Seismic waves!

are waves of energy that travel through the Earth's layers, and are a result of an earthquake

There are 3 types of Seismic waves.

- P wave (Primary waves) : they are the waves that come first, it is not so dangerous and it moves the crust right and left.

- S waves (Secondary Waves) : They are the second waves to arrive and they move the crust up and down.

- L waves: This kind of waves come at last and it is the most dangerous and destructive waves. It moves the crust in a circular way which cause many buildings to be destroyed.

These waves are measured by seismograph.