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Chap17 vocab
Question | Answer |
---|---|
Wegener's hypothesis that Earth's continents were joined as a single landmass, that broke apart about 200 mya and slowly moved to their present positions. | Continental drift |
Ancient landmass made up of all continents that began to break apart about 200 mya. | Pangaea |
A device that can detect small changes in magnetic fields. | Magnetometer |
The flow in the outer core changes, and Earth's magnetic field changes direction. | Magnetic reversal |
The study of the history of Earth's magnetic field. | Paleomagnetism |
An imaginary line on a map that shows points that have the same age, that is formed at the same time. | Isochron |
The theory that explains how new ocean crust is formed at ocean ridges and destroyed at deep-sea trenches. | Seafloor spreading |
Huge pieces of crust and rigid upper mantle that fit together at their edges to cover Earth's surface. | Tectonic plate |
Regions where two tectonic plates are moving apart. | Divergent boundaries |
Continental crust begins to separate, the stretched crust forms a long, narrow depression. | Rift valley |
Two tectonic plates are moving toward each other. | Convergent boundaries |
Two plates collide, the denser plate eventually descends below the other, less-dense plate in a process. | Subduction |
Place where two tectonic plates slide horizontally past each another; is characterized by long faults and shallow earthquakes. | Transform boundary |
The weight of the uplifted ridge is thought to push the oceanic plate toward the trench formed at the subduction zone in a process. | Ridge push |
The weight of a subducting plate pulls the trailing slab into the subduction zone much like a tablecloth slipping off the table can pull articles off with it. | Slab pull |