Seismic Waves
When plates slip suddenly, the energy is released as seismic waves. There are three main types of seismic waves that radiate outwards in all directions from the earthquake source, travelling at different speeds and shaking the earth in different ways.
Types of Seismic Waves
There are two types of body waves which move through the earth. Primary waves (P-waves) are the fastest moving waves and can travel at up to 8km per second. They can travel through solids, liquids and gases easily and travel to the earth’s surface. P-waves force the ground to move back and forth as it compresses and expands in the same direction as the waves. Secondary waves (S-waves) move slower with a swaying, rolling motion and shake the ground up and down and back and forth, perpendicular to the direction of the waves. The P-waves can produce an audible sound when they arrive at the earth's surface. A more shallow earthquake produces a louder rumble.
Surface waves are the slowest moving waves, meaning the most intense shaking comes at the end of the earthquake. They move along the surface of the earth and are responsible for most damage caused by earthquakes because they move up and down the earth’s surface, therefore, rocking the foundations of any
man-made structure.
Surface waves are the slowest moving waves, meaning the most intense shaking comes at the end of the earthquake. They move along the surface of the earth and are responsible for most damage caused by earthquakes because they move up and down the earth’s surface, therefore, rocking the foundations of any
man-made structure.