Earth Science Final

What kinds of rocks do we find on Mars? What else do we find evidence of?

- Geologists have turned their attention to other planets like mars, where we are now finding sedimentary rocks and evidence of running water.

What controls the global distribution of earthquakes (where do they primarily occur)?

- Main source of seismic waves /where earthquakes occur is at faults: planes within the Earth along which movement occurs. Every plate boundary is a fault, but not every fault is a plate boundary. -faults are where most earthquakes occur -most earthquakes occur on plate boundaries

What is the IPCC, and what is their job?

- One way to do this: by modeling future climate change. -The IPCC (Intergovernmental Panel on Climate Change) is an international group that assesses and disseminates the science associated with climate change. a. The reports are assembled by teams of scientists, reviewed by hundreds of other scientists, and also reviewed by government representatives. They are released every few years and include summaries of the physical science, summaries of the most vulnerable people and areas, and options for mitigating climate change - how we predict climate change: through generalized circulation models OR global climate models a. These models treat the atmosphere and oceans as essentially boxes, which are filled with different concentrations of greenhouse gases, etc. We can run these models forward to predict climate change impacts at different places on Earth

What is a proxy, in general? What are some of our proxies, and how do they work/what do they tell us about, specifically?

- We infer climate by using proxies: measurements or observations of physical variables that tell us about climate. -General proxies: a. Glacial extent: how extensive were glaciers, globally? Lots of glaciers = colder climate. 1. Leaf shape b. Dendrochronlogy--? c. Pack rat middens--? -Stable isotopes: a really precise temperature proxy -Ice cores: another really precise proxy (especially for CO2)

How and why did the Himalayas form, and what boundary type did they form along? What do they look like, and what are associated hazards?

- continent-continent convergence: the himalays a. india and the eurasian plate produced these mountains where they collided -as the indian subcontinent pushes against eurasia, pressure is released in the form of earthquakes. The constant crashing of the two plates forms the himalayan mountain range a. crust is deformed, fractured,and piled on top of itself -finish hazards/???

what is fractionation:

- it is sorting: this occurs when chemical and biological processes preferentially sort light and heavy isotopes. a. This results in a change in the ratio of heavy- to light- isotopes in our final product (shells, ice, etc.). -Fractionation processes are frequently temperature dependent.

We talked about physical changes that you might see in rocks due to metamorphism. Know the three changes that we might anticipate, and be able to give examples of rocks where we would see reorientation of crystals as well as rocks where we might instead see only recrystallization of minerals into fewer, larger grains.

--finish this answer????

What were Alfred Wegener's 4 pieces of evidence to support his theory of continental drift?

-1. Faunal distributions: extinct organisms (fossil fauna) have distributions across unconnected continents. Scientists used to explain this as resulting from land bridges that rose up out of the ocean and then sank back into it, but you need a LOT of mysterious land bridges for this to work. -2. fit of edges of continents -a. it looks like a lot of the continent edges would fit pretty nicely with each other, if we could just rearrange them... -3. matching rock types -a. (old rocks matched together from different continents)--some mountain belts seem to be split by oceans, and are currently on different continents. -4. record of past glaciations -a. Tillites: big piles of unsorted rocks and dirt -formed by glaciers moving sediment around like bulldozers -b. Glacial deposits (and sense of motion indicators) do not make sense given the current position of continents -c. If continents are fixed: glaciers would have to have formed at equators and moved north, and would have had to flow onto land and uphill from the sea -d. If we reposition the continents into a supercontinent (Wegener proposed the supercontinent Pangea), the glaciers can behave in a "normal" fashion (form at high latitudes, flow from inland outwards towards the sea)

What are some of the modern sources of support for plate tectonics theory?

-1. GPS: network of 30 satellites with ground-based receivers. These very precisely track plate motion (if you have a Garmin in your car, you know that they're really good at locating stuff on the surface of the Earth. Some phones also have GPS chips). -2. inSAR: (Interferometric Synthetic Aperture Radar) is a completely satellite based method for measuring ground movement. a. In contrast, GPS relies on earth-based equipment as well as satellites. b. InSAR satellites operate using a similar principle to sonar-they bounce signals off of Earth's surface:

How do the two different stable isotopes of oxygen that we discussed in class today differ in terms of their physical behavior? How are they fractionated during evaporation?

-16O isotopes of oxygen have less neutrons than 18 O isotopes do so that means they are lighter -delta notation: standardized way to express the heavy isotopes to light isotopes -Light isotope evaporates faster (it is easier to pick up the more rapidly vibrating isotope)...this means that they evaporate quickly out of the ocean and are what leads to forming our clouds and later glaciers -heavier isotope precipitates out faster a.precipitation starts out light, and gets lighter as you move away from coastlines -colder temperatures lead to stronger sorting

You should be familiar with our four different types of seismic waves and their properties. Relatedly, why can scientists learn about the Earth's interior by studying seismic waves?

-2 types: body waves and surface waves -body waves: travel in the interior of earth→ they tell us about the interior structure of the Earth. -Seismic wave velocity varies as the properties of the material that they are passing through changes (properties include density, elasticity, composition, pressure, and temperature) -When waves pass from one material into a different material, they can be bent (refracted) and may also bounce off of the new material (reflected). a. s waves: secondary, second to arrive, shear material (wave-through material), cant travel through liquids b. p waves: primary, first to arrive, compress material→ pushing it, stretch out, pushing (FASTEST WAVE); deflected in interior of earth when traveling through outer core -surface waves: they travel only on the outside of the earth a. love waves: shearing along the earth's surface; very damaging b. rayleigh waves: move like ocean waves (make buildings go up and down)

What are our three kinds of chemical weathering?

-3 types of chemical weathering: a. Water: transport of chemical species involved in reactions. b. Dissolution: promoted by acidic water. c. Hydrolysis: reaction of mineral with water, where... -1. Hydrogen ion attacks and replaces other ions. e. Oxidation: rock exposure to atmospheric oxygen.

What are the three primary energy sources today?

-36% petroleum, 31% natural gas, 13% coal, 8% nuclear power, and 11% renewables

What 5 fundamental sources provide energy on Earth?

-5 fundamental sources provide energy on earth -a. 1. solar -2.gravity -3.nuclear fission reactions -4.earth's internal energy -5.energy in chemical bonds

What percentage of greenhouse gases are absorbed by the oceans and forests?

