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The Contribution of Postcritical Moho Reflections SmS to Ground Motions of the 2008 Mw 7.9 Wenchuan Earthquake

2019; Seismological Society of America; Volume: 109; Issue: 1 Linguagem: Inglês

10.1785/0120180188

1943-3573

Wei Zhu, Sidao Ni, Xiangfang Zeng, Paul Somerville,

earthquake and tectonic studies

Research Article| January 02, 2019 The Contribution of Postcritical Moho Reflections SmS to Ground Motions of the 2008 Mw 7.9 Wenchuan Earthquake Wei Zhu; Wei Zhu aSchool of Earth and Space Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, Anhui, China, zhuwei07@mail.ustc.edu.cn Search for other works by this author on: GSW Google Scholar Sidao Ni; Sidao Ni bState Key Laboratory of Geodesy and Earth's Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, 340 Xudong Street, Wuhan 430077, Hubei, China, sdni@whigg.ac.cn, zengxf@whigg.ac.cn Search for other works by this author on: GSW Google Scholar Xiangfang Zeng; Xiangfang Zeng bState Key Laboratory of Geodesy and Earth's Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, 340 Xudong Street, Wuhan 430077, Hubei, China, sdni@whigg.ac.cn, zengxf@whigg.ac.cn Search for other works by this author on: GSW Google Scholar Paul Somerville Paul Somerville cAECOM Technology Corporation, One California Plaza, 300 S Grand Avenue, Los Angeles, California 90017, paul.somerville@aecom.com Search for other works by this author on: GSW Google Scholar Author and Article Information Wei Zhu aSchool of Earth and Space Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, Anhui, China, zhuwei07@mail.ustc.edu.cn Sidao Ni bState Key Laboratory of Geodesy and Earth's Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, 340 Xudong Street, Wuhan 430077, Hubei, China, sdni@whigg.ac.cn, zengxf@whigg.ac.cn Xiangfang Zeng bState Key Laboratory of Geodesy and Earth's Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, 340 Xudong Street, Wuhan 430077, Hubei, China, sdni@whigg.ac.cn, zengxf@whigg.ac.cn Paul Somerville cAECOM Technology Corporation, One California Plaza, 300 S Grand Avenue, Los Angeles, California 90017, paul.somerville@aecom.com Publisher: Seismological Society of America First Online: 02 Jan 2019 Online Issn: 1943-3573 Print Issn: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2019) 109 (1): 298–311. https://doi.org/10.1785/0120180188 Article history First Online: 02 Jan 2019 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Wei Zhu, Sidao Ni, Xiangfang Zeng, Paul Somerville; The Contribution of Postcritical Moho Reflections SmS to Ground Motions of the 2008 Mw 7.9 Wenchuan Earthquake. Bulletin of the Seismological Society of America 2019;; 109 (1): 298–311. doi: https://doi.org/10.1785/0120180188 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 Studies of strong ground motion of the 2008 great Mw 7.9 Wenchuan earthquake indicate that the horizontal‐component peak ground acceleration (PGA) is significantly enhanced within the 100‐ to 300‐km fault distance range. In this article, through analysis of waveform recordings of Wenchuan aftershocks of single earthquakes at multiple stations and multiple earthquakes at single stations, we confirm the existence of large‐amplitude SmS within the critical epicentral region (⁠∼100–300 km⁠) in this area, with amplitude consistently 3–5 times stronger than direct S. Based on synthetic modeling of the horizontal‐component peak ground velocity (PGV) and PGA attenuation relationships, it is found that in the same epicentral distance range, the postcritical SmS arrivals clearly enlarge the amplitude, which also explains the increased PGA values of the Wenchuan mainshock within the critical distance range. We also quantify the influence of SmS on the ground‐motion amplitudes and modify an existing model to obtain a new hinged‐trilinear attenuation model of this area, which provides a better fit to the recorded PGA amplitudes of the Wenchuan mainshock. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.