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ES. Ch 17 Vocab.
Vocab.
Term | Definition |
---|---|
continental drift | wegener developed an idea |
Pangaea | a greek word that means all the earth, and suggest that Pangaea began to break apart about 200 mya |
magnetometer | small changes in magnetic fields |
magnetic reversal | happens when the flow in the outer core changes, and Earth's magnetic field changes direction |
paleomagnetism | is the study of the history of Earth's magnetic field. |
isochron | is an imaginary line on a map that shows points that have same age- that is, they formed at the same time. |
seafloor spreading | is the theory that explains how new ocean crust is formed at ocean ridges and destroyed at deep-sea trenches.. |
tectonic plate | are huge pieces of crust and rigid upper mantle that fit together at their edges to cover Earth's surface |
divergent boundary | regions where two tectonic plates are moving apart |
rift valley | when continental crusts begins to separate, the stretched crust forms, a long, narrow depression |
convergent boundary | two tectonic plates are moving toward each other |
subduction | when two plates collide, the denser plate eventually descends below the other, less-dense plate in a process |
transform boundary | a region where two plates slide horizontally past each other |
ridge push | as the older portion of the sea floor sinks, the weight of the uplifted ridge is thought to push the oceanic plate toward the trench formed at the subduction zone in process |
slab pull | tectonic process associated with convection currents in Earth's mantle that occurs as the weight of the subducting plate pulls the trailing lithosphere into subduction zone. |