Earthquakes

Earthquakes:

Earthquakes waves rapidly transport energy away from the focus, radiating out like ripples in a pond when a stone is thrown in, three important types of waves and they travel and different speeds.

First come the primary or compression P-wave. These squeeze the stretch the rock as they pass through at about 8kms-1.
Next come the secondary or shearing S-waves which make the crust shake side ways and up and down as they radiate at about 5kms-1. Liquids absorb S-waves.
The last waves to be felt are the L-waves which travel about 4kms-1 they cause the most damage because they only travel near the surface of the crust. Depending on the nature of the crust, L-waves can make the ground roll like and ocean beneath your feet.