This is the first frame of what is called a "rupture animation," a graphical model of the energy wave of an earthquake as it passes through the ground. The different colors show the relative strength of the wave as it propagates along the fault line (the dark line in the middle of the frame). This is a rupture animation for the Landers earthquake, a real quake that hit southern California in 1992. The Investigators saw a number of real rupture animations like this one at the seismology lab. Animation provided by John Marquis.

Click on the picture below to load a QuickTime movie of the rupture animation.

For more information about real rupture animations and earthquake science visit the Southern California Earthquake Data Center