What Types of Seismic Waves are Generated?
There are three types of waves that are created when energy is released in an earthquake. The P wave, or primary wave, is the fastest and can move through both liquid and solid rock. P waves, like sound waves, are compressional waves, which mean that they compress and expand matter as they move through it. S waves, or secondary waves, are the waves directly following the P waves. S waves travel at right angles to the direction of motion and can only travel through solid matter. S waves are more significant than P waves because they are usually larger and produce both vertical and horizontal motion in the ground surface. Both P and S waves are called body waves because they move within the Earth’s interior. The third type of wave is the surface wave, which is the slowest of the three waves. These waves move close to or on the outside surface of the ground. How are Earthquakes Measured? Geologists use seismographs to record the surface and body waves. When motion is recorded a seismogram
