When an earthquake occurs, it releases energy in the form of seismic waves that radiate from the earthquake source in all directions.



The waves differ in their velocities and the type of tremor that they generate.

The fastest wave, and therefore the first to arrive at a given location, is called the P wave. The P wave alternately compresses and expands material in the direction that it travels.

The S wave (the destructive wave), is slower than the P wave and arrives next, shaking the ground up and down perpendicular to the direction it is traveling.

Earthquake Alert™ is designed to detect the first to arrive wave (P wave) to let you know the destructive wave (S wave) is on the way. Earthquake Alert™ thus, gives you an opportunity to get yourself and your family out of harm's way.