Japan Geoscience Union Meeting 2025

Presentation information

Print

[J] Oral

S (Solid Earth Sciences ) » S-CG Complex & General

[S-CG63] Reducing risks from earthquakes, tsunamis & volcanoes: new applications of realtime geophysical data

Thu. May 29, 2025 10:45 AM - 12:15 PM 201B (International Conference Hall, Makuhari Messe)

convener:Yuki Kodera(Meteorological Research Institute, Japan Meteorological Agency), Masumi Yamada(Disaster Prevention Research Institute, Kyoto University), Yusaku Ohta(Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University), Naotaka YAMAMOTO CHIKASADA(National Research Institute for Earth Science and Disaster Resilience), Chairperson:Yuki Kodera(Meteorological Research Institute, Japan Meteorological Agency), Naotaka YAMAMOTO CHIKASADA(National Research Institute for Earth Science and Disaster Resilience)

10:45 AM - 11:00 AM

[SCG63-01] Assessing the CWA EEW System’s Response to the 2025 Dapu M6.4 Taiwan Earthquake

★Invited Papers

*Da-Yi Chen1, Guan-Yi Song1, Yu-Hsuan Chang1 (1.Seismological Center, Central Weather Administration of Taiwan)

Keywords:earthquake early warning, Public Warning System, communication delay

On January 20, 2025, a magnitude 6.4 earthquake struck southwestern Taiwan at a depth of 9.7 km, causing strong ground motion near the epicenter, with a maximum seismic intensity of lower 6, shown in the figure. The Central Weather Administration (CWA) operates the eBEAR earthquake early warning (EEW) system to deliver real-time alerts. During this event, eBEAR issued its first and second warnings approximately 7.9 and 9.0 seconds after the earthquake’s onset, achieving an accuracy rate exceeding 80% (within one intensity rank). The alerts from the eBEAR system were broadcast island-wide via Taiwan’s Public Warning System (PWS), reaching millions of people within approximately 5.5 seconds, despite communication delays. Additionally, a low-latency method using direct connections between CWA and end-user devices reduced alert delays to just 0.1 seconds. This approach provided lead times ranging from a few seconds to tens of seconds, depending on the location. The eBEAR system’s performance in this earthquake highlights the effectiveness of Taiwan’s real-time EEW system in mitigating earthquake impacts. These timely warnings were instrumental in minimizing damage and bolstering the resilience of high-tech industries.