Comment: 15:32 - 16:10 (00:38)
Source: Annenberg/CPB Resources - Earth Revealed - 6. Plate Dynamics
Keywords: "plate tectonics", convection, plate, theory, "mid-oceanic ridge", gravity, geologist
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Our transcription: There are a great many questions concerning the convection process.
Perhaps the most fundamental of these is the role of convection in plate motion.
According to one theory, plates are pushed apart as the hot rock beneath them convects upward.
Another view suggests that upward convection creates the mid-ocean ridges.
Plates slide away from the ridges by a combination of gravity and drag from the convection currents themselves.
But some geologists believe that there is a third possibility, that the plates are literally being pulled down into the Earth.
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Geology School Keywords
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