[S-CG63] 地震動・地殻変動・津波データの即時把握・即時解析・即時予測

[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)

キーワード：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.