# Shared Flashcard Set

## Details

chapter 8 and 9
Study guide
25
Environmental Studies
03/05/2013

Term
 what causes an earthquake?
Definition
 earthquakes are caused by vibrations of earths produced by the sudden release of energy
Term
 describe the location of an epicenter and focus.
Definition
 epicenter is the location on the surface of earth directly above the focus.focus the the point within the earth where the earthquake starts.
Term
 what is the elastic rebound hypothesis? how does it relate to earthquakes?
Definition
 elastic rebound hypothesis is the release of built-up energy. most earthquakes are porduced by the release of elastic energy stored in rocks that has been subjected to great forves.
Term
 describe aftershock and foreshock.
Definition
 aftershock are small quakes that come after a major earthquake. foreshock are small quakes that come before a major earthquake.
Term
 how are earthquakes measured?
Definition
 historically, scientist have used two different type of measurement to describe the size of an earthquake-intensity and imgnitude
Term
 describe the location of an epicenter and focus.
Definition
 epicent is the location on the surface of earth directly above the focus. focus is the point within the earth where the earthquake starts
Term
 what is the elastic rebound hypothesis?how does it relate to earthquakes?
Definition
 elastic rebound hypothesis is the release of built-up energy. most earthquakes are produced by release of elastic energy stored in rocks that has been subjected to great forces.
Term
 describe aftershocks and foreshocks.
Definition
 aftershock are small quake that come after a major earthquake. foreshocks are small quakes that come before a major earthquake
Term
 how are earthquakes measured?
Definition
 historically, scientist have used two different types of measurements to describe the size of an earthquake-intensity and magnitude
Term
 describe the following earth waves: surface, S waves, and P waves
Definition
 surface waves=seismic waves that travel along earth's outer layers. they move up, down and side to side.
Term
 how do scientist locate earthquakes? (distance direction)
Definition
 the difference in velocities oh P waves provides a way to locate the epicenter. scientist use a travel-time graph, in which one needs at lease 3 seismograph station data
Term
 where do most earthquakes occur?
Definition
 most of these earthquakes occur around the outer edge of the pacific ocean. this zone is known as the circum-pacific belt. active earthquake area in this zoned include japan, the phillipines, chile, and alaska's aelutian island
Term
 describe each of the different scales used to measure earthquaje. which one measures intensity and which one measures magnitude?what is the difference between magnitude and intensity?
Definition
 richter scale=measure the magnitude of an earthquake. based on the amplitude of the largest seismic wave. a ten fold system. news reporter use this scale, but scientist no longer use this scale
Term
 what is liquefaction?
Definition
 stable soil turns into a liquid that is not able to support building or other structure.
Term
 what causes tsunami? what warning system is used?
Definition
 a tsunami is called a seismic sea weave. a tsunami is triggered by an earthquake. it occur where a slab of ocean is displaced vertically along a fault. a tsunami also can occur when the vibration of a quake sets an underwater landslide into motion.
Term
 what are some other dangers that occurs due to earthquakes.
Definition
 landslide and ground subsidence or the sinking of the ground triggered by the vibration occurs.
Term
 describe the layers of earth:
Definition
 crustMantleouter coreinner core
Term
 describe continental drift.
Definition
 the contionental drift hypothesis stated that the continents had once been joined to form a single super continent
Term
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Definition
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition