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A smaller earthquake that follows a larger earthquake

Body Waves

Waves of energy that travel from the focus of an earthquake through the material of Earth's body; P waves and S waves are two types of body waves


The shaking of Earth's crust caused by a release of energy


The point on Earth's surface directly above the focus of an earthquake


A break in the lithosphere along which movement has occurred


The point at which the first movement occurs during an earthquake


A temporary state in which loose soil and rock materials take on the property of liquid, often as a result of severe ground shaking


The measure of the amount of energy released in an earthquake

P Waves

Body waves that squeeze and stretch rock materials as they pass through Earth; also known as a compressional waves or primary waves

S Waves

Body waves that cause particles of rock material to move at right angles to the direction in which the waves are traveling; also known as shear waves or secondary waves

Seismic Gap

An area along a seismically active fault where no earthquake activity has occurred over a long period of time


The recording of an earthquake made by a seismograph


An instrumentthat detectst and records waves produced by earthquakes

Surface Waves

Earthquake waves that travel along Earth's surface; Love waves and Rayleigh waves are two types of a surface waves


A larage ocean wave that results from an underwater earthquake, landslide, or volcanic eruption

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