geology exam 3 (2)

normal fault has what stress type

tension

reverse fault has what stress type

compression

strike slip faults have _____ movement

horizontal movement

strike slip faults have what kind of stress

shear stress

nromal faults land ___

drops

as linear ridges can form

reverse faults land ___

pushes up

mountains form

types of strike slip faults:

right-lateral : opposite side slides right

and left-lateral : opposite side moves left

whats an example of a strike slip fault

The San Andreas Fault in California

what are rock folds caused by?

ducile deformation under compressive stress during long periodsd 

faults

crack in the earth with offset

joints

cracks in the earth without offset

fault scarp

cliff formed from earthquake movement 

what are the 3 fold types

Anticline,

Syncline,

monocline.

Anclien shape is

convex upward

syncline shape is

concave upward

mooncline shape is

Steplike folds

what plate boundary is the san andreas fault

transform 

Sesmic waves

when rocks break it realses sesmic waves

Primary waves (P waves)

• fasrest waves

• comes first

• push pull movement (compresses than expands)

Secondary waves (s waves)

• slower than P waves 

• comes second 

• moves side to side 

• cannot move through liquid 

Surface waves

• slowest seismic waves

• travel along the Earth's surface

• cause the most damage during an earthquake \

• come after secondary waves

love waves

• very damaging

• moves side to side

Rayleigh waves

• make the ground roll in waves

What kind of plate boundary produces the largest, most powerful earthquakes

converget

focus

where the earthquake starts underground

epiccenter

the point directly above the focus on the Earth's surface where seismic waves are first felt.

fault

a crack that moves 

slipage

the movement along a fault line that occurs during an earthquake or tectonic activity.

amount the rocks have moved

seismograph

an instrument that detects and records the intensity, duration, and direction of seismic waves generated by earthquakes.

seismogram

a visual record produced by a seismograph, showing the seismic waves and their characteristics during an earthquake.

magnitude scales

measures the energy that was released

Richer scale

• old system

• based on wave amplitudes

Logarthmic

scale used in the Richter scale

to quantify the amount of seismic energy released,

where each whole number increase represents a tenfold increase in measured amplitude.

moment magnitude scale

• used today 

• based on: area of fault, slip, and rock strength 

Intensity scale

• measures the effects of earthquakes on people and structures, describing how much shaking is felt and the damage caused.

• based on damage and peoples experience

I

barley felt

XII

total destruction

earthquakes can cause

• ground shaking 

• liquefaction 

• landslides 

• surface rupture 

• Tsunamis 

ground shaking 

the main cause of destruction

Liquefaction

• wet loose soil turns into a liquid

• buildings sink or fall over

Landslides

• hillslides collapse

Surface Rupture

• fault breaks the ground surface

Tsunamis

• caused by underwater earthquakes

• huge waves that travel fast across the ocean

• convergent boundaries

plate boundaries and Earthquakes

convergent → biggest earthquakes 

transform → strong shallow quakes 

divergent → small, frequent quakes 

Elastic rebound theory

A theory that describes how energy is released during an earthquake.

Intraplate earthquake

Earthquake that occurs within a plate, away from plate boundaries

main shock

Largest earthquake in an earthquake sequence.

Foreshock

An earthquake that sometimes occurs before the larger mainshock.

Aftershock

Earthquake(s) that occur after the mainshock, usually decreasing in amount and magnitude over time.

Seismic gap

Length of fault without earthquake activity, due to a locked segment of a fault

Confining stress

Non-directional stress resulting from burial; also called lithostatic stress

Elastic deformation

A type of deformation that reverses when the stress is removed.

Ductile deformation

A bending, squishing, or stretching style of deformation where an object changes shape smoothly.

Brittle deformation

A style of strain in which an object suddenly breaks, fractures, or otherwise fails.

Elastic limit

An amount of strain

where the substance has a maximum amount of elastic deformation

and switches to ductile deformation.

Dip

The angle at which a rock layer or fault is inclined from the horizontal.

Dip-slip faults

Faulting that occurs with a vertical motion.

Thrust fault

A low-angle reverse fault, common in mountain building.

Strike-slip faults

Faulting that occurs with shear forces,

typically on vertical fault planes,

as two fault blocks slide past each other.

Oversteepen

A slope, that by natural or human activity, becomes steeper than the angle of repose.

Creep

Slow, downward progression of regolith down a low grade slope

Slump

Movement of regolith along a curved slip plane

Debris flow

A mixture of coarse material and water, channeled and flowing downhill rapidly

Mud flow

Flow of water that contains a large amount of suspended particles and silt

Rock slide

Failure and movement of rock along failure surface

Debris slide

Failure and movement of debris along failure surface

Rock fall

Detached, free-falling rocks from very steep slopes.