Earthquakes test 1/21/16 Flashcards
What causes Earthquakes
plate tectonics, drilling, explosions, volcanoes, etc…
focus/epicenter
the center of the earthquake
how do you find an epicenter on a map
find the difference between P waves and S waves in arrival time from 3 different seismographs, then measure that in km, then make three circles and the middle will be the epicenter
seismograph
an instrument that records and measures an earthquake’s seismic wave and put data into the seismogram
Different types of stress
tension, shearing, compression
types of faults
normal, reverse, strike slip
types of seismic waves
(p) primary, (s) secondary, surface waves
p waves
p waves are seismic waves that compress and expand like an accordian
s waves
S waves are seismic waves that can vibrate from side to side, up or down
eqipment for measuring earthquakes
modified Mercalli scale, Richter scale, moment magnitude scale
surface waves
surface waves are seismic waves that go in a circle, and makes buildings shake and roll from side to side
focus of an earthquake
The focus of an earthquake is the area beneath the Earth’s surface where rock that was under stress begins to break
epicenter of an earthquake
The epicenter is the point on the surface directly above the focus
stress
a force that acts on a rock to change its shape or volume
normal fault
a fault caused by tension in the earth’s crust pulling the earth;s crust apart