Earthquakes

Front 1

Define: Earthquake

Back 1

a sudden motion or trembling of Earth, caused by the abrupt release of energy that is stored in rocks

Front 2

Define: Plastic Deformation

Back 2

when elastic limit is reached, a rock continues to deform like putty

Front 3

Earthquakes don't occur when rocks deform ______.

Back 3

plastically

Front 4

most movement of crustal rock occurs by slippage along _____ ______.

Back 4

established faults

Front 5

earthquakes often occur repeatedly along ____ ____.

Back 5

established faults

Front 6

Define: Seismic Waves

Back 6

waves of energy that travel through Earth's layers as a result of an earthquake

Front 7

2 kinds of seismic waves

Back 7

1. Body Waves

2. Surface Waves

Front 8

Define: Body Wave

Back 8

seismic wave that moves through the interior of the earth and carry some of the energy from the focus to the surface

Front 9

Define: Surface Waves

Back 9

a wave that travels along the surface of Earth or along a boundary between layers within the Earth

Front 10

2 types of Body Waves

Back 10

1. P Waves

2. S Waves

Front 11

Define: P Wave

Back 11

a compressional elastic wave that causes alternate compression and expansion of the rock the type of body wave that reaches observers first

Front 12

Define: S Wave

Back 12

the type of body wave that reaches observers after a P wave and only travels through solids

Front 13

Define: Surface Waves

Back 13

a seismic wave that travels slower than a body wave

Front 14

2 types of surface waves that occur at once

Back 14

1. an up-and-down rolling motion

2. a side-to-side vibration

Front 15

before seismographs, the _____ _____ was used

Back 15

Mercalli Scale

Front 16

Define: moment magnitude

Back 16

the product of the amount of movement and the surface area of a fault that moved during an earthquake

Front 17

on both the Richter scale and the moment magnitude, the energy of the earthquake increases by a factor of ___ for each increment on the scale

Back 17

30

Front 18

the largest possible earthquake is determined by :

Back 18

the strength of rocks

Front 19

Define: time-travel curve

Back 19

the graph created used to measure the distance between a recording station and an earthquake whose epicenter is unknown

Front 20

Define: Strike-Slip Fault

Back 20

vertical fractures where the blocks have mostly moved horizontally

Front 21

Define: Fault Creep

Back 21

when rocks slip past one another at a continuous, snail-like pace

Front 22

this movement occurs within violent and destructive earthquakes because the rocks move continuously and slowly

Back 22

Fault Creep

Front 23

Define: Subduction Zone

Back 23

where a cold, rigid lithospheric plate dives beneath another plate and slowly slips into the mantle

Front 24

Define: Benioff Zone

Back 24

the upper part of the sinking plate where it scrapes past the opposing plate in a subduction zone

Front 25

many of the world’s strongest earthquakes occur in ______ ______.

Back 25

subduction zones

Front 26

earthquakes frequently shake the Mid-Oceanic Ridge system as a result of faults that form....

Back 26

when the 2 plates seperate

Front 27

only ____sha earthquakes occur along the Mid-Oceanic Ridge

Back 27

shallow

Front 28

What is long-term prediction?

Back 28

tells us where earthquakes will occur; earthquakes have recurred many times along existing faults and will probably happen in these same regions again

Front 29

what is short-term prediction?

Back 29

forecasts that an earthquake may occur at a specific time and place

Front 30

Define: Foreshocks

Back 30

relatively smaller earthquakes that precede the largest earthquake in a series

Front 31

2 changes in land near an active fault zone that indicate an earthquake may occur

Back 31

1. distortions of the crust

2. rising water levels

Front 32

structural damage, injury, and death depend on 5 things

Back 32

1. magnitude of earthquake

2. proximity to population centers

3. rock and soil types

4. topography

5. quality of construction

Front 33

what forms a desirable foundation?

Back 33

bedrock

Front 34

what kind of sediment/soil settles during an earthquake, causing buildings to tip, pipelines to break, and roads to fracture?

Back 34

sandy

Front 35

Define: liquefaction

Back 35

water-saturated sediment temporarily loses strength and acts as a fluid, caused by earthquakes

Front 36

Define: Focus

Back 36

the initial rupture point, where abrupt movement creates an earthquake that lies below of the surface

Front 37

Define: Epicenter

Back 37

the point on Earth’s surface directly above the focus

Front 38

Define: Mercalli Scale

Back 38

a scale of earthquake intensity that measures the strength of an earthquake based off its effect on buildings and people

Front 39

Define: Richter Scale

Back 39

a numerical scale of earthquake magnitude measured by the amplitude of the largest wave on a seismograph