For earthquakes of M3.5 and higher, the CISN produces maps depicting the intensity of ground shaking. These maps are based on shaking parameters from stations in the combined seismographic networks, supplemented with predicted ground motions in areas where limited data are available, and are distributed electronically within minutes of the occurrence of the earthquake. Maps are updated as additional data becomes available.
At the present time, different and multiple Web sites provide access to the CISN ShakeMaps in northern and southern California. We hope to simplify this interface in the future.
Other sources of ShakeMaps include:
For more information on ShakeMaps and what they mean, please see
ShakeMaps can be used by public and private agencies to facilitate their earthquake response. ShakeCast is a prototype software package for the rapid distribution of ShakeMaps to critical users. In addition to delivering ShakeMaps, the software allows users to define locations of interest and set shaking levels to trigger automatic notification, provide electronic ntofication of events and projected intensity levels, and integrate with in-house GIS systems.