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25 Cards in this Set
- Front
- Back
Pangaea (2)
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- one-piece landmass that once existed on earth
- means "all earth" |
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Theory of Continental Drift (4)
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- continents were once joined together in 1 piece & have since drifted apart horizontally
evidence - rocks & fossils - coal mines - mountain ranges |
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Midocean Ridges (2)
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- underwater mountain chain
- has deep crack called rift valley |
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Ocean Floor Spreading (5)
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- new ocean floor is created by lava
1. lava flows out of crack of midocean ridges 2. this creates new ocean floor 3. new ocean floor pushes away old ocean floor - allows continent to drift: as ocean floor moves, it takes continent w/ it |
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Trenches (2)
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- deepest part of ocean
- where old ocean floor moves deep down into earth's mantle; this is called subduction |
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Subduction (3)
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- process where old ocean floor plunges back down into earth
1. some material will rise up & form volcanoes 2......!! |
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Theory of Plate Tectonics
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- theory that links together ideas of continental drift and ocean-floor spreading to explain formation, movements, collision, and destruction of crust
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Plates of Lithosphere (3)
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- 7 major plates and many smaller plates
- plates move in diff speeds & directions due to convection currents - most plate boundaries on ocean floor |
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Types of Plate Boundaries (2)
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- Divergent
- Convergent |
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Divergent Boundaries (2)
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- when plates move apart, occurs at mid ocean ridges
- constructive |
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If two continental plates diverge...
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a rift valley forms
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If 2 oceanic plates diverge...
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a midocean ridge forms
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Convergent Boundaries (4)
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- when plates come together
- occurs at ocean trench - subduction may also occur - destructive |
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If an oceanic plate converges w/ continental plate... (2)
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- ocean plate is subducted
- volcanic mountains form |
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If 2 oceanic plates collide... (2)
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- older plate is subducted under younger plate
- island arcs form |
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If 2 continental plates collide...
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- edges fold to form mountains
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Strike-Slip Boundaries (3)
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- plates grind together & slip past each other horizontally
- no new plate material is made/destroyed - conservative |
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Earthquakes (2)
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- shaking/trembling that results from sudden movement of part of earth's crust
- most common cause is faulting |
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Focus
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- underground point of origin
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Epicenter
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- located on earth's surface directly above focus
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Seismic Waves (3)
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Primary - P waves
Secondary - S waves Surface - L waves |
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P Waves (4)
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- primary waves
- fastest - push-pull - trave through solids, liquids, and gases |
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S Waves (4)
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- secondary waves
- side to side - travels through solids only - slower than P, faster than L |
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L Waves (4)
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- surface waves
- slowest - causes surface of earth to move up and down - cause most damage |
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Seismograph
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- measure the waves of an earthquake
- creates seismogram - heights of waves on seismogram used to calculate strength on Richter Scale |