A preliminary report on the Great Wenchuan Earthquake

The May 12, 2008 Great Wenchuan Earthquake has resulted in more than 68,858 deaths and losses in the hundreds of billions RMB as of May 30, 2008, and these numbers will undoubtedly increase as more information becomes available on the extent of the event. Immediately after the earthquake, the China Earthquake Administration (CEA) responded quickly by sending teams of experts to the affected region, eventually including over 60 staff members from the Institute of Engineering Mechanics (IEM). This paper reports preliminary information that has been gathered in the first 18 days after the event, covering seismicity, search and rescue efforts, observed ground motions, and damage and loss estimates. The extensive field investigation has revealed a number of valuable findings that could be useful in improving research in earthquake engineering in the future. Once again, this earthquake has shown that the vertical component of ground motion is as significant as horizontal ground motions in the near-source area. Finally, note that as more information is gathered, the numbers reported in this paper will need to be adjusted accordingly.