offset the effects of the CO2, but don't count on it.

What is the "Ring of Fire"? A) The ring of Coke drinkers around a Pepsi machine. B) The circle of basaltic volcanoes around Death Valley. C) The melted outer core ringing the solid inner core of the planet. D) The complex of volcanic arcs fed by subduction zones encircling the Pacific Ocean. E) The circle of lava flows seen at night around a Hawaiian shield volcano.

D) The complex of volcanic arcs fed by subduction zones encircling the Pacific Ocean.

The map above [See image: UNIT 6.10] shows the Birdfoot Delta of the Mississippi River, where it empties into the Gulf of Mexico. The river is shown in blue, as is the Gulf of Mexico. The river "wants" to leave this delta, and flow somewhere else, far to the west of the area covered by this map. Why? A) Humans have been damming the river at the end, so the river must go elsewhere. B) Hurricane Katrina, in 2005, plugged many of the river channels, so the river must go elsewhere. C) As the mud of the delta sinks, the river loses its river banks, so it flows elsewhere. D) The delta has built up as well as out, and that makes some other path to the Gulf steeper and shorter than the one now being taken, and during a flood the river tends to take that shorter path and cut a new channel. E) The meandering of the river has tied it in a knot, so it has to take a different path.

D) The delta has built up as well as out, and that makes some other path to the Gulf steeper and shorter than the one now being taken, and during a flood the river tends to take that shorter path and cut a new channel. Feedback: The river very nearly broke through the Old River control structure in a big flood, to take the shortcut down the Atchafalaya. The long path out to the end of the delta is not very favorable for the river, which has switched naturally in the past and would switch if humans allowed it to.

At Cade's Cove in the Great Smoky Mountain National Park, there is an unusual arrangement of rocks where older rocks are sitting on top of younger rocks, though neither layer has been overturned. This is because: A) The younger layer was injected as molten material under the older rock and then solidified. B) George the Marmot did it. C) The younger layer subducted under the older layer. D) The older layer was thrust over the younger layer by the forces of obduction.

D) The older layer was thrust over the younger layer by the forces of obduction. Feedback: The Great Smokies are an example of obduction, as are the Ridge-and-Valley mountains of the folded Appalachians, which include Penn State's University Park campus. However, up here the rocks were "rumpled up" but down in Cade's Cove, one set of rocks was thrust over another resulting in older rocks riding over younger rocks.

Dr. Alley once helped a Grand Canyon ranger answer a tourist's question: "Why is the Canyon wider at the top than at the bottom?" The tourist had their own favorite theory. Based on the materials that have been presented to you've in this class, what geologically accepted answer would Dr. Alley and the ranger have given the tourist? A) The river used to be much wider because it was not steep, and water spreads out when running slowly (a little tap feeds a big bathtub...); then, as the Rockies were raised, the river steepened and narrowed, so it used to cut a wide canyon and now cuts a narrow one. B) The canyon is really the same width at the top as at the bottom, but the well-known "optical illusion" of distant things appearing smaller causes it to look as if the canyon is narrowing downward. C) The bulldozer that made the canyon was wearing out its blade as it dug down. D) The river cuts down, and that steepens the walls of the canyon, which fall, topple, slump, creep or flow into the river to be washed away, thus widening the canyon above the river. E) The river used to be much wider before the desert formed, and so cut a wide canyon, but the river has narrowed as the drying occurred, and now cuts only a narrow canyon.

D) The river cuts down, and that steepens the walls of the canyon, which fall, topple, slump, creep or flow into the river to be washed away, thus widening the canyon above the river. Feedback: The tourist suggested that the river has gotten narrower over time. Dr. Alley asked the tourist whether he would ever consider going out on a particular narrow pillar of rock (already teetering dangerously and separated from the walls of the canyon by a huge crack) with a few hundred of his closest friends, and jumping up-and-down vigorously. Predictably, the tourist said "of course not, it might fall over." Dr. Alley then pointed out the many places where rocks clearly had fallen off the cliffs and moved downhill, at which point the tourist quickly switched his opinion to the "down-cutting" river explanation, with the ranger thoroughly enjoying the show.

Shown above [See image: UNIT 8.9] is Great Rock, Cape Cod National Seashore, with some of Dr. Alley's relatives for scale. The rock is metamorphic. The picture includes most but not all of the above-ground portion; the rock goes about as far below ground as above. What is the rock doing here in the middle of Cape Cod? A) Tsunami waves washed it here, when a huge landslide occurred from a volcanic island in the Atlantic Ocean. B) The rock rose up through the sand during a giant earthquake, the way large rocks are "floated" up in permafrost regions. C) The rock was thrown here by the giant meteorite impact that hollowed out Hudson Bay. D) The rock was carried here by glacier ice and left when the ice melted. E) The rock was used as ballast on the Mayflower, and left at First Encounter Beach as a present to the native Americans because the Mayflower no longer needed ballast in thenear-coastal waters.

