Geology Final

Pataasin ang iyong marka sa homework at exams ngayon gamit ang Quizwiz!

What are some of the benefits / drawbacks to using coal? How does the CO2 emission output of coal compare to that of oil and gas? (pp. 338-343; see also lecture notes, pp. 5-6).

-benefits: doesn't migrate bc it's a solid, occurs in well-defined beds, don't have to look in ancient rocks -drawbacks: not as versatile as oil/gas (e.g. can't fill up a car or plane w coal), it's dirty coal produces far more CO2 per unit energy than either oil or natural gas

What is the difference between source rock and reservoir rock? (p. 323)

-source: fine grained clastic sedimentary rocks -resorvoir: permeable, porous rock

What are some of the environmental impacts of coal mining? What is done with the waste product, ash? (pp. 340-341)

-underground fired in coal seams can run for decades -acid runoff can kill vegetation and pollute ground/surface waters it goes into landfills or containment ponds, dumping coal ash in the nearby river

What are some of the challenges involved in land reclamation once the mining operation is completed? (p. 343)

-water availability in dry areas -sometimes requires removal of entire mountaintop

What is the minimum estimated burial time needed to produce oil and gas to form? (p. 323)

1-2 million years

Of the nonmetallic metals, which are economically (or environmentally) significant? (pp. 298-299)

1. Sulfur is created as a by-product of mining sulfide minerals, and used by industry to create sulfuric acid 2. Halite, or salt, and gypsum

What is albedo? What substances have high albedo and why? How does albedo influence climate change? What are some examples of positive feedback and negative feedback regarding climate change? (what does positive & negative feedback mean?) (pp. 235-236).

Glaciers, being white in color, typically help reduce global warming levels by reflecting sunlight back into outer space..this reflectivity is called albedo. Glacial ice has a high albedo. As the Earth warms, glaciers retreat, and so their albedo potential decreases, and the Earth warms up slightly more quickly than if the glacier had been fully present. positive feedback cycle: the warming trend reinforces itself. The more glaciers retreat, the lower the albedo, the more quickly the Earth warms up. negative feedback: the warming induces changes that encourage the opposite. It is possible that as temperatures rise, large-scale storms will become more frequent, and the increased cloud coverage would potentially offset the albedo lost by retreating glacial activity, and help slow down the rate of global warming

What influences the temperature of the Earth?

Human activity, among other things. The Sun, and greenhouse gases as well.

Igneous rocks and magmatic deposits can produce large ore repositories under certain tectonic conditions. What might some of these conditions be? (pp. 292-294

Igneous Rocks and Magmatic Deposits: commonly found along plate boundaries (areas with extensive magmatic activity)

How far back do glacial ice-core records date? (p. 232)

The oldest ice-core records come from the Antarctic and date back 800,000 years. Modern CO2 levels are unprecedented in the history of modern humans.

What were the circumstances behind the Exxon Valdez and Deepwater Horizon incidents? What were some of the options used in the clean-up of the spills? (pp. 333-338)

a. -toxic to wildlife -cost both companies billions of dollars -11 killed in deepwater horizon incident b. skimmer ships, chemical dispersants, burning of oil slicks

What is a dune? How do they move? (pp. 211-212)

a. usually made of sand, but snow dunes are also possible. The orientation of the dunes reflects the prevailing wind direction (if there is one), which the shallower slope side facing upwind b. Dune Migration: if there is a strong enough prevailing wind direction, a dune can migrate: its particles get blown up the side of one shallower surface and slide down the steep slip face. As layer upon layer of sediment slides down the slip face, slanted crossbeds develop in the dune.

What is cap rock and how does it influence oil production? (p. 323)

cap rock- A layer of impermeable rock that stops gas and oil from escaping from a reservoir. a large quantity of oil / gas has been trapped by and concentrated in cap rocks

What was the intention behind creating the Strategic Petroleum Reserve? (pp. 327-328, Fig. 14.8)

concern about dependence on imported oil

How do the future prospects look for oil and gas? (pp. 330-331)

not good. preserves continue to decline with prices rising. some oil companies have been branching out into other energy sources to shift away from petroleum in the future

What are oil shales? Where is the major US resource located and what type of petroleum deposit is formed there? (p. 344)

oil shales- fine-grained sedimentary rock rich in solid organic material called kerogen -Eocene Green River Formation that runs through Colorado, Wyoming, and Utah -fish fossils

What is the difference between petroleum, oil, and natural gas? (pp. 322-323) What is the chemical make-up of natural gas? (lecture notes, p. 1)

petroleum: complex suite of chemical compounds including oil and natural gas associated with it oil: liquid petroleum, made up of a variety of liquid hydrocarbon compounds (molecules that consist primarily or entirely of the elements hydrogen and carbon) natural gas: petroleum in the gaseous phase, including the compound methane compound methane (CH4)

Why is sulfur content significant with regard to coal? What are "scrubbers?" (p. 340)

when sulfur is burned along with coal, a poisonous sulfur gas is produced called sulfur dioxide (SO2) Scrubbers: Systems that remove certain gases and particles from industrial exhaust.

