Signals from earthquakes main content.

Signals from earthquakes

Part of Hall of Planet Earth.

Signals From Earthquakes AMNH/R.Mickens

As the shock waves spread away from a rupture, the motion is recorded by seismographs at various distances from it. By knowing when the earthquake waves arrive at different seismograph recording stations, geologists can determine the precise location of the earthquake epicenter. First to arrive are the P (primary) waves, which travel more slowly. Then come the surface waves, which spread across the Earth’s sufrace and cause most of the damage.