HR: 09:00h
AN: S21B-04 [PDF]
TI: Progress on Earthquake Rapid Reporting and Early Warning Systems in Taiwan
AU: * Wu, Y
EM: ym.wu@socmail.cwb.gov.tw
AF: Central Weather Bureau, 64 Kung-Yuan Road, Taipei, 100
Taiwan
AU: Teng, T
EM:
AF: University of Southern California, 3651 Trousdale Parkway, Los Angeles, CA 90089-0742 United States
AU: Hsiao, N
EM:
AF: Central Weather Bureau, 64 Kung-Yuan Road, Taipei, 100
Taiwan
AU: Shin, T
EM:
AF: Central Weather Bureau, 64 Kung-Yuan Road, Taipei, 100
Taiwan
AU: Lee, W H
EM:
AF: University of Southern California, 3651 Trousdale Parkway, Los Angeles, CA 90089-0742 United States
AB:
We report the recent progress on real-time seismic monitoring in Taiwan. Particularly on the earthquake rapid reporting (RRS)
and earthquake early warning (EWS) systems developed by us at the Central Weather Bureau (CWB), using the telemetered
signals from strong-motion instruments in the free-field. For the RRS, CWB has provided intensity map, hypocenter, and
magnitude within one minute of the occurrence of large (M$>4$) earthquakes since 1995. The reliability, as documented by
electronic messages to government agencies and scientists, has a nearly perfect record, especially for large damaging
earthquakes. Using a set of empirical relationships from a study of the 1999 Chi-Chi earthquake, CWB has been able to release
through RRS the estimated distributions of PGA, PGV and potential damage within a few minutes after a big earthquake. This
near real-time damage assessment is useful for rapid post-disaster emergency response and rescue missions. The concept of a
virtual sub-network (VSN) has been implemented at CWB. The VSN-approach reduces the earthquake rapid reporting time to about
30 seconds or less. This represents a significant step towards a more realistic earthquake early warning capability, and has
been in operation at CWB since December 2000. A 6-month result shows successful locations of 54 earthquakes with equivalent
estimates of moment magnitude. The RRS and EWS have been in operation for several years essentially without false reports.
For EWS since 2002, comprehensive earthquake reports have been issued mostly in less than 30 seconds, with an average of
about 22 seconds from the origin time. At 3 km/sec for a typical shear wave velocity, the present operation is not useful if
an earthquake occurs less than 66 km from a city, but the lead time will increase to more than 10 seconds for cities at
distances greater than 100 km from the source. In the latter case, a lead time of several seconds will allows pre-programmed
emergency response to take place prior to the arrival of strong shaking. The CWBÝs RRS and EWS reports are open to
scientists (by e-mail) if a request is sent to ym.wu@socmail.cwb.gov.tw. Besides the earthquake-related information, these
reports also document the processing time.
DE: 7200 SEISMOLOGY
DE: 7223 Seismic hazard assessment and prediction
DE: 7294 Instruments and techniques
SC: Seismology [S]
MN: 2003 Fall Meeting