The earliest scientists first observed the waves that earthquakes produce before they could accurately describe the nature of earthquakes or their fundamental causes, as discussed in Lessons 1–5.

This seismogram shows a 24-hour record of how much the ground moves at Weston Observatory in Weston, Massachusetts. Viewing other seismic stations will show you how much the ground moves in those ...

A seismometer is an instrument that records the shaking of the Earth's surface caused by seismic waves. The term seismograph usually refers to the combined seismometer and recording device. The first ...

That sudden breaking of the foam rubber is the earthquake. That's what happens along a strike-slip fault. Seismic waves can also be caused by natural processes other than earthquakes and by human ...