D) The rock was carried here by glacier ice and left when the ice melted. Feedback: Glaciers carry rocks of all sizes easily. Cape Cod is the product of glaciers, and almost everything natural on the Cape was delivered by glaciers originally. There rarely are big tsunamis in the Atlantic, but not this big. Nor is there any evidence of a big meteorite impact that is as young as Cape Cod. The east coast is rather free of large earthquakes, although Charleston, South Carolina gets a few occasionally. And the early settlers would not have put such a huge thing in the bottom of their ship (imagine having that bouncing around in a storm!), nor could they have taken such a rock out easily upon arrival.

Soil is produced by weathering of rocks. In the natural state of affairs, on a hillside covered by soil: A) The soil layer gets thicker and thicker over time as weathering breaks down more rocks. B) The soil layer gets thinner and thinner over time as gravity and streams remove older soils. C) The soil thickness never changes over time; a perfect balance is achieved between soil production and removal so no matter how long you wait or when you measure, the thickness will be the same. D) The soil thickness tends to a nonchanging value as production is balanced by removal, but you may have to watch for a while, as sometimes production may go faster and sometimes removal may go faster. E) The soil is mainly produced by human pets.

D) The soil thickness tends to a nonchanging value as production is balanced by removal, but you may have to watch for a while, as sometimes production may go faster and sometimes removal may go faster. Feedback: Naturally, there is a balance between production and removal of soil over large areas and long times, but at any moment in a particular place, production and removal may be out of balance, as during a fast-moving landslide or when a marmot is digging a new hole. Human pets (including orange-and-white Coral and gray Prancer Alley, seen here in a group hug with Eeyore), do affect things but are not major sources of soil.

Statistically, and based on how many people are likely to die if they engage in or are exposed to the following problems, which is most dangerous to residents of the United States: A) Meteorite impacts. B) Commercial airline crashes. C) Earthquakes. D) The various diseases that come from smoking, overeating and under-exercising for a long time. E) Tornadoes.

D) The various diseases that come from smoking, overeating and under-exercising for a long time. Feedback: There are still meteorites in the solar system that can hit and kill, and a reputable study found that a meteorite impact might not occur for millions of years (or might occur next year...) but then might kill billions. Add up the deaths over a sufficiently long time, and plane crashes (which kill a few to a few hundred people per year) and meteorite impacts likely would be similarly dangerous. Earthquakes and tornadoes, as devastating as they can be, don't kill as many people in this country as do airline crashes. Smoking, overeating and underexercising are way more dangerous to us.

Which is most accurate about tsunamis? A) They are big waves caused by changes in the way the Earth rotates from day to day. B) They are big waves caused only by earthquakes. C) They are waves caused by big tides, such as the tidal bore at the Bay of Fundy in Canada. D) They are big waves caused by very rapid displacement of a lot of water, which may occur in response to an undersea landslide, earthquake, volcanic eruption, or other cause. E) They are primarily caused by belching belugas.

D) They are big waves caused by very rapid displacement of a lot of water, which may occur in response to an undersea landslide, earthquake, volcanic eruption, or other cause.

Which is most accurate about tsunamis? A) They are big waves caused by changes in the way the Earth rotates from day to day. B) They are waves caused by big tides, such as the tidal bore at the Bay of Fundy in Canada. C) They are primarily caused by belching belugas. D) They are big waves caused by very rapid displacement of a lot of water, which may occur in response to an undersea landslide, earthquake, volcanic eruption, or other cause. E) They are big waves caused only by earthquakes.

D) They are big waves caused by very rapid displacement of a lot of water, which may occur in response to an undersea landslide, earthquake, volcanic eruption, or other cause.

[See image: UNIT 7.11] The ptarmigan and the marmot have something in common, other than being cute. What is it? A) They are both mineral-like silica-based life forms. B) They both are standing on cirques. C) They both are standing on moraines. D) They both are standing on glacially eroded surfaces. E) They both are hyper-flatulent reptiles.

D) They both are standing on glacially eroded surfaces. Feedback: The carbon-based bird, top, and the carbon-based mammal, bottom, would be unhappy if you accused him of being a silicon-based flatulent reptile. Cirques are bowl-shaped, and moraines are composed of small pieces including till with pieces of many sizes. The striated, polished granites under these cold-climate critters were eroded by glaciers.

You are magically able to map where the sand grains go for over a few years on an east coast beach. MOST of the motion is: A) Along the shore, in the longshore drift. B) Toward the shore in the winter, and away from the shore in the summer. C) Toward the shore in the summer, and away from the shore in the winter. D) Toward and away from the shore with individual waves. E) Into deep water.

D) Toward and away from the shore with individual waves. Feedback: A beach sand grain spends most of its time coming in, going out, coming in, going out, and not getting anywhere. A tiny bias exists, such that the in and out will move slightly along the coast, and will cause seasonal changes, and will move some sand to deep water.

The "Law" of Faunal Succession: A) Requires that evolution occurred. B) Was developed by theoretical biologists to explain evolution. C) Was passed in Congress to dictate equal teaching of different theories of origins. D) Was developed by an engineering geologist to aid in construction projects. E) Requires that evolution was a catastrophic process.

