Report on Progress at the Center for Engineering Strong Motion Data (CESMD) H. Haddadi, A. Shakal, M. Huang & J. Parrish California Geological Survey, USA C. Stephens, W. Savage & W. Leith U. S. Geological Survey, USA SUMMARY: Strong-motion data of engineering and scientific importance from the United States and other seismically active countries are served through the Center for Engineering Strong Motion Data (CESMD) at www.strongmotioncenter.org . Recently, the CESMD staff, with cooperation from colleagues at international strong-motion seismic networks, has disseminated strong-motion data from significant earthquakes that occurred in Italy, Haiti, Mexico, New Zealand, Chile, Japan, Turkey, and the United States. The CESMD now automatically posts strong-motion data from an increasing number of seismic stations in California within a few minutes following an earthquake as an Internet Quick Report (IQR). As appropriate, IQRs are updated by more comprehensive Internet Data Reports that include reviewed versions of the data and maps showing, for example, the finite fault rupture along with the distribution of recording stations. Automated processing of strong-motion data will be extended to post the strong-motion records of the regional seismic networks of the Advanced National Seismic System (ANSS) outside California. Transfer of the operational and maintenance responsibilities for the Consortium of Organizations for Strong Motion Observation Systems (COSMOS) Virtual Data Center (VDC) from the University of California at Santa Barbara to the CESMD is nearing completion. The VDC Tagged Format (VTF) file format has been adopted by the CESMD as the standard for converting strong motion data to facilitate the process of uploading data into the VDC database. The CESMD now provides strong-motion records from lower magnitude (<M3.5) and smaller amplitude (<0.5%g) records for use in developing ground motion prediction equations in areas with less frequent earthquakes, such as the Central and Eastern US. Keywords: Earthquake strong motion data, strong motion networks 1. CESMD OBJECTIVES AND OPERATION The Center for Engineering Strong Motion Data (CESMD) collects and disseminates records of ground and structural responses to earthquake strong motions of engineering interest. It is a cooperative effort between the California Geological Survey and the U.S. Geological Survey. Within the United States the primary sources for these records are the extensive accelerograph networks operated by the USGS National Strong Motion Project nationally and the CGS California Strong Motion Instrumentation Program in California, and records are also contributed by many other local, state, and federal agencies. Increasingly, international agencies are also contributing strong-motion records from significant earthquakes that occur globally. More information about the history and background of the CESMD is given in Shakal et al., 2000, and 2003, Lin et al., 2002, Huang et al., 2004, and Haddadi et al., 2008. The CESMD website allows users to view and download records from recent or archived historical