Earthquakes

Vocabulary 13

Fault: a huge crack in the crust, at or below the surface, the sides of which may show evidence of motion.

Focus: the point where an earthquake starts, where rocks begin to slide past each other.

Seismic waves: a vibriation that spreads out away from a focus when am earthquake happens.
Epicenter: the point on Earth surface directly above the focus.

Aftershock: the shaking of the crust after the initial shaking of an earthquake.

Seismograph: a sensitive divice that detect the shaking of the crust.
Magnitude: the amount of energy released by an earthquake.