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80 Cards in this Set
- Front
- Back
A really cold winter is proof that global warming is a hoax?
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False
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A release of methane hydrates or clathrates (same thing) would lower global temperatures by reflecting incoming sunlight?
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False
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Carbon dioxide in the atmosphere has increased by about how much in the past century?
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100 ppm
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Carbon dioxide in the atmosphere is at an all-time high?
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False
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During the last 800,000 years, northern hemisphere glaciations have occurred about how often?
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Every 100,000 years
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Earth gets more total sunlight when eccentricity is high?
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True
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Faster plate spreading rates at mid-ocean ridges are a likely cause of higher sea level in the past?
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True
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For the same slope, would shear stress be greater on the Earth or the Moon.
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Earth
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From which direction does the wind in MN usually come
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West
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Ice ages are common throughout Earth's history?
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False
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Mass wasting is an important process on rocky (i.e., sediment poor) shorelines?
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True
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Mean annual temperature in the northern hemisphere has increased by about how much in the last century?
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.5 C
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Milankovitch hypothesized that ice ages developed when winters are coldest?
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False
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One can discern the direction of longshore drift by examining the amount of sand on the two sides of a jetty or groin?
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True
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Output of the Sun is effectively constant?
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False
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Over the last 500 Ma, sea-level is thought to have varied by roughly how much?
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500m
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Rocky beaches are more common on uplifted coastlines?
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True
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Surface currents and water waves are the same thing?
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False
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Surface currents rotate clockwise in the northern hemisphere?
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True
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The Atlantic Ocean off of the east coast of the US has high salinity because evaporation significantly exceeds precipitation there?
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True
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The cations that comprise part of ocean salinity are largely from terrestrial weathering?
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True
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The greenhouse effect works by atmospheric absorption of visible light from the sun?
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False
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The little ice age, a period of cold temperatures in N. America and Europe, occurred about how long ago?
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400 Years ago
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The net transport of water is parallel to average wind direction?
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False
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The superstorms in The Day After Tomorrow are (think about the direction of vertical airflow; is it up or down?) Ignore what they may have called them in the movie, focus only on the direction of airflow. Once you have that, high or low pressure will follow.
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High pressure cells
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The Younger Dryas, a period of cold climate that followed deglaciation in the northern hemisphere occurred about how many years ago?
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10,000
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Thermohaline circulation is driven by density variations of seawater?
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True
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To what does angle of repose refer?
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the steepest stable angle loose sediment can maintain
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Tsunamis are just long wavelength ocean waves?
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True
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Water vapor is the primary greenhouse gas?
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True
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Wave base is about what fraction of wavelength deep?
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One-half
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Wave refraction creates longshore drift or, at least, accentuates it?
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False
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We live in the hottest period of Earth's history?
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False
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What does water do to shear strength?
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can both increase and decrease it
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What is regolith?
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unconsolidated material on the Earth's surface
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What would have the higher angle of repose?
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A mixture of sand and gravel
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When the volume of ice in ice caps increases, the ratio of oxygen 18 to oxygen 16 in the oceans increases?
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True
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When was the last snowball Earth thought to have occurred?
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500 Ma
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Which of the following has little or no effect on global temperature? Volcanoes, output of the sun, ocean circulation, orbital variations, none of the above.
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None of the above
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Where is a place where surface water descends to form deep water?
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The North Atlantic
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Which of the following is closest to the angle of repose of dry sand (all numbers stated in degrees) ?
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35
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Which of the following is not a means of removing dissolved content from ocean water?
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Volcanic outgassing
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What are potential sinks of sand to a beach?
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Dune growth, stream discharge, longshore drift
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What are potential sources of sand to a beach?
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Dune erosion, stream dischange, longshore drift, onshore transportation.
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Which of the following is not evidence of creep on a hillslope?
-curved tree trunks -large rocks covering the surface -tension cracks -none of the above |
large rocks covering the surface
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Which of the following is the least likely mass wasting trigger?
