Earth Science Chapter 6

Front 1

how does stress in the crust change earths surface?

Back 1

streches, slips, folds earth

Front 2

Where are the faults usually found, and why do they form?

Back 2

occur along plate boundaries where the forces of plate motion push or pull the crust so much that the crust breaks

Front 3

What land features result from the forces of plate movement?

Back 3

anticlines and synclines

Front 4

stress

Back 4

a force that acts on rock to to change its shape or volume.
- it can stretch fold or slip rocks in the crust.

Front 5

tension

Back 5

pulls on the crust, streching rock so that it becomes thinner.
-occurs when 2 plates move apart.

Front 6

compression

Back 6

squeezes rock until it folds or breaks.
-when one plate pushes against another plate.

Front 7

shearing

Back 7

a type of stress that pushes a mass of rock in two opposite directions.
- causes rock to break or slip apart

Front 8

normal faults

Back 8

A type of fault where the hanging wall slides downward.
- the rocks move at an angle
- they move apart

Front 9

hanging wall

Back 9

the block of rock that lies aboe the fault.

Front 10

foot wall

Back 10

the block of rock that lies underneath the fault.

Front 11

reverse fault

Back 11

when the blocks of the faults move in opposite directions.
-when rocks push each other

Front 12

strike-slip fault

Back 12

when the blocks of the faults slide side ways.
-because rocks move past each other
-no up or down motion (moves side ways)

Front 13

anticline

Back 13

a fold in the rocks that nbends upward into an arch.

Front 14

syncline

Back 14

a fold in rock that bends downward to form a valley.

Front 15

How does the energy of an earthquake travel through Earth? Describe the steps.

Back 15

seismic waves carry energy from an earthquake away from the focus, through earths interior, an across the surface.
- first waves that arrive are P waves.
- Second are S waves
- and last are surface waves which destroy places.

Front 16

What are the scales used to measure the strength of an earth quake?

Back 16

the most common scales are the mercalli scale, richter cale, and the moment magnitude scale.

Front 17

earthquake

Back 17

the shaking annd trembling results from the movement of rock beneath earths surface.

Front 18

focus

Back 18

the area beneath earths surface where the rock that is under stress breaks making an earthquake.
- the place where the earth quake is triggered.

Front 19

epicenter

Back 19

the center right above the focus

Front 20

P waves

Back 20

are siesmic waves that compress and expand the ground
- first waves to arrive.
- compress ad expand ground
- they damage buildings

Front 21

S waves

Back 21

siesmic waves the vibrate sid to side and up and down.
- they are the second to arrive
-they shake buildings violently
-do not move through liquid

Front 22

Surface waves

Back 22

are siesmic waves the exspand out wards.
- last to arrive (when s waves reach epicenter)
- produce severe ground movements
- they roll the ground like ocean waves and shake buildings.

Front 23

mercalli scale

Back 23

a scale to measure earthquakes from 1 to 12
-ratings based on damage
- not used much because the same earth quake could have different rating in certain locations because it is based on damage.

Front 24

Ritcher Scale

Back 24

a scale that bases the earthquake on the size of its siesmic waves.
- fault movements.
- not that accurate.

Front 25

Seismographs

Back 25

measures and records seismic waves.

Front 26

magnitude

Back 26

a number that scientist assighn to the earthquake according to its size.

Front 27

moment magnitude scale

Back 27

a rating system that estimates the total energy released by an earthquake.
-rates earthquakes by there
sizes.
- works for all earthquakes.

Front 28

How do scientist locate the epicenter of an earthquake?

Back 28

they use siesmic waves to locate an earthquakes epicenter.- they measure the diffrence of the P and S waves

Front 29

3 types of sttress

Back 29

tension, comperssion, shearing

Front 30

what causes folds?

Back 30

compression

Front 31

What do folds do to earth?

Back 31

make mountains.

Front 32

What is a fault block mountain?

Back 32

ain that is formed when there are 2 normal faults formed parralel to each other.

Front 33

What is a Plateau?

Back 33

a large are of lfat land elevatred high above sea level.
-they form when forces in the crust push up a large flat block.

Front 34

What is a fault?

Back 34

when enough stress builds in a rock and the rock breaks.

Front 35

What are the three types of faults?

Back 35

-Normal Faults
- Reverse fault
- strike-slip faults.

Front 36

Compare the way that comperssion affects the crust to the way that tension affects the crust?

Back 36

tension stretches the crust and compression folds or breaks the crust

Front 37

What are the three types of siesmic waves?

Back 37

- P waves (primary waves)
-S waves (secondary waves)
- Surface Waves

Front 38

How does an earthquake form?

Back 38

the forces of plate movement, when to plates collide.

Front 39

Where does an Earth quake begin- what layer?

Back 39

in the lithsophere, upper mantle

Front 40

What type of siesmic waves make ground roll like ocean waves?

Back 40

Surface waves

Front 41

what is magnitude for a small, moderate, powerful earthquake?

Back 41

it would be a small number because the earth quake is small and it is rated on its size.

Front 42

how is magnitude measured using Richter scale?

