Estimating Strong Ground Motion Parameters Using Monitoring Video——Two Cases in the May 12,2008,Wenchuan Earthquake

How to get as many local strong ground motion data as possible is one of the important issues in earthquake disaster investigation.In this paper we studied two cases in the May 12,2008,Wenchuan earthquake,exploring the possibility of recovering strong ground motion parameters from public monitor- ing video which were deployed for security purposes.We used the video of the Ningqiang No.1 Middle School,Hanzhong,Shaanxi Province,and estimated that the felt local strong ground motion lasted 80～100 s.The ground motion started with weak motion,increased gradually,with the peak value appeared at about 40 s.We used the video of a bank in Dujiangyan,Sichuan Province,and estimated that the local ground motion acceleration was at least 0.14 g.