Earthquakes!!Earthquakes!!

Shake, Rattle and RollShake, Rattle and Roll

Earthquake VideoEarthquake Video

EarthquakesEarthquakes

EarthquakesEarthquakes are the rapid shaking of are the rapid shaking of the the lithospherelithosphere at at faultsfaults, caused by , caused by the release of the potential energy the release of the potential energy stored in the rock layers.stored in the rock layers.

FocusFocusEpicenterEpicenterSeismic WavesSeismic Waves

P-wavesP-wavesS-wavesS-waves

Click Map for Link to USGS Website

Click Map for Link to USGS Website

Elastic Rebound HypothesisElastic Rebound Hypothesis

Elastic ReboundElastic Rebound

EarthquakesEarthquakes

The The focusfocus is the point of stress relief is the point of stress relief in an earthquake (the point inside in an earthquake (the point inside Earth).Earth).

The The epicenterepicenter is the location directly is the location directly above the focus on Earth’s surface.above the focus on Earth’s surface.

Focus, Epicenter, and FaultFocus, Epicenter, and Fault

Seismic WavesSeismic WavesP-wavesP-waves

Primary seismic wavesPrimary seismic waves that travel fastest that travel fastest after an earthquakeafter an earthquake

Arrive firstArrive firstKnown as compression waves (push and pull Known as compression waves (push and pull

motion)motion)Movement is in the direction of wave motion Movement is in the direction of wave motion

(slinky)(slinky)

S-wavesS-wavesSecondary seismic wavesSecondary seismic waves that travel slower that travel slower

after an earthquakeafter an earthquakeArrive secondArrive secondKnown as transverse waves (shaking up and down Known as transverse waves (shaking up and down

motion)motion)Movement is perpendicular to the direction of Movement is perpendicular to the direction of

motion (slinky)motion (slinky)

Seismic WavesSeismic Waves

Earthquake WavesEarthquake Waves

Seismic Wave AnimationSeismic Wave Animation

Seismic Wave MotionSeismic Wave Motion

SeismographSeismograph

An instrument An instrument that measures that measures seismic waves seismic waves and records and records themthem

SeismogramSeismogram

SeismographsSeismographs

Locating an Earthquake Locating an Earthquake EpicenterEpicenter

ESRT p. 11

Earthquake MagnitudesEarthquake Magnitudes

Emergency PlanningEmergency PlanningDeath and injury from earthquake Death and injury from earthquake

damage can be greatly reduced with damage can be greatly reduced with proper planning.proper planning.Remember: Remember: DropDrop, , CoverCover, and , and HoldHold

DropDrop down under a strong object down under a strong objectCoverCover your eyes with one hand your eyes with one handHoldHold the strong object with the other hand the strong object with the other hand

Earthquakes last 10-30 secondsEarthquakes last 10-30 secondsPractice earthquake drillsPractice earthquake drillsHave emergency suppliesHave emergency supplies

Flashlight w/ extra batteriesFlashlight w/ extra batteriesFirst AidFirst Aid

TsunamiTsunami

Large wavelength wave produced by Large wavelength wave produced by strong underwater earthquakes in strong underwater earthquakes in the oceanic crust.the oceanic crust.

As wave approaches shore the height As wave approaches shore the height grows and can produce 30 m waves grows and can produce 30 m waves in extreme cases.in extreme cases.

TsunamiTsunami