click below
click below
Normal Size Small Size show me how
UNIT 3 Vocab Aidan B
Plate tectonics
Term | Definition |
---|---|
Asthenosphere | |
Subduction | Process by which one tectonic plate slips beneath another tectonic plate. |
Seafloor spreading | The hypothesis that new ocean crust is formed at mid-ocean ridges and destroyed t deep-sea trenches;occurs in a continuous cycle of magma intrusion and spreading |
Mantle convection | |
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 has flowed out onto the surface |
Magma | |
Tectonic plate | Huge pieces of Earth's crust that covers its 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 about 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; is associated with volcanism, earthquakes, and high heat flow, and is found primarily on the seafloor |
Transform boundary | Place where two tectonic plates slide horizontall past each another; is characterized by long faults and shallow earthquakes. |
Hot spot | Unusually hot area in Earth's mantle where high-temperature plumes of mantle material rise toward the surface. |
Epicenter (in regards to earthquakes) | Point on Earth's surface directly above the foxus of an earthquake |
Focus (in regards to earthquakes) | Point of the intial fault rupture where an earthquake originates that usually lies at least several kilometers beneath Earth's surface |
Pangaea | Ancient landmass made up of all the continents that began to break apart about 200 mya. |
Geohazard | |
Reverse fault | |
Strike-slip fault | |
Normal fault | |
Compression | |
Tension | |
Shearing | |
Felsic | |
Mafic |