Earthquakes

What is an earthquake? The shaking and trembling that results from the sudden movement of part of the Earth’s crust.

Fault A break or crack in Earth’s crust along which movement has occurred.

Focus / Epicenter Focus: The point beneath the earth’s surface where the rocks break and move. Epicenter: The point on the earth’s surface directly above the focus

Seismic Waves P-Waves (Primary Waves): These compression waves travel the fastest and can pass through solids, liquids and gases. P-wave movie

S-Waves (Secondary Waves) These waves travel slower than P-waves and can travel through solids, but not liquids. S-wave movie

L-Waves (Surface Waves) The slowest and most damaging wave that moves through the earth like an ocean wave. L-Wave Movie

Seismograph This is an instrument detects and measures earthquakes.

Tsunamis Also known as Tidal waves, these are ocean waves created by earthquakes.