The Earthworm Based Earthquake Alarm Reporting System in Taiwan by Da-Yi Chen, * Nai-Chi Hsiao, and Yih-Min Wu Abstract For more than 10 years, the Central Weather Bureau of Taiwan has op-

erated an earthquake early warning (EEW) system and has issued warnings for specific agencies. For the past two years, the Earthworm platform has been used to integrate real-time seismic data streams from different types of seismic stations and to monitor seismicity in Taiwan. Using the Earthworm platform, the Earthworm Based Earth-quake Alarm Reporting (eBEAR) system is currently in development for shortening reporting times and improving the accuracy of warnings for EEW purposes. The eBEAR system consists of new Earthworm modules for managing P-wave phase pick-ing, trigger associations, hypocenter locations, magnitude estimations, and alert filter-ing prior to broadcasting. Here, we outline the methodology and performance of the eBEAR system. To calibrate the eBEAR system, an offline test was implemented us-ing 154 earthquakes with magnitudes ranging fromML 4.0 to 6.5. In a comparison of online performance using the current EEW system, the eBEAR system reduced report-ing times and improved the accuracy of offshore earthquake locations and magnitudes. Online performance of the eBEAR system indicated that the average reporting times afforded by the system are approximately 15 and 26 s for inland and offshore earth-quakes, respectively. The eBEAR system now delivers warnings to elementary and junior high schools in Taiwan