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Chapter 17
Term | Definition |
---|---|
Continental drift | Proposed that Earths continents had once been joined as a single landmass that broke apart and sent the continents adrift. |
Pangaea | Greek word that means all the earth, suggested that pangaea began to break apart about 200 mya. |
Magnetometer | Is a device that can detect small changes in magnetic fields. |
magnetic reversal | Happens when the flow in the outer core changes , and the Earth magnetic field changes direction. |
paleomagnetism | Is the study of the history of Earths magnetic field. |
Isochron | Imaginary line on a map that shows time. |
Sea floor spreading | Is the theory that explains how new ocean crust forms a ocean ridge and destroyed at deep sea trenches. |
Tectonic plate | Huge pieces of crust and rigid upper mantle that fit together at their edges. |
Rift Valley | Crust begins to seperate, the stretched crust forms a long, narrow depression. |
Convergent boundaries | two tectonic plates are moving toward each other. |
Subduction | Two plate tectonics collide the denser plate eventually descends below the other less dense plate process. |
Transform boundary | A region where two plates slide horizontally past each other. |
Ridge push | plate toward the trench formed at the subduction zone in a process. |
Slab pull | The movement of tectonic plates. |