EARTHQUAKES

ALL OF CH.4

earthquake

a sudden shaking of the ground caused by the movement of tectonic plates in the earth's crust

epicenter

the point on the earth's surface directly above the focus of an earthquake, often experiencing the strongest shaking

seismic wave

a wave of energy that travels through the earth's layers, generated by the release of stress during an earthquake

three types of seismic waves are…

p-waves, s-waves, and surface waves.

s-wave

a type of seismic wave that is slower than p-waves and can only travel through solids, often breaking the ground

p-wave

a type of seismic wave that travels fastest and can move through both solids and liquids, compressing and expanding the material as they pass

surface wave

a type of seismic wave that travels along the earth's surface, causing the most damage due to their larger amplitudes and longer durations

focus

the area beneath Earth’s surface where rock that was under stress begins to break or move

seismograph

an instrument that records and measures an earthquake’s seismic waves

Modified Mercalli Scale

rates the amount of shaking from an earthquake

magnitude

a single number geologists assign to an earthquake based on it’s size

Richter Scale

a magnitude scale rates the magnitude of a small earthquake based on the size of the waves recorded by seismographs

The moment magnitude scale

used to rate the total energy an earthquake releases

longitude waves

are also p-waves

traverse waves

also s-waves

more magnitude equals

more effects

magnitude above 6 causes…

LOTS of damage

how is an epicenter located?

seismic waves locate it

locating epicenter helps…

find future prone areas

seismic waves travel at…

different speeds