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 thehundreds of billions RMB as of May 30, 2008, and these numbers will undoubtedly increase as more information becomesavailable on the extent of the event. Immediately after the earthquake, the China Earthquake Administration (CEA) respondedquickly by sending teams of experts to the affected region, eventually including over 60 staff members from the Instituteof Engineering Mechanics (IEM). This paper reports preliminary information that has been gathered in the first 18 daysafter 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 inearthquake engineering in the future. Once again, this earthquake has shown that the vertical component of ground motionis as significant as horizontal ground motions in the near-source area. Finally, note that as more information is gathered, thenumbers reported in this paper will need to be adjusted accordingly.