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Unit3 Vocab+Danielle
Plate Tectonics
Term | Definition |
---|---|
Asthenosphere | The very upper layer of the mantle, and maybe the lowest part of the crust, that is solid that sometimes acts like a liquid (like silly putty or hot wax) |
Subduction | The process that occurs at convergent boundaries where, when the two plates collide, the denser of the two sinks below the plate that is less dense |
Seafloor Spreading | The theory that explains how new oceanic crust is formed in mid-ocean ridges, the old oceanic crust spreads out, and then it destroyed at deep sea trenches to start the cycle again;this theory gave the "why" to Wegener's theory of continental drift |
Mantle Convection | The process that occurs in the mantle that is the driving force of tectonic plates; hotter material rises because the atoms spread out making it less dense and the cooler material sink because the atoms get closer together making it more dense (repeats) |
Ridge Push | The process where the older oceanic crust/seafloor sink, the the weight of the uplifted/higher ridge pushes the oceanic plate toward the trench that was formed at the subduction zone |
Slab Pull | The process where the weight of the subducting plate pulls that connecting/trailing slab into the subduction zone |
Lava | The molten rock that is outside of the Earth |
Magma | The molten rock that is inside of the Earth |
Tectonic Plate | The massive, irregularly shaped pieces/slabs of solid rock |
Theory of Continental Drift | A theory (believed idea) that was first proposed by Alfred Wegener that all current continents were once joined together in a supercontinent called Pangaea and slowly drifted apart |
Convergent Boundary | The area where two (2) tectonic plates are moving TOWARD each other; three types: oceanic - continental, oceanic - oceanic, and continental - continental; features include trenches, volcanoes, subduction zone, mountains, etc... |
Divergent Boundary | The area where two (2) tectonic plates are moving AWAY from each other; features are mid-ocean ridges and rift valleys; Ex. Red Sea |
Transform Boundary | The area where two (2) tectonic plates slide roughly past each other building up pressure which can cause earthquakes; features are faults; Ex. San Andreas Fault |
Hot spot | Hot areas of Earth's mantle where very hot/high-temperature "tunnels" of magma rise to the surface |
Epicenter (in regards to earthquakes) | The point on Earth's surface directly above the focus; where surface waves originate from |
Focus (in regards to earthquakes) | The area where the waves originate from during an earthquake (point of failure) |
Pangaea | The supercontinent that all of the current continents are thought to have broken away from; mean "all the earth" |
Geohazard | Something that can happen geologically (mudflow, landslides, etc...) that can cause property damage or potentially injure/harm people |
Reverse Fault | Formed from horizontal and vertical compression that squeezes the rock and creates a shortening of the crust; causes rock on side of reverse fault to be pushed up relative to the other side; convergent plate boundaries |
Strike-slip Fault | Caused by horizontal shear; Ex. San Andreas Fault; can be found/are similar to transform boundaries |
Normal Fault | Movement is partially horizontal and partially vertical; pulls rock apart and stretches the crust; one side of the fault moves down relative to the other side; similar to/are divergent boundaries |
Compression | Stress that decreases the volume of a material |
Tension | Stress that pulls a material apart |
Shearing | Stress(ing) that causes a material to twist |
Felsic | Lighter colored rocks/minerals |
Mafic | Darker colored rocks/minerals |