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Ch. 12
Vocabulary
Term | Definition |
---|---|
Core | the dense center of the earth made of solid and molten iron and nickel |
Mantle | the layer of earth that surrounding the core; made of both molten magma and solid rock |
Crust | the thin,solid,rocky outermost layer of the earth |
Differentiation | the process of Earth materials separating and sorting by density resulting in a layered structure with the densest material (Fe & Ni) setting in the core |
Tectonic Plate | a large section of the earth’s crust that moves and carries everything on it |
Hotspot | a stationary, high temperature area of melting within the earth’s mantle that can last for several millions of years where superheated mantle magma rises towards the surface |
Rift Valley | a long’ narrow rip or opening, made by the stretching,pulling,or splitting apart of the earth’s crust through which mantle magma reaches the surface adding new crust to the edge of a tectonic plates |
Seafloor Spreading | he theory that oceans widen (open up) and continents are pushed apart as new crust is formed at mid ocean ridges |
Plate tectonic | the theory that the earth’s surface is made of large sections of crust that move and interact with each other |
Continental Drift | the theory that the major landmasses of the earth were once part of one large single super continent that broke apart 200 million years ago |
Mid-Ocean Ridge | a long, underwater mountain range that is split by a rift valley where mantle magma rises and forms new oceanic crust |
Convection current | the circular flow of magma within the molten part of the mantle as it heats up and cools down |
Seismic Wave | a type of vibrating or shaking activity produced by the movement of earth’s tectonic plates |
Palaeomagnetism | a record of the earth’s magnetic field preserved by the alignment of magnetic minerals in the rock of earth’s crust at the time that the rocks were formed at mid-ocean ridges |
Focues | the point inside the earth where rock first moves, starting an earthquake |
Epicenter | the point on the earth’s surface directly over the focus of an earthquake |
Richter Scale | the scale used to measure the magnitude or strength of an earthquake |
Deformation | the process of physically changing the earth’s crust as a result of tectonic forces |
Deformation | the ability of a substance to resist flowing |
Viscosity | a break or fracture in the earth’s crust caused by tectonic plates |
Fault | a scientist that studies the behaviors and characteristics of earthquakes |
Seismologist | the amount of time that passes between the arrival of the first P wave and the first S wave |
Lag Time | a measure of the amount of energy released during an earthquake |
Magnitude | the edges of the continents below sea level that represent the shallowest parts of the oceans |
Continental Margin | an area on the earth’s surface where the edges of tectonic plates are interacting |
Plate Boundary | the geologic process by which one tectonic plate is forced downward into the mantle under another tectonic plate |
Seduction | an area of high subduction activity and frequent volcanic eruption surrounding the Pacific Plate |
Ring of Fire | a renewable energy source that originates from the earth’s own internal heat |
Tectonic Forces | forces generated from within the earth that result in uplift movement or deformation of the earth’s crust |
Volcanic Arc | an arcing chain of volcanic island volcanic mountains formed by the subduction of an oceanic plate into the mantle under another tectonic plate |