Back 42

its is rated on the earthquakes siesmic waves.

Front 43

how doe seismographs work?

Back 43

sesimic waves cause the seismographs drum to vibrate. but the suspended weight with the pen attached moves very lttle. There fore the pen stays in place and records the drums vibrations.

Front 44

how do geologists monitor faults?

Back 44

with instruments to measure changes in elevation, tilting of the lands surface and ground movements along faults.

Front 45

seismogram

Back 45

the record of an earthquakes seismic waves produced by a seismograph.
- zig zag pattern of lines

Front 46

how do you read a seismograph?

Back 46

when the zig zags are bigger it means that the seismic waves are bigger, when the waves are smalller it means
the the siemic waves are smaller.
-p waves are smaller, followed by S waves, the surface waves

Front 47

What are the 4 types of instuments scientist use to monitor faults?

Back 47

tiltmeters, creep meters, laser-ranging devices, and satellites.
- measure change in elevation , tilting of land, ground movements along fault

Front 48

What are tiltmeters?

Back 48

- instruments that measure tilting or raising of the ground.
- they have two bulbs that are filled with liquid connected to a hollow system.
- if the land tilts then the liquid will go from one light bulb to another.

Front 49

what are creep meters?

Back 49

instruments that measure horizontal movement of the ground around fault
- they consist of a wire stretched across a fault. on pone side of the fault the wire is anchored to a post. on the other side the wire is attached to a whieght that slides every time the fault moves.

Front 50

What are laser- ranging devices?

Back 50

an instument to detect horizantal fault movements.
- it uses a laser the device time the laser as it gos from one place and back.
If the time changes it because the fault has moved.

Front 51

What are GPS Satellites?

Back 51

an instrument that monitors the change in elevation.
- Locate points on earth surface so if earth rises it can tell that the land is cloder up to the satellite.

Front 52

How is siemograph data used?

Back 52

used to map faults and detect changes in faults.
- also scientist are trying to find a method to predict earth quakes.

Front 53

Mapping Faults

Back 53

when siesmic waves hit a fault they bounce off them.
- scientist can use the date to see how deep and long the faults are.

Front 54

Friction

Back 54

the force that opposes the motion of one substance as it moves across another substance.

Front 55

What happens to faults with not much friction?

Back 55

they can slip past eachother.
- can only produce small earth quakes because not much stress in faults.

Front 56

Can scientist predict Earth Quakes?

Back 56

No

Front 57

Why is it difficult to predict earthquakes?

Back 57

because many times scientist think an earthquake is gonna happen but then it fails and notthing happens.

Front 58

how do geologist determine earthquake risk?

Back 58

by studying where faults are active and where past earthquakes have occured.
- earth quakes are likely where faults are storing energy

Front 59

what kinds of damage does an earth quake cause?

Back 59

earthquakes cause damage like
- shaking
- liquifaction
-tsunamis
- after schocks

Front 60

What can be done to increase earthquake saftey ad reduce earthquake damage?

Back 60

is to drop, cover and hold
- drop- to drop down
-cover- to go underneath a tabe or desk
-hold- to hold onto the table or desk as hard as you can
- to prepare buy canned food and water with a first aid kit.

Front 61

What bad does shaking cause after an earth quake?

Back 61

it can cause
-land slides
- avalanches
- it can destroy bridges or buildings.

Front 62

What area of the United States has the highest earthquake risk?

Back 62

the coast of california.
- in the pacific ocean

Front 63

Liquefaction

Back 63

when an earhquakes violent shaking suddenly turs loose and into soft soil to make it into liquid mud.
- cracks open in ground.

Front 64

Aftershock

Back 64

an earth quake that occurs right after a large earthquake.

Front 65

What weakends buildigs alot after earthquakes?

Back 65

aftershcoks

Front 66

tsunamis

Back 66

the water dispaced by an earthquake that forms a large wave.
- happens when an earth quake jolts ocean floor.

Front 67

How an furniture be dangerous during a quake? How can it protect you?

Back 67

- it can fall on you.
- you can hold on to it.

Front 68

How do you reduce earthquake damage?

Back 68

buil stronger buildings and more flexible buildings.

Front 69

base-isolated building

Back 69

a desighn that reduces the amount of energy that reaches a building during an earthquake.
- rest on shock absorbing pads

Front 70

Why do scientists monitor faults?

Back 70

to predict when an earthquake is coming.

Front 71

where is the lowest risk in the U.S. of earth quakes?

Back 71

South east portion.

Front 72

What determines how strong the shaking is in an Earthquake?

Back 72

the plants and soil.
-loose soil more shaking

Front 73

When is liquifaction more likely?

Back 73

when there is a tsunami or an earth quake and the soil under your house turns to mud and your house moves.

Front 74

What is the best way to protect your self in an earthquake?

Back 74

to drop down to the floor and holdon to a piece of furniture.

Front 75

How do tsunamis form?

Back 75

they begin as a low wave and the gradually become a bigger wave.

Front 76

What can you do when desighning a house to make it more Earth quake proof?

Back 76

you can bolt hyour house to the ground, not put and heavy furniture in your room.