HR: 1340h
AN: S13C-1451    [Abstracts]
TI: Modelling transmission properties for seismic waves near important cities worldwide for loss estimates in real-time after earthquakes
AU: ROSSET, P
EM: p_rosset@wapmerr.org
AF: WAPMERR - World Agency for Planetary Monitoring and Earthquake Risk Reduction, Rue de Jargonnant, 2, Geneva, 1207, Switzerland
AU: * WYSS, M
EM: wapmerr@maxwyss.com
AF: WAPMERR - World Agency for Planetary Monitoring and Earthquake Risk Reduction, Rue de Jargonnant, 2, Geneva, 1207, Switzerland
AB: For estimating losses due to earthquakes in real-time and scenario mode, the intensity of ground motion should be calculated as accurately as possible. We have started to assemble a database for transmission properties of seismic waves beneath and in the vicinity of important cities worldwide. Although one may argue that so little is known about local and regional differences in attenuation that a "one-size-fits-all" approach may be justified, it seems clear that, with time, more information will accumulate to justify differentiating regional attenuation properties.
Thus, we begin already now to compile a list of regional attenuation relationships that will cover the world for a database of the loss estimating tool QUAKELOSS2. However, QUAKELOSS2 will allow the user to replace our suggestions for attenuation laws with his own, or one single function for the entire globe. In addition, we are compiling a catalog of microzonation information on cities in seismically active regions. Currently we estimate losses without information on local amplification of ground motion due to soil conditions. This approach works, if a thousand settlements with hundreds of thousands of buildings are affected because then the differences in soil conditions tend to average out.
To improve this first approximation approach, we are beginning to model cities by districts. Each district has its own coordinates, its amplification factor due to soil conditions, its population number, and its composition of building stock, in the ideal case where all this information is available. In our mission to construct a worldwide database, some of these factors will not be known, but with time the database will improve.
Up to now, we have identified about 50 cities for which some information on soil condition is described in the literature. As a first step we are implementing a system of ranking this information according to the detail and usefulness for our purpose, namely to obtain an amplification factor. The testing phase on how much better we may be able to model intensities of past earthquakes, using microzonation data, will begin shortly.
We request that specialists with microzonation information contact us so we can include their data in this worldwide database. In turn, we will assist our collaborators with loss estimates in their country.
DE: 7212 Earthquake ground motions and engineering seismology
DE: 7299 General or miscellaneous
SC: Seismology [S]
MN: 2007 Fall Meeting