CHRISTIAN KOCH, MICROCHEMICALS / SCIENCE PHOTO LIBRARY CHRISTIAN KOCH, MICROCHEMICALS / SCIENCE PHOTO LIBRARY
Computer simulation of wave propagation during an earthquake. The earthquake begins when two tectonic plates suddenly move past each other. One plate is orange, and in the other the rock is represented by a block of spheres connected with springs. Earthquakes generate several different types of wave, including body waves that move through the rock and surface waves at its surface. Body waves are the fastest, and P waves are the fastest body waves. These are longitudinal compression waves that travel through rock as sound does through air. The earthquake also generates transverse waves called S waves, where the movement is perpendicular to the direction of the wave's travel. Surface waves are slower still, but are far more destructive than the body waves within the Earth. As body waves arrive at a location significantly earlier than surface waves, in some cases they can be used to provide a warning of the arrival of the damaging ground shaking seen in earthquakes.
Model release not required. Property release not required.