-55% absorbed by oceans and forests; 45% remains in the atmosphere

What are the two processes by which glaciers flow? How fast can they move?

-Accumulation of snow and ice at high elevation causes glacial ice to flow downslope because of the pull of gravity. -Types of glacial flow a. Basal Slip: mechanism of glacial movement in which the ice mass slides over the surface below; most glaciers are thought to move by this process b. Plastic Flow: movement of ice within a glacier when, under pressure, ice behaves as a plastic material; typically occurs below 50 meters of ice (where ice is unfractured). 1. This is a kind of ductile deformation.

What happened during the PETM, and why (what was our source of greenhouse gases)?

-An example of the greenhouse effect: the Paleocene-Eocene Thermal Maximum (PETM): ~55 million years ago the Earth got REALLY warm, very rapidly. a. The Earth warmed at least 5° C in a few thousand years (so not as fast as current warming, but VERY rapid by all standards). -What drove this: the release of massive amounts of methane by the destabilization of methane hydrates (methane locked in ice crystals, stored on the ocean floor and shelves--methane clathrates built up by archaebacteria). This would create runaway warming, and also further warm the ocean, melting and releasing more methane. a. this was not good for animals (unless you were a massive snake that existed at this time!) -main GHG was methane

You should also be able to determine which igneous rock textures are associated with intrusive vs. extrusive environments.

-Aphanitic textures are very fine grained-you can see grains if you are holding the rock but need a microscope to identify minerals. These form in extrusive environments: basically, your magma gets thrown to the surface of the earth and cools so quickly that there is no time to grow big crystals. -Phaneritic textures have coarse, big mineral grains that can be identified in hand sample. They form in rocks that cooled intrusively-in the earth. Atoms had a lot of time to get organized as the magma cooled slowly, which is why they were able to make big crystals

what kind of deposits do we find copper in, in Utah?

-Bingham canyon open pit mine, UTAH a. 12 million tops of copper since 1904 b. Where copper occurs: in copper bearing minerals (bornite and chalcopyrite) in veins which cut across hydrothermally altered granite. c. Size of pit: 2.75 miles wide, 4,000 ft. deep. d. Located 20 miles outside of Salt Lake City

What is a biofuel? What are some examples of different biofuels? What are some disadvantages to using biofuels in your engine?

-Biofuel: fuel derived from biomass (recently living organisms or their metabolic byproducts); -a. Pros: Biofuels are a renewable resource; -b. Cons: Combustion produces carbon dioxide and other greenhouse gases. -example of biofuels: BioEthanol: the most common type of biofuel; obtained through fermentation, distillation, dehydration, and denaturing of starch or sugar found in many crops; -a. Pros: Can be blended with petroleum gasoline; US blends are typically 5-20% ethanol; -b. Cons: Some engines are not compatible with ethanol; use can result in corrosion and deposits. -1. You can get corrosion and deposits when you use this in these engines (Dr. Kosloski has been told that using high bioethanol gasoline as a fuel source will wreck her lawnmower). -ex 2: switchgrass: a hardy, perennial grass native to the North American tall grass prairie, considered a good candidate for biofuel (especially ethanol fuel):

If we melted the Antarctic ice sheet, by how much would sea level rise?

-Contains 80% of Earth's ice and 66% of fresh water; -Covers almost 150% of the area of the United States; -If melted, global sea level would rise 60 - 70 meters

How do continents grow, and what is a terrane? Know the different things that we can accrete onto continents to grow them.

-Continents have grown through geologic time by accretion of material derived from the upper mantle.-Plate tectonics constantly rearranges the continents and adds new material -Accretion of Terranes: Small crustal fragments collide and merge with continental margins. → occurs due to plate tectonic processes -Terrane: crustal fragments whose geologic history is distinct from that of the adjoining terranes.

how do diamonds reach the surface?

-Diamonds: a form of carbon created at great depths under high pressure; once crystallized diamonds are carried up through conduits within ultramafic rock called kimberlite pipes. -kimberlite represents material coming from the base of the lithosphere, reaching the crust at high speeds

How has resource use changed in the last 100 years (both in terms of total amount used, and in terms of what we are using to produce energy)?

-Energy consumption has increased significantly over the last 100 years. 75% from fossil fuels. -the kinds of resources that we exploit have changed (we see shifts from using predominantly wood to coal to petroleum, with other energy resources also being utilized). -energy consumption vs. population -a. 1800: 1 billion (population) -b. 2019: 7.7 billion

From lecture, you should know our main felsic and mafic minerals (be able to distinguish between these in a list) and should also know how these relate to plate tectonic settings (which is associated with oceanic crust? Which is associated with continental crust?) How do we generally distinguish between these two groups of minerals, and how do they differ chemically?

-FELSIC (non‐ferromagnesium): light in color, higher silica content‐quartz, potassium feldspar, muscovite, Na‐rich plagioclase feldspar a. relates to plate tectonic settings bc is associated with continental crust -MAFIC (ferromagnesium-minerals): dark in color, includes pyroxene, olivine, amphibole, biotite mica; lower silica content a. more Mg (magnesium) and Fe (iron) rich (EITHER OR) b. relates to plate tectonic settings bc is associated with oceanic crust c. And the mantle is ULTRAMAFIC: lots of ferromagnesium (Iron/Magnesium rich) minerals that are stable under high temperature and pressure conditions -we distinguish btwn these two groups by their composition (what elements are in them) -they differ chemically because one has more silica than the other

What are the primary types of fossil fuels, and what are they derived from?

-Fossil Fuel: general term for any hydrocarbon (organic material) used as a fuel: oil, coal, natural gas, bitumen from oil sands and oil shale. -made from hydrocarbon compounds / organic material -Derived from the remains of marine plants and animals; (this is why we call them fossil fuels-they are made from dead organisms).

What are gas hydrates, and where do we find them? What is the big downside of potentially utilizing them as a fuel source?

-Gas Hydrate: a solid form of water that contains a large amount of methane within its ice-like crystals; a. Exists at low temperature and high pressure; b. Natural deposits on ocean floor and in permafrost -Pros: Natural gas hydrate deposits contain significant amounts of methane, a potential energy source; -Cons: Methane is an even more efficient greenhouse gas than carbon dioxide

What is a glacier, and what cycles are they a part of? How much of the Earth do they cover?

