Los Angeles Earthquake Maps
Earthquake activity measured by magnitude in the LA area for the last hour, day, and week.

Current and historic information on Southern California earthquakes.  Also included are: Research Archives; Clickable Fault Map of So. Calif., Historical Earthquakes in So. Calif., and more.  You can also read-online or download the full-text of a SCEC earthquake preparedness handbook.

Color-coded map of California from the U.S. Geological Survey that shows the probability that "strong shaking" will occur at a specific location within the next 24 hours.  "Strong shaking" is defined as strong enough to throw objects off shelves.  Updated hourly, the map would be most useful after a trembler powerful enough to break windows.  Residents could then check the possibility of strong aftershocks in their area. 

National Earthquake Information Center (NEIC) USGS lists current worldwide earthquakes and large/significant earthquakes this year.  Included are aerial photos of faults, information on earthquake hazards and prevention.