DOI: 10.1016/j.epsl.2017.12.045
Scopus记录号: 2-s2.0-85044345685
论文题名: Southeastward increase of the late Quaternary slip-rate of the Xianshuihe fault, eastern Tibet. Geodynamic and seismic hazard implications
作者: Bai M. ; Chevalier M.-L. ; Pan J. ; Replumaz A. ; Leloup P.H. ; Métois M. ; Li H.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 485 起始页码: 19
结束页码: 31
语种: 英语
英文关键词: earthquake hazard
; eastern Tibetan Plateau
; late Quaternary slip rate
; Selaha fault
; tectonic-geomorphology
; Xianshuihe fault system
Scopus关键词: Earthquakes
; Embankments
; Geodynamics
; Hazards
; Levees
; Strike-slip faults
; Earthquake hazard
; Eastern Tibetan plateau
; Slip rates
; Tectonic geomorphology
; Xianshuihe fault
; Fault slips
; earthquake event
; emplacement
; geodynamics
; geomorphology
; levee
; moraine
; Quaternary
; seismic hazard
; slip rate
; tectonics
; China
; Kangding
; Qinghai-Xizang Plateau
; Sichuan
; Xianshuihe Fault Zone
; Xizang
英文摘要: The left-lateral strike-slip Xianshuihe fault system located in the eastern Tibetan Plateau is considered as one of the most tectonically active intra-continental fault system in China, along which more than 20 M > 6.5 and more than 10 M > 7 earthquakes occurred since 1700. Therefore, studying its activity, especially its slip rate at different time scales, is essential to evaluate the regional earthquake hazard. Here, we focus on the central segment of the Xianshuihe fault system, where the Xianshuihe fault near Kangding city splays into three branches: the Selaha, Yalahe and Zheduotang faults. In this paper we use precise dating together with precise field measurements of offsets to re-estimate the slip rate of the fault that was suggested without precise age constraints. We studied three sites where the active Selaha fault cuts and left-laterally offsets moraine crests and levees. We measured horizontal offsets of 96 ± 20 m at Tagong levees (TG), 240 ± 15 m at Selaha moraine (SLH) and 80 ± 5 m at Yangjiagou moraine (YJG). Using 10Be cosmogenic dating, we determined abandonment ages at Tagong, Selaha and Yangjiagou of 12.5(+2.5/−2.2) ka, 22 ± 2 ka, and 18 ± 2 ka, respectively. By matching the emplacement age of the moraines or levees with their offsets, we obtain late Quaternary horizontal average slip-rates of 7.6(+2.3/−1.9) mm/yr at TG and 10.7(+1.3/−1.1) mm/yr at SLH, i.e., 5.7–12 mm/yr or between 9.6 and 9.9 mm/yr assuming that the slip rate should be constant between the nearