Any sudden shaking of the ground caused by the passage of seismic waves through Earth's rocks

Describes the severity of an earthquake in terms of its effects on the earth's surface and on humans and their structures

Fastest kind of seismic wave, and, consequently, the first to 'arrive' at a seismic station

The point on the earth's surface vertically above the focus of an earthquake

Seismologists are the scientists who study earthquakes and seismic waves.

A number that characterizes the relative size of an earthquake

Secondary waves are slower than P-waves and can only move through solid rock, not through any liquid medium.

The shaking during an earthquake is caused by seismic waves.

Deeper focus earthquakes are often less damaging because the rocks absorb more energy before the waves hit the surface.