Earthquakes

Earthquake An earthquake is a sudden and violent shaking of the ground as a result of movements within the Earth’s crust. A fault is a break in the Earth’s crust. The focus of an earthquake is the spot in the crust where the break occurs during an earthquake. The epicenter is the point on the Earth’s surface directly above the focus.

Label the fault, focus and epicenter.

Waves A P wave is a wave that moves through the crust in alternating compressions and stretches. An S wave transmits energy through the Earth at right angles to the path of the wave. A seismograph is an instrument that detects and records earthquakes.