Managed by Caltech, the aptly named ShakeMovie offers a valuable resource for residents of Southern California—downloadable videos (in MPEG format) of recent local seismic events. The videos depict local topography, including cities and major highways, with seismic waves overlaid as they propagate away from a fault rupture. Produced automatically by a computer cluster, they should be available for download within 45 minutes of a local quake of magnitude 3.5 or greater.

The site includes a listing of recent activity, and users can search for quakes by magnitude, by location, by date or by ID number within the database. A well-executed "Science" section explains the mechanics of the system and provides answers to common questions about earthquakes. Users can even sign up for e-mail notifications of new seismic activity.

This is a noteworthy achievement, of value not only to geoscientists but also to the population of Los Angeles and its environs, raising awareness of seismic activity and providing much-needed, and now timely, information.