Frequently Asked Questions About Compression, Compression Stockings, and Armsleeves. We're always glad to any questions you may have. If you need a quick answer, please use our Live Chat service, available from 9:00 a.m. to 6:00 p.m. Monday to Friday by clicking the Chat Now button to the left.
Seismic waves are waves of energy that travel through the Earth's layers, and are a result of earthquakes, volcanic eruptions, magma movement, large landslides and large man-made explosions that give out low-frequency acoustic energy.
Two types of seismic wave exist, P-and S-waves. They are different in the way that they travel through the Earth. P-waves (P stands for primary) arrive at the detector first. They are longitudinal waves which mean the vibrations are along the same direction as the direction of travel.