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61 Cards in this Set
- Front
- Back
geomorphology |
is hte study of landforms and the processes that created them |
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landforms |
elements of earths sueface that have such identifiable form, mountains, valleys, hills, and depressions |
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endogenic porcesses |
are forces that cause movements beneath or at earths surface such as mountain building and earthquakes |
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exogenic processes |
are forces of erosion such as running water, wind , and chemical actions that occur at earths surface |
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plate tectonic theory |
wegener's theory that was reject , but in the 1960s researchers vindicated him by working out an explanaiton |
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mantle |
rock just beneath the crust |
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tectonic plates |
earths rigid crust that move |
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earthquakes |
sudden movements of earths crust |
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focus of an earthquake |
the focus is generally near the surface but can be as deep as 600 kilometers (370 miles) |
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epicenter |
area of surface directly above the focus |
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seismograph |
a device that records the quakes seismic waves or vibrations |
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magma |
molten rock |
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lava |
when magma reaches the surface and erupts |
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volcano |
sruface vent where lava emerges |
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shield volcanoes |
their shape |
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composite cone volcanoes |
explosive volcanoes that cause death and descruction |
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divergent plate |
spreading apart |
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seafloor spreading |
where two plates are diverging on the seafloor , lava continues to erupt and is rapidly chilled by seawater it solidifies to form a new seafloor crust |
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convergent plate boundary |
a boundary where plates push together |
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transform plate boundary |
a boundary where the plates neither converge nor diverge but grind past each other |
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isostatic ajustments |
the vertical movement caused by loading or unloading the crust |
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igneous rocks |
are formed when molten crustal material cools and solidfies |
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sedimentary rocks |
result when rocks eroded from higher elevations accumulate at lower eleveation |
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metamorphic rocks |
are created when rocks are exposed to great pressure and heat altering them into more compact, crystalline rocks |
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sima |
denser rocks are dominated by compunds of silicon, magnesium, and iron minerals |
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sial |
less dense rocks are dominated by compounds of silicon and aluminum minerals |
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shields |
the formation and distribution of many minerals is caused by the movements of earths crust, vast areas of the continental crust |
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faults |
when stressed far enough, fracture along cracks will form |
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structural landforms |
variation in the resistance of rocks to exogenic processes cause weak rocks to be removed more rapidly while more resistant rocks remain in place |
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weathering |
process of breaking rocks into pieces ranging in size from boulders to pebbles, sand grains, and silt down to microscopic clay particles |
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chemical weathering |
is a change in the element that compose rocks when they are exposed to air and water |
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karst |
limestone being eaten away by water creates sinkholes then the topography that's left over is called |
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mechanical weathering |
rocks expand and contract with frequent changes in temp, causing them to break apart |
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mass movement |
rocks roll, slide, or free-fall downhill under the steady pull of gravity |
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surface erosion |
water which flows downhill because of gravity carries solid rock particles with it |
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soil creep |
a very slow, gradual movement of material down the slope of a hill |
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groundwater |
water that soaks into the soil and accumulates |
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overland flow |
when the soil cannot keep up with the rain fall, the rain will flow directly into the streams |
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drainage basin |
a stream drains groundwater and overland flow from an area |
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discharg |
the volume of water tha astream carries per unit of time |
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drainage density |
combined length of all of the stream channels in a basin, divided by the area of he drainage basin |
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sediment transport |
the movement of material in a stream |
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floodplain |
is anearly level surface at he bottom of hte valley trhrough which the stream is flowing |
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meander |
a stream tends to change directions from side to side which contributes to widening he channel
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grade |
a graded stream transports exactly as much sediment as it has collected |
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delta |
where a river enters the sea, the water velocity drops abruptly and the sediment may form a large are of deposited sediment |
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alluvial fan |
a prominent land-form in many deserts, broad, gently sloping deposit formed from sand and gravel where a fast moving stream emerges from a narrow canyon onto a broad valley floor |
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glaciers |
high mountain areas are currently covered with thick layers of moving ice |
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alpine glaciers |
form wherever snow accumulates year after year without melting |
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continental glaciers |
over 3 kilometer thick cover vast areas of Greenland and Antarctica |
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moraines |
when a glacier rapidly melts dropping large quantities of material forming moraines |
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terminal moraine |
is a ridge of material dumped at the end of the glacier |
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outwash plain |
meltwater leaving a glacier deposits, some of the debris close the the glacier in a broad gently sloping plain |
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dunes |
sand accumulates because of wind |
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desert pavement |
after sand is eroded from the soil surface larger rocks, pebbles and gravel are left behind |
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loess |
thick layers of windblown silt |
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wavelength |
a small ripple ravels very slowly |
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tsunamui |
which is an extremely long wave created by an underwater earthquake |
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longshore current |
traveling parallel to the shore |
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longshore transport |
longshore current is like a river carrying sediment, from areas where it is eroded by waves and depositing it where breaking waves lose the energy to carry it usually in deep water |
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marine terrace |
former shore lines that are now above sea level |