Seismic Waves
Seismic waves are energy waves that are created by earthquakes or explosions. There are three different types of seismic waves: the Primary, Secondary and Surface waves. Have you ever heard your plates banging against each other? Well maybe an earthquake is going to happen, keep reading to know more about it.
Primary Waves
Primary waves or P waves travel the fastest of all three types of waves. Primary waves can pass through solids, liquids and gases. They cause a slight vibration (compression). Primary waves provide warnings that an earthquake is happening, and are able to prepare people a few seconds before the earthquake and the other waves that will follow.
Secondary Waves
Secondary waves or S waves travel slower than the P waves. They can pass through solids, but not liquids or gasses.
Surface Waves
Surface waves are the slowest of the three waves, but their rolling motions can break through roads and buildings. Surface waves cause the most damage during an earthquake. Have you ever thrown a small pebble into water? Well if you have and watched the ripples spread out from the point the pebble entered the water then you have seen surface waves. Surface waves caused by earthquakes travel the Earth the same way. Surface waves cause parts of buildings to move up, while others move down. Rigid structures will collapse if the movement is really big.