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170 Cards in this Set
- Front
- Back
What are our five sources of energy? |
--the Sun --Gravity --Chemical reactions (including fossil fuels) --Nuclear fission --Earth’s internal heat |
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anoxic water |
sea water, fresh water, or groundwater that is depleted of dissolved oxygen |
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What causes fossil fuels to work as a source of energy? |
a chemical reaction: chemical bonds in fossil fuels store energy that is released when it's burned |
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Fossil fuels |
carbon-rich materials formed in the geologic past from the decomposition of buried dead organisms under anoxic conditions |
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Oil and gas consist of hydrocarbons of varying _________ _________ |
chain length |
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What are the three different forms of petroleum? What determines the form they take? |
-- gas, liquid, and solid -- form related to the number of Carbon atoms that make up the hydrocarbon |
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A known supply of oil or gas is called a ___________ ______________
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Hydrocarbon reserve |
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Where do hydrocarbon reserves originate and get stored? |
Underground |
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Source of fossil fuels (oil and gas) |
1) Dead photosynthetic organisms sink and get buried with sediment at the bottom of the ocean,
2) the organic material is preserved under anoxic conditions
3) Mud + organics are lithified under burial and compaction to form black shale (petroleum source rock)
6) The shale is heated as it’s buried at depth
7) Heating breaks organics down into waxy kerogen
8) Kerogen breaks down to form oil and gas as it continues to be buried and heated |
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Oil window |
Temperature range in which kerogen becomes oil. |
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Gas window |
Temperature range in which kerogen becomes natural gas. |
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__________________ organisms live in the shallow part of oceans where they can grow and store the energy of the sun in their chemical bonds. |
Photosynthetic |
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Oil shales |
Kerogen-rich source rocks that have not been in the oil window. Heating transforms the kerogen into liquid hydrocarbon (shale oil) that is different from petroleum. |
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Kerogen |
fossilized waxy molecules that are formed from heating the organic materials in shale. yields petroleum products on distillation |
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Specifically which two photosynthetic organisms eventually form oil and gas? |
Phytoplankton and algae |
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The largest oil reserves formed during the late _________, causing __________ supergrowth |
Mesozoic; phytoplankton |
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How do we access tar sands? |
Mining |
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Tar sands |
deposits of residual petroleum in loose sand or partially-consolidated sandstone. Contains mixture of sand, clay, and water, saturated with tar |
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tar |
a dense and extremely viscous form of petroleum |
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About how much tar sand is required to produce one barrel of oil? |
about two tons |
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How are tar sands processed? |
After mining, they are transported to an extraction plant, where a hot water process separates the tar from sand, water, and minerals |
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What formation contains the largest oil shale deposit in the world? From where does its organic matter come? |
The Green River Formation; blue-green algae |
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Natural gas |
short chain hydrocarbons (C1 – C4) which float on top of oil in a reservoir. More abundant than oil and a “cleaner” fuel, but requires expensive high-pressure (dangerous) pipelines |
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Four types of natural gas |
1) Methane, 2) ethane, 3) propane, 4) butane |
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Hydraulic fracturing |
after a well is drilled, a high pressure mixture of water, chemicals, sand is used to blast fractures & hold them open so gas can escape up the well |
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The Marcellus Shale |
a "juicy" (presence of abundant fluids) sedimentary rock formation deposited over 350 million years ago in a shallowinland sea. Contains large quantities of natural gas. located on what is now considered the eastern United States. |
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Coal |
Black, carbonaceous sedimentary rock formed from the remains of organic matter in vegetation, mostly during the carboniferous. Only found in rocks younger than 350 Ma. |
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Coal formation process |
1) trees in wetlands and swamps grow and store energy harvested from the sun in their chemical bonds
2) Dead plants accumulate in shallow anoxic water
3) anoxic conditions prevent decomposition (preserving the energy stored in the chemical bonds).
4) Sea-level rises and falls and buries wetland deposits under sediments
5) compaction and decay turn plant debris into peat
6) peat is buried in a basin
7) Compaction during burial squeezes out water.
8) the heat at depth alters the plant material--- most Hydrogen, Nitrogen, and Sulfur content is expelled as gases, and Carbon content increases.
