Earthquake Vocabulary

Earthquake Vibrations in the earth caused by the sudden release of energy, usually a result of the movement of rocks along a fault.

Fault A fracture in bedrock, along which the opposite sides of the fracture move in opposite directions.

Focus The location where the rupture of an earthquake begins and energy is released. This happens below the earth’s surface.

Epicenter The point on the surface of the earth directly above the focus of an earthquake.

Aftershock An earthquake that follows the main shock of an earthquake.

Seismograph The instrument that detects, records, and measures the vibrations produced by an earthquake.

Seismogram The record made by a seismograph; the paper on which earthquake waves are recorded.

Richter Scale The scale used to categorize the intensity of earthquakes

Plate Tectonics A theory stating that the earth’s surface is broken into plates that move.

Plate A large section of the earth’s surface made of the crust and the rigid top part of the mantle.