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11 Cards in this Set
- Front
- Back
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with the use of __________, scientists were able to make better observations and gather new informations about the ocean floor. |
sonars and submersibles |
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According to this theory, hot, less dense material from below the earth's crust rises towards the surface at the mid-ocean ridge. This material flows sideways carrying the seafloor away from the ridge, and creates a crack in the crust. The magma flows out of the crack, cools down, and becomes the new seafloor. |
Seafloor Spreading Theory |
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who suggested an explanation to Alfred Wegener's continental drift? |
Harry Hess together with Robert Dietz |
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A ______ tells us directions on Earth. |
Magnetic Compass |
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If subduction is faster than seafloor spreading, then the ocean ________. |
shrinks |
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If seafloor spreading is faster than subduction, the ocean __________. |
widens |
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Fossilized leaves of an extinct plant _________ were found in 250 million years old rocks. |
Glossopteris |
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The hot, less dense rising material spreads out as it reaches the upper mantle causing upward and sideward forces. |
Convection Current |
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As an oceanic crust moves away from a divergent boundary, it becomes denser than the newer oceanic crust. As the older seafloor sinks, the weight of the uplifted ridge pushes the oceanic crust toward tge trench at the subduction zone. This process is called _________. |
Ridge Push |
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The other possible process involved in tectonic plate movement. |
Slab Pull |
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The weight of the subducting plate pulls the trailing slab into the subduction zone like a tablecloth slipping off the table and pulling items with it. |
Slab Pull |
