Earth Science- Quiz #3 Earthquakes

Richter scale

A measurement of magnitude and strength

Secondary waves

Arrive 2nd, can only travel through solids(outer core=shadow zone)

Maximum earthquake intensity is usually found at the earthquake's

Epicenter

T or F - S-waves do not travel through Earth's mantle

False

T or F: surface waves are the first to arrive at a seismic facility

False

Primary waves

Fastest, arrive first, stretch and compress the ground, can travel through liquids and solids

A break in the earths crust that is a result of an earthquake is called a

Fault

Too much stress=

Fault(a break in the crust)

One factor that determines the strength of an earthquake is the depth of its

Focus

The point of crystal failure beneath earths surface and where earthquakes originate is called the

Focus

How can a magnitude 6 earthquake do more damage than a magnitude 7 earthquake

Focus is more shallow

All seismometers include a ____ that is anchored to the ground and vibrates during an earthquake.

Frame

As you get farther away from the epicenter what happens to the difference in p and a wave arrival times

Increases

travel-time graph

Locate the epicenter measure difference in arrival times of p and s waves

The Richter scale is a numerical scale used to describe an earthquake's

Magnitude

All seismometers include a ____ suspended from a wire.

Mass

Where do earthquakes happen

Near major plate boundaries

Tensions stress

Normal fault

Can pass through Earth's interior

P and S waves

The type of seismic waves that travels the fastest is

P waves

Focus

Point beneath earths surface where an earthquake starts=crustal failure

Epicenter

Point on earths surface directly above the focus(when under the ocean=tsunami)

Compression stress

Reverse fault

How are earthquakes measured?

Richter scale, travel time graph, triangulation

Famous California strike-slip fault

San Andreas

Seismologist

Scientist who studies earthquakes

Caused rock to move at right angles to the direction in which the wave travels

Secondary waves

What is an earthquake

Shaking or trembling of the Earth that results from rock being stresseed

Shearing stress

Strike slip fault

Seismograph

Tool that records ground movement Information about:earthquake, volcanic activity, earths interior

seismic waves

Travel out in all directions from the focus of the earthquake

Triangulation

Travel time data from 3 locations to find epicenter

T or F - P-waves travel through Earth's mantle

True

T or F - Seismic waves change speed and direction when they encounter different materials

True

Fracture along which movement occurs

fault

Fault surface along which movement takes place

fault plane

As the distance from a quake's epicenter increases,

intensity decreases

Fracture caused by horizontal tension

normal fault

Squeezes and pulls rock in the same direction as the wave travels

primary waves

Fracture that forms as a result of horizontal compression

reverse fault

Each whole number increase on the Richter scale corresponds to a 32 fold increase in

seismic energy

A paper or computer record of earthquake vibrations is a called _______.

seismogram

A ____________ is an instrument that records earthquake vibrations

seismometer

Fracture caused by horizontal shear

strike-slip fault

Causes rock to move both up and down and from side to side

surface waves

Earthquake intensity depends primarily on the height of

surface waves

Travels only along Earth's surface

surface waves