Chapter 08 Vocab

Question 1

Aftershock

Answer 1

The series of smaller earthquakes that follow a major earthquake.

Question 2

Body Wave

Answer 2

Seismic waves that pass through the interior of the Earth.

Question 3

Compressional Wave

Answer 3

Waves in which particles of material move back and forth parallel to the direction in which the wave itself moves.

Question 4

Displacement

Answer 4

The amount of movement or slip across a fault plane.

Question 5

Earthquake

Answer 5

A vibration caused by the sudden breaking or frictional sliding of rock in the Earth.

Question 6

Earthquake Early Warning

Answer 6

A communications network that provides an alert within microseconds after the first earthquakes waves arrive at a seismograph near the epicenter, but before damaging vibrations reach population centers.

Question 7

Earthquake Engineering

Answer 7

The design of buildings that can withstand shaking.

Question 8

Epicenter

Answer 8

The point on the surface of the Earth directly above the focus of an earthquake.

Question 9

Fault

Answer 9

A fracture on which one body of rock slides past another.

Question 10

Fault Scarp

Answer 10

A small step on the ground surface where one side of a fault has moved vertically with respect to the other.

Question 11

Fault Trace

Answer 11

The intersection between a fault and the ground surface.

Question 12

Foreshock

Answer 12

The series of smaller earthquakes that precede a major earthquake.

Question 13

Friction

Answer 13

Resistance to sliding on a surface.

Question 14

Intensity

Answer 14

A measure of the relative size of an earthquake (the severity of ground shaking) at a location, as determined by examining the amount of damage caused.

Question 15

Intraplate Earthquake

Answer 15

Earthquakes that occur away from plate boundaries.

Question 16

Modified Mercalli Scale

Answer 16

An earthquake characterization scale based on the amount of damage that the earthquake causes.

Question 17

Moment Magnitude Scale

Answer 17

A scale that defines earthquake size on the basis of calculations involving the amount of slip, length of rupture, depth of rupture, and rock strength.

Question 18

Recurrence Interval

Answer 18

The average time between successive geologic events.

Question 19

Richter Scale

Answer 19

A scale that defines earthquakes on the basis of the amplitude of the largest ground motion recorded on a seismogram.

Question 20

Seismic Belt

Answer 20

The relatively narrow strips of crust on Earth under which most earthquakes occur.

Question 21

Seismicity

Answer 21

Earthquake activity.

Question 22

Earthquake activity.

Answer 22

The strengthening of an already existing structure (building, bridge, etc.) so that it can withstand earthquake vibrations.

Question 23

Seismic Wave

Answer 23

Waves of energy emitted at the focus of an earthquake.

Question 24

Seismogram

Answer 24

The record of an earthquake produced by a seismograph.

Question 25

Seismometer

Answer 25

An instrument that can record the ground motion from an earthquake.

Question 26

Shear wave

Answer 26

Seismic waves in which particles of material move back and forth perpendicular to the direction in which the wave itself moves.

Question 27

Stick-slip behavior

Answer 27

Stop-start movement along a fault plane caused by friction, which prevents movement until stress builds up sufficiently.

Question 28

Stress

Answer 28

The push, pull, or shear that a material feels when subjected to a force; formally, the force applied per unit area over which the force acts.

Question 29

Surface Wave

Answer 29

Seismic waves that travel along the Earth’s surface.

Question 30

Travel-Time Curve

Answer 30

A graph that plots the time since an earthquake began on the vertical axis, and the distance to the epicenter on the horizontal axis.

Question 31

Tsunami

Answer 31

A large wave along the sea surface triggered by an earthquake or large submarine slump.

Question 32

Wadati- Benioff zone

Answer 32

A sloping band of seismicity defined by intermediate- and deep-focus earthquakes that occur in the downgoing slab of a convergent plate boundary.