-Glacier: thick mass of ice originating on land from the accumulation, compaction, and recrystallization of snow. a. Glaciers are part of both Earth's Hydrologic Cycle and Rock Cycle; -Glaciers cover nearly 10% of Earth's land surface, and are a significant force of erosion.

What was Glacial Lake Missoula, and what happened there?

-Glaciers can also be associated with violent flooding events: Glacial Lake Missoula had frequent catastrophic flooding events, where water rushed from this lake out towards the Columbia River. a. These megaflood events shaped many land surfaces in the west.

How much of Earth's surface was covered by glaciers during the Pleistocene (and when was the Pleistocene)? How did this impact sea level, and what happens to sea level when glaciers melt?

-Glaciers covered 30% of the ground surface in the Pleistocene. a. pleistocene was from 2.58 million years ago - 0.012 million years ago (11,700 years ago) 1. the most recent Ice age occurred then 2. it is during the pliocene epoch ; it is preceded by the pliocene epoch of the neogene period -during the last ice age the sea level was about 400 ft lower than it is today -when glaciers melt, sea level rises -finish????

When can we form a glacier (what process needs to outweigh wastage), and how do we make glacial ice (4 steps)?

-Glaciers form in areas where more snow is added (accumulation) than melts or evaporates (wastage) a. A glacier is a balance between these two factors, with accumulation at the head and wastage at the foot. -formation of glacial ice: a. -1) Snowflakes become smaller, thicker, & more spherical; b. 2) Air is forced out of pore spaces; c. 3) Snowflakes recrystallized into denser masses of small grains called firn; d. 4) Under pressure, firn fuses into solid mass of interlocking ice crystals (glacial ice).

what are our three different kinds of hydrothermal deposits?

-Hydrothermal Deposits: Solutions of hot, metal-rich fluids move through rock, depositing metals (usually as sulfides) as the fluid cools; -Hydrothermal deposits are among the best-known and important ore deposits. a. Vein Deposits: Solution moves along fractures, cools, and precipitates within cracks; b. disseminated deposit: ores precipitated as minute masses throughout entire rock mass (small amounts everywhere) c. Surface Deposit: Where magma is near surface, dissolved metals precipitate when water cools in air d. Hydrothermal deposits are driven by magma chambers, which heat and drive hydrothermal circulation that moves metal deposits around.

Where does Iowa rank in terms of using wind energy in the United States?

-Iowa is the 2nd largest producer of wind energy in the US; -Most large wind farms are concentrated in northwestern Iowa; -Location and orientation of turbines and wind farms are optimized with climate and atmospheric circulation data

With increasing metamorphic grade, how would you expect crystal size and foliation to change?

-Just like in igneous rocks, different minerals form under different temperature and pressure conditions. a. So we can tell what happened to our metamorphic rocks by looking at their mineral assemblages! -With increasing metamorphism, we will see an increase in crystal size and increasing coarseness of foliation, in rocks that have foliation textures

What are the two different ways by which magmatic segregation can concentrate minerals?

-Magmatic Segregation: the local concentration of minerals formed during the cooling and crystallization of magma-types: a. separation of heavy minerals that crystallize early; b. enrichment of rare elements in the residual melt

What are mineral resources? What is an ore (how is it defined)?

-Mineral resources: The naturally occurring variety of useful and essential minerals from Earth's crust, ultimately available commercially according to value a. examples: iron ore, lead, tin, copper, zinc, mercury, bauxite -ore: a rock containing useful metallic minerals that make it valuable for mining; also used to refer to some nonmetallic minerals such as fluorite and sulfur

What kind of a volcano is Mt. Rainier, and what is the structure of these volcanoes and the plate tectonic setting that they are associated with?

-Mt. Rainier is a stratovolcano (composite volcano) that is currently active (located in Washington) a. structure: Symmetrical and steep (35° slopes)...these are our CLASSIC looking volcanoes 1. intermediate to felsic in composition 2. volcanoes erupt explosively, flow very short distances because of their high viscosity (they will often form domes), and generate pyroclastic deposits. They are also extremely hazardous. b. plate tectonic setting: convergent boundaries (subduction zones) --> Particularly ocean-continent subduction zones at convergent boundaries, since this makes the melt more felsic because you're moving through continental crust -these volcanoes also have a lot of layers-ash, lava, and pyroclastic flows. This is because they have complicated eruption histories.

what are PGE's? what are they associated with?

-Ni-cu-platinum group elements (PGE) a. ex: Nickel, copper, platinum -associated with magma chamber -associated with specific / big impact site --forming at these sites a. ex: 1850 Ma impact at Sudbury: Melted part of mantle 1. Impacts can have many valuable associated deposits due to formation of melt -big mafic systems & big magma systems -example: large layered intrusion in russia at noril'sk -Noril'sk: Minerals settle at base of magma chamber -PGE potential from Minnesota and Michigan to Iowa

Recognize the different types of nonmetallic mineral resources.

-Nonmetallic mineral resources a. Building Materials: 1. Natural aggregates (crushed stone, sand, gravel); 2. Gypsum (used to make plaster and wallboard); 3. Clay (used to make tile, bricks, and cement). -a. Different kinds of clay exist: kaolinite, illite, bentonite. These are also used to manufacture paper, china and ceramics, and different kinds of food. b. industrial minerals: 1. Fertilizers (nitrate, phosphate, and potassium compounds); 2. Sulfur (sulfuric acid to manufacture phosphate fertilizers); 3. Salt (used in chemical industry, "softening" residential water, and keeping streets ice-free). c. clay: kaolinite, illite, bentonite....paper, china/ceramics, food d. sand: sand mining by penn. Glass & shared corp. Near columbia, SC e. olivine????

How do renewable and non-renewable resources differ? You should know, given a resource, which category it falls within.

-Nonrenewable Resources form or accumulate over millions of years, so quantities are considered fixed. a. Examples: coal, natural gas, iron. -Renewable resources are either virtually inexhaustible or can be replenished relatively quickly (months, years, decades). a. Examples: Sun, wind, tides

know your renewable vs. non-renewable resources:

-Nonrenewable Resources form or accumulate over millions of years, so quantities are considered fixed. -a. Examples: Fuels (coal, oil, natural gas) Metals (iron, copper, uranium, gold) Groundwater (sometimes!) -Renewable resources are either virtually inexhaustible or can be replenished relatively quickly (months, years, decades). -b. example: biofuels

What are oil sands, and what are some of the pros and cons of using them as a fuel source? Where do we find them, worldwide?

