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9 Cards in this Set
- Front
- Back
what is a hotspot? |
volcano within a plate, which is the surface expression of a mantle plume |
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what is a mantle plume? |
column of hot rock rising through the mantle, which melts to produce magma that feeds hot spot volcanoes |
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the what is fixed relative to a moving plate? |
mantle plume |
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what does an active volcano represent? |
the current present position of the heat source |
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the chains of which 2 underwater volcanoes represent the locations on the plate that were once over a heat source? |
seamounts anf guyots |
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what is ridge push? |
a force induced by the upwelling of asthenosphere and magma, which causes MORs to rise up to 2km above the abyssal plane. |
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what is slab pull? |
the force exerted by the cold, dense plate,which pulls the plate along as it subducts down into the mantle. |
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desribe what happenes in convection currents |
radioactive decay in the core releases heat, lowering the density of lower mantle rocks and causing them to rise. As the upwelling reaches the surface it starts to cool, becomes more dense and starts to descend. |
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what is seismic tomography |
computer imaging in 3D which is based on seismic wave velocities |