WHAT IMPACT DO WHAT IMPACT DO EARTHQUAKES HAVE ON EARTHQUAKES HAVE ON

OUR LIVES?OUR LIVES?

WHAT IS A WAVE?WHAT IS A WAVE? WaveWave: Transference of energy: Transference of energy P WaveP Wave (longitudinal): A (longitudinal): A primaryprimary wave vibrates wave vibrates

parallel to direction of movementparallel to direction of movement S WaveS Wave (transverse): A (transverse): A secondarysecondary wave vibrates wave vibrates

perpendicular to the direction it advancesperpendicular to the direction it advances L WaveL Wave: When S and P waves reach surface and : When S and P waves reach surface and

cause horizontal movement of earthcause horizontal movement of earth

WHAT CAUSES WHAT CAUSES EARTHQUAKESEARTHQUAKES??

Movement of plates cause stress and tension to build upMovement of plates cause stress and tension to build up FocusFocus: Location inside earth where earthquake originates : Location inside earth where earthquake originates

also called hypocenteralso called hypocenter EpicenterEpicenter: Point on earth’s surface directly above focus: Point on earth’s surface directly above focus Shadow zoneShadow zone: Area on earth where there are no waves, : Area on earth where there are no waves,

caused by the inner corecaused by the inner core

HOW DO WE DETERMINE THE HOW DO WE DETERMINE THE LOCATION OF THE EPICENTER?LOCATION OF THE EPICENTER? SeismographSeismograph: :

Instrument that Instrument that measures measures earthquakesearthquakes

Need Need threethree seismograph seismograph readings to readings to determine the determine the locationlocation

HOW DO WE MEASURE HOW DO WE MEASURE EARTHQUAKES?EARTHQUAKES?

Richter Richter ScaleScale: : Measures Measures magnitude magnitude or power of or power of earthquakeearthquake

Mercalli ScaleMercalli Scale: Measures : Measures IntensityIntensity

What are the major types of What are the major types of faults?faults?

Normal FaultNormal Fault: divergent : divergent boundary, caused by boundary, caused by tensiontension

Thrust (reverse) FaultThrust (reverse) Fault: : convergent boundary, convergent boundary, caused by compressioncaused by compression

Strike-Slip FaultStrike-Slip Fault: : Transform boundary, Transform boundary, caused by shearcaused by shear

What factors play a role in the What factors play a role in the amount of damage caused by an amount of damage caused by an

earthquake?earthquake?

MagnitudeMagnitude Location of the epicenterLocation of the epicenter Man made structuresMan made structures

What are some safety tips for What are some safety tips for home/school?home/school?

Secure large standing cabinetsSecure large standing cabinets Place safety locks on kitchen Place safety locks on kitchen

cabinetscabinets Secure gas pipesSecure gas pipes Have a main shut off for gas/electricHave a main shut off for gas/electric Do not place loose items high on Do not place loose items high on

shelvesshelves