With what is happening in Nepal and surrounding areas, earthquakes might be on your mind right now, especially if you live and work in SoCal. Here are some maps, data, and resources you can check out.
USGS Seismic Hazard Maps and Data

Caltech Southern California Earthquake Data Center

California Seismic Hazard Zonation Program

American Red Cross PrepareSocal

Global Seismic Hazard Map (1999)

JPEG and PDF versions.
Please post in the comments if you want to share your favorite earthquake sites.


ESRI’s Earthquake Public Information Map: http://www.arcgis.com/apps/PublicInformation/index.html?appid=de7c7b077c0144149fe5f9dd7857361d