2018/01/09 by Hu Wang, Mingjian Liang, Shuaipo Gao +2 · 1 voice
Earth and Planetary Sciences · #Geological and Geochemical Analysis #High-pressure geophysics and materials #earthquake and tectonic studies
paper · doi:10.1785/0120170202
openalex publication_date 2018/01/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
Research Article| January 09, 2018 Reevaluation of Coseismic Surface Ruptures Produced by the 1850 M 7.5 Xichang Earthquake on the Southeastern Margin of the Tibetan Plateau and Implications for Rupture Propagation at Bends on Strike‐Slip Faults Hu Wang; Hu Wang aFaculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China, [email protected] Search for other works by this author on: GSW Google Scholar Mingjian Liang; Mingjian Liang bKey Laboratory of Active Tectonics and Volcano, Institute of Geology, China Earthquake Administration, Beijing 100029, China Search for other works by this author on: GSW Google Scholar Shuaipo Gao; Shuaipo Gao bKey Laboratory of Active Tectonics and Volcano, Institute of Geology, China Earthquake Administration, Beijing 100029, China Search for other works by this author on: GSW Google Scholar Yongkang Ran; Yongkang Ran bKey Laboratory of Active Tectonics and Volcano, Institute of Geology, China Earthquake Administration, Beijing 100029, China Search for other works by this author on: GSW Google Scholar Lichun Chen Lichun Chen cDivision of Medium to Long‐Term Earthquake Prediction, Institute of Geology, China Earthquake Administration, Beijing 100029, China Search for other works by this author on: GSW Google Scholar Author and Article Information Hu Wang aFaculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China, [email protected] Mingjian Liang bKey Laboratory of Active Tectonics and Volcano, Institute of Geology, China Earthquake Administration, Beijing 100029, China Shuaipo Gao bKey Laboratory of Active Tectonics and Volcano, Institute of Geology, China Earthquake Administration, Beijing 100029, China Yongkang Ran bKey Laboratory of Active Tectonics and Volcano, Institute of Geology, China Earthquake Administration, Beijing 100029, China Lichun Chen cDivision of Medium to Long‐Term Earthquake Prediction, Institute of Geology, China Earthquake Administration, Beijing 100029, China Publisher: Seismological Society of America First Online: 09 Jan 2018 Online Issn: 1943-3573 Print Issn: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2018) 108 (1): 101–115. https://doi.org/10.1785/0120170202 Article history First Online: 09 Jan 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Hu Wang, Mingjian Liang, Shuaipo Gao, Yongkang Ran, Lichun Chen; Reevaluation of Coseismic Surface Ruptures Produced by the 1850 M 7.5 Xichang Earthquake on the Southeastern Margin of the Tibetan Plateau and Implications for Rupture Propagation at Bends on Strike‐Slip Faults. Bulletin of the Seismological Society of America 2018;; 108 (1): 101–115. doi: https://doi.org/10.1785/0120170202 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Abstract Fault strike changes can play an important role in the earthquake rupture process. Specifically, a fault bend may act as a nucleation point or a termination point for earthquake rupture. This phenomenon has been studied by numerical models that could predict surface‐rupture extent based on bend geometry but has not been well verified with field geologic observations. Therefore, to better explore rupture behavior of fault bends, more case studies of coseismic slip distribution of surface ruptures at fault bends associated with historical earthquakes are needed. Here, we reevaluate surface ruptures produced by the A.D. 1850 Xichang earthquake to determine the coseismic rupture length and slip distribution at an extensional fault bend of about 30°. The fault bend is located at the intersection between the Anninghe fault (ANHF) and Zemuhe fault (ZMHF) in the southeastern region of the Tibetan plateau. Integrated with the previous studies of surface ruptures along the ZMHF associated with the A.D. 1850 earthquake, we find new surface ruptures along the southern segment of the ANHF and suggest that the earthquake ruptured both the ANHF and ZMHF coseismically. This result indicates that an angle of 30° at an extensional bend may not effectively stop seismic ruptures. Based on the analysis of coseismic horizontal displacement of 1–1.5 and 3–5 m along the ANHF and ZMHF, we estimate slip gradient to be ∼15.4±3.7 and ∼1.7±1.6 cm/km to the right and left side of the Xichang fault bend, respectively. Though we cannot completely rule out nucleation on the ANHF, we suggest that a high slip gradient on the ZMHF with a sudden decrease at the Xichang fault bend is associated with the release of high seismic energy, which could enable coseismic rupture on the nonoptimally oriented ANHF. Moreover, based on detailed investigations, the rupture length associated with the earthquake is determined to be about 150 km, and the corresponding magnitude is suggested to be M 7.6±0.3. A rupture length of 150 km for the A.D. 1850 Zemuhe earthquake is consistent with the distribution of shaking in historical records. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.