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Chapter 7 vocab
Term | Definition |
---|---|
Pangaea | over time Pangaea began breaking apart, and the continents slowly moved to their present positions. |
continental drift | which suggested that continents are in constant motion on the surface of earth. |
mid-ocean ridges | the mountain ranges in the middle of the oceans. |
Seafloor spreading | is the process by which new oceanic crust forms along a mid-ocean ridge and older oceanic crust moves away form the ridge. |
normal polarity | a state in which to point north |
magnetic reversal | occurs and the magnetic field reverses direction |
reversed polarity | a state in which magnetized objects would reverse direction and orient themselves to point south. |
plate tectonics | states that Earth's surface is made of rigid slabs of rock, or plates |
lithosphere | the cold and rigid outermost rock layer |
divergent plate boundary | forms where to plates separate |
transform plate boundary | forms where two plates slide past each other |
convergent plate boundaries | form where two plates collide |
subduction | the denser plate sinks below the more buoyant plate in process |
convection | the circulation of material caused by differences in temperature and density |
ridge push | ridge push moves thee lithosphere in opposite directions away from the mid-ocean ridge |
slab pull | as a slab sinks, it pulls on the rest of the plate with a force |