D) Was developed by an engineering geologist to aid in construction projects. Feedback: In the late 1600s in England, William Smith discovered that putting the rocks in time order put the fossils in time order, allowing him to use the fossils as a shortcut in understanding the rocks. We will see soon that faunal succession is consistent with evolution but does not require it, does not require but might allow catastrophism, and informed but was not developed by theoretical biologists. Faunal succession was known before Congress was founded.

The law that established Yellowstone as the first national park: A) Was written by socialists, because it mentions the word "society". B) Clearly was written by politicians running for reelection, because it required that the parks make people happy today even if things are damaged for the future. C) Was written by communists, because park rangers have installed commodes in commodious outhouses. D) Was written to help people today and in the future, by requiring that the parks provide enjoyment today while preserving the parks for the future. E) Clearly was written by political conservatives, because it required conservation of the parks even if that means locking people out today.

D) Was written to help people today and in the future, by requiring that the parks provide enjoyment today while preserving the parks for the future.

In the picture above, Dr. Alley is on the South Rim of the Grand Canyon. What problem with the Canyon is he discussing? A) A dire shortage of Pepsi has developed at the Canyon, forcing people to actually drink water. B) Arizona has raised the tax on well-drilling, and the Park Service is having trouble paying for the water used at the Canyon. C) A dire shortage of Pepsi has developed at the Canyon, forcing people to actually drink water, and the people have found they like water. D) Water is being pumped out of the ground on the plateau south of the Canyon, and used by humans and evaporated or dumped in streams, so the water does not flow to the springs in the Canyon. E) Human wastes are being dumped on and pumped into the ground, polluting the springs in the Canyon.

D) Water is being pumped out of the ground on the plateau south of the Canyon, and used by humans and evaporated or dumped in streams, so the water does not flow to the springs in the Canyon. Feedback: Water soaks into the ground on the plateaus beside the canyon, seeps down to hit a rock layer that blocks the flow, and flows along that layer to feed beautiful and biologically important springs in the Canyon. Pumping water out of the ground on the plateaus to use for humans generally allows the water to evaporate (say, from the grass of a golf course) or run down a stream (say, below a sewage treatment plant), so the water doesn't flow through the ground to the springs.

You are dating a lava flow by the potassium-argon system. However, the offspring in this system are leaking out of the minerals. Which is accurate? A) You will think that the lava flow is older than it really is, and you will have no way to detect your error. B) You will think that the lava flow is younger than it really is, and you will have no way to detect your error. C) You will think that the lava flow is older than it really is, but you will be able to detect the error by comparing concentrations of offspring from the edges and centers of grains. D) You will think that the lava flow is younger than it really is, but you will be able to detect the error by comparing concentrations of offspring from the edges and centers of grains. E) You will get the age exactly right without worrying about any complications.

D) You will think that the lava flow is younger than it really is, but you will be able to detect the error by comparing concentrations of offspring from the edges and centers of grains. Feedback: Argon-40 leakage will make the lava flow appear young even if the flow is old; however, the edges of grains will lose more argon-40 than will the centers, pointing to the source of the error.

Global warming is being caused by: A. The sun getting a lot brighter. 7% B. Volcanic eruptions. 6% C. Changes in Earth's orbit. 14% D. Fossil-fuel burning, plus a bit of cow flatulence. 72%

D. Fossil-fuel burning, plus a bit of cow flatulence. 72% Notes: You're on a roll—the majority of you nailed this one, too. We have had satellites watching the sun for more than 30 years, and the sun hasn't gotten brighter, just little wiggles with the sunspot cycle and perhaps a very slight dimming. (We believe that the sun did get a bit brighter about a century ago, giving a little boost to the temperatures, but the warming accelerated during the slight dimming more recently.) Single large volcanic eruptions tend to cool the world a bit by blocking the sun. If you were to "turn up" volcanism, you would get centuries or longer of cooling, followed eventually by warming as the slow buildup of carbon dioxide came to outweigh the sun-blocking effect of the particles. But, there have been no large trends in volcanism (we actually have pretty good records from icecore and other samples). The cold of the Little Ice Age was caused more by a small blip of extra volcanic eruptions than by the weak drop in the sun, and the warming of about a century ago involved a coincidental drop in volcanic eruptions with the slight rise in solar output. More recently, a couple of big volcanic eruptions pushed toward cooling, yet the world warmed overall. Orbits matter over 10,000 years, but have almost no effect over a century or less. All the evidence points strongly to D, with a slight warning: although cow flatulence is real, cows emit most of their methane out the front rather than out the back. We often hear people agree that the world is warming, but suggest that a lot or all of the warming trend is coming from something other than greenhouse gases. But, over the last few decades nature has pushed weakly toward cooling, and we have put up a lot of particles that mimic volcanic particles in blocking the sun. Thus, if someone asks "How much of the recent warming was caused by human greenhouse gases", some uncertainty remains, but the central estimate is "More than all of it", because the world has warmed in response to greenhouse gases despite the cooling influence of our particles, a couple of big volcanic eruptions, and a slightly dimming sun, and us cutting dark forests to replace them with more reflective grasslands (corn, wheat, ...). Furthermore, because heat is now going into the big, cold ocean, but as the ocean warms more of the heat will stay in the atmosphere, we have not seen the full warming from our greenhouse gases yet. So in some sense our greenhouse gases have caused notably more warming than has occurred.