-Oil Sand: a mixture of clay and sand combined with water and bitumen (a viscous, degraded form of oil); -a. Pros: There are several substantial oil sand deposits around the world; -b. Cons: Obtaining oil from oil sands is difficult and expensive to extract and has major environmental drawbacks -Canada has extensive oil sand deposits associated also with oil fields and gas fields; all part of a foreland fold and thrust belt. -a. Heavy and extra-heavy oil basins are widespread worldwide (127 basins, according to USGS) b. active extraction in canada, meaning this is not great for the environment

What do you need to capture oil and natural gas? You should be able to recognize and define source rocks, cap rocks and trap rocks, and should also know the different kinds of common traps. What are oil and gas made of?

-Oil Trap: A geologic environment that allows economically significant amounts of oil and natural gas to accumulate underground.-Necessary conditions: -A cap rock that is virtually impermeable to oil and gas; -A porous, permeable reservoir rock. Types of oil traps: -Anticlinal Trap: Rising oil and gas collect at a fold apex in an up-arched series of sedimentary strata-Fault Trap: Upward migration of oil and gas is trapped where displaced strata bring a dipping reservoir rock opposite an impermeable bed.-Salt Dome Trap: Rising oil and gas accumulate in deformed, upturned sandstone beds adjacent to salt dome;-Stratigraphic Trap: Rising oil and gas is trapped by an original sedimentary structure: a sloping bed of reservoir rock thins to point of disappearance (pinches out). -sand bars -Cap rock is punctured by drill; -Oil and gas, under pressure from overlying rock, migrate from pore spaces of reservoir rock into drill hole; -Oil and gas are pumped to surface; or may rise (if under sufficient pressure) without pumping to surface

when did we start using oil widely?

-Oil has been utilized heavily over the past 150 years, with the first oil well drilled in 1847 in Baku, Azerbaijan -The history of oil has multiple phases, with the "Modern" petroleum industry starting around the 1880s. Global discovery and acquisition followed, and then post WWII significant technological advances and subsurface imaging techniques improved our ability to locate this resource. -Global oil and gas field development and deep water discoveries occurred in the late 1900s. We may be headed towards peak production in the next few decades

How do we get oil out of shales? Why do we need sand to do this?

-Oil shale: fine-grained, dark sedimentary rock with enough organic material to yield oil or combustible gas upon distillation; -a. Pros: Enormous amounts of untapped oil are contained in oil shales -b. Cons: Current technologies for distilling oil shale are expensive; huge environmental risks if not done properly -how we get this out: hydrofracking → Deep wells are drilled, and water is pumped down them at very high pressures. Water forces fractures to form, proppant in the water holds fractures open, allowing oil to flow out. a. the proppant is sand--SO, when fracking, rocks have tiny holes/pockets of oil and gas that are not connected together until fracking occurs and you connect them all (BC you are pumping water that create a fracture network so that the oil and gas would come out) b. we put sand down because it works as a pillars that prop all the fractures open; as if you are making a big hole to connect each of the rock holes

How old is the oldest ocean crust, and how much of the rock record is therefore missing on the ocean floor given the age of the Earth (4.56 billion years)?

-Oldest ocean floor is only 200 MYA (MYA = million years old)! -So we are missing more than 95% of the Earth's 4.5 billion year record!

What major deposits do we find in Iowa, associated with limestones?

-Pb-Zn deposits in Iowa area a. these are associated with galena which occurs within limestone -Pb & Zn deposits in limestone Mississippi valley type (MVT) in iowa a. Mining lead by 1650 in Iowa -- Native Americans and French trappers did some mining and smelting b. 1790-1810: Dubuque operated "Mines of Spain

What is a placer deposit? What are the physical characteristics of minerals associated with these types of deposits?

-Placers: deposits formed when heavy minerals are mechanically concentrated by currents, most commonly streams and waves; typically heavy and durable minerals. a. Examples: Gold, tin, platinum, diamonds. -Extracting placer deposits can greatly disturb the surface, and may require reclamation/remediation

how can weathering cause secondary enrichment of ore deposits?

-Secondary enrichment: Concentration of scattered, minor amounts of metals by weathering processes. -Two Types: a. Chemical weathering and water percolation remove undesirable elements from decomposing rock, leaving desirable elements; b. Desirable elements found near surface are carried to lower zones, and concentrated

How do oxygen stable isotopes work? To understand this, you should know the differences in behavior between 16O and 18O, what fractionation is, and how this changes with temperature. When there are lots of glaciers, will oceans be heavy or light?

-Stable isotopes do not decay: they do not change. They therefore preserve environmental signatures recorded at the time that they get incorporated into material, like shells and ice sheets. -16O and 11O are both stable isotopes of oxygen and have 8 protons a.16O has 8 neutrons (8+8=16) b.18O has 10 neutrons (8+10=18) c. 16O vibrates more rapidly than 18O, and this difference becomes more pronounced at lower temperatures. -light isotope evaporates faster because it is easier to pick up the more rapidly vibrating isotope a. so, when there are a lot of glaciers: oceans will be heavy because 16O was taken into the atmosphere to form the clouds and glaciers 1. glaciers are isotopically light

What did the Earth look like during the Pleistocene?

-The pleistocene - observations -1. 1/3 Earth's landmass buried beneath 40 million km3 of ice -2. Extensive glacial deposits -3. Shifts in species ranges -4. Sea level up to 120 meters lower (Pleistocene= ice-to-cene)

know the greenhouse effect from earlier in the semester. You should also know that carbon (part of carbon dioxide) moves into and out of reservoirs over both long and short time scales. Know additionally what combustion does (how does it generate carbon dioxide?).

