EEW
Earthquake early warning (EEW) systems attempt to provide seconds to tens of seconds of warning before the onset of damaging ground motions during an earthquake. The Real-Time Seismology group at the SED focuses its EEW efforts on the Virtual Seismologist (VS) algorithm, a Bayesian approach to regional, network-based EEW.
The VS algorithm (1) rapidly detects the initiation of an earthquake, (2) estimates magnitude and location, and (3) predicts the expected peak ground motion throughout the region. As a Bayesian approach, VS has the potential to use prior information such as the Gutenberg-Richter magnitude-frequency relationships, network topology, and various timescales of earthquake forecasts.
VS has been tested offline in Switzerland, and in real-time in California since July 2008.
VS is one of the three EEW algorithms (along with the ElarmS approach of UC Berkeley and the TauC/Pd approach of Caltech) contributing to the California Integrated Seismic Network (CISN) ShakeAlert system, a prototype, state-wide EEW system for California.
VS implementation efforts have been supported by the US Geological Survey (2009-2012) and by the SAFER (Seismic Early Warning for Europe) project (2006-2009).
Downloads
G. Cua, M. Fischer, M. Caprio, T. Heaton, J. Clinton, and the CISN Earthquake Early Warning Project Team (2010), Faster Alert Information Through Multiple Threshold Event Detection in the Virtual Seismologist (VS) Earthquake Early Warning Algorithm. American Geophysics Union Fall Meeting, San Francisco, California, cua10vs-mted.pdf
Cua, G, M. Fischer, T. Heaton, S.
Wiemer (2009), Real-Time Performance of the Virtual Seismologist
Earthquake Early Warning Algorithm in Southern California, Seism.
Res. Lett. 80 (5), p740-747 doi:10.1785/gssrl.80.5.740, cua09realtime-virtual-seismologist.pdf
Cua, G. and the CISN EEW group (2009),
CISN ShakeAlert: Three Years of Comparative Real-Time Earthquake
Early Warning Testing in California. American Geophysics Union Fall
Meeting, San Francisco, California, cua09eew-testing-california.pdf