9) At 70% carbon, this solid material becomes coal. |
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Peat |
compacted and partially decayed vegetation accumulating beneath a swamp |
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Upon what is coal rank/classification based? |
Carbon content
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Carbon content of peat |
50% |
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Carbon content of lignite |
70% |
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Carbon conten of bituminous |
85% |
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Carbon content of anthracite |
95% |
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Carbon content of graphite |
100% |
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Coal mining type depends upon the depth of the _____ ______. Within 100m, coal is ______ mined. At greater depth, _____________ mining is required. |
coal seam; strip; underground |
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What caused Centralia, PA to become an abandoned town? |
An underground coal mine fire |
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What makes a good oil reserve? |
Being able to easily extract oil from rock using conventional methods of extraction. |
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Creation of an oil reserve depends on what four factors? |
1) A source rock – where the oil is made
2) A migration pathway – where the oil moves in the subsurface
3) A reservoir rock – where the oil is stored underground
4. A trap or seal (cap rock) – what traps the oil below ground |
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Source rock |
a rock containing the organic matter from which hydrocarbons eventually form; typically a black shale. |
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Migration pathway |
the route that oil and gas take as they move from a source rock to a reservoir rock. Oil migrates away from the source rock as it’s squeezed out. |
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How are oil and gas able to migrate through porous and permeable rocks in the subsurface? |
they are less dense than water |
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Reservoir rock |
a rock with high porosity and high permeability that can contain abundant, easily accessible oil and/or natural gas |
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What two rocks are known for making great reservoir rocks? |
Sandstone and limestone |
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Trap |
a subsurface arrangement of impermeable cap rocks and structures that keep oil and gas underground |
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Three types of traps |
stratigraphic, anticlinal, and fault traps |
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Stratigraphic trap |
a trap created by depositional features where the reservoir rock “pinches out” between two impermeable rocks. Oil/gas gets trapped at the pinch. Unconformities form excellent stratigraphic traps |
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Anticline trap |
oil and gas trapped by an arch feature of permeable rock underneath an impermeable rock |
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Fault traps |
displacement from faulting creates contact between rocks with different permeability and, oil and gas get trapped between impermeable rocks |
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Most coal contains what iron sulfide mineral that reacts with water and oxygen to form sulfuric acid? |
pyrite |
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Four major energy resources found within rocks and sediment |
oil, natural gas, coal, uranium |
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Geologic cross section |
an interpretation of what’s below the surface based on evidence (rock type, contacts) observed at the surface, made by using available mappable features found on the surface or interpreted from data about the subsurface |
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2 rules of stratigraphic sequence (abc abc order) |
1) Folding results in repetition of rock layers that are repeated ‘in-sequence’ across the core of the fold
2) Faulting displaces rock layers, making them ‘out-of-sequence’. |
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How does faulting affect stratigraphic sequence? |
omits or repeats units – making them out of stratigraphic sequence (order) at the earth’s surface |
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How does folding impact stratigraphic sequence? |
produces repetition of sedimentary rock layers on either side of the fold andlimbs which commonly dip or tilt away from each other |
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To form an oil reserve, oil must migrate from a ______ rock into a _________ rock |
source; reservoir |
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tar sand, gas shale, and oil shale, are called ____-__________ reservoirs |
non-conventional |
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How do nuclear power plants generate energy? |
by using the heat released from the fission of uranium |
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How does geothermal energy generate power? |
it uses Earth’s internal heat to transform groundwater into steam that drives turbines |
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How does hydroelectric power generate power? |
by using the potential energy of water. Dams halt the flow of water, storing it at high elevation Water that is released flows through turbines to create electricity.
Associated problems: flooding and population displacement during construction, alteration of stream habitat and local ecosystems |
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How does solar energy generate power? |
uses solar cells to convert sunlight to electricity |
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All minerals used by industrial societies must be extracted from the ________ crust. |
Upper |
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Strip mining |
the practice of mining a seam of mineral, by first removing a long strip of overlying soil and rock (the overburden). Hazard: acid mine drainage. |
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Primary recovery |
Uses reservoir pressure and pumping to extract oil. Inefficient; only able to recover about 30% of the oil. |
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Secondary recovery |
Fluids (steam, CO2 ) are injected to heat and push the oil upward. Hydraulic fracturing – Artificially increases permeability. |
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Metals come from.... |
ore |
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Mountaintop removal mining |
Tops of mountains are blasted off to expose coal seams;valleys filled with rock. Landscape is leveled; environment is permanently altered |
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Acid Mine Drainage |
(associated w/ coal mining) When pyrite is exposed to the atmosphere, it weathers to release acid, iron, and heavy metals. Kills fish and other aquatic organisms |
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Nuclear fission |
Enormous amounts of energy are released from splitting atoms into smaller pieces |
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How do nuclear power plants generate electricity? |
Heat released from fission is used to create high pressure steam in the reactor. Steam spins turbines in a generator to create electricity. |
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How do we access uranium? |
Uranium leaches out of rocks, is carried by water, and precipitates as a uranium oxide mineral in veins and fractures |
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238-U |
99.3% of Uranium is of isotope 238. This isotope is not fissionable (useless!) |
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235-U |
0.7% of uranium is of isotope 235. this isotope is fissionable (electricity, bombs) |
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Nuclear power typically uses __________ |
uranium |
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Why is nuclear waste (radioactive nuclear waste rock from uranium mining) difficult to store? |
The fission process generates highly radioactive wastes that remain radioactive for thousands of years |
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Biofuel |
Using plant and animal matter as an energy source. Produces CO2, but also pulls CO2 from atmosphere (net zero) |
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Ethanol |
the most commonly used biofuel today - derived from corn, sugar cane, cellulose, algae, etc. Added to gasoline as a motor vehicle fuel |
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_____________ panels are used to convert light to electricity |
Photovoltaic |
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Ore deposit |
rock or sediment with high enough concentration of a valuable mineral that it is economically worth extracting |
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Ore deposits form when.... |
valuable elements and minerals-- which normally exist in very small amounts in normal rocks and seawater-- are leached from one rock, moved to another location (usually in a fluid), then re-precipitated in a concentrated mineral form |
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Three steps of ore formation |
1) Source rock from which the element is originally derived 2) Transport 3) Trapping (required to concentrate the metal) |
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Magmatic ore deposits form when... |
ore minerals settle to the floor of a magma chamber |
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Pyrite |
iron ore |
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Galena |
lead ore |
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Rare Earth Elements (REEs) |
Very large, heavy elements that are often found together in geologic deposits. Heavily used for technology, especially cell phones and computers. High demand |
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Why do REEs remain in the melt after other minerals have crystallized? |
they are too large to fit in common minerals that formed earlier. they go into forming unusual often valuable minerals (beryl, monazite, topaz, molybdenite, etc.) |
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Hydrothermal deposits |
Ore minerals precipitate from hot groundwater solutions near magma sources and dissolve metals from rocks. Water transports metals to cooler regions where they precipitate in fractures to form veins. Also found on the ocean floor at the mid-ocean ridge. |
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Secondary-enrichment ore deposits |
Groundwater dissolves an existing ore mineral (typically made of a metal and sulfur) and replaces the sulfur with oxygen or carbonate to form a new (secondary) mineral in a new location. |
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What type of minerals are Malachite and Azurite? |
copper carbonate minerals |
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Mississippi Valley Type (MVT) ores |
Form when hot groundwater gets squeezed out of a mountain belt and deposits minerals upon reaching the cooler surface. |
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Sedimentary ore deposits settle out of.... |
water |
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Banded Iron Formations (BIFs) |
Sedimentary ore deposits that were deposited when bacteria began to produce oxygen gas ~2.4 billions years ago, while the oceans were full of dissolved iron that combined with the new oxygen to create rich iron-oxide deposits |
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Residual ore deposits |
Extreme chemical weathering in tropical environments leaches most minerals out of the soil, except aluminum oxides and iron oxides |
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Almost all Aluminum comes from _______, the rock material left behind when granite weathers. This is an example of a ________ ore deposit. |
bauxite; residual |
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Placer Deposits |
Heavy minerals settle out of flowing water and concentrate along a stream bed; Important for gold, tin, and iron; Can be re-lithified |