-The process of global warming is very similar to what happens in your car in the summer...if you leave it closed, sunlight enters through the windshield and heats the interior of the car. This heat has a difficult time escaping a. this is why your car gets extremely hot when you leave it sitting in parking lots. -If we look at the greenhouse effect on the Earth, the sun emits solar radiation. Much of this passes through the atmosphere unchecked (some is reflected off of the atmosphere) and hits the surface of the Earth. There, it may be reflected back into space (especially from surfaces with high albedo) or it may be absorbed and re-radiated as infrared radiation. -Infrared radiation can then be trapped by greenhouse gas molecules in the troposphere, which as complex molecules are good at "grabbing" this kind of radiation. Some infrared heat also escapes into space, and some gets radiated between molecules. By these actions, greenhouse gases serve as a sort of insulating blanket for the Earth: they catch re-radiated heat and warm the surface of the Earth and the lower atmosphere. -On long time scales, we see significant movement of greenhouse gases between different reservoirs. Oil and gas are made up of formerly living and therefore carbon rich plants and animals that have died and been transformed: in stored fossil fuels within the Earth, we have locked up a lot of carbon. When we burn fossil fuels, we combust them (fuel reacts with oxygen to produce heat/energy) a. this releases trapped organic material (and produces CO2). -reservoirs: atmosphere‐ocean‐vegetation‐animals‐limestonecoal‐ oil‐natural gas‐Earth's mantle a. release in volcanoes -combustion uses complex carbon molecules and it chemically breaks it down and changes it and that is what generates CO2

What do diamonds and graphite (pencil lead) have in common? Why are they so different?

-They are both made of carbon/carbon chains -whats different is how the carbon chains are arranged --> when you get to the atomic level in graphite. it is very different than diamonds a. in diamonds it is a perfect arrangement of carbon chains and overall structure of the carbon atoms (inbreakable bonds) --> covalent bonds in all directions 1. covalent bonds are very strong and stable--> known as sharing b. graphite structure: bonded sheets held together by van der waals forces -AKA main difference is the structure of their atoms

what are our three different kinds of plate boundaries? know associated features!

-Transform: plates slide horizontally past each other -divergent: plates move apart and create new lithosphere -convergent" plate collide and one is pulled into the mantle and recycled

how do we optimize placement of wind farms?

-Use climate and atmospheric data to make sure we are putting in area that has regular decent winds but not overwhelmingly strong 70 mi/hr winds

What are the two different types of glaciers? Under what conditions will a glacier form?

-Valley (Alpine) Glacier: glacier confined to flow down a mountain valley (typically a former stream valley) from an accumulation center at its head. a. Examples: Bucher Glacier, Alaska and Franz Joseph Glacier, New Zealand. -Ice Sheet: very large, thick mass of glacial ice flowing outward in all directions from one or more accumulation centers; Continental ice sheets because they exist on such a large scale

Know the vocabulary terms (*ed, bolded, italicized). You should be able to identify these on a diagram. Glaciers leave a lot of signs and records, and we want you to be familiar with them!

-Zone of Accumulation: area where there is a net accumulation of snow and ice; -Zone of Wastage: area where there is a net loss to the glacier due to melting or calving -Snowline: lower limit of snow accumulation; the elevation of the snowline can vary greatly. -erratics: Glacial erratics are stones and rocks that were transported by a glacier, and then left behind after the glacier melted. Erratics can be carried for hundreds of kilometers, and can range in size from pebbles to large boulders. Scientists sometimes use erratics to help determine ancient glacier movement

what is bitumen?

-a black viscous mixture of hydrocarbons obtained naturally or as a residue from petroleum distillation. It is used for road surfacing and roofing. -Fossil Fuel: general term for any hydrocarbon (organic material) used as a fuel: oil, coal, natural gas, bitumen from oil sands and oil shale.

What is a packrat, and how can they help us learn about climate?

-a packrat is a little rat that builds garbage middens and puts everything within a 30-100 meter radius of its midden into it. a. this gets cemented together with its viscous urine, which forms a substance called "amberat". -Middens can be tens of thousands of years in age, may be stratified, and are frequently found in clumps a.packrats like to build them under sheltered shelves. b.We use radiocarbon dating on these..The composition of middens tells us about changes in species abundance, and changes in plant communities

What is albedo, and how can it drive changes in climate? You should know, given a comparison like soil vs. snow, which surface has a higher albedo.

-albedo: the proportion of the incident light or radiation that is reflected by a surface, typically that of a planet or moon. -higher albedo = more reflective, so more energy sent back to space -albedo of different surfaces: a. soil: 0.17 b. forest: 0.09 - 0.15 c. ice: 0.45 d. green grass: 0.25 e. fresh snow: 0.8-0.9 -When we form snow, it reflects incoming solar insolation. This can drive global cooling

How does ductile deformation differ from brittle formation, and how does this relate to whether we see faults or folds?

-brittle deformation: a. rapid deformation b. has joints and faults -ductile deformation a. slow deformation b. plastic look, has folds -Factors that influence the strength of a rock and how it will deform include: a. temperature b. confining pressure c. rock minerals d. time

You should be able to talk about our large-scale drivers of global climate and how they work.

-changes in incoming solar insolation a. early sun 30% less luminous; thus, solar luminosity has increased by approx 30% through time -configuration of continents a. Continent positions are not at all stable through time (plate tectonics!). The opening between South America and Antarctica is geologically somewhat recent as a feature, and this opening changed global circulation significantly. Our current ocean circulation is driven by winds, differences in density of different water masses that are governed by salinity content and temperature, and the edges of continents, which direct currents. This can hugely impact how heat is distributed globally. Continents over the poles also drive cooling cycles, in part because they impact global albedo. -changes in albedo -changes in atmospheric composition (movement of primarily CO2 and methane into and out of reservoirs, including plate tectonic processes and weathering as well as combustion of fossil fuels) -milankovitch cycles a. these cycles change amount of solar insolation received at high latitudes 1. eccentricity, tilt/obliquity, precession/wobble

What are the two different ways that we classify the outer layers in the Earth (crust/mantle versus lithosphere/asthenosphere)? How do crust and lithosphere differ?

-chemistry vs. strength a. memorize graph *** -crust is a chemical term; lithosphere is a mechanical term a. crust is part of lithosphere

What is mineral cleavage? How do cleavage and fracture relate to mineral structure?

-cleavage is what happens when you hit a mineral with a hammer a. cleavage: tendency of some minerals to break along flat, parallel surfaces (cleavage planes) that are weak planes within the crystal. -This produces flat, shiny surfaces: minerals are breaking along internal planes of weakness. a. Affected by types of bonds (ex.: weak inter-molecular bonds in muscovite allow it to cleave in sheets, galena will form perfect cubes infinitely, salt will make little cubes too) - Cleavage is described by the geometric shape formed: the number of planes and the angles between them (as well as how good they are-are they really shiny?) -Fracture is the tendency of a mineral to break along curved surfaces without a definite shape. These minerals do not have planes of weakness and break irregularly

What are some environmental consequences of using coal to generate power?

