Earthquakes

Front 1

Earthquake

Back 1

Phenomenon that results from the sudden release of stored energy.

Front 2

Fault

Back 2

Fracture or discontinuity in a volume of rock.

Front 3

Seismic Waves

Back 3

Release of stored energy in the form of waves.

Front 4

Seismology

Back 4

Study of elastic waves (seismic waves) that travel through the earth.

Front 5

Seismograph

Back 5

Instrument that records earthquakes (movement of Earth).

Front 6

Seismograms

Back 6

Movement of Earth generates?

Front 7

Wave Frequency

Back 7

Measure of how fast a wave travels (# of wavelenghts in unit time).

Front 8

Wave Amplitude

Back 8

Measure of how strong a wave is.

Front 9

Focus

Back 9

Place within Earth where earthquake waves originate.

Front 10

Epicenter

Back 10

Point on the surface of the Earth, directly above the focus.

Front 11

Elastic rebound theory

Back 11

Explains earthquakes

Front 12

Elastic rebound theory

Back 12

energy is accumulated on opposite
sides of a fault subjected to force
üinitially rocks deform
üwhen their internal strength is
exceeded, a sudden movement occurs
along the fault
üenergy is released and the rocks snap
back to their undeformed shape

Front 13

Foreshocks and Aftershocks

Back 13

Earthquakes are often preceded by _________
and followed by ____________

Front 14

Foreshock

Back 14

Earthquake that occurs before a
larger seismic event (the main shock) and is
related to it in both time and space.

Front 15

Aftershocks

Back 15

Smaller earthquake that occurs
after the main shock, in the same area

Front 16

Surface Waves

Back 16

Travel along the Earth's surface.

Front 17

Surface Waves

Back 17

Complex motion and destructive
Slowest velocity

Front 18

Body Waves

Back 18

Travel through the interior of the earth.

Front 19

P-Waves (Primary)

Back 19

Compressional waves (push–pull)

Travel through solids, liquids, and gases
Greatest velocity

Front 20

S-Waves (secondary)

Back 20

Shear waves

Travel only through solids
Slower than P-waves

Front 21

Intensity

Back 21

Measure effects of earthquakes on the
Earth's surface, humans, objects of nature, and
man-made structures

Front 22

Modified Mercalli Intensity Scale

Back 22

Intensity is most often measured by the

Front 23

Magnitude

Back 23

Measure size of earthquakes in terms of energy released.

Front 24

Richter scale

Back 24

Based on amplitude of largest seismic wave.

Front 25

Moment Magnitude Scale

Back 25

Derived from amount of displacement that occurs along a fault zone.

Front 26

Earthquake Damages

Back 26

Ground shaking

Liquefaction: saturated material turns fluid

Tsunamis: series of water waves caused
by the displacement of a large volume of
water because of a disturbance on the
ocean floor

Mass wasting and ground subsidence

Fires

Front 27

Crust & Upper Mantle

Back 27

Large increases in seismic velocities and density.

Front 28

Mantle

Back 28

Gradual velocity and density increase.

Front 29

Outer Core

Back 29

Dramatic density increase and no S-waves.

Front 30

Inner Core

Back 30

Jump in density and P-wave velocity, S-waves return.

Front 31

Classifying the Layers

Back 31

By chemical composition:

crust: thin, light outermost layer

mantle: made of oxygen
and silicon with Fe and Mg

ücore: consists mainly of Fe
and Ni

Front 32

Mohorovicic Discontinuity

Back 32

Chemical boundary between crust and
mantle

Velocity of seismic waves increases
abruptly across this layer

Front 33

S-waves shadow zone

Back 33

On the side of the earth opposite to the location of an earthquake, indicates the existence of the outer liquid core.

Front 34

Granite

Back 34

Continental crust is mainly composed of

Front 35

Basalt

Back 35

Oceanic crust is composed of

Front 36

Classifying the Layers

Back 36

By physical properties:
ülithosphere: rigid outer
layer, crust + uppermost
mantle
üasthenosphere: deformable
layer of upper mantle
ülower mantle: denser and
less deformable
üouter core: dense, viscous
liquid
üinner core: solid, very
dense