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Earth & Space Ch.7
Ch.7 Study Stack
Term | Definition |
---|---|
aftershock | smaller earthquakes that follow the main earthquake |
asthenosphere | A subdivision of the mantle situated below the lithosphere. this zone of weak material exists below a depth of about 100 kilometers and in some regions extends as deep as 700 kilometers. the rock within this zone is easily deformed. |
body wave | Seismic waves that travel through Earth's interior. |
core | Located beneath the mantle, it is the inner most layer of earth. the core is divided into an outer core and an inner core. |
crust | the very thin outermost layer of earth |
earthquake | the vibration of earth produced by the rapid release of energy. |
elastic rebound | the sudden release of stored strain in rocks that results in movement along a fault. |
epicenter | the location on earth's surface that lies directly above the focus of an earthquake. |
fault | a break in a rock mass along which movement has occurred. |
focus | the zone within earth where rock displacement produces an earthquake. |
foreshock | small earthquakes that often precede a major earthquake. |
inner core | the solid innermost layer of earth, about 1,300 kilometers (800) miles in radius. |
intensity | a measure of the degree of earthquake shaking at a given locale based on the amount of damage. |
liquefaction | a phenomenon, sometimes associated with earthquakes, in which soils and other unconsolidated materials containing abundant water are turned into a fluid-like mass that is not capable of supporting buildings. |
lithosphere | the rigid outer layer of earth, including the crust and upper mantle. |
magnitude | the total amount of energy released during an earthquake. |
mantle | the 2,900-kilometer- (1,800-mile-) thick layer of earth located below the crust. |
Modified Mercalli Intensity Scale | a 12-point scale developed to evaluate earthquake intensity based on the amount of damage to various structures. |
moment magnitude | a more precise measure of earthquake magnitude than the Richter scale that is derived from the amount of displacement that occurs along a fault zone. |
outer core | A layer beneath the mantle about 2,200 kilometers (1,364) thick that has the properties of a liquid. |
primary waves or P waves | a type of seismic wave that involves alternating compression and expansion of the material through which it passes. |
Richter scale | a scale of earthquake magnitude based on the motion of a seismograph. |
secondary waves or S waves | a seismic wave that involves oscillation perpendicular to the direction of propagation. |
seismic gaps | a segment of an active fault zone that has not experienced a major earthquake over a span when most other segments have. such segments are probable sites for future major earthquakes |
seismic sea waves | large undersea earthquakes occasionally set in motion massive waves that scientists call? |
seismic waves | a rapidly moving ocean wave generated by earthquake activity capable of inflicting heavy damage in coastal regions. |
seismogram | the record made by a seismograph. |
seismograph | an instrument that records earthquakes wave |
seismology | the study of earthquakes and seismic waves |
surface wave | seismic waves that travel along the outer layer of earth. |
tsunami | the Japanese word for a seismic sea wave |
Plate tectonics theory | the theory that proposes that earth's outer shell consists of individual plates that interact in various ways and thereby produce earthquakes, volcanoes, mountains, and the crust itself. |