P-Alert earthquake early warning system: case study of the 2022 Chishang earthquake at Taitung, Taiwan
Abstract A series of earthquakes that struck Taiwan's southern Longitudinal Valley on September 17 and 18, 2022 severely damaged several buildings in Taitung and Hualien. The Chishang earthquake, which had a magnitude of ML 6.8 and a large foreshock with a magnitude of ML 6.6 the day before, wa...
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| Format: | Article |
| Language: | English |
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Springer
2023-12-01
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| Series: | Terrestrial, Atmospheric and Oceanic Sciences |
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| Online Access: | https://doi.org/10.1007/s44195-023-00057-z |
| _version_ | 1827399501292240896 |
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| author | Benjamin M. Yang Himanshu Mittal Yih-Min Wu |
| author_facet | Benjamin M. Yang Himanshu Mittal Yih-Min Wu |
| author_sort | Benjamin M. Yang |
| collection | DOAJ |
| description | Abstract A series of earthquakes that struck Taiwan's southern Longitudinal Valley on September 17 and 18, 2022 severely damaged several buildings in Taitung and Hualien. The Chishang earthquake, which had a magnitude of ML 6.8 and a large foreshock with a magnitude of ML 6.6 the day before, was the mainshock in this sequence. The strongest intensity reported in the epicentral region during this earthquake sequence, which was 6 + , is the highest ever recorded since the Central Weather Bureau (CWB, renamed as the Central Weather Administration since September 15, 2023) revised its seismic intensity scale. National Taiwan University (NTU) has operated a low-cost earthquake early warning (EEW) system known as the P-Alert for a decade. In this study, we demonstrate the performance of the P-Alert network during the 2022 Chishang earthquake and the largest foreshock. The P-Alert network plotted shake maps during these earthquakes that displayed various values within 5 min. The high shaking areas on these maps were in good agreement with observed damages during this earthquake, providing valuable insights into rupture directivity, a crucial component of earthquake engineering. Individual P-Alert stations acted as on-site EEW systems and provided a lead time of 3–10 s within the blind zone of CWB. For the ML 6.8 mainshock, there was a lead time of at least 5 s, even up to 10 s, demonstrating their effectiveness in the blind zone. The P-Alert regional EEW system provided the first report about 9 s and 7 s after the mainshock and the largest foreshock occurrence, respectively, with estimated magnitudes of 5.74 and 5.67. The CWB system estimated magnitudes of 6.72 and 6.16 in the first report, respectively, about 7 s and 9 s after the earthquake occurrence. The timeliness of the two systems were not significantly different. Despite the effectiveness of the P-Alert network, data loss due to connection interruptions prompted us to develop a new compact data logger for improved data availability. |
| first_indexed | 2024-03-08T19:46:52Z |
| format | Article |
| id | doaj.art-fa011ed2a3854875b83d26c901abdd86 |
| institution | Directory Open Access Journal |
| issn | 1017-0839 2311-7680 |
| language | English |
| last_indexed | 2024-03-08T19:46:52Z |
| publishDate | 2023-12-01 |
| publisher | Springer |
| record_format | Article |
| series | Terrestrial, Atmospheric and Oceanic Sciences |
| spelling | doaj.art-fa011ed2a3854875b83d26c901abdd862023-12-24T12:20:55ZengSpringerTerrestrial, Atmospheric and Oceanic Sciences1017-08392311-76802023-12-0134111410.1007/s44195-023-00057-zP-Alert earthquake early warning system: case study of the 2022 Chishang earthquake at Taitung, TaiwanBenjamin M. Yang0Himanshu Mittal1Yih-Min Wu2Department of Geosciences, National Taiwan UniversityNational Center for Seismology, Ministry of Earth Sciences, Government of IndiaDepartment of Geosciences, National Taiwan UniversityAbstract A series of earthquakes that struck Taiwan's southern Longitudinal Valley on September 17 and 18, 2022 severely damaged several buildings in Taitung and Hualien. The Chishang earthquake, which had a magnitude of ML 6.8 and a large foreshock with a magnitude of ML 6.6 the day before, was the mainshock in this sequence. The strongest intensity reported in the epicentral region during this earthquake sequence, which was 6 + , is the highest ever recorded since the Central Weather Bureau (CWB, renamed as the Central Weather Administration since September 15, 2023) revised its seismic intensity scale. National Taiwan University (NTU) has operated a low-cost earthquake early warning (EEW) system known as the P-Alert for a decade. In this study, we demonstrate the performance of the P-Alert network during the 2022 Chishang earthquake and the largest foreshock. The P-Alert network plotted shake maps during these earthquakes that displayed various values within 5 min. The high shaking areas on these maps were in good agreement with observed damages during this earthquake, providing valuable insights into rupture directivity, a crucial component of earthquake engineering. Individual P-Alert stations acted as on-site EEW systems and provided a lead time of 3–10 s within the blind zone of CWB. For the ML 6.8 mainshock, there was a lead time of at least 5 s, even up to 10 s, demonstrating their effectiveness in the blind zone. The P-Alert regional EEW system provided the first report about 9 s and 7 s after the mainshock and the largest foreshock occurrence, respectively, with estimated magnitudes of 5.74 and 5.67. The CWB system estimated magnitudes of 6.72 and 6.16 in the first report, respectively, about 7 s and 9 s after the earthquake occurrence. The timeliness of the two systems were not significantly different. Despite the effectiveness of the P-Alert network, data loss due to connection interruptions prompted us to develop a new compact data logger for improved data availability.https://doi.org/10.1007/s44195-023-00057-zEarthquake early warningOn-siteShake mapsRegionalPGAPGV |
| spellingShingle | Benjamin M. Yang Himanshu Mittal Yih-Min Wu P-Alert earthquake early warning system: case study of the 2022 Chishang earthquake at Taitung, Taiwan Terrestrial, Atmospheric and Oceanic Sciences Earthquake early warning On-site Shake maps Regional PGA PGV |
| title | P-Alert earthquake early warning system: case study of the 2022 Chishang earthquake at Taitung, Taiwan |
| title_full | P-Alert earthquake early warning system: case study of the 2022 Chishang earthquake at Taitung, Taiwan |
| title_fullStr | P-Alert earthquake early warning system: case study of the 2022 Chishang earthquake at Taitung, Taiwan |
| title_full_unstemmed | P-Alert earthquake early warning system: case study of the 2022 Chishang earthquake at Taitung, Taiwan |
| title_short | P-Alert earthquake early warning system: case study of the 2022 Chishang earthquake at Taitung, Taiwan |
| title_sort | p alert earthquake early warning system case study of the 2022 chishang earthquake at taitung taiwan |
| topic | Earthquake early warning On-site Shake maps Regional PGA PGV |
| url | https://doi.org/10.1007/s44195-023-00057-z |
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