Science-Chapter 11

Front 1

earthquake

Back 1

vibrations produced when rocks break along a fault.

Front 2

epicenter

Back 2

point on Earth's surface directly above an earthquake's focus.

Front 3

fault

Back 3

surface along which rocks move when they pass their elastic limit and break.

Front 4

focus

Back 4

in an earthquake, the point below Earth's surface where energy is released in the form of seismic waves.

Front 5

liquefaction

Back 5

occurs when wet soil acts more like a liquid during an earthquake.

Front 6

magnitude

Back 6

measure of the energy released during an earthquake.

Front 7

normal fault

Back 7

break in rock caused by tension forces, where rocks above the fault surface moves down, relative to the rock below the fault surface.

Front 8

primary wave

Back 8

seismic wave that moves rock particles back-and-forth in the same direction that the wave travels.

Front 9

reverse fault

Back 9

break in rock caused by compressive forces, whererock above the fault surface moves upward, relative to the rock below the fault surface.

Front 10

secondary wave

Back 10

seismic wave that moves rock particles at right angles to the direction of the wave.

Front 11

seismic wave

Back 11

wave generated by an earthquake.

Front 12

seismograph

Back 12

instrument used to register earthquake waves and record the time that each arrived.

Front 13

strike-slip fault

Back 13

break in rocks caused by shear forces, where rocks move past each other without much vertical movement.

Front 14

surface wave

Back 14

seismic wave that moves rock particles up and down in a backward rolling motion, and side to side in a swaying motion.

Front 15

tsunami

Back 15

seismic sea wave that begins over an earthquake focus and can be highly destructive when it crashes on shore.