-wildfire -rain -floods -earthquakes -tornadoes |
Tornadoes
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Which value is closest to the amplitude of the tides in open water?
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1 m
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What value is closest to the average salinity of ocean water?
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40 per mil
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Without a moon, Earth would not have ocean tides?
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False
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At what depth does hte wave motion vanish?
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1/2 the wavelength
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Do waves slow down or speed up in shallow water?
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Slow down.
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What is refraction?
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Bending of wavefront due to velocity changes
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What is a longshore drift?
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Definition: shore parallel transport of sand
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What is a berm?
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Berm: topographic high marking limit of wave run up at high tide
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What is a backshore?
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Beach back of berm (not affected by waves)
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What is a foreshore?
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Intertidal zone
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What is nearshore?
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The wavebreaking area
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What are inputs of the sand budget?
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Rivers, clidd and dune erosion, on-shore transport, littoral drift.
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What are outputs of the sand budget?
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Dune formation, off-shore transport, littoral drift
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What are the characteristics of rocky shorelines?
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Wave-cut bench: wavebase at low tide
Wave-cut notch: erosional "pit" at base of cliff Beaches tend to be small "pocket" beaches in sheltered bays Mass wasting is important Most common on uplifted coasts |
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How fast is the sea level rising in this century?
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2 mm/yr
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What is mass wasting?
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The movement of rock and regoloth by gravity
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What is regolith?
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The irregular blanket of unconsolidated rock and soil on the surface
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What is shear stress?
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-A component of gravity parallel to slope
-Zero for horizontal surface -increases as slope increases |
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What is shear strength?
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-the product of compenent of gravity perpendicular to slpe and frictional properties of sediment
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What are some characteristics of shear strength?
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-decreases as slope increases
-increases witha ddition of water, but drops when saturated -increases with root binding and cementing |
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What is a trigger?
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A sudden change in conditions (rain, fire, earthquake, road cuts)
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What are characteristics of rock falls?
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Granular flow, very high velocities. Often forms conical pile of unsorted debris: talus slope
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What are characteristics of mud flows?
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Slurry flow, moderate velocity, water saturated, common in hilly regions with seasonal rains, common on strato volcanoes
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What are characteristics of debris flow?
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Slurry flow, usually sand and large size clasts dominant, water lowers viscosity, often called landslides in popular media
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What are the characteristics of slump?
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Consolidated slide, low velocity, water important as a trigger, often leave crescent-shaped head scarps and have back-titled beds, also called landslides in popular media
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What are the characteristics of creep?
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Coherent downslope movement of soil at rates of cm/yer, almost all unconsolidated slopes undergo creep, look for inclined or bent tress, tilted telephone poels and fences, inclined tombstones, etc, slow, but pervasive
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What are the characteristics of the greenhouse effect?
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Incoming sunlight primarily in the visible band, outgoing radiation is primarily infrared- atmosphere absorbs/reflects much of this
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What is the biggest componenet of greenhouse gases?
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Water (95%)
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What are Milankovitch Cycles?
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-Changes to Earth's orbit due to gravitational interactions with Moon, Sun, and large planets
-Result in changes in amount and distribution of solar insolation |
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What are the characteristics of eccentricity?
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Affects total sunlight received each year (more sunlight in elliptical extreme, affects the severity of seasons (winter is worse if spent further from sun), alternates between extremes every 100 ka
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What are the characteristics of obliquity?
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-causes the seaons
-grater obliquity= greater seasonality Alternates between extremes every 41ka |
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What are the characteristics of precession?
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determines timing of seasons, makes one cycle ever ~23 ka
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What is Milankovitch's Theory?
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Severity of summer determines if ice grows or shrinks in NH
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What are the characteristics of a snowball earth?
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Hard to get into, hard to get out of
-ice reflects most incoming sunlight keeping the planet cold -the way out is mounting CO2 |