Seismic Waves

Seismic Waves runs under MS-Windows on PCs. It illustrates how earthquake waves propagate through the earth. The user can select from one of several earthquakes distributed with the program. New events can be easily added. When the program starts, the user can bring up a world map on which stars represent the locations of the events. By clicking on a star the user selects an event. Then the user can select GO to start the animation or can select which stations to use and which components for each station. When the animation starts, the user sees a 3-dimensional view of the earth in the lower left hand corner of the screen, a cross-sectional view of the earth in the lower right-hand corner, and a seismograph window at the top. A blast appears on the screen at the hypocenter along with a rumbling sound. The waves then begin to propagate through the earth and the seismograms develop. Each time a major component (P, PP, S, or SS) arrives at a station, a sound is heard.