Terms

Question 1

Accelerometer

Answer 1

Sensors that measure changes in speed, such as the shakes produced by earthquakes

Question 2

Seismometer

Answer 2

An instrument that measures earth waves

Question 3

Earthquake

Answer 3

A series of low-frequency shock waves traveling through the earth

Question 4

Stress

Answer 4

A measure of force exerted within an object

Question 5

Compression

Answer 5

A force being pressed down onto an object

Question 6

Tension

Answer 6

Taking slack out of a flexible object-as in pulling on a rope in tug-of-war.

Question 7

Shear

Answer 7

Exists when forces are acting in opposite directions on different parts of the same object

Question 8

Divergent Boundaries

Answer 8

The plate sections of the earth that move apart

Question 9

Convergent Boundaries

Answer 9

The plates that move toward each other

Question 10

Transform Boundaries

Answer 10

Places where plates slide past each other in opposite directions along long cracks in the crust.

Question 11

Strain

Answer 11

The distortion, bending, stretching, or compression of a material under stress.

Question 12

Joints

Answer 12

Cracks in rocks

Question 13

Fault

Answer 13

Occurs when the sections of rock on opposite sides of the crack move relative to each other

Question 14

Fault Plane

Answer 14

The smooth surface between two pieces of a broken rock

Question 15

Strike

Answer 15

The direction of a fault

Question 16

Dip

Answer 16

The angle of the fault face downward from the horizontal

Question 17

Normal Fault

Answer 17

When the block above the faults surface drops in relation to the block under the fault

Question 18

Reverse Fault

Answer 18

Upper block rises in relation to lower block

Question 19

Dip-Slip Fault

Answer 19

A fault’s motion that is parallel to its dip (up and down).

Question 20

Strike-Slip Fault

Answer 20

Strike-Slip Fault

Question 21

Lubricants

Answer 21

Oil, grease, and other substances used to reduce friction

Question 22

Locked Fault

Answer 22

Builds up shear stresses, as the adjacent plates continue to move slowly

Question 23

Aftershock

Answer 23

Secondary earthquakes

Question 24

S Waves

Answer 24

The second type of waves to arrive at a seismic station

Question 25

P Waves

Answer 25

The fastest body waves

Question 26

Body Waves

Answer 26

waves that pass right through the earth

Question 27

Focus

Answer 27

center of earthquake - underground

Question 28

Epicenter

Answer 28

A spot of the earth’s surface directly above the focus

Question 29

Richter Scale

Answer 29

A scale that measures the strengths of earthquakes

Question 30

Magnitude

Answer 30

Indicates the energy released by the earth movement

Question 31

Intensity

Answer 31

A measure of how much damage that actually results from the earthquake

Question 32

Modified Mercalli Intensity (MMI)

Answer 32

The earthquake destructiveness scale

Question 33

Two types of surface waves

Answer 33

love and rayleigh waves

Question 34

amount of energy change with each level on the Richter scale

Answer 34

31.6

Question 35

Analogous day theory

Answer 35

a symbolic day where any period of time on Earth could pass for one “workday” and not a literal 24 hours