How might energy be harnessed from the oceans? (p. 368)

1. Harness energy from the tides: at least a 5 meter (16') difference needed between high and low tide to be effective for generating electricity, in addition to a bay / inlet with a narrow opening that could be dammed to regulate the water flow in and out. Examples where tidal-power is used to generate electricity includes St. Malo, France and the Bay of Fundy in Nova Scotia. 2. Ocean thermal energy conversion (OTEC): still in the development stages, this approach takes advantage of temperature differences between warmer surface waters and cooler deeper waters. Presently being developed in tropical island locales, where such temperature differences are at their maximum, such as Hawaii 3. Harness energy from the waves: even the bobbing of water in a wave can be harnessed to generate electricity: the bobbing can push water through a turbine (albeit slowly). Currently in use off the coast of Portugal.

What are the two categories of surface mining? What are some of their environmental hazards? (pp. 312-313)

1. Open-pit mining (and quarries): a. Extracts rock either intact (for building) or crushed (for making cement, roads, etc.). b. Practical when the ore is located near the surface. c. End product leaves a large hole, which may fill with water, which may then carry pollutants elsewhere d. Sulfide minerals in the open pit mine react with oxygen and water to form sulfuric acid as a weathering product, creating acid runoff water 2. Strip mining: a. commonly used to extract coal, but also limestone and other materials. b. practical when ore is near the surface and runs in layered seams (like layers of a cake). c. When mining operations are completed, the land is reclaimed and restored to habitable levels (in the past, however, before stricter laws were enacted, the waste rock and soil were simply dumped back on top as spoil banks, which then led to chemical and sediment pollution from spoil bank runoff).

What is the difference between a pedalfer soil and a pedocal soil? (pp. 273-274)

1. Pedalfer soils (more leached) a. reflect soils developed in more humid (wetter) regions. b. these soils are more leached, leaving behind more aluminum and iron minerals c. These soils are usually acidic. d. In North America, these soils are found in higher-rainfall areas: eastern US, NW US, most of Canada. 2. Pedocal soils: (less leached) a. reflect soils developed in drier regions (less rainfall). b. these soils are less leached, leaving behind more calcium carbonate minerals c. These soils are usually more alkaline (less acidic). d. In North America, these soils are found in the southwestern US.

What are some risks associated with spent fuel and nuclear waste handling? (p. 354)

1. Radioactive material remains radioactive: it cannot be broken down into non-radioactive components. 2. Lack of permanent long-term storage: all of the world's radioactive waste is in temporary - as opposed to permanent - storage. Decisions have not yet been made as to how to store radioactive waste long-term. In the US, much of the high-grade nuclear waste is stored at the reactor site. 3. Decommissioning: nuclear power plants built in the US in the 1970s have been in operation for 40+ years. Reactors are aging and the cost to take one out of operation, break it down, and deliver the most radioactive elements of the plant to radioactive-waste disposal sites takes years of work and can tally nearly $1 billion per plant. 28 US reactors have been retired since 2010.

Where are some geographic areas within North America whose landscapes have been influenced by glacial activity?

1. The Rocky Mountains (from the Midwest extending all the way to the west coast): many of its peaks and valleys were glacially carved. 2. The Great Lakes: the lakes occupy basins carved and deepened by glaciers and filled with glacial meltwater. 3. Canada's Hudson Bay is a depression formed by the weight of the ice sheets and flooded with seawater after the ice melted away. 4. The drainage of the Mississippi river in part was formed by meltwater from retreating ice sheets. The sediments carried along with that meltwater ("loess" see below) are in part responsible for the fertility of the Midwestern farmland, and supply the groundwater tapped today for irrigation.

What are some risks associated with fission nuclear reactors? (p. 351)

1.Core meltdown: this occurs when the flow of cooling water to the reactor core is interrupted. The core overheats and turns into a molten mass that melts its way out of the containment building and into the environment, releasing high levels of radiation.There are also issues as to where to situate a nuclear reactor. Below are some of the considerations: 1. Reactors needs a water source for cooling purposes: this necessitates placing reactors are near rivers or large bodies of water, which makes water pollution a potential concern. New York City, for example, has 2 active nuclear reactors just 30 miles upstream that have only recently been legislated to shut down due to their longevity. 2. The further away the reactor is from a city, the higher the transmission costs: putting a plant too close to a city could place the population at risk; while putting the plant too far away means a higher cost of transmitting the generated electricity. Recall that at least 1/3 of the electrical power transmitted is lost as heat. 3. Underlying geology: reactors should perhaps not be placed along fault lines, near flood zones, or regions subject to tsunamis; but several in the US and abroad lie near such regions.

What are some of the pros and cons of nuclear energy? (pp. 354-356)

About 100 commercial nuclear reactors in the US are currently in operation. Those nuclear power plants account for about 9% of the nation's energy needs. Though nuclear power plants are more costly to build and pose a significant environmental risk, their operating costs are lower than that of a coal-fired plant, and the amount of energy released from the fission of 2.2 lbs of uranium is equivalent to 35,000 lbs of coal. Nuclear energy's strongest appeal, however, is that it emits no CO2 emissions. When countries sign pacts to limit their greenhouse gas emissions, their primary two options to choose from are nuclear power and hydroelectric power (i.e., building a dam).

