What is an Earthquake?

Aftershocks

Adjustments following a major earthquake often generate these smaller earthquakes

Earthquake

Ground shaking caused by the sudden and rapid movement of rock slipping past another.

Seismic waves

Huge amounts of stored up energy released by earthquakes

Faults

Large fractures in the Earth's crust where earthquakes form from rock slippage.

Subduction

the sideways and downward movement of the edge of an oceanic plate into the mantle beneath another plate.

seismic waves

vibrations that travel through Earth carrying the energy released during an earthquake

Richter scale

A scale that rates an earthquake's magnitude based on the size of its seismic waves.

moment magnitude scale

A scale that rates earthquakes by estimating the total energy released by an earthquake

Focus (Hypocenter)

The location below the earth's surface where the earthquake starts. The location where rock slippage begins.

Epicenter

The point on Earth's surface directly above the focus (hypocenter)