Global warming: A. Is really bad because it caused the ozone hole. 23% B. Is the greatest hoax ever perpetrated on the American people. 10% C. Is likely to be a problem in the future, about which nothing can be done. 12% D. Is likely to be a problem in the future, but is fixable if we get busy. 55%

D. Is likely to be a problem in the future, but is fixable if we get busy. 55% Notes: The scientifically correct answer is D, and most of you picked that one. The ozone hole is mostly from chlorofluorocarbons. There is a little relation of the ozone hole to global warming (adding CO2 causes warming down near the Earth's surface but cools the upper stratosphere, which causes formation of more polar stratospheric clouds, which catalyze the chemical reactions with chlorofluorocarbons that break down the ozone—but the release of chlorofluorocarbons is much more important than global warming in causing the ozone hole). I believe that even most of the people who claim in public that global warming is a hoax really know better. I can tell you that getting a dozen scientists to agree where to go for lunch is a real effort, and the idea that thousands and thousands of scientists somehow got together, agreed to lie to everyone, and succeeded in doing so, is just ludicrous, especially if you remember that the big awards in science go to people who overturn accepted views, and not to people who support their professors. Suppose that Einstein, after a career of doing physics, had announced that he had nothing new to add because Newton got everything right—would we remember Einstein today? Fortunately, there really are answers, if we get busy.

What do you think is shown in the picture above? A. The surface of obsidian, volcanic glass, broken by native Americans making spear points, on the South Rim of the Grand Canyon. B. The surface of rock scratched and polished by wind on the Tonto Platform of the Grand Canyon. C. The surface of rock scratched and polished by glaciers, on the North Rim of the Grand Canyon. D. The surface of rock scratched and polished by the river, along the Colorado in the Grand Canyon. E. The surface of Dr. Alley's bald spot, magnified a whole lot of times.

D. The surface of rock scratched and polished by the river, along the Colorado in the Grand Canyon. Notes: Down along the river in the Grand Canyon, there are some beautiful rock outcrops that are underwater during floods, but can be walked on between floods. There aren't many floods these days, because of the Glen Canyon Dam upstream, and the river isn't carrying a lot of little rocks to "sandblast" the bedrock, but the river flooded and sandblasted before the dam was built. This is the result. Glaciers make much longer and straighter scratches. Wind can make similar things, but not identical. So, D is correct.

Which of the following was probably important in contributing to extinction of most species at the same time the dinosaurs became extinct? A) Cold from the change in Earth's orbit caused when the meteorite shoved the planet farther from the sun. B) Heat from the change in Earth's orbit caused when the meteorite shoved the planet closer to the sun. C) Centrifugal forces caused when the meteorite impact temporarily stopped the rotation of the Earth, causing the sun to appear to stand still. D) Silicosis caused by dissolution of the meteorite in Pepsi in the ocean. E) "Impact winter" caused when tiny pieces of dust or other materials, which were put in the air by the impact, blocked incoming sunshine for months or years, after larger pieces had fallen back to Earth. Which of the following was probably important in contributing to extinction of most species at the same time the dinosaurs became extinct? A) Cold from the change in Earth's orbit caused when the meteorite shoved the planet farther from the sun. B) Heat from the change in Earth's orbit caused when the meteorite shoved the planet closer to the sun. C) Changed weather patterns because the meteorite caused large true polar wander (the north pole shifted rapidly in comparison to the continents because the meteorite rolled the planet on its side). D) Silicosis caused by dissolution of the meteorite in the ocean. E) Acid rain, from sulfuric acid from the meteorite hitting sulfur-bearing rocks, and from nitric acid from the heat of the meteorite burning the air.

E) "Impact winter" caused when tiny pieces of dust or other materials, which were put in the air by the impact, blocked incoming sunshine for months or years, after larger pieces had fallen back to Earth. Feedback: The "impact winter" likely did occur; we know that the materials thrown up by a big volcano cool the planet a degree or two for a year or two, and the meteorite would have thrown up a lot more stuff. The meteorite impact was not nearly large enough to move the planet notably or to stop the rotation. Silicosis is a lung disease caused by breathing too much silica-laden dust; other dust materials are typically more damaging, but too much of any dust can be bad. Dissolution in water does not cause lung disease. (Just for your information, some dictionaries list the long version of one form of the disease, pneumonoultramicroscopicsilicovolcanoconiosis, as the longest word in the English language.) E) Acid rain, from sulfuric acid from the meteorite hitting sulfur-bearing rocks, and from nitric acid from the heat of the meteorite burning the air. Feedback: The acid rain very likely did occur, at levels far above those from human-produced air pollution. The meteorite impact was not nearly large enough to move the planet notably or to roll the planet over. Silicosis is a lung disease caused by breathing too much silica-laden dust; other dust materials are typically more damaging, but too much of any dust can be bad. Dissolution in water does not cause lung disease. (Just for your information, some dictionaries list the long version of one form of the disease, pneumonoultramicroscopicsilicovolcanoconiosis, as the longest word in the English language.)

