We present a new strategy to estimate the geometry of a rupture on a finite fault for rapid reporting of seismic intensity. We use envelope attenuation relationships which were presented by Huo et al. （Acta Seismol Sin 16：519-525, 1994）. An important base of this work is the fault finiteness theory. We propose a new model to simulate high-frequency motions from earthquakes with large rupture dimension. The envelope of high-frequency ground motion from a large earthquake can be expressed as a rootmean-squared combination of envelope functions from smaller earthquakes. We use simulated envelopes of ground acceleration to estimate the direction and alongstrike length of a rupture. Using the Wenchuan and Jiji （Chi-Chi） earthquake dataset, we parameterize the fault geometry with an epicenter, a fault strike, and along-strike rupture lengths. So this methodology seems quite appropriate for the rapid reporting systems of seismic intensity.
As a result of our ability to acquire large volumes of real-time earthquake observation data, coupled with increased computer performance, near real-time seismic instrument intensity can be obtained by using ground motion data observed by instruments and by using the appropriate spatial interpolation methods. By combining vulnerability study results from earthquake disaster research with earthquake disaster assessment models, we can estimate the losses caused by devastating earthquakes, in an attempt to provide more reliable information for earthquake emergency response and decision support. This paper analyzes the latest progress on the methods of rapid earthquake loss estimation at home and abroad. A new method involving seismic instrument intensity rapid reporting to estimate earthquake loss is proposed and the relevant software is developed. Finally, a case study using the ML4.9 earthquake that occurred in Shun-chang county, Fujian Province on March 13, 2007 is given as an example of the proposed method.
Hongsheng HuangLin ChenGengqing ZhuLin WangYanzhao LinHuishan Wang
