Surface ruptures of the 2022 Guanshan-Chihshang earthquakes in central Longitudinal Valley area, eastern Taiwan

Surface ruptures of the 2022 Guanshan-Chihshang earthquakes in central Longitudinal Valley area, eastern Taiwan

The Mw 6.4 and 6.8 Guanshan-Chihshang earthquakes occurred on 17 and 18 September 2022 resulted in prominent surface ruptures within the Longitudinal Valley in eastern Taiwan, particularly along the Yuli fault. Approximately 18 h after the mainshock, we began to document the surface rupture near Yul...

Full description

Saved in:
Bibliographic Details
Published in:TAO : Terrestrial, atmospheric, and oceanic sciences Vol. 35; no. 1; pp. 16 - 25
Main Authors: Wang, Yu, Wu, Sheng-Han, Chou, Hoi Ling Birdie, Li, Yi-Yu, Cheng, Wai San, Ho, Andrew, Chen, Jian-Ming, Liu, Sze-Chieh, Hsieh, Chia-Yun, Duan, Siang, Saw Myat Min, Ei Mhone Nathar Myo, Tsai, Yuan-Lu, Liang, Nai-Wun, Liao, Jhih-Hao, Lam, Tsz Yau Amundsen, Chang, En-Wei, Shyu, J. Bruce H.
Format: Journal Article
Language:English
Published: Singapore Springer Nature Singapore 01-12-2024
Chinese Geoscience Union (Taiwan)
Springer
Subjects:
2022 Guanshan and Chihshang earthquakes
Atmospheric Sciences
Central Range fault
Deformation
Earth and Environmental Science
Earth Sciences
Earthquake damage
Earthquakes
Elastoplasticity
Fault lines
Fault scarps
Geological faults
Geology
Lateral displacement
Longitudinal Valley
Oceanography
Original Article
Post-seismic afterslip
Residential areas
Rice fields
Rupture
Rupturing
Sediments
Seismic activity
Seismic response
Surface rupture
Valleys
Yuli fault
Philippine Sea
Taiwan
Yuli fault
Central Range fault
Post-seismic afterslip
Longitudinal Valley
Surface rupture
2022 Guanshan and Chihshang earthquakes
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The Mw 6.4 and 6.8 Guanshan-Chihshang earthquakes occurred on 17 and 18 September 2022 resulted in prominent surface ruptures within the Longitudinal Valley in eastern Taiwan, particularly along the Yuli fault. Approximately 18 h after the mainshock, we began to document the surface rupture near Yuli Town. Our result suggests the surface rupture formed a confined single left-lateral trace in the town of Yuli, characterized by a series of en échelon right-stepping left-lateral faulting geometry. The rupture of 2022 roughly matches the locations of 1951 surface ruptures inside Yuli Town, with a similar amount of left-lateral cross-fault displacement. North and South of the Yuli residential area, we identified several sections of the surface rupture distributed in the water-saturated paddy fields. The maximum left-lateral displacement recorded across the rupture can reach 1.4 m just south of Yuli, with the fault scarp resembling a high-angle west-dipping fault geometry. In addition to the co-seismic surface ruptures, our repeating cross-fault measurements show significant post-seismic shallow after-slip along the Yuli fault. The amount of post-seismic deformation within 3 months after the mainshock is close to, or even higher than the co-seismic cross-fault displacement, consistent with local witness accounts and post-event field photos which showed continuous damage and displacement of building floors and roads after the earthquake. Such shallow post-seismic slips were also observed along the main fault trace in the 2014 South Napa earthquake, and likely represent the shallow elastoplastic behavior of the sub-vertical fault in the young alluvial sediments. Key points We documented surface ruptures and cross-fault displacements in the vicinity of Yuli after the 2022 Guanshan-Chihshang earthquakes. The surface ruptures in Yuli showed clear left-lateral displacements along the previously mapped Yuli fault that ruptured in November 1951. Rapid and persisted after-slip was observed along this section of the Yuli fault trace.
ISSN:1017-0839
2311-7680
DOI:10.1007/s44195-024-00077-3