A new prototype system for earthquake early warning in Taiwan

摘要

A new prototype earthquake early warning (EEW) system is being developed and tested using a realtime seismographic network currently in operation in Taiwan. This system is based on the Earthworm environment which carries out integrated analysis of real-time broadband, strong-motion and short-period signals. The peak amplitude of displacement in the three seconds after the P arrival, dubbed P*. is used for the magnitude determination. Incoming signals are processed in real time. When a large earthquake occurs, P-wave arrival times and Pa will be estimated for location and magnitude determinations for EEW purpose. In a test of 54 felt earthquakes, this system can report earthquake information in 18.8 ± 4.1s after the earthquake occurrence with an average difference in epicenter locations of 6.3 ± 5.7 km, and an average difference in depths of 7.9 ± 6.6 km from catalogues. The magnitudes approach a 1:1 relationship to the reported magnitudes with a standard deviation of 0.51. Therefore, this system can provide early warning before the arrival of S-wave for metropolitan areas located 70 km away from the epicenter. This new system is still under development and being improved, with the hope of replacing the current operational EEW system in the future.