Earthquakes and seismic waves

A sudden and violent shaking of the ground, caused by the movement of tectonic plates and release of energy in the Earth's crust.

earthquake

A sudden and violent shaking of the ground, caused by the movement of tectonic plates and release of energy in the Earth's crust.

Seismic waves

waves and vibrationsproduced by earthquakes that travel through the Earth's layers.

what causes earthquakes?

Earthquakes are caused by the movement of tectonic plates, stress accumulation in the Earth's crust, and the subsequent release of energy.

types of seismic waves

Seismic waves are categorized into two main types: body waves, which include primary (P) waves and secondary (S) waves, and surface waves, which travel along the Earth's surface.

P waves

compress and expand

S waves

vibrate side to side

Surface waves

can produce severe ground movement

focus

the area beneath the surface where rock begins to break or move

Epicenter

point on the surface directly above the focus

how are earthquakes measured

Earthquakes are measured using two primary criteria: Magnitude (the amount of energy released) and Intensity (the amount of shaking and damage caused)

seismograph

scientific instrument used to measure and record ground movements during an earthquake

mercalli scale

rate the amount of shaking produced by an earthquake

magnitude

a single # that describes the strength of an earthquake

Richter scale

the earliest magnitude scale

how is an epicenter located

using seismic waves