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Unit 3 Vocab Angel P
Plate Tectonics
Term | Definition |
---|---|
Asthenosphere | The uppermost part of the mantle. |
Subduction | When one tectonic plate slips under another. |
Seafloor Spreading | The idea that new ocean crust is formed at mid-ocean ridges and destroyed at deep-sea trenches. |
Mantle Convection | The reason why tectonic plates move. |
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 | When tectonic plates subduct and start pulling down on the whole plate. |
Magma | Molten rock underneath the earth's surface. |
Tectonic Plate | Huge pieces of Earth's crust that cover 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 million years ago and slowly moved to their present positions. |
Convergent Boundary | Two tectonic plates moving towards each other and forming mountains. |
Divergent Boundary | Two tectonic plates moving away from each other and forming volcanoes. |
Transform Boundary | Two tectonic plates rubbing against each other and causing earthquakes. |
Hot Spot | An unusually hot area in Earth's mantle where high-temperature plumes of mantle material rise towards the surface. |
Epicenter (in regards to earthquakes) | Point on the surface that is directly above the focus of an earthquake. |
Focus (in regards to earthquakes) | The origin of an earthquake that usually lies at least several kilometers beneath Earth'es surface. |
Pangaea | Ancient landmass made up of all the continents that began the break apart about 200 million years ago. |
Geohazard | Hazards to the Earth. |
Reverse Fault | A fault where the hanging walls move up instead of down. |
Strike-Slip Fault | A fault where the hanging walls move sideways instead of up or down. |
Normal Fault | Where two hanging walls are compressed together and move downwards. |
Compression | When to blocks of rocks are pushed tightly together; like a convergent boundary. |
Tension | Stress that pulls rocks apart; like a divergent boundary |
Shearing | Stress that is applied in different directions that are towards the other; like a transform boundary. |
Felsic | Rocks with a lighter colour. |
Mafic | Rocks with a darker colour. |