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73 Cards in this Set
- Front
- Back
dip slip fault |
relativemovement is vertical (primarily), parallel to dip
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strike slip fault |
relativemovement is horizontal, movement is horizontal along the fault plane, caused byshearing or tearing stress
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tensional stress |
pulling material apart |
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compressional stress |
force which shortens or squeezes the rock |
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shear stress |
one part slides over another |
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terranes |
exotic pieces of crustal material |
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craton |
a core of stable continental crust |
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aquifer |
permeable sediment or rock that transmits groundwater freely |
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aquiclude |
impermeable layers that prevent movement from occurring |
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aquitard |
impermeable layers that hinders movement |
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spring |
water table that intersects the surfaces resulting in an outflow of groundwater |
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water table |
upper limit of saturated zone |
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saturated zone |
all available pore spaces are filled with water |
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unsaturated zone |
pore spaces have air and water |
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porosity |
the percentage of the total volume of rock or sediment that consists of pore spaces |
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permeability |
the ability of a material to transmit a fluid; how interconnected are the pore spaces |
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subsidence |
overburden packs down sediment after pore spaces are emptied of water due to high rate of groundwater pumping |
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saltwater intrustion |
where overpumping occurs in coastal areas, a lowering of the water table allows saline groundwater to travel further inland, sometimes leading to contamination of the freshwater zone |
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discharge |
volume of water moving past a given point in a given time |
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drainage basin |
total area drained by a stream and its tributaires |
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base level |
the lowest level to which the land will erode; ultimate base level is sea level |
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meandering |
the river continuously moves outwards and downstream as a whole system |
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braided |
stream divide and subdivides |
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cut bank |
outside bank is eroded |
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point bar |
deposition occurs on inside bank |
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oxbow lake |
meander loops eventually come back on themselves to form cutoffs, the stream becomes straighter again and the cutoff forms an oxbow lake |
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hydrograph |
a graph showing the rate of flow versus time past a specific point in a fiver |
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terrace |
former abandoned floodplains |
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alluvial fan |
fan shaped deposits |
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floodplain |
relatively flat surface extending to the base of the valley walls alongside the channels |
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aeolian |
desert wind and ability to shape the earth's surface |
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ventifacts |
side of rock facing the wind is polished |
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yardangs |
bedrock and semi-consolidated sediments, eroded into linear ridges |
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desert pavement |
coarse sediment is left on the ground as finer grains are blown away |
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pans |
deflation form, shallow depressions due to removal of material by the wind |
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playa |
large wind-eroded basins |
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loess |
extensive blankets of silt, windblown silt that mantles the surface |
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barchan dune |
crescent shaped dune, tips point downward, flat surface, lack of vegetation and sand |
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star dune |
complex forms, isolated hills of sand, variable wind direction, grow upwards rather than migrating downwind |
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ephmeral |
streams present only after rainfall events |
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mass balance |
glacier budget, accumulation=abalation |
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accumulation |
glacier is advancing |
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abalation |
glacier is retreating |
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cirque |
an amphitheatre-like valley head, formed at the head of avalley glacier by erosion
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tarn |
a mountain lake formed in a cirque excavated by a glacier |
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hanging valley |
a shallow valley carved by a small glacier and thus the elevation of the valley floor is hanging high above the elevation of the valley floor |
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fjord |
a long, narrow, deep inlet of the sea between high cliffs, typically formed by submergence of a glaciated valley |
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morraine |
glacier melts down in height, large plain of till is left |
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erratic |
a very large boulder that has been deposited by a melting glacier |
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esker |
a very large boulder that has been deposited by a melting glacier |
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esker |
long ridges of sediment caused by deposition by a river flowing within or under a glacier |
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kettle |
small, steep sided lake formed when blocks of stagnant ice are covered with sediment and eventually melts |
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outwash plain |
reworking of glacial debris by meltwater, fairly well sorted, mainly sands and gravels |
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isostacy |
the weight of ice sheets causes downward flexing of the earth's crust, removal of ice during deglaciation leads to a rise in the land surface |
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eustasy |
global changes in sea level associated with glacial advance and retreat |
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creep |
slow downslope movement of material due to gravity |
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soliflucation |
slow downslope movement in permafrost zones |
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slump |
mass of rock or unconsolidated material, rotates as a cohesive unit along a curved surface |
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mudflow/debris flow |
a flow of water soaked soil and sediment |
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rock/debris slide |
bedrock breaks off, travels rapidly downslope |
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rock/debris fall |
free fall of weathered material from steep slopes |
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mitigation |
the elimination or reduction of the frequency, magnitude, or severity of exposure to risks or minimization of the potential impact of a threat or warning |
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angle of repose |
angle at which a slope of unconsolidated material is stable |
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oversteepening |
undercutting base by river or wave erosion or through building roads or railroads |
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p-waves |
primary, compression waves (push-pull) first to reach recording station 6-13 km per hour |
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s-waves |
secondary, ground moves perpendicular to the wave direction 3-8km/h |
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focus |
subsurface area along a fault plane where the motion of seismic waves is initiated |
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epicenter |
surface position directly above the focus |
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Richter scale |
measures magnitude, energy released, measured by seismographs, smaller earthquakes |
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Moment measure |
measures magnitude, measures amount of displacement along a fault zone, bigger earthquakes |
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Mercalli scale |
measures intensity, eyewitness accounts, seismometer |
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tsunami |
earthquake at sea causing an enormous sea wave, build up of waves when approaching coastline |
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liquefaction |
water saturated soil or sediment turns from a solid to a liquid state |