Death Valley National Park preserves the lowest-elevation, hottest piece of the U.S. The park is fascinating for many reasons. What is accurate about volcanoes and Death Valley National Park? A) Death Valley had active volcanoes millions and millions of years ago—heck, most places had volcanoes at some time—but the volcanoes have been dead for millions of years. B) There are no volcanoes in Death Valley; even though the valley has hot air, the rocks beneath are far too cool to support volcanoes. C) Death Valley has special Diet Pepsi volcanoes, and the Pepsi Corporation was founded to run the 20-mule teams that hauled the Diet Pepsi out of the valley, to be bottled in California and shipped around the world. D) When the ice-age ice sheets grew into Death Valley, volcanoes melted them, which is why Death Valley had a lake then; but, the volcanoes all died more than 10,000 years ago when the ice age ended. E) Although no volcanoes are actively erupting at the moment this is being typed, eruptions have occurred in the geologically recent past (the most recent centuries or millennia), demonstrating the presence of hot rock at shallow depth beneath the valley.

E) Although no volcanoes are actively erupting at the moment this is being typed, eruptions have occurred in the geologically recent past (the most recent centuries or millennia), demonstrating the presence of hot rock at shallow depth beneath the valley. Feedback: Death Valley, and many of the surrounding parts of Nevada and California, have experienced geologically recent volcanic activity. This is one of the problems facing the plan to put nuclear waste in an underground repository in Nevada and leave that waste—are we sure that a volcano won't erupt through the repository? There has not been enough lava erupted to fill the valley, however, nor do volcanoes erupt Diet Pepsi (although you can make a nice volcano model by quickly popping the top of a hot, shaken can of pop).

If you were looking for different types of coal, you likely would find: A) Lignite in the metamorphic rocks of eastern Pennsylvania, and anthracite in the sedimentary rocks of western Pennsylvania. B) Lignite in the metamorphic rocks of eastern Pennsylvania, and more lignite in the sedimentary rocks of western Pennsylvania. C) Bituminous in the metamorphic rocks of eastern Pennsylvania, and lignite in the sedimentary rocks of western Pennsylvania. D) No coal in Pennsylvania. E) Bituminous in the sedimentary rocks of western Pennsylvania, and anthracite in the metamorphic rocks of eastern Pennsylvania.

E) Bituminous in the sedimentary rocks of western Pennsylvania, and anthracite in the metamorphic rocks of eastern Pennsylvania. Feedback: Bituminous is found with sedimentary rocks, but ones that have been squeezed and heated a bit so they are far from being loose sediment; such rocks are common in western Pennsylvania. Anthracite is the most-cooked coal, and is found with metamorphic rocks in eastern Pennsylvania. Pennsylvania has lots of coal, but not much lignite, which would not be found in metamorphic rocks anyway.

Tsunamis: A) Always are huge and destructive. B) Invariably involve water moving away from the coast before extra water comes in. C) Are completely unpredictable, so there is nothing we can do about them. D) Can be predicted accurately months in advance, allowing evacuations. E) Can be predicted with some accuracy seconds to hours before the waves strike in most cases, allowing quick warnings to save many lives.

E) Can be predicted with some accuracy seconds to hours before the waves strike in most cases, allowing quick warnings to save many lives.

The jobs of geologists include: A) Supervising taste-tests between Coke and Pepsi. B) Writing new computer viruses, to make people really depressed. C) Cloning new organisms to sabotage competing companies. D) Supervising taste-tests between Coke and Pepsi, and not telling anyone that the geologists drink coffee at home. E) Finding valuable things in the Earth, warning about hazards, learning how the Earth works, and educating and entertaining people.

E) Finding valuable things in the Earth, warning about hazards, learning how the Earth works, and educating and entertaining people.

Icebergs float in water and continents float above the mantle because: A) Icebergs/continents are denser than the stuff they float in. B) Icebergs/continents are filled with helium. C) Icebergs/continents are colder than the stuff they float in. D) Icebergs/continents are warmer than the stuff they float in. E) Icebergs/continents are less-dense than the stuff they float in.

E) Icebergs/continents are less-dense than the stuff they float in. Feedback: Flotation and buoyancy are driven by density differences. In general, less-dense objects float higher up than more-dense objects would. Sometimes the density differences are due to temperature, sometimes due to composition. In the case of icebergs, water is denser than ice, so ice floats. Similarly continental crust is less dense than the mantle.

