Chapter 12

Question 1

the sudden return of elastically deformed rock to its undeformedshape.

Answer 1

Elastic rebound

Question 2

a break in abody of rock along which one block slides relative to another

Answer 2

Fault

Question 3

The state a fault is in when it has become immobile

Answer 3

Locked

Question 4

The location within Earth along a fault at which the first motionof an earthquake occurs

Answer 4

Focus

Question 5

The point on Earth’s surface directly above the focus

Answer 5

Epicenter

Question 6

the rocks release energy in the form of vibrations

Answer 6

Seismic waves

Question 7

waves that travel through the body of a medium.

Answer 7

Body waves

Question 8

travel along the surface of a body rather than through themiddle.

Answer 8

Surface waves

Question 9

the fastest seismicwaves and are always the first waves of an earthquake to be detected.

Answer 9

P waves

Question 10

are the second-fastest seismic waves andarrive at detection sites after P waves.

Answer 10

S waves

Question 11

cause rock to move side to side and perpendicular to thedirection in which the waves are traveling.

Answer 11

Love waves

Question 12

cause theground to move with an elliptical, rolling motion.

Answer 12

Rayleigh waves

Question 13

movements of the ground that are caused by a sudden release of energy whenrocks along a fault move.

Answer 13

Earthquakes

Question 14

locations on Earth’s surface where nobody waves from a particular earthquake can be detected.

Answer 14

Shadow zones

Question 15

regions of numerous, closely spaced faults

Answer 15

Fault zones

Question 16

The study of earthquakes and seismic waves

Answer 16

Seismology

Question 17

An instrument that detects and records vibrations in the ground

Answer 17

Seismograph

Question 18

A tracing of earthquake motion that is recorded by a seismograph

Answer 18

Seismogram

Question 19

The measure of the strength of an earthquake

Answer 19

Magnitude

Question 20

A scale that measures the ground motion from an earthquake to find the Earthquake’s strength

Answer 20

Richter scale

Question 21

a measurement of earthquake strength based on the size of the area of the fault that moves, the average distance that the fault blocks move, and therigidity of the rocks in the fault zone.

Answer 21

Moment magnitude

Question 22

A Measure of the effects of an earthquake

Answer 22

Intensity

Question 23

A modified scale that expresses intensity in Roman numerals from I to XII and provides a description of theeffects of each earthquake intensity

Answer 23

Mercalli scale

Question 24

a giant ocean wave

Answer 24

Tsunami

Question 25

an area along a fault where relatively few earthquakes have occurred recently butwhere strong earthquakes occurred in the past.

Answer 25

Seismic gap

Question 26

little earthquakes

Answer 26

Foreshocks