What is kimberlite? For what mineral is it known? (p. 294)

Diamonds also form in this method: one reason diamonds are so rare is that they are only created at very high pressures in the Earth's mantle, and then brought up rapidly into the crust. Diamonds are mined from an igneous rock called kimberlite, which forms large pipe-like intrusions that rise up from the mantle

How does wind influence upwelling along a coast, and what is its effect on local ecosystems? How does El Nino disrupt this system along the western shore of South America? (pp. 224-227)

As winds blow offshore, the warm surface water is pushed away from the coast, and the deeper, cooler waters upwells (rises up) toward the ocean surface. El Niño refers to a periodic halt in this upwelling, where the fertile cold waters no longer rise up along the western South American coasts. There is concern that a rise in global temperatures will cause El Niño events to occur with greater frequency.

By what process do glaciers move / slide? (p. 201)

Basal sliding (this type of movement does not occur in glaciers at the poles, it is too cold for water to form): the presence of liquid water or a wet slurry (also called meltwater) may appear beneath a glacier, reducing friction, allowing the glacier to glide along the equivalent of a wet cushion of water Plastic deformation: occurs at depths of 60 m (~200') in a glacier, ice grains change shape very slowly as the glacier moves, and/or new grains grow while old ones disappear. Above this, ice is too brittle to flow, and instead moves by cracking: the cracks are called crevasses.

What is the difference between physical and chemical weathering? (p. 268)

Chemical weathering: breakdown of minerals either 1. by chemical reaction with water, or 2. with other chemicals dissolved in the water, or 3. with gases in the air Mechanical weathering: aka physical weathering: anything that breaks up a rock without altering its composition; e.g. ice, wind, water. This type of weathering breaks larger chunks of rock into smaller ones, increasing the exposed surface area. Mechanical weathering breaks up the rock without changing its composition.

How does mining contribute to pollution? What is the environmental concern regarding smelting? (p. 315)

Current technology, however, uses the process of smelting, which extracts the metal by using heat. The downside of smelting is that it produces sulfuric acid as a waste product gas, contributing to acid rain

What is fission? What isotope of what element is used in the production of nuclear energy? (p. 349)

Fission involves the splitting of a atom's nucleus into smaller ones. This releases energy. fission is the only commercially feasible process. In fission, the nucleus of most interest in modern nuclear power reactors is the isotope uranium-235, with 92 protons and 143 neutron

What are some ways that future mineral-resource shortages might be averted... or ways in which the projected lifetime of reserves could be extended? (pp. 299-306, 310-312)

For some materials, e.g. aluminum, platinum, gypsum, reserves are expected to last for nearly a century if not more. For many others, however, the reserves are estimated to be good for only ~20 years: e.g., lead, chromium, gold, and silver. As reserves supplies decrease, prices tend to rise, leading to the opening of new mines or extraction technologies that may not have been practical to use when the prices to extract were too costly. This will further redefine what is termed a "reserve" and bump the numbers back up. Alternately, more materials may be recycled, or lower-grade ores may be tapped for extraction. The easiest way to keep reserve levels healthy would be to reduce consumption rates.

What are banded iron deposits and why are they a valuable economic resource? (pp. 295-296)

Iron ore deposits comes primarily from some of the world's oldest known sedimentary rocks: banded iron formations. These ancient deposits (3-4 billion years in age) consist of alternating layers of sedimentary rock and iron oxides (magnetite, Fe3O4, or its cousin hematite Fe2O3). They initially formed in the sea, but are now found and mined above ground, and their range may stretch for 10s of kilometers. In the US, these deposits are found around Michigan and the Great Lakes. They were responsible for fueling the rise of the iron industry in cities like Pittsburg, PA and Baltimore, MD.

Who was Charles Keeling and what was his contribution to the study of climate change? Why are there fluctuations in the curve over the course of a single year? (p. 220, see also class notes and: https://www.acs.org/content/acs/en/education/whatischemistry/landmarks/keeling-curve.html

Modern C02 levels were first measured in 1958, by Ralph Keeling, of Scripps Institution of Oceanography, in California, and its levels then were 310 ppm (or 0.031%). Current atmospheric CO2 levels are at 410 ppm. Fluctuations are a result differing levels of photosynthesis based on the season.

What is loam? (p. 272)

Loam: refers to a soil that has a roughly equal mix of sand, silt, and clay.

Are minerals renewable resources?

No- minerals are nonrenewable resources

What are the US's predominant mineral resources (and are they metal-based?)? Of the metal-based minerals, which is our most abundant ore? (p. 292 and Fig. 13.2)

Note that our primary mineral resources are not metals such as gold and silver (of which the global industry mines 10,000 tons or less). Rather, they are more mundane items such as salt , magnesium, and potassium: of which we consume over one billion tons per year. Iron

What is the greenhouse effect? (p. 220)

Part of the reason is due to the presence of gases in our atmosphere that insulate the Earth like a blanket, trapping the longwave radiation emanating out from the Earth's surface. This is called the greenhouse effect and is a natural phenomenon that has been occurring for millions of years on Earth (and other planets); and without this effect, the Earth would effectively be, on average, ~40°C cooler. I.e., cold!

What are placer deposits? What type of ore deposits are they known for, and in what kind of depositional environment do they form? (p. 296)

Placer deposits are formed by flowing water, e.g. streams or along coasts. As the water velocity slows down, e.g. at a point bar in a stream, minerals may, over time, settle out and accumulate in these regions. The California gold rush of 1849 began when someone discovered a placer deposit of gold draining from the Sierra Nevada mountains.

What is the difference between a mineral reserve and a mineral resource? (p. 291)

Resources: any useful economic commodity, one that also changes with time or context (i.e., some cultures place little importance on materials that may be valuable to others). Reserves: Portion of a resource that has been discovered and currently available to be extracted

Approximately by how much have CO2 levels risen since the Industrial Revolution (mid-1800s)? (p. 220 & en.wikipedia.org/wiki/Greenhouse_gas - see Table: Current greenhouse gas concentrations") Approximately by how much has global surface temperature risen since the Industrial Revolution? (p. 221)

Since the onset of the Industrial Revolution in the late-1700s, CO2 levels have steadily been rising in our atmosphere, upwards of 40%, and its levels continue to rise. Since the mid-1800s, the Earth's surface temperature has risen ~ 0.85°C (1.5°F). This may not sound like very much, but as we shall see that small rise in temperature is having a dramatic impact around the world. The Paris Climate Accord, drafted in 2015, is trying to limit global temperatures from rising any higher than 2°C

What is the difference between an alpine and continental glacier? Which are more numerous today? Where are continental glaciers found today? (p. 200)

The 70,000 - 200,000 glaciers known today fall into one of two categories: 1. Alpine: numerous today, also called mountain or valley glaciers. 2. Continental: larger, rarer these days, aka ice caps or ice sheets. Continental glaciers can span entire continents and reach thicknesses of greater than one kilometer. In the present day, the two main continental glaciers are the Greenland and the Antarctic ice sheets (the latter is larger than the continental US). During the Pleistocene Ice Ages, much of the northern hemisphere was covered in glaciers.

What are the two most heavily consumed metals used in the US? From where are they mined? (p. 298)

The greatest metal mineral resource consumed in the US are: 1. iron, used for steel products 2. aluminum, mined from bauxite (see above), used in canning and construction industries. Close to 5% of the electricity consumed in the US is used in the production of aluminum metal from aluminum ore. Australia, Africa, South America and the Caribbean.

How does rising CO2 in the atmosphere affect ocean acidity levels? What implications does this have for limestone reefs (recall what concentrated acids do to limestone) and photosynthetic marine microorganisms? (p.229)

The oceans are capable of absorbing excess CO2 and thus help slow the rate of global warming. But as CO2 levels build up in the oceans, the oceans become more acidic. Carbonic acid and H+ both lower pH levels, making solutions (such as ocean water) more acidic. Increased acidity levels weakens or outright dissolves the limestone shells of marine invertebrates such as coral and phytoplankton, species that forms the base for entire ecosystems.

How do the oceans play a role in climate change and global warming? (i.e., how are they effective as reservoirs and for what materials / states of matter?) (p. 223)

The oceans store and transport a tremendous amount of heat around the globe. Much of the heat currently absorbed by the Earth is stored in its oceans. The increased heat supplies energy to spawn hurricanes of greater intensity.

What is the relationship between snow, firn, and ice? (pp.199-200)

The transformation of snow to glacier ice is slow: the process can take decades or thousands of years(depending on the rate of snowfall). Initially, loose snow is 90% air. As more snow is deposited on top of it, the snow becomes denser, more compacted, and turns into firn (25% air); and eventually compacts further to form glacial ice (20% air). Glacial ice consists of interlocking ice crystals. Eventually, if there is a slope, the mass of ice moves, forming a glacier.

How do greenhouse gases contribute to global warming?

These gases trap heat and warm the lower atmosphere, similar to the effect of the trapping of solar heat by a greenhouse.

How are 18O / 16O levels used as a proxy for measuring ancient climates? Why are they found in ice cores, and how do their levels change with global warming and cooling trends? (pp. 231-235, pp.3-4 lecture handout)

To summarize, the O18 / O16 ratio would be larger during ice ages because ocean water would be enriched in O18 and O16 would be trapped in ice caps

What is the difference between how a U-shaped vs a V-shaped valley formed? (p. 202)

U-Shaped valley: carved by an alpha glacier V-Shaped valley: Carved by a stream - glacial erosion modifies valleys from V-shaped to U-shaped

In general, what happens in a nuclear fission chain reaction? (p. 349)

Uranium-235 is induced to undergo fission by firing a free neutron into the nucleus of one U-235 atom. When the neutron strikes the U-235 nucleus, the uranium nucleus splits into two smaller nuclei and produces subatomic particles, free neutrons, and heat. Each released neutron then strikes another U-235 atom, releasing more neutrons, beginning a nuclear chain reaction.Fission-powered nuclear reactors rely on controlled chain reactions for their energy supply. The energy released heats cooling water that circulates through the reactor's core. That heat is converted into steam, which runs turbines to produce electricity.

How is plutonium-239 created? What is its role in a nuclear reaction? (p. 350)

When an atom of uranium 239 absorbs a neutron, it is converted into plutonium 239. It's role is spent fuel can be reprocessed to extract this plutonium, which could be purified into fuel for future reactors.

How is wind energy generated? What are some of its benefits and limitations? (p. 369-372)

Wind Energy is energy captured from moving air. Wind spins the rotor blades of a turbine which runs the generator which generates electricity. ... This is because wind is created by the uneven temperatures of the Earth's surface. Benefits-Wind power is, like solar, renewable, but like solar it is also variable. A benefit is that as wind speed increases, power output increases to the cube. So if wind speed doubles, power output goes by a factor of 8 (23). In 2010, wind-powered electric generating facilities in the US accounted for less than 3% of actual electricity generation. However, wind-power capacity has been rising sharply in the US since 2000 and some hope that wind-power can supply 20% of our energy supply by 2030. Limitations-Again, in the US, the windiest spots in the country are unfortunately far removed from the areas that could make the best use of the wind-generated electricity. We are strongly limited by inefficiencies of long-distance electrical transmission. Another limiting factor is that strong winds do not always blow. As with solar, no effective way exists yet to store the electricity generated for later use. So despite the prevalence of wind on our planet, we have yet to find an effective way to harness it. About 1,000 wind generators (wind turbines) are required to generate as much power as an equivalent coal or nuclear-powered electric generating plant. There is also strong interest in constructing wind turbines offshore. Not only would the wind supply be plentiful, but transmission costs would be minimized for turbines that bordered coastal cities.

What is coal-bed methane? (p. 329)

a form of natural gas associated with coal deposits

What are the three primary soil horizons and how do they differ? What does it mean to say that a soil is leached? (pp. 271-272)

a. The A horizon: has three subdivisions: O, A, and E -1. The "O" in O horizon stands for "organic layer" and consists of organic matter, or humus. -2. The O and A horizon together make up topsoil, the fertile portion of soil that farmers till for planting crops. -3. Below the A horizon is the E horizon. The O, A, and E horizon form the zone of leaching because rainwater percolates through this initial layer, dissolves soluble minerals, and carries them away. The B horizon lies in the zone of accumulation. The B horizon is called the subsoil, where ions, clay minerals, and iron oxides accumulate. Organic matter from the surface is largely absent from this layer. The C horizon consists of material from the underlying bedrock that has undergone some weathering. It consistsmostly of broken-up bedrock. b. Leaching: removal of dissolved material from the soil by water percolating downward

What is coal and how does it form? How does the chemical composition of coal differ from that of oil and gas; and how does the origin of coal differ from that of oil and gas? (p. 338)

a. -supplies about 21% of total US energy needs -half of US electric power generation -formed from the remains of land plants b. -coal: solid, carbon -oil: liquid, hydrocarbons -natural gas: gas, methane c. coal is formed from land-based plants in bogs and coastal swamps, while oil and gas are derived from tiny marine organisms, such as algae and phytoplankton

What are the main grades of coal and how are they defined? What is the estimated reserve supply of coal in the US? (p. 338-339)

a. 0. peat 1. lignite 2. subbituminous 3. bituminous 4. anthracite b. classified based on carbon content, sulfur content, and combustion values (calories) c. ~1 trillion tons ; -total resources ~ 10 trillion tons

What are some of the environmental conditions needed to create fossil fuels? Under what temperatures do fossils fuels ideally form? (pp. 322-323)

a. 1. large supply of organic matter 2. rapid burial, to protect it from being broken down by oxygen in the atmosphere b. hot temperatures

How many gallons are in a barrel of oil? Roughly, what is the number of global oil reserves? Roughly, what is the number of proven US reserves? About how long would they be expected to last if no new reserves were found? (p. 323-324)

a. 42 gallons b. ~1.26 trillion barrels c. 22 billion barrels d. 53.3 years

How many billions of barrels of oil does the US consume per year, and how much overall energy does it supply to our total needs? About how much oil (%) do we import, and what are the primary countries from whom we import oil? (p. 325, lecture notes, p. 2)

a. 7 billion barrels b. to supply 37% of its energy needs c. 20% d. half from Canada, Saudi Arabia, Mexico, Venezuela, Iraq+

What are the major greenhouse gases? (for some reason, this is not defined in the text; see Lecture Handout, or find this on en.wikipedia.org/wiki/Greenhouse_gas) Of these, which are the most abundant greenhouse gases?

a. 78% nitrogen • 21% oxygen • 0.1% argon • and just 0.04% carbon dioxide (or 400 parts per million, or 400 ppm) b. C02 is one of several atmospheric greenhouse gases. Greenhouse gases trap infrared rays and promote the warming of the atmosphere.