You hear an astronomer on the evening news, pointing out a coming alignment of planets and predicting that the extra gravitational attraction is sure to trigger a huge earthquake in California during the few hours of alignment. Based on what has been covered in this class, a reasonable approach is to: A) Take it seriously; maybe the quake isn't certain, but a big quake is much more likely than not during those few hours. B) Go to California with your camera to take pictures of the buildings falling down during the alignment so you can sell the pictures for lots of money. C) Invest in coffee; people always want caffeine after earthquakes, and an earthquake is highly likely at the time and place predicted. D) Stay the heck out of California, because if you go, you will be trampled to death by all the scientists running to California to observe the quake. E) Ignore it; although gravitational forces such as tides and planetary pulls might possibly exert a very small effect on earthquakes, no one has successfully predicted the where-and-when of earthquakes.

E) Ignore it; although gravitational forces such as tides and planetary pulls might possibly exert a very small effect on earthquakes, no one has successfully predicted the where-and-when of earthquakes. Feedback: By keeping track of where earthquakes happen, combing written and oral histories of past earthquakes, looking at geological deposits to see where shaking has occurred and broken rocks or tree roots or caused sand boils, and measuring where rocks are moving and where they aren't, good estimates can be made of earthquake hazards; but, we can't figure out exactly when the next quake will hit. Planetary-alignment predictions have been made, and have failed miserably. The tiny effect of gravity of the planets on the Earth has not been shown to affect earthquakes at all, although it remains possible that some very small influence exists.

What sort of rock is the dark material very close to the pink granite that Dr. Alley is pointing to in the picture above? A) Sedimentary; The layering was caused by changes in the flow velocity of the river that deposited the material B) Marmot #2 C) Sediment that isn't rock yet. The layers are alternating silt and sand from deposition from landslides off the Olympic Peninsula into the trench offshore. D) Igneous; The layers were caused by flow processes during the eruption that released this. E) Metamorphic; The rock separated into layers as it was cooked and squeezed deep in a mountain range.

E) Metamorphic; The rock separated into layers as it was cooked and squeezed deep in a mountain range.

The processes that made Death Valley have been operating for millions of years, and continue to operate today. For this question, ignore the sand and gravel moved by water and wind, and think about the big motions of the rocks beneath. If you had visited Death Valley 1 million years ago, you would have found the valley then to have been (choose the best answer): A) Wider and deeper than it is today. B) The same width and depth as it is today. C) Wider than it is today, with no change in the depth. D) Deeper than it is today, with no change in the width. E) Narrower and shallower than it is today.

E) Narrower and shallower than it is today.

Extinction of existing species: A) Is an unconformity. B) Occurred at a low level throughout geologic history. C) Is a process that happened in the past but cannot happen today. D) Occurred only at times of catastrophic mass extinctions. E) Occurred at a low level throughout geologic history, punctuated by mass extinctions when many types were killed over very short times.

E) Occurred at a low level throughout geologic history, punctuated by mass extinctions when many types were killed over very short times. Feedback: Extinction has happened slowly throughout geologic history, but with a few dramatic, catastrophic mass extinctions. We may be causing the latest of those mass extinctions.

A scientist gains knowledge about how the world works, and uses that information to successfully predict what will happen in an experiment. This proves that the scientist's knowledge is: A) Close; no one really knows what is going on, but people sort of know. B) Cheating. C) Lucky; no one knows what is going on, so only lucky people get things right. D) True; you can't get it right unless you know what is going on. E) One or more of True, lucky, or close to being true (or cheating), but we can't tell which.

E) One or more of True, lucky, or close to being true (or cheating), but we can't tell which. Notes: If you guessed "heads" before a coin flip, and it came up heads, that would NOT prove that you can predict all coin flips; you will get half of such guesses correct by chance. You might be cheating, you might be lucky, or you might have figured something out.

The picture above shows a fault in a place where mountains come down near the coast. [See image: UNIT 2.12] What likely happened to form the ramp (also called a scarp) behind the person? A) Pull-apart forces shoved one side up over the other, making the break. B) Slide-past forces shoved one side up over the other, making the break. C) An earthquake agitated a great underground lake of Pepsi until "kablam" the top blew off, making this feature. D) Slide-past forces pulled the rocks apart, making the break, and allowing one side to drop relative to the other. E) Pull-apart forces pulled the rocks apart, making the break, and allowing one side to drop relative to the other.

E) Pull-apart forces pulled the rocks apart, making the break, and allowing one side to drop relative to the other. Feedback: The down-side dropped along the ramp compared to the up-side. (This is actually an interesting one; it formed in Alaska during the 1964 earthquake. That was a push-together quake, but it was so huge and moved so much rock in different directions that some of the rock ended up having pull-apart motions, such as this one.)

What tectonic setting is primarily responsible for producing Mt. St Helens? A) Hot Spot B) Slide Past C) Pull-Apart D) Push-together Obduction E) Push-together Subduction

E) Push-together Subduction Feedback: Mt. St. Helens sits above a subduction zone, where one tectonic plate goes below another as they come together.

