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62 Cards in this Set
- Front
- Back
Soil Creep |
Consists of a very gradual downhill movement of soil & regolith. Can only be recognized by indirect evidence. Super slow. |
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Solifluction |
Form of creep that is largely restricted to high latitude and high elevation ("soil flowage") |
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What is a good facilitator of mass wasting? |
Clay |
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Why is clay a good facilitator of mass wasting? |
Clay absorbs water and becomes a very slippery and mobile substance. Can be set in motion by rainfall or earthquake shock. |
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Denudation |
Disintegration wearing away and removal of rock material. Implies a lowering of continental surfaces. Weathering occurs first. |
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Which mass wasting movement does not associate itself with gravity? |
Hydrolysis |
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What is the best climate for mass wasting/movement to occur? |
Heavy rain |
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Describe Bedrock |
Bedrock - solid rock underlying loose deposits such as soil or alluvium. *Important effect of mechanical weathering is to expose bedrock to the forces of chemical weathering, & shows how effective chemical weathering is. |
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Chemical Weathering relies most on what substance? |
Water/Moisture |
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Exfoliation |
Curved layers peeling off bedrock |
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Talus Slopes |
Debris is added to the slope, the slope adjusts to reestablish the angle. |
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Talus Cone |
Debris collected on the bottom from falling off the slope |
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What happens to water when it freezes that makes it a major agent of mechanical weathering? |
Water seeps into the rocks and as it freezes, it breaks the rock into smaller pieces. Expands by Volume |
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Perennial Stream |
Humid Regions -> Permanent |
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Intermittent Stream |
More Arid -> Seasonal Streams that flow for only part of the year |
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Ephemeral Stream |
Only carry water during or immediately after a rain |
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Exotic Stream |
Flows into a dry region, bringing the water from somewhere else |
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Oxbow Lakes |
Formed when a stream channel shifts through lateral erosion and cuts a new channel across it's neck, & the old loop gets cut off. |
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Alluvium |
Any stream-deposited sedimentary material |
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Largest With a Delta |
Pakistan |
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Largest without a Delta |
Amazon |
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First Order Stream |
Stream without tributaries Most numerous |
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Second Order Stream |
2 first order streams unite |
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Third Order Stream |
Joining of 2 second order streams |
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Saltation |
Smaller particles are moved along with the general stream flow in a series of jumps/bounces |
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Traction |
Coarser pieces roll or slide along the streambed |
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Stream Discharge |
Volume of flow of a stream |
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Affect erosive effectiveness of a stream |
Flow Speed -> governed by gradient (slope angle) Steeper = Faster Shape of the channel -> Narrower = Faster Volume of the flow -> More Water = Faster |
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Natural Levees |
Slightly higher ground fringing a stream channel in a flood plain; formed by deposition during flood time |
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Yazoo Stream |
A tributary unable to enter the main stream because of natural levees along the main stream. Flows parallel to a large/main stream |
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Splash Erosion |
Impact of a raindrop causes material to be loosened |
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Sheet Erosion |
Water flows across it as a thin sheet, transporting materials already loosened by splash erosion |
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Terminal Moraine |
Ridge of till that marks the outermost limit of glacial advance. Maximum extent of a glacier |
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Recessional Moraine |
Glacial deposit of till formed during a pause in the retreat of the ice margin |
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Ground Moraine |
Formed when large quantities of till are laid down from underneath the glacier rather than from its edge |
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Neve (Firn) |
Snow granules that have become packed and begin to coalesce due to compression, achieving a density about half as great as that of water |
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Zone of Ablation |
Lower portion of a glacier where there is a net annual loss of ice due to melting and sublimation |
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Zone of Accumulation |
Upper portion of a glacier where there is a greater annual accumulation of ice than there is wastage |
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Equilibrium Line |
A Theoretical line separating the ablation zone and accumulation zone of a glacier along which accumulation exactly balances ablation. |
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Glacial Erratics |
Outsize boulder included in the glacial till, which may be different from the local bedrock |
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Continental Ice Sheets |
Smooth & Round (reshape) the terrain |
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Mountain Glaciers |
Steepen Slopes & increase local relief |
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Earth has been deglaciating for... |
2 1/2 million years |
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Average speed of movement of glaciers |
Centimeters per day |
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Roche Moutonnees |
Glacial landform produced when a bedrock hill or knob is overridden by moving ice |
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Cirques |
Broad amphitheater hollowed out at the uppermost head of a glacial valley |
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Glacial Abrasion |
Bedrock is worn down by the rock debris being dragged along in the moving ice Glacial scouring by bedrock embedded by ice |
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Contemporary Ice Sheets Cover... |
10% of Earth's land surface |
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What would happen if all the ice in Antarctica were to melt? |
The sea level would rise significantly. |
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Divergent Plate Boundary |
Location where 2 lithosphere plates spread apart. 2 plates may diverge from one another Ex: Great East African Rift Valley |
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Convergent Plate Boundary |
Location where 2 lithosphere plates collide Converge toward one another Ex: Andes range in South America & Cascades in NW North America |
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Transform Plate Boundary |
2 Plates slipping past one another laterally Ex: San Andreas Fault in California. Between Pacific and North American Plates |
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Crater Lake, Oregon |
Walls were weakened & collapsed as enormous volumes of pyroclastic material were ejected from the Volcano |
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Flood Basalt |
Large-scale outpouring of basaltic lava that may cover an extensive area of Earth's surface |
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Columnar Basalt |
Lava flow cools uniformly, it contracts & forms a distinctive pattern of vertical joints, leaving hexagonal columns |
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Evidence used to verify seafloor spreading: |
Paleomagetism - Studying paleomagnetic data from a portion of the midocean ridge system Ocean Floor Cores - Sea-bottom sediments were analyzed |
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Pacific Ring of Fire |
Rim of Pacific ocean basin due to widespread volcanic & seismic activity; associated with lithospheric plate boundaries (Transform & Divergent) |
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Continental Drift/Pangea |
Continents were originally together in a massive super continent, & then broke apart into smaller pieces. Proposed by Alfred Wegener |
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Mantle Plumes |
Midplate volcanic activity develops over narrow plumes of heated material rising through the mantle. Ex: Hawaiian Islands, Yellowstone, Iceland, & Galapagos Islands |
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Earthquakes |
Produced by shock waves resulting from a sudden displacement along a fault, or from the movement of magma, or sudden ground subsidence |
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Epicenter |
Location on the surface directly above the center of fault rupture during an Earthquake |
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Why do glaciers carve U-Shaped Valleys? |
Because they flowed down pre-existing river or V-shaped valley during the last glaciation |