Development of an Integrated Earthquake Early Warning System in Taiwan-Case for the Hualien Area Earthquakes

In order to explore the feasibility of an earthquake early warning sys tem for Taipei, two prototype seismic early warning systems have been implemented in Hualien, about 120 km away. The Taiwan Rapid Earth quake Information Release (TREIRS) can routinely determine earthquake location and magnitude in about one minute after the earthquake occurred. However, this reporting_ time is too long for earthquake early warning pur poses. A dense, real-time monitoring system composed of 8 strong-motion stations was installed in Hualien area for testing earthquake early warning capability. For the 27 earthquakes occurred during August 1998 to April 1999, this system has successfully reported earthquake information in about 18 sec after the origin time. Therefore, it provided about 15 sec of early warning time before shear waves arrival in the Taipei urban area. Based on ciur experience of these two systems, we are encouraged to proceed for ward in the development of an earthquake early warning system.