-coal is the largest single source of fuel for the generation of electricity world-wide a. major producer of electricity: 30% of US production -problems with coal use: a. Coal takes millions of years to form, non-renewable resource; b. Mining can result in major environmental damage; c. Coal combustion results in significant air pollution d. the consequences of using these diff fuel sources are.... 1. fossil fuel combustion: -The combustion of fossil fuels results in significant environmental problems, including urban air pollution, acid rain, and global warming. (from increasing levels of greenhouse gases within the atmosphere) -a. Combustion of fossil fuels by humans is the largest source of carbon dioxide emissions on Earth; -b. increased levels of greenhouse gases (such as carbon dioxide) in results in warming of Earth's atmosphere (global warming). 2. Air Pollutants: airborne particles and gases in concentrations that endanger the health of organisms and disrupt the orderly functioning of the environment. 3. health risks: Increased levels of air pollution are responsible for a variety of health risks, principally affecting the body's respiratory system and cardiovascular system. -a. Examples: Aggravated asthma, bronchitis, emphysema, lung and heart diseases; -b. Results: Increased medication use, increased doctor or emergency room visits, more hospital admissions. -acid rain: which causes increased acidity of soil and water, which can damage vegetation, chemical weathering increases

How do plate boundaries relate to hazards, like earthquakes and volcanoes?

-convergent boundaries: a. ocean/ocean: volcanoes, huge earthquakes b. continent/continent: mountain building, earthquakes c. ocean/continent: volcanoes/earthquakes -Divergent boundaries : volcanoes -transform boundaries/strike-slip: earthquakes ONLY

Given a description of the characteristics of a hypothetical boundary, be able to infer boundary type (i.e., if I tell you I am studying a boundary with linear offsets, no volcanoes and shallow earthquakes, you should be able to tell me that this sounds like a transform boundary).

-convergent boundary: 2 plates come together, makes the lithosphere shorter (we recycle old lithosphere (destructive) in subduction zones) a. you get a trench (where the plate gets stuck) & mountain ranges result as well b. as the plate subducts, it melts, which creates volcanoes c. causes earthquakes because of the slipping on the fault -ex: continent-continent: himalaysas a. ocean-ocean will show as islands b. ANDES MOUNTAINS -divergent boundary: a. mantle below it, has higher pressure...when the mantle comes up: you get VOLCANOES b. as it erupts, it cools at the ocean floor=creating new plates c. minor earthquakes; usually seen in the ocean /midalantic ocean -ex: african rift --> continent and divergent boundary - volcanism in the continent -transform: 2 plates sliding past eachother --> creates lots of earthquakes bc plates are getting caught a. ex: california is transform (san andreas fault)

How do we build 10,000 year old chronologies using tree rings if the oldest tree is only 5,000 years old?

-dendrochronology: the study of tree time a. the science that uses tree rings dated to their exact year of formation to analyze climate b.Why this works: seasonal variation drives variation in growth, which we recognize as tree rings. -We look at earlywood (bud to full leaf out, what is forming now) vs. latewood (after full leaf out, to dormancy), which forms at different times of growing season. Individual trees provide chronologies of their lives, and we can "stack" these to get longer records -we use cross dating to get exact years a. spacing btwn the rings is very specific, every year is a specific amount better or worse than the year before it --using cross reference from a tree that died in that area to get an extension of that area b. build back from the core

what kinds of deposits are associated with divergent margins?

-divergent plate boundary: these are our constructive boundaries (constructive plate margin) a. Seafloor spreading at ocean ridges: creation of new oceanic crust. -Submarine hydrothermal systems: smokers (associated deposits): here, these minerals (listed below) may precipitate out of cooling material) a. copper-lead-zinc-silver-gold b. also form in back-arc settings that are associated with convergent margins may also have associated ores forming by similar mechanisms.

During glaciations, would you expect the global oceans to be isotopically heavy, or light? Why? What about the shells of organisms that form in the oceans, assuming that these organisms passively record ocean composition?

-during glaciations, you would expect the global oceans to be isotopically heavy because 18O is left within the ocean; rather than 16O which is lighter. 16O is what composes our oceans and clouds and leaves larger amounts of 18O within our ocean systems -variation in isotope value reflects temperature and growth and decay of ice sheets -shells of organisms would also be isotopically heavy because they are reflecting the isotopes that the ocean has

What is fractional crystallization and how does it affect the rock that we might form? Relatedly, what is Bowen's reaction series?

-fractional crystallization changes melt composition a. when minerals crystallize, they leave the melt...thus, when we are talking about a melt, we are talking about liquid below ground ; we talk about how melt changes into a rock -as things cool, they crystallize into rock -In essence, fractional crystallization is the removal of early formed crystals from an originally homogeneous magma (for example, by gravity settling) so that these crystals are prevented from further reaction with the residual melt. The composition of the remaining melt becomes relatively depleted in some components and enriched in others, resulting in the precipitation of a sequence of different minerals

What is uniformitarianism, and why is it useful?

-geology tells us about the age of the earth and when/how things happened -james hutton (1785) coined this term: the present is the key to the past a. looking at modern processes allows us to interpret the geological past as preserved in the rock record b. we use uniformitarianism to infer history/understand the rock record c. we assume that how rocks form today is how they have worked in the past

How do we work out a glacial budget (what happens if we have more or less accumulation relative to loss)?

-glacial budget: = the balance (or lack of balance) between accumulation at the upper end of the glacier, and loss at the lower end. This determines the fate of the glacier a. Advance: = accumulation exceeds loss; b. Retreat: = loss exceeds accumulation; c. Balance: = accumulation roughly equivalent to loss (glacial front is stationary)

You should know the general impacts that we predict with climate warming (how warm Iowa will get, changes in precipitation and drought, changes in sea level). You should also know how this will impact living things, and what we predict/are already observing. Be able to recognize the specific examples from lecture today!

