HR: 14:20h
AN: S23E-03    [Abstracts]
TI: Calibrating and Implementing the Virtual Seismologist Approach for Earthquake Early Warning in Switzerland
AU: * Cua, G B
EM: georgia.cua@sed.ethz.ch
AF: Swiss Seismological Service ETH Zurich, Schaffmattstrasse 30, Zurich, CH-8093, Switzerland
AU: Fischer, M
EM: michael.fischer@sed.ethz.ch
AF: Swiss Seismological Service ETH Zurich, Schaffmattstrasse 30, Zurich, CH-8093, Switzerland
AU: Clinton, J F
EM: john.clinton@sed.ethz.ch
AF: Swiss Seismological Service ETH Zurich, Schaffmattstrasse 30, Zurich, CH-8093, Switzerland
AU: Wiemer, S
EM: stefan.wiemer@sed.ethz.ch
AF: Swiss Seismological Service ETH Zurich, Schaffmattstrasse 30, Zurich, CH-8093, Switzerland
AU: Heaton, T H
EM: heaton@caltech.edu
AF: California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, United States
AU: Giardini, D
EM: domenico.giardini@sed.ethz.ch
AF: Swiss Seismological Service ETH Zurich, Schaffmattstrasse 30, Zurich, CH-8093, Switzerland
AB: The Virtual Seismologist (VS) method for earthquake early warning is a Bayesian approach to estimating earthquake source parameters (magnitude, location) and predicting the spatial distribution of peak ground motion in real-time. Among the critical components of the VS method are a suite of relationships describing the magnitude, distance, and site-dependence of P- and S-wave amplitudes in various frequency bands and sensor orientations, as well as relationships between the ground motion ratios (between acceleration and displacement) and magnitude. The VS method was originally developed using a southern California database, and hence, its ground motion models are primarily valid for southern California. However, recent attenuation studies by Stafford et al (2007) have suggested that the differences between ground motion attenuation characteristics in areas characterized by shallow, crustal seismicity are small, and that the ground motion models Next Generation Attenuation (NGA) project are valid in Europe. This would suggest that the southern California ground motion models for the VS method (which are essentially attenuation relationships) would be valid in Switzerland, a region of dispersed seismicity and moderate seismic activity. To test this hypothesis, we derive a new set of VS ground motion models, using records from M&>&2.5 events recorded on the Swiss Digital Seismic Network (SDSN) and the Swiss Strong Motion Network (SSMN), and compare these with the southern California relationships. Implementation efforts of the Virtual Seismologist method in real-time currently under way in California, as part of the CISN Early Warning implementation project, and in Europe, as part of the EU-funded SAFER (Seismic eArly warning For Europe) project. We describe the current status of these implementations, and illustrate the method's performance and limitations on Swiss and California waveforms.
DE: 7212 Earthquake ground motions and engineering seismology
DE: 7294 Seismic instruments and networks (0935, 3025)
DE: 7299 General or miscellaneous
SC: Seismology [S]
MN: 2007 Fall Meeting