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Dimension stone, crushed stone, clay, sand, and many other materials are all examples of ______________ |
Nonmetallic resources |
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Where are ore deposits formed? |
1) Where igneous/magmatic and hydrothermal activity occur (plate boundaries, rifts, hot spots) 2) Where tectonic effects are overprinted by the hydrologic cycle(water transports elements away from the source) |
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Are mineral resources renewable or non-renewable? |
Non-renewable |
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Weather |
the short-term variation in temperature, humidity, atmospheric pressure, wind, etc. in a given region. |
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Climate |
a measure of the average of weather variables over longer periods of time |
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Mountain (alpine) glaciers |
Glaciers that exist in higher altitude regions at the top of mountains and fill cirques and valleys. travel downslope |
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Why do continental glaciers flow? |
because of pressure applied by the weight of ice at their source areas |
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Glacial horn |
a pointed mountain peak; formed by three or more cirques surrounding the peak |
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Cirque |
bowl-shaped basin high on a mountain |
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Arete |
“knife-edge” ridge; formed by 2 cirques |
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Fjords |
drowned glacial valleys |
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U-shaped valleys are formed by _________, while V-Shaped valleys are formed by |
Glaciers; rivers |
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Dropstones |
sediments moved off continents by icebergs that drop into ocean mud |
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Glacial till |
unsorted, unconsolided debris transported by glaciers |
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Glacial erratics |
large boulders dropped by ice;don’t match surrounding bedrock |
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Glaciers deposit eroded material __________ from where it’s eroded |
downhill |
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Moraines |
unsorted glacial debris piles |
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Lateral Moraine |
moraines accumulate along the side of a valley glacier |
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Medial moraine – mid-ice moraine |
mid-ice moraines that form in the middle of a glacier |
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Terminal/end moraine |
moraines that form along the front edge (snout) of the glacier |
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What do moraines tell us about the geologic past? |
how far glaciers traveled during ice ages |
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Where do continental glaciers (ice sheets) form? |
They spread over substantial areas of the continents. Found at the higher latitudes, near the poles. |
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Why do sea level falls during an ice age? |
because the water is stored in ice on land-- deglaciation returns water to the oceans and floods the coasts. |
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Why is the North American continent slowly rising? |
The weight of the ice sheets during the ice age pushed the continent down into the mantle. A huge weight was lifted off the land when the ice melted. |
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temperate glaciers |
melt during at least part of the year |
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Polar glaciers |
Remain frozen throughout the year |
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Zone of ablation |
area of net ice loss (melting, calving, etc) |
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Zone of accumulation |
glacial buildup of snow under cold temperatures and precipitation |
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Advance or retreat is determined by difference between_______________ and _______. |
accumulation and loss |
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Glacier toe (terminus) |
the end of a glacier |
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Albedo |
The ability of Earth to reflect light |
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What 3 things are required to warm the earth? |
1. A source of heat (solar radiation) 2. Something that will trap heat near the surface of the Earth (Greenhouse gases) 3. Something that will distribute this heat throughout the planet (Wind and Ocean currents) |
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Snow and ice reflect large amounts of incoming ______ energy |
Solar |
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Warming creates a positive __________ _____ for albedo |
feedback loop (warmer temperatures --> melting of snow and ice ---> decreased albedo (more solar radiation absorbed) ---> warmer temperatures.....) |
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10,000-100,000 year climate cycles are called __________ cycles, and are driven by small changes in Earth’s orbit(eccentricity, tilt, and precession) called _______ __________ |
Milanković; “orbital forcing” |
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Orbital eccentricity |
the degree to which Earth’s orbit is circular or elliptical – impacts seasonality of solar insolation |
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Solar insolation |
the amount of solar radiation hitting the surface of the earth. Basically that means how much sunlight is shining down on us |
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Do high northern latitudes receive more or less solar radiation when tilt is small? |
less |
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Precession |
changes in the orientation of the spin axis with respect to the earth’s orbit |
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During glacial periods, continental ice moves towards ___-latitudes. During interglacial periods, permanent ice exists only at the ____. |
low; poles |
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Milankovich cycles only impact the________ and________ of insolation, not the total amount of energy hitting the earth. |
seasonality; location |
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The Permo-Triassic Hothouse |
A massive volcanic eruption in Serbia whcih continued for hundreds of years, igniting coal deposits and released CO2. Formed Large Igneous Provinces. Release of sulfur gases acidified the oceans and killed marine life. Event led to the End Permian Mass Extinction |
