Southern California ShakeOut
The Great Southern California ShakeOut earthquake drill is based on a magnitude 7.8 scenario earthquake on the San Andreas fault in southern California. This portion of the San Andreas fault has been identified as the most likely source of a very large earthquake in California (Working Group on California Earthquake Probabilities). As part of the earthquake drill, computer simulations of the ground shaking from this scenario earthquake were constructed through a collaborative effort between the USGS and the Southern California Earthquake Center, which involved researchers from the USGS, URS Corporation, San Diego State University, and Carnegie Mellon University. These computer simulations capture the shaking at length scales larger than about 300 ft (100 m) and provide detailed pictures of the shaking for this scenario earthquake. The magnitude 7.8 scenario earthquake ruptures 186 miles (300 km) of the San Andreas fault from Bombay Beach at the edge of the Salton Sea in the south to Lake Hughes northwest of Palmdale in the north. The final slip (offset across the fault) ranges from 6-23 ft (2-7 m). The colors in the movies indicate the peak intensity of the shaking up to the current time at each location. See Explanation of Colors for a more detailed description of the color scheme. The movies are available as QuickTime files in three different resolutions. The low resolution versions movies are typically 5-10 MB in size. The high resolution versions are typically 10-20 MB in size and best downloaded using a high-speed internet connection. The high definition (HD) versions are typically 50-80 MB in size and are best viewed on high resolution displays. These images and movies are in the public domain and may be used freely. Please credit the U.S Geological Survey and the Southern California Earthquake Center.