A strong earthquake struck Central California on Tuesday that was felt from San Francisco to the Los Angeles area. There were no immediate reports of injuries.
Automatically and rapidly generated computer maps of the intensity of ground shaking (ShakeMaps) are now available within 5 minutes after an earthquake in southern California.
The map available here shows the influence of a third important factor, the site effect: conditions at a particular location can increase (amplify) or decrease the level of shaking that is otherwise expected for a given magnitude and distance.
This map will assist cities and counties in fulfilling their responsibilities for protecting the public safety from the effects of earthquake-triggered ground failure as required by the Seismic Hazards Mapping Act.