Opinion polls show most residents of the US do not believe they understand science very well, but they do favor more government support of science. Why do most US residents favor government support of science? A) Scientists apply their scientific method, which allows them to learn the Truth. B) Science is so boring that almost everyone uses public-broadcasting science programming as a sleep aid, and government funding is needed to insure a steady supply of boredom. C) Science is simply so fascinating that almost everyone can't wait to see what will be discovered next. D) Scientists are so breath-takingly sexy that most people are drawn through sheer carnal lust to support the scientific enterprise. E) Science has helped make our lives healthier, wealthier, easier, safer, etc., and people hope that more funding of more science will provide even more health, wealth, ease, safety, etc.

E) Science has helped make our lives healthier, wealthier, easier, safer, etc., and people hope that more funding of more science will provide even more health, wealth, ease, safety, etc. Without science and technology, the great majority of us would be dead, so we tend to be supporters of science. Although we know that science works, we're never sure that it is completely right. Students so often discover things that professors missed, or that professors got wrong, that scientists would be silly to claim Truth. Comparing the TV ratings of the latest hit to the ratings of the latest science program on public broadcasting shows that many Americans are not fascinated by science, but the science-show ratings are above zero, so some people are fascinated by science. And hope as we might, it is, unfortunately, clear that not every scientist is sexy (just most of them are).

There are many large mammals on Earth today. This is because: A) Dinosaurs in hibernation were killed by acid rain, which didn't hurt things that could run away. B) Small mammals wanted to become bigger, and after the dinosaurs were killed, the small mammals had their chance and so made themselves bigger. C) The warm blood of the many large mammals that lived before the meteorite impact allowed them to survive the cold from the meteorite impact that killed the dinosaurs. D) The very large mammals that were alive on Earth with the dinosaurs have gotten smaller over time because the mammals don't have to be big to compete with the dinosaurs any more. E) Small mammals were not able to outcompete the dinosaurs for big-animal jobs, but after the dinosaurs were killed, some large mammals evolved from small mammals to fill the large-animal jobs.

E) Small mammals were not able to outcompete the dinosaurs for big-animal jobs, but after the dinosaurs were killed, some large mammals evolved from small mammals to fill the large-animal jobs. Notes: There are "big-animal" jobs—eating tall trees, eating smaller animals, etc. But the total number of big-animal jobs is limited. The dinosaurs filled the big-animal jobs before mammals really got going, and mammals were not able to displace the dinosaurs. Some small mammals survived the meteorite that killed the dinosaurs, and then evolved to give big mammals over millions of years and longer. There were almost no big mammals before the dinosaurs were killed off, volition has nothing to do with evolution, and running away doesn't avoid acid rain.

Glaciers form where: A) The average temperature is well below freezing for a long enough time. B) Winters are really snowy for a long enough time. C) Melting exceeds snowfall for a long enough time. D) Rocks are being raised by tectonic motions. E) Snowfall exceeds melting for a long enough time.

E) Snowfall exceeds melting for a long enough time. Feedback: Anyone from Erie can tell you that a snowy winter does not guarantee a glacier, and anyone from the permafrost of Siberia could add that cold does not guarantee a glacier. Many high mountains are free of ice, and some warm places are being raised tectonically. The way to make a glacier is to pile up more snow than melts.

Mass wasting delivers sediment to streams. We believe that in regions such as Pennsylvania or the hills around Washington, DC, most of the mass that is delivered to streams arrives by: A) Very fast debris avalanches and flows B) Grain flows that occur when the soil dries out during summer droughts C) Slumps, like someone slumping down in an easy chair D) Careless people taking leaks in sinkholes after drinking too much Pepsi E) Soil creep, slow motion of pieces from freeze-thaw action, throw by falling roots, downhill motion of rocks during digging of gopher holes, etc.

E) Soil creep, slow motion of pieces from freeze-thaw action, throw by falling roots, downhill motion of rocks during digging of gopher holes, etc. Notes: As rocks move to streams in many places, such as Pennsylvania or near Washington, DC, the slow and steady motions are more important than the few dramatic events. In very steep mountains, fast landslides may dominate, and slumps can be important, but although Pennsylvania does have both, they are not especially common. On the side of a sand dune, you often can see a dry grain flow. (If you've ever sat high on a beach and sifted dry sand through your fingers, you've made a grain flow.) But these are very rare in Pennsylvania or near DC, where the soil tends to stick together even in summer. And while there may be careless people who misbehave in sinkholes, this won't get too many rocks to streams.

In the Great Smokies: A) All of the rocks were turned upside-down by push-together thrust faulting. B) Giant deposits of marmot #2 were squeezed geologically to make the mountains. C) All of the rocks were brought in from Florida by slide-past faulting. D) All of the push-together action caused folding of rocks, with no breakage anywhere. E) Some older rocks were shoved on top of younger ones by push-together thrust faulting.

E) Some older rocks were shoved on top of younger ones by push-together thrust faulting.

Most of the material moved by volcanoes is from the few, big ones rather then from the many, little ones. Most of the material moved downhill in landslides is in the many, little ones rather than the few, big ones. In comparing the importance of the few, big earthquakes to the many, little earthquakes, are earthquakes more like volcanoes (the few big ones matter most) or like landslides (the many little ones matter most)? A) The many, little earthquakes matter most (like landslides). B) Earthquakes don't do any damage, just like volcanoes and landslides. C) The few, big earthquakes are exactly as important as the many, little earthquakes (exactly halfway between volcanoes and landslides). D) All earthquakes have been retribution for the Simpsons. E) The few, big earthquakes matter most (like volcanoes).

