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Unit 3 Vocab- Deanna
Plate Tectonics
Term | Definition |
---|---|
Asthenosphere | The upper layer of mantle of Earth's surface |
Subduction | Process by which one tectonic plate slips beneath another tectonic plate |
Sea Floor Spreading | The hypothesis that new ocean crust is formed at mid-ocean ridges and destroyed at deep-sea trenches; occurs in a continuous cycle of magma intrusion and spreading. |
Mantle Convection | When the density of the mantle causes it to rise and sink |
Ridge Push | Tectonic process associated with convection currents in Earth's mantle that occurs when the weight of an elevated ridge pushes an oceanic plate toward a subduction zone |
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 a subduction zone. |
Lava | Magma that flows out onto Earth's surface |
Magma | Molten rock |
Tectonic Plate | Huge pieces of Earth's crust that cover it's surface and fit together at their edges. |
Theory of continental drift | Wegener's hypothesis that Earth's continents were joined as a single landmass, called Pangaea, that broke apart 200 mya and slowly moved to their present positions |
Convergent Boundary | Place where two tectonic plates are moving toward each other; is associated with trenches, islands arcs, and folded mountains, |
Divergent Boundary | Place where two of Earth's tectonic plates are moving apart |
Transform Boundary | Place where two tectonic plates slide horizontally past each other. |
Hot spot | Unusually hot area in Earth's Mantle where high temperature plumes of mantle material rise toward the surface. |
Epicenter | The point on Earth's surface directly above the focus of an earthquake. |
Focus | The point of initial rupture of the earthquake |
Pangaea | Ancient landmass made up of all the continents that began to break apart 200 mya |
Geohazard | A hazard due to rocks or other loose materials. |
Reverse Fault | Form as a result of horizontal and vertical compression that squeezes the rock and creates a shortening of the crust. |
Strike Slip Fault | Shear causes horizontal movement along a fault plane |
Normal Fault | Tension causes vertical movement downward along a fault plane |
Compression | Causes a material to shorten |
Tension | Causes a material to lengthen |
Shearing | Causes a distortion of a material |
Felsic | Granite rocks |
Mafic | Basaltic rocks |