-global warming means that there will be more frequent severe weather a. dryer areas get dryer, wet areas get wetter -We don't attribute specific weather events to climate change. But... -1. Warmer SST=potential for more powerful hurricanes -2. 1°C increase = 15% decreased corn yields -3. 1°F increase = 4% more atmospheric water→ potential for more floods -4.increased severity and duration of droughts, and related loss of surface water and groundwater resources (like lake chad) a. Once the 6th largest lake in the world, Africa's Lake Chad is now 1/20th the size it was in 1960. -loss of ice at the poles (and more polar vortex) a. breaking up of petermann glacier: greenland -june 2010→ piece that broke off is 4 times larger than manhattan -sea level rises, both as a result of thermal expansion and due to the melting of glaciers. We have a lot of coastal cities that are vulnerable to this, and there are many places around the world that are already experiencing the impacts of sea level rise. -Iowa will raise 8-10 deg F if these rates continue -ask about other things to know/disease vectors?

What information about climate can we get from ice cores? What is the temporal resolution of this record?

-ice cores are another really precise proxy (especially for CO2) -oxygen isotopes: temperature when snow fell a. These have annual resolution. !!! 1. These can tell us about shifts in atmospheric composition, and also let us know whether we're going outside the recent range of variability. -How we check ages: count back from the surface (like varves and tree rings), model with computers, cross correlate with other ice cores, and cross correlate with other similar temporal climate data.

Be able to identify positive vs. negative feedback cycles.

-in positive feedback cycles warming and cooling processes amplify each other and we get runaway warming/runaway cooling trends. -in negative feedback cycles, processes provide checks and balances on warming and cooling -ex 1: CO2 is added to the atmosphere through combustion, which increases the growth of forests. Increased plant biomass results in increased uptake of atmospheric CO2. a. this is a negative feedback cycle -ex 2: Ice caps have started to form at the poles, increasing the Earth's albedo and leading to the direct reflection of more incoming solar radiation back into space without it being absorbed and re-radiated. a. this is a: positive feedback cycle -***key: anything that gets worse and worse /runs away is a positive cycle a. negative: if there are more clouds in the atmosphere, it bounces energy into atmosphere and to the earth --cooling the earth and setting a balance

What is an isotope, and what is a stable isotope?

-isotopes: atoms with the same number of protons but a diff number of neutrons -Stable isotopes do not decay: they do not change. They therefore preserve environmental signatures recorded at the time that they get incorporated into material, like shells and ice sheets

What factors impact local climate variation (local climate drivers in notes)?

-latitude (determines incoming solar insolation) a. (solar energy received in W/m2) -proximity to large bodies of water a. this stabilizes climate, and warm currents can heat high latitudes. - elevation: we lose 5.4° F (if air is dry) for every thousand feet that we gain! This is because air is a poor conductor, and as we go up in altitude particles are farther apart under decreased pressure. a. pressure decreases with increasing elevation/altitude : air loses heat b. why: air is not a good conductor c. higher altitudes: particles are farther apart -topography (think about rain shadows here) a. windward vs. leeward sides b. windward: gets precipitation, where winds come off of water c. leeward: where cold, dry air descends. Deserts form here

How does climate differ from weather?

-main difference in time -Weather: minutes‐to months changes in the atmosphere -Climate is: "...the description of the long term pattern of weather in a particular area. " a. Temperature, precipitation, humidity, sunshine, wind velocity, etc. b. climate occurs at both a local and a global level

How do oceanic and continental crust differ from each other?

-oceanic: a. DENSE (3.2 g/cm3) b. Thinner (7-10km) c. Rocks: basalt, gabbrod. The older, the colder (& denser) -continental crust a. less dense (2.7 g/cm3) b. thicker (25-70km) c. rocks: granite, rhyolite -both types of crust can be present on the same tectonic plate

what are the two different kinds of crusts?

-oceanic: a. mafic (ferromagnesium minerals, lower silica content) b. dense (3.0 g/cm3) c. thinner (7-10km) -continental: a. felsic (non-ferromagnesium minerals, higher silica content) b. less dense (2.7 g/cm3) c. thicker (25-70km) -With the less dense continental crust too buoyant to subduct at convergent boundaries, and the oceanic crust often subducting to great depths in the mantle, where it may produce melt and generate volcanoes way above it on the surface.

How do earthquakes relate to plate boundaries?

-our plate boundaries are outlined by earthquakes a. interactions at plate boundaries control the distribution of many of the hazards that we worry about no the Earth's surface

What is "peak production", in terms of petroleum? When do we think peak oil might happen? What is the Hubbert Curve, and what does it show?

-peak production: the maximum extraction point of oil, then we get less and less every year a. we may be headed towards peak production in the next few decades -the hubbert curve (1956): shows that global oil production has, or likely soon peak a. illustrates the idea that oil is a nonrenewable resource b. shows that we keep pushing the curve further into the future, as technology advances; so there is always going to be more oil to get out of the system -The extraction of oil can have disastrous ecological and human impacts if done incorrectly.

How do tectonic processes facilitate the formation of economically valuable mineral deposits?

-plate tectonics explains a lot of geology, including where we find minerals. Tectonic processes facilitate the movement of elements in the mantle and crust via fluids and heat. a. to form an ore deposit, collect element, transport to one place, deposit it. b. For example, In forearc basins in front of convergent margins, we find lead, zinc, and copper. In magmatic arcs, we find copper in intrusives, vein deposits of lead, gold, silver, molybdenum, zinc, tin and tungsten, and chromium, copper, zinc and lead in ophiolites -Divergent & convergent plate boundaries a. Most important for mineral deposits: major cause of magmatism which drives most fluid flow

What is a poililotherm, and what happens to poikilotherms when temperatures go up?

-poikilotherms are any organisms that cannot regulate its body temperature except by behavioral means such as basking or burrowing...SNAKES -Snakes are poikilotherms: a.body temperature is dependent on ambient temperature....and size is dependent on this, too -Hot Earth=big snakes (I think this is one of the better reasons to try to curb global warming).--> they grow when temperatures go up

What is a protolith, and why does it matter in metamorphic rock formation?

-protolith: the parent rock a. Most metamorphic rocks are overall similar in chemical composition to the parent rocks from which they formed. They can both lose and gain volatiles through metamorphic processes. -metamorphism= a. prolith (parent rock) + temperature and / or pressure and/or fluids = end rock - it matters because it determines the relative composition of the future rock that is formed through metamorphism --> thus, it will define the structure and composition

What types of boundaries are reverse vs. normal faults associated with? What do these two different kinds of faults look like? Be able to identify them in diagrams

-reverse faults: compression (like at convergent boundaries) a. the hanging wall moves up and over the other side (of the footwall) b. a thrust fault is a reverse fault that is at an incline of less than 45 degrees -normal faults: tensional boundaries (like at divergent boundaries)--> crust is being pulled apart a. the hanging wall moves down relative to the footwall ... so the footwall goes above the hanging wall

Given images of two leaf assemblages, be able to assess which group likely grew in a warmer climate.