E) The few, big earthquakes matter most (like volcanoes). Feedback: An increase of 1 in earthquake magnitude increases ground shaking about 10-fold, increases energy release about 30-fold, and decreases frequency about 10-fold; the 30-fold increase in energy more than offsets the 10-fold decrease in frequency of occurrence. We wish earthquakes did no damage, but the millions of people who have been killed in earthquakes over the centuries would, if they could, testify to the damage done by earthquakes. And historical records of earthquakes clearly preceded the Simpsons.

Dave Janesko holds two rocks next to each other. The black one (to the upper left in the picture) is from a lava flow, and is much younger than the red one (to the lower right in the picture), which is a lake sediment. In nature, these rocks are found the way Dave is showing, with the younger black one next to the older red one rather than being on top of the older red one. This actually is related to Death Valley, although these rocks are a good bit east of Death Valley. As described by Dave Janesko in the online video, what happened here? A) The lava flow set the red rocks on fire, giving them their red color, the way forest fires have colored some of the rocks of Death Valley. B) A collision between two continents bent the rocks, forcing the lava flow next to the lake sediments, the way the drifting plates of California have bent the rocks to make Death Valley. C) The lake sediments were deposited, eroded into a big cliff, and then the lava flow filled the valley next to the cliff, the way lava flows sometimes flow down from the peaks to fill Death Valley. D) There once was a mid-ocean ridge here, and the black lava squirted up through a crack in the red lake sediments and then hardened the way volcanoes do in Death Valley; Dave Janesko is demonstrating what one side of the crack looks like. E) The lake sediments were deposited, then the lava flowed on top, and then a pull-apart Death-Valley-type fault formed, breaking the rocks and dropping the lava flow to be next to the lake sediments.

E) The lake sediments were deposited, then the lava flowed on top, and then a pull-apart Death-Valley-type fault formed, breaking the rocks and dropping the lava flow to be next to the lake sediments.

Stephanie and Topher are standing next to the Colorado River in the Grand Canyon. What can be said of the water here? A) The river water is naturally clear, fed by snowmelt from the Colorado Rockies. B) The river is really filled with 7-UP, hence the green color. C) The river water is kept clear by the Park Service to keep the trout healthy. D) The river was cleaned up briefly by the Park Service to help Stephanie and Topher in their filming. E) The river was naturally muddy, but has been made clear because most of the sediment is settling out in the reservoir behind the dam upstream.

E) The river was naturally muddy, but has been made clear because most of the sediment is settling out in the reservoir behind the dam upstream. Notes: Native species that lived in the muddy waters are now in danger of becoming extinct, because the clear water released from the dam makes those fish too easy for predators to see.

The things that glaciers deposit include: A) Striations and polish. B) Cirques and hanging valleys. C) Bedrock knobs that are rough on the upglacier side and rounded on the downglacier side. D) Till (which is sorted) and outwash (which is unsorted). E) Till (which is unsorted) and outwash (which is sorted).

E) Till (which is unsorted) and outwash (which is sorted). Feedback: Striations, polish, cirques, hanging valleys, and rough-downglacier/rounded-upglacier (not vice versa) bedrock knobs are all features of glacier erosion, not deposition. Till, deposited directly from the ice, includes pieces of all different sizes because ice can carry all sizes without sorting by size; outwash is washed out of a glacier by meltwater and sorted by size.

The mountain range that contains the folded Appalachians, including Mt. Nittany near Penn State's University Park Campus, and the Great Smoky Mountains, was raised to high elevation primarily: A) When the Atlantic Ocean formed, at a pull-apart boundary. B) When Death Valley opened, squeezing the east coast. C) When a hot spot erupted under the east coast, and the surrounding rocks slid down the hill it made and rumpled while sliding. D) When a subduction zone formed under Oregon, rumpling the rocks to the east. E) When the proto-Atlantic ocean closed, at a push-together boundary.

E) When the proto-Atlantic ocean closed, at a push-together boundary.

The cartoon above illustrates a specific geologic process. Which of the additional geologic images DOES NOT feature this same process at work? [See image: UNIT 4.5.1, 4.5.2]

Feedback: The folded Appalachians, including the region of central Pennsylvania around Penn State's University Park campus, shown in the satellite image here, as well as the Great Smokies and the Blue Ridge, formed when Africa and Europe collided with the Americas, much as the two cars in the picture collided. Death Valley records different processes.

The cartoon above illustrates a specific geologic process. In which of the additional images can the same geologic process be seen?

Feedback: The folded Appalachians, including the region of central Pennsylvania around Penn State's University Park campus, shown in the satellite image here, formed when Africa and Europe collided with the Americas, much as the two cars in the picture collided. Death Valley, Crater Lake, and George the Immense Marmot record different processes.

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