Earth Science Chapter 6 Vocabulary

Front 1

earthquakes

Back 1

vibrations of the earth's crust

Front 2

elastic rebound theory

Back 2

theory that rocks that are strained past a certain point will fracture and spring back to their original shape

Front 3

aftershocks

Back 3

a series of small tremors that usually follow an earthquake

Front 4

focus

Back 4

the area along a fault where the slippage first occurs

Front 5

epicenter

Back 5

the point on the earth's surface directly above the focus

Front 6

Pacific Ring of Fire

Back 6

major earthquake zone that forms a ring around the Pacific Ocean

Front 7

fault zones

Back 7

groups of interconnected faults at some plate boundaries

Front 8

seismograph

Back 8

an instrument that detects and records seismic waves

Front 9

P waves (primary waves)

Back 9

move the fastest ad are the first to be recorded by a seismograph, can travel through solids and liquids

Front 10

S waves (secondary waves)

Back 10

the second waves to be recorded on a seismograph, can only travel through solids

Front 11

surface waves

Back 11

slowest moving waves, the last to be recorded on a seismograph

Front 12

magnitude

Back 12

a measure of the energy released by an earthquake and is also described as the amount of ground motion

Front 13

microquakes

Back 13

earthquakes with magnitudes of less than 2.5

Front 14

Mercalli scale

Back 14

scale that expresses the intensity of an earthquake with a Roman numeral and a description

Front 15

intensity

Back 15

amount of damage it causes

Front 16

tsunami

Back 16

a major earthquake with an epicenter on the ocean floor that sometimes causes a giant ocean wave

Front 17

seismic gaps

Back 17

a place where the fault is locked and unable to move