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Ch.12
Vocabulary
Term | Definition |
---|---|
Core | The dense of the earth made of solid and molten iron and nickel . |
Mantle | The layer of earth that surrounds the core ;made of both molten magma and solid rock . |
Crust | the thin , solid , rocky outermost layer of the earth . |
Differentiation | The process of the earth materials separating and sorting by density resulting in a layered structure with the densest material ( Fe & Ni ) settling 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 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 | the theory that oceans widen ( open up ) and continents are pushed apart as new crust is formed at mid-ocean ridges |
PLATE TECTONICS | 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 magma rises and forms new oceanic crust |
CONVECTION CURRENT | the circular flow of magma within the molten as it heats up and cools down |
SEISMIC WAVE | a type of vibrating or shaking activity produced by the movement of magnetic os earth’s tectonic plates |
PALEOMAGNETISM | 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 rock formed at mid-oceanic ridges |
FOCUS | he point inside the earth’s surface directly over the focus of 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 a result of tectonic forces |
VISCOSITY | the ability of a substance to resist flowing |
FAULT | a break or fracture in the earth’s crust caused by tectonic forces |
SEISMOLOGIST | scientist that studies the behaviors and characteristics of e earthquake |
LAG TIME | the amount of time that passes between the arrival of the first P wave and the first S wave |
MAGNITUDE | a measure of the amount of energy released during an earthquake |
CONTINENTAL MARGIN | the edges of the continents below sea level that represent the shallowest parts of the ocean |
PLATE BOUNDARY | an area on the earth’s surface where the edges of tectonic plates are interacting |
SUBDUCTION | the geologic process by which one tectonic plate is forced downward into the mantle under another tectonic plate |
RING OF FIRE | an area of high subduction activity and frequent volcanic eruptions surrounding the Pacific Plate |
ENERGY | a renewable energy source that originates from that earth’s own internal heat GEOTHERMAL |
VOLCANIC ARC | an arcing chain of volcanic islands or volcanic mountains formed by the subduction of an oceanic plate into the mantle under another tectonic plate |