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Internal Structure
Vocab
Term | Definition |
---|---|
lithosphere | the rigid outer part of the earth, consisting of the crust and upper mantle. |
asthenosphere | the upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur. |
hydrosphere | all the waters on the earth's surface, such as lakes and seas, and sometimes including water over the earth's surface, such as clouds. |
magnetic field | a region around a magnetic material or a moving electric charge within which the force of magnetism acts. |
Magnetosphere | the region surrounding the earth or another astronomical body in which its magnetic field is the predominant effective magnetic field. |
Atmosphere | the envelope of gases surrounding the earth or another planet. |
dynamo effect | a geophysical theory that explains the origin of the Earth's main magnetic field in terms of a self-exciting (or self-sustaining) dynamo. |
continental drift hypothesis | A term, no longer used by geologists, that refers to the fact that continents are not stationary, but move across the Earth's surface. |
subduction zone | is the biggest crash scene on Earth. These boundaries mark the collision between two of the planet's tectonic plates. |
lamproites | are ultrapotassic mantle-derived volcanic and subvolcanic rocks. They have low CaO, Al2O3, Na2O, high K2O/Al2O3 |
transform plate boundaries | A transform fault or transform boundary, is a type of fault whose relative motion is predominantly horizontal, in either a sinistral or dextral direction. |
divergent plate boundaries | A tectonic boundary where two plates are moving away from each other and new crust is forming from magma that rises to the Earth's surface between the two plates. |
convergent plate boundaries | a destructive plate boundary (because of subduction), is an actively deforming region where two (or more) tectonic plates or fragments of the lithosphere move toward one another and collide |
conduction | the process by which heat or electricity is directly transmitted through a substance when there is a difference of temperature or of electrical potential between adjoining regions, without movement of the material. |
convection | the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat. |
radiation | divergence out from a central point, in particular evolution from an ancestral animal or plant group into a variety of new forms. |
plasma | an ionized gas consisting of positive ions and free electrons in proportions resulting in more or less no overall electric charge, typically at low pressures. |
Geomagnetic reversals | a change in a planet's magnetic field such that the positions of magnetic north and magnetic south are interchanged, while geographic north and geographic south remain the same. |
Coriolis effect | an effect whereby a mass moving in a rotating system experiences a force (the Coriolis force ) acting perpendicular to the direction of motion and to the axis of rotation |
ophiolite | an igneous rock consisting largely of serpentine, believed to have been formed from the submarine eruption of oceanic crustal and upper mantle material. |
Global warming | a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants. |
plate tectonics | a theory explaining the structure of the earth's crust and many associated phenomena as resulting from the interaction of rigid lithospheric plates that move slowly over the underlying mantle. |
Doppler Effect | an increase (or decrease) in the frequency of sound, light, or other waves as the source and observer move toward (or away from) each other. |
Greenhouse Effect | the trapping of the sun's warmth in a planet's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface. |
Mantle | is the part of the earth between the core and the the crust is the MANTLE. It is about 1,800 miles(2,900 km) thick and makes up nearly 80 percent of the Earth's total volume. |
seismograph | an instrument that measures and records details of earthquakes, such as force and duration. |
seismic waves | an elastic wave in the earth produced by an earthquake or other means. |
sea-floor spreading | the formation of new areas of oceanic crust, which occurs through the upwelling of magma at midocean ridges and its subsequent outward movement on either side. |
xenolith | a piece of rock within an igneous rock that is not derived from the original magma but has been introduced from elsewhere, especially the surrounding country rock. |