-shape can be indicative of climate a. the smoothness or jaggedness of leaf margins can be a useful proxy for temperature. -trees raised further south have smoother margins, whereas trees raised to the north have more jagged margins. a. if you transplant seeds, they will develop smoother margins in warmer climates

You should be able to write a paragraph or two that relates viscosity and cooling speed to crystal lattices and intrusive vs. extrusive environments.

-temperature affects viscosity -Viscosity: how easy it is for atoms to move around a. Measure of resistance to flow b. (i.e., maple syrup is viscous and flows slowly; orange juice is less viscous and flows more easily). Viscosity of magma and lava determines how hard it is for atoms to migrate and form bigger crystals. Hot rocks are less viscous than cold rocks (atoms have an easier time getting around). Wet rocks are less viscous than dry rocks. You can think of atoms as trying to build large crystal lattices - if viscosity stays low for longer, they get more of a chance to do this, which is reflected in the size of crystals in your rock. c. Hot rocks have a lower viscosity: they flow easier e. rocks with higher water content have a lower viscosity -from dry melting and wet melting, it takes a higher temp to melt dry crust/material f. maple syrup is both viscous and delicious at room temperature -viscosity matters bc its easy for atoms to migrate (less viscious) if it stays hot, harder for atoms to migrate if material cools very rapidly a. this controls crystal size - we can then use crystal size to infer where and how rocks formed

What do glaciers do to the underlying land? You should be able to explain why glacial rebound happens, and what this process is. Where is it currently happening in North America?

-the additional weight of continental glaciers causes subsidence; when it is removed, the land rebounds a. this means that the earth's crust rises as the ice sheets recede in the after math of deglaciation -parts of canada are still rising up to 5 mm/year -Glaciers are capable of great erosion and sediment transport. -Types of Glacial Erosion: a. Plucking: lifting of rocks by ice; b. Abrasion: rocks within ice act like sandpaper to smooth and polish surface below. -Products of glacial abrasion a. Glacial polish: polished bedrock surface; b. Glacial striations: grooves in the bedrock; c. Rock flour: finely pulverized rock, ground up by the glacier

What are our three Milankovitch cycles and what do they impact?

-the cycles change amount of solar insolation received at high latitudes -1. Eccentricity: how elliptical is Earth's orbit? -2. Tilt/obliquity (tilt of Earth's axis varies from about 22-24.5 degrees) -3. Precession/wobble: change in orientation of Earth's axis (it spins like a top) -When looking at our current climate, we need to be able to compare it to past changes and see whether or not it is in line with these natural cycles and forcings. a. Is our current climate in line with prior cycles? 1. if it is, we are all good that means milankovitch is doing its job 2. if not, we might want to start worrying 1. how we assess this: geologic climate records

You should be familiar with the major and most important greenhouse gases

-the greenhouse gases: a. 1. Water vapor (major greenhouse gas! But not hugely variable in terms of how much there is through time) b. 2. Carbon dioxide (CO2)-a major player in terms of climate change, since over geologic time scales huge amounts move in and out of reservoirs c. 3. Methane (CH4)-20 times more powerful, molecule for molecule, than carbon dioxide at driving warming d. 4. Nitrous oxide (NO2) e. 5. Fluorinated gases -Greenhouse gases that cause warming to the Earth exist mainly in the troposphere: the closest layer to the Earth

What is the Zachos curve, and how far back in time does it extend?

-the zachos curve is a compilation of Cenozoic oceanic oxygen and carbon isotopic data a.derived from different proxies/animals/snails/any indirect -a record of the last ~65 million years of climate change. This is an important and relatively high precision record of climate change that lets us investigate not only the magnitude and rate of past changes, but also impacts on the flora and fauna. a. used to calculate ice volume and global temperature -- gives us a great view of isotopic trends (a lot of stable isotope work)

Can a dog predict an earthquake? Can we make an earthquake???

-there are reports of weird animal behavior before earthquakes; however, animals always act weird. -Right now we don't have a mechanism for why animals could predict them. They can, however, likely sense the arrival of P waves which we cannot feel.

When we study ice cores, what are scientists analyzing (what are they looking at specifically within the ice)?

-they are looking for CO2 (carbon dioxide) and methane concentration from within the ice (by looking at the bubbles)

how can glaciers impact drainage systems?

-they modify drainage systems because they can completely change it -they rework it

What are our two types of weathering processes? Can they occur at the same time?

-weathering can produce useful deposits a. Mechanical weathering: (disintegration) breaks rocks into smaller pieces without changing their chemical composition. b. Chemical weathering: (decomposition) chemical reactions between rock minerals and air + water: -1. form new minerals. -2. release ions into solution -both types of weathering processes can operate simultaneously

How does magma silica content relate to explosivity?

-when you get more silica, magma gets more sticky a. ex: Hawaii is like a maple syrup & mt. st. helens is like a peanut butter -all magma has gas tract in it -in Hawaii, if you put gas in the maple syrup it'll get out more likely a. but if you put gas in peanut butter, hard to escape, gets stuck underneath -if its more viscious, its more explosive bc higher visc. Means it cant flow -explosivity is influenced by: a. volatile content (how much gas is trapped in the magma?) b. temperature (colder=more viscous / sticky) c. chemical composition: how much silica in our magma ? 1. how felsic is our magma?

Did dinosaurs have feathers? What sounds did some of the Cretaceous (specifically, 66-68 MYA) birds make?

-yes, dinosaurs have feathers a. we use these preserved feathers to understand what color dinosaurs were 1. electronic site processes help us get readings that give us pigment references on their color -some of the cretaceous bird made duck sounding noises

What are our three different kinds of plate boundaries and How do we classify the layers of the Earth (two methods)?

1. Convergent boundary (plates collide) 2. Divergent (plates move apart) 3. Transform (plates slide past each other) -you can define earth's layers based on either chemistry (what theyre made of) or strength (are they squishy? are they brittle?) a. chemistry: crust: lighter silicates; mantle: ferromagnesium silicates, iron/nickel core b. strength (outer to inner): solid lithosphere (both the crust and some of mantle), ductile asthenosphere, solid lower mantle, liquid outer core, solid inner core