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How does mountain building lead to overall climatic cooling? |
process consumes CO2 in rock weathering |
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Pliocene Ice Age |
Past 1-2 million years has seen dramatic climate variation, with five major glaciations and 20-30 minor glaciations separated by interglacial periods |
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Carbon Cycle |
The cycle through which carbon passes back and forth among the biosphere, atmosphere, hydrosphere, and lithosphere. |
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How do tectonics regulate global temperature over long time scales? |
through the following steps:
1)volcanoes release CO2 to the atmosphere;
2) CO2 reacts with rain water to form carbonic acid;
3) carbonic acid reacts with silicate rocks during weathering to release bicarbonate ions into surface water;
4) bicarbonate ions are transported to the oceans where they combine with calcium ions to form calcium carbonate minerals that are deposited on theocean floor;
5) calcium carbonate minerals are eventually subducted back into the mantle, and carbon dioxide gas is released from the rocks during melting and rises up through volcanoes back to the atmosphere. |
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The Terrestrial Carbon Cycle |
Fast carbon cycling between soil,biomass, and the atmosphere |
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Respiration |
Animals and other organisms (bacteria,fungi) use O2 to break down biomass and release CO2 back to the atmosphere |
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Atmospheric carbon concentrations pulse(ebbs and flows) on a ______ cycle |
yearly |
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Long-term carbon cycle |
Silicate rocks react with atmospheric CO2 during weathering . Volcanoes release CO2 as carbonate rocks are subducted. |
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Tools for documenting global climate change include... |
-- the stratigraphic record --paleontology --oxygen–isotope ratios -- bubbles in ice -- growth rings in trees -- human history |
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What term refers to how geology regulates climate over long timescales and includes volcanic degassing, rock weathering, carbonate formation in oceans, and subduction? |
the "global weathering thermostat" |
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Snowball Earth |
an icehouse period that resulted from extreme chemical weathering following the formation of the supercontinent Rodinia. A positive feedback between cooling and increased albedo caused the entire Earth to be covered in snow and ice. |
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____________ __________ ___________ deposited in the Snowball Earth period indicate that the oceans were cut off from the atmosphere during this time |
Banded Iron Formations |
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Gradual global cooling during the ________ has resulted from increased rock weathering following the uplift of the Himalayas |
Cenozoic |
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Today, ______ provides over 80% of the world’s energy. |
fossil fuel |
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The Keeling Curve |
Atmospheric CO2 measurements at Moana Loa Observatory since 1958 |
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What condition must be met to produce oil from kerogen? |
the temperature must fall in the window between the 90° and 150°C. |
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Oil and natural gas rise into oil traps because… |
hydrocarbons are less dense than water, so they are relatively buoyant and float above groundwater |
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As the rank of coal increases, the proportion of carbon in it ________ . |
Increases |
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The basic reaction that takes place in a nuclear power plant is ________ . If the fuel rods get too hot, they can cause a _________ . |
Fissioj; meltdown |
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Why isn’t a typical outcrop of granite considered an ore deposit? |
It does not contain a high enough concentration of valuable metals |
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A common way to mine placer ores is to … |
pan the sediments at the bottom of a stream. |
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What process occurs during glacial retreat? |
The position of the glacier's toe (end point) moves back toward the origin of the glacier, even though ice continues to flow toward the toe |
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How can you tell the direction that ice flowed in a region that was covered by ice during the last ice age? |
Flow direction is parallel to the direction of glacial striations. |
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CO2 gas dissolves in rain water to form _________ acid, which attacks ________ minerals in rocks and releases various ions into water |
Carbonic; silicate |
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Bicarbonate ions combine with ________ ions to form ________ _________ minerals, which are deposited on the ocean floor to form limestone |
calcium; calcium carbonate |
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What do tree rings tell us about paleoclimate? |
Trees grow more in warm/wet years and less in cold/dry years. |
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What can the study of fossil pollen in sediments tell us about climate change? |
shifts the occurrence of cold-adapted and warmth-adapted plant species at different latitudes |
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18-O/16-O in ice cores reveal the temperature in which snow formed. Higher 18-O/16-O ratio indicates a _____ climate. Lower 18-O/16-O ration inidicates a _______ climate |
warmer; colder |
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In a very cold climate,what is the behavior of oxygen isotope ratios in plankton fossils? |
the ratio of 18-O to 16-O is high because most of the 16-O is trapped in ice on the continents |
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The record of CO2 concentration in the atmosphere shows that the concentration of this gas has steadily _______________ since the mid-19th century |
increased |
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What is the main control on global climate over geologic timescales? |
Fluctuations in solar output |
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Is nitrogen a GHG? |
no |
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What is the term that has been proposed to describe Earth’s most recent epoch? |
Anthropocene |