Why are there deserts at 30° north and south latitude? What is a rain shadow and where / how do they form? (pp. 214-215)

a. Deserts are found at all latitudes: the largest are subtropical (at 30°N and 30°S of the Equator) but deserts can also be found at the poles. Most of the world's deserts are located near 30 degrees north latitude and 30 degrees south latitude, where the heated equatorial air begins to descend. The descending air is dense and begins to warm again, evaporating large amounts of water from the land surface. The resulting climate is very dry. b. As a result, one side of the mountain range is extremely wet, but the opposite side is dry, as the now-dry air forms a Rain shadows are formed by the Sierra Nevada mountains of California and the Cascade Range of the Pacific Northwest (Oregon, Washington)rain shadow.

What is the difference between a glacial and interglacial period? (see handout, p. 3) What is the relationship between climate change, glacial activity, and changes in global sea level?

a. Glacial Period: when temperature are under the overall average which causes ice sheets to extend their range Interglacial Period: time between when glaciers retreat and advance b. When glaciers begin to melt, global sea level rises

What is a glacier? What conditions are needed for one to form? (p. 199)

a. Glaciers: masses of ice that move under their own weight, under the force of gravity. Glaciers can take several centuries to form (and melt), and are typically form at high latitudes b. For glaciers to form, the following conditions must be met: 1. Precipitation: glaciers, after all, are reservoirs of frozen water. 2. A higher rate of snowfall than melt each year. This allows the glacier to grow over time. 3. Mountains: most glaciers begin in the mountains as snow patches that survive the summer. This is favored on north-facing slopes. 4. Gentle slope: if the slope is > 30°, avalanches may form, clearing the glacier away.

What is a lateritic soil? In what regions are such soils founds? What are such soils not advantageous for longterm farming? (pp. 274-275)

a. Lateritic Soil: heavily leached, very oxidized (hence red in color), an extreme pedalfer b. common in rainforests: laterite soils develop in tropical climates with high temperatures and heavy rainfall c. rainforests are lush: so the soil should be organic rich and good for farming right? No, for two reasons: a. soil is highly leached: few soluble nutrients left in it. If the forest is cleared for planting crops, the soil is so nutrient poor that extensive fertilizers are needed (which are not always affordable in developing countries). b. when laterite soil is exposed to sunlight (e.g., the forest is cleared for farming), the soil clumps up like a brick- it turns "hard" - resulting in poor irrigation (though good for building material)

How are hydrothermal deposits formed? What type of metals do they produce? What are black smokers? (pp. 294-295)

a. Magmas also contain water and other fluids that, because they are under pressure, can seep into the cracks of surrounding rocks. These fluids, often super-heated, can leach out minerals and ions from the rocks through which they pass. As the fluids cool, they deposit their minerals, forming a hydrothermal deposit. b. Sulfide, copper, galena, zinc c. Hydrothermal deposits are also a common feature of "black smoker" vents - undersea hydrothermal vents that spew metal rich sulfides onto the sea floor.

What is an ore? What is a concentration factor used for and how is it determined? (p. 292)

a. Ore: rock or metallic mineral that is economically worth mining (i.e., can be mined for a profit). b. Concentration factor: the concentration necessary for profitable mining, determined as a ratio: 𝑇ℎ𝑒 𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 𝑡ℎ𝑒 𝑚𝑒𝑡𝑎𝑙 𝑖𝑛 𝑡ℎ𝑒 𝑜𝑟𝑒 𝑑𝑒𝑝𝑜𝑠𝑖𝑡 / 𝑇ℎ𝑒 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 𝑡ℎ𝑒 𝑚𝑒𝑡𝑎𝑙 𝑖𝑛 𝑡ℎ𝑒 𝑐𝑟𝑢𝑠𝑡 = Concentration factor

What is permafrost and why is it of concern with regard to global warming? (pp. 222-223)

a. Permafrost: permanently frozen ground, seen in northern latitudes above 60°, underlying about 20% of the land area in the world. b. Changes in permafrost affects the distribution of surface water and groundwater.

Where is the biggest oil field in the US? What is the significance of the NPRA and the ANWR (and what do the acronyms stand for?), and what are some of the issues regarding to drill or not to drill in these areas? About how long does it take to develop a new oil field? How is oil transported from the Alaskan North Slope to the southern part of the state? (Case Study 14.1, pp. 326-327)

a. Peudhoe Bay field on North Slope of Alaska b. NPRA -National Petroleum Reserve-Alaska -west of Prudhoe Bay and exploratory drilling has confirmed the presence of both oil and natural gas ANWR -Arctic National Wildlife Refuge -east of Prudhoe Bay, making up the northeast corner of the state, and is thought to contain several billions gallons of oil c. -drilling costs -development of new oil fields is never quick d. 10 years e. Trans Alaskan pipeline

What is the difference between the rigid zone and the plastic zone of a glacier? At what depth is the boundary between the two zones? (see handout, pp. 1-2; textbook Fig. 9.5, p. 200)

a. The plastic zone is below the surface of the ice where pressure allows the ice to flow (in a glacier, ice grains change shape very slowly as the glacier moves, and/or new grains grow while old ones disappear) The rigid zone is near the top of the glacier, the ice here is too brittle to flow so instead it moves by cracking (these cracks are called crevasses) b. 60 meters

What does peak oil production refer to? Do we run out of oil at that point? What is expected to happen to the price of oil after this occurs? Globally, around what year is peak production predicted to occur? When did it occur in the US? Who was M. King Hubbert? (pp. 324-325, Fig. 14.7 and lecture notes, p. 3)

a. The year in which the world or an individual oil-producing country reaches its highest level of production, with production declining thereafter. b. no c. go up d. 2020 e. 1970 f. He made several important contributions to geology, geophysics, and petroleum geology, most notably the Hubbert curve and Hubbert peak theory

What is thermohaline circulation? What does the phrase "ocean conveyor" refer to and how does it influence regional temperatures? (p. 224)

a. Thermohaline Circulation ("thermo" = heat, "haline" = salt; the roles of temperature and salinity in moving water around the globe. is a part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes. b. Ocean conveyor belt: global circulation of ocean waters contributes to the change. The Gulf Stream (not to be confused with the Jet Stream, a wind current) is part of this larger belt, whereby warm surface water is transported east and north to Greenland, where it cools from contact with cold Canadian air. As the water cools, it increases in density and sinks to the bottom (a process called downwelling), then flows south and east to the Pacific, where it warms up again and upwelling occurs. The heat released to the atmosphere from the Gulf Stream helps keep Northern Europe at least 10°F warmer than it would be if this thermohaline circulation pattern was not present.

What defines a desert? What are some ways in which deserts form naturally? What is desertification and why is it a cause of environmental concern? (pp. 214, 216)

a. a barren area of landscape where little precipitation occurs and consequently living conditions are hostile for plant and animal life b. 1. High surface temperatures. The sinking cool air at 30°N and 30°S of the Equator results in desert environments due to the cooler air warming as it reaches the surface, taking with it much of the moisture, causing rapid evaporation. 2. Topography. Mountains ranges that lie in the path of air currents may push the air in higher altitudes as the air rises over the range, causing the air to cool and for it to lose its moisture (which precipitates out as rain). As a result, one side of the mountain range is extremely wet, but the opposite side is dry, as the now-dry air forms a rain shadow. Rain shadows are formed by the Sierra Nevada mountains of California and the Cascade Range of the Pacific Northwest (Oregon, Washington). Elsewhere, the Tibetan plateau creates a rain shadow as air rises up over the Himalaya mountains, as do the Andes Mountains in South America (e.g. Atacama Desert in Chile). c. Desertification: the rapid development of deserts (or expansion of existing deserts) caused by the impact of human activities, usually as a consequence of land-use practices. E.g. Dust Bowl of the 1930s in the US Midwest as a result of decades of misguided farming practices that caused the topsoil to erode away. Removing native vegetation and replacing them with crops leaves the land vulnerable to degradation during drier conditions (the native plants would be better adapted to dry conditions); similar results with raising livestock. Desertification reduces the amount of arable land on which the world depends for food.

What are oil sands (also called "tar sands")? What is the name of the petroleum product that they produce? What country possesses most of the world's oil sand reserves and where is it located? (pp. 328-329)

a. oil sands (tar sands)- sedimentary rocks that contain a thick, semisolid, tar-like petroleum called bitumen b. bitumen c. Canada

What are some examples of fossil fuels? Why are they called fossil fuels? What two elements are fossil fuels predominantly composed of? What percentage (%) of our nation's energy supply comes from fossil fuels versus, say, hydropower / nuclear power? Are fossil fuels renewable?

a. oil, natural gas, coal, fuels derived from oil shale and tar sand b. because they formed from the remains of once living organisms c. oil and natural gas d. 83% e. no

In what type of geological environments does oil get trapped? Which of these reflects the vast oil reserves found in Saudi Arabia? (p. 323 and see slides)

a. permeable sandstone b. permeable reservoir rocks

What are Milankovitch cycles and, in general, how are they thought to contribute to Ice Ages? (p. 209)

a. the Milankovitch cycles look at the change in shape of the Earth's orbit, tilt, and wobble in the axis over time b. they account for the ice advances and retreats over time but it is less clear that they can account for the initiation of an ice age

How does a glacier form? What is the difference between the zone of ablation and the zone of accumulation? (pp. 200-201)

a. the amount of snow fall exceeds the amount of melting every year. b. Zone of Accumulation: The part of a glacial system where snow and ice are accumulating faster than they are melting away. This is when snow adds ice to a glacier Zone of Ablation: Removal of ice

Why are biofuels called unfossil fuels? What is the difference between waste-derived and alcohol-derived fuels? What crop is used to create ethanol? What are some benefits and drawbacks to relying on ethanol as an alternative fuel source? (pp. 373-375)

biofuels uses the remains (or biomass) of dead organisms to produce energy. Indirectly, since these organisms need sunlight to grow, biofuels can be considered a type of solar energy. They are also considered "unfossil fuels" because they are created from recently dead organisms, as opposed to long-fossilized ones. Waste-Derived Fuels There is increasing interest in burning waste plant materials - either crop waste or urban refuse to provide heat for electric generating plants. Some waste-derived fuels are liquids, or research is ongoing to derive liquid fuels from animal waste, such as manure, which is rich in organic matter. Fuels can be derived from vegetable oil or animal fats to run diesel- powered engines. Another waste-derived biomass fuel growing in use is "gas from garbage," or biogas. Landfills and manure piles can contain large amounts of trapped methane gas (CH4) that develop when organic waste breaks down. Alcohol Fuels Most gasoline contains about 10% ethanol, an alcohol produced from domestically-grown corn. The reason for the mix is that the more alcohol can be used, the further the gas supply can be stretched, lessening our reliance on imported fuels. This method became popular in the 1970s as gasoline prices began to increase. The concern about ethanol as a fuel source is that it can take more energy to grow and harvest the corn than is released from burning the ethanol. A further concern is that food is being grown for use other than to feed those who might otherwise need it, and has led to pressure to grow crops on land that might be normally unsuitable or unsustainable for short or long-term use. These reasons, among other, are in part why researchers are trying to produce ethanol from waste organic matter instead of from living crops

Be able to define the following terms: cirque, arête, horn, glacial striations, glacial till, lateral moraine, middle (or medial) moraine, terminal moraine (pp. 203-205)

cirque: bowl-shaped depression that develops on the side of the mountain at the head of a glacier arête: knife-edge ridge of rock that separates two adjacent cirques horn: pointed mountain peak surrounded by at least three cirques (e.g. Matterhorn in Switzerland) glacial striations: Glacial activity often leaves grooves / scratches in rocks called glacial striations that form parallel to the flow direction of the glacier. glacial till: sediment transported by ice and deposited beneath, at the side, or at the toe of a glacier. The sediment is usually poorly sorted compared to stream-deposited sediment: glacial ice can carry clasts of all sizes. When till mixes with meltwater, the result is called outwash. Till and outwash are two types of glacial drift. lateral moraine & middle (or medial) moraine: the side edge of the glacier. Where two valley glaciers merge, the debris in the two lateral moraines merge to become a medial moraine, which is often seen as a stripe running down the composite glacier. terminal moraine: The debris deposited by the furthest extent of glacial ice is called the terminal moraine.

What is shale gas, and how is it typically mined? What are some of its environmental impacts? (pp. 329-330)

fine sediments that are later lithified to become shale are rich in organic matter. over time, heat and pressure may break this down into natural gas -can cause groundwater pollution through fracking (technology to increase permeability by hydraulic fracturing) -minor induced seismicity related to disposal of waste fluids

What is the difference between primary, secondary, and enhanced recovery of oil and gas? (p. 331)

primary recovery of oil- recovery using no techniques secondary recovery of oil- water being pumped into the reservoir, filling empty pores and buoying up more oil to the well enhanced recovery of oil- methods beyond conventional secondary recovery

What are some environmental / health issues associated with underground mining operations? (p. 312

soil erosion, habitat destruction, acid runoff from mine tailings, air pollution from machinery and smelting. Mercury poisoning

What are spoil banks? What are tailings? What is heap-leaching? How do these potentially lead to a source of pollution? (pp. 313-315)

spoil bank = is a pile built of accumulated spoil - the overburden or other waste rock removed during coal and ore mining Mineral processing to extract a specific metal from an ore can also cause serious environmental problems. Processing involves crushing the ore. The waste materials from this process are called tailings. --> Weathering of the tailings may produce acid drainage, similar to spoil banks of strip mines, and leach out harmful elements such as uranium, mercury, cadmium, arsenic, etc. that contaminate ground waters. Heap-leaching = an industrial mining process to extract precious metals from ore via a series of chemical reactions that absorb specific minerals and then re-separates them after their division from other earth materials. Cyanide, a highly toxic compound, is used to extract gold from its ore and also when used to recover additional gold from old tailings (i.e. from deposits where most gold was already extracted, miners are trying to extract every last ounce), a process called "heap-leaching," whereby cyanide solutions percolate through the tailing piles to dissolve out the gold. Source of pollution because they chemicals can seep into the water supplies

How is hydroelectric power generated? What are some of its benefits and limitations? (pp. 365-367)

the power is generated from the energy of the flowing or falling water. Usually, this is generated by damming up a river and releasing the water slowly so that the energy generated is constant as opposed to seasonal. Hydropower is a clean energy source, and a further benefit is that the water used is not consumed - it is just "passing through" and then returns to its source. Limitations on Hydropower Development 1. Loss of ecological habitats, both upstream (which gets flooded by the dam) and downstream (which loses its water source, sediment supply and reduction in periodic floods). 2. Silting up of reservoirs: because only water passes through the dam, the regions downstream lose their sediment supply, which leads to erosion of the downstream sedimentary structures (deltas, beaches, etc.); while the region above the dam accumulates an excess sediment supply, which can choke up the streambed. 3. Dam failure: there are over 1,000 dams in the US (not all for hydropower) and invariably some fail, either due to poor construction or underlying geology

What are evaporate deposits? In general, how do they form, and what type of ore deposits do they leave behind? (p. 296)

vaporite deposits: salt deposits that form when a body of shallow seawater gets "trapped" (cannot connect back out to the ocean) and dries up: the water evaporates and a layer of salt is left behind. Gypsum, a mineral used in plaster, drywall, fertilizer, and chalk, is another common evaporite-mined mineral Halite is the mineral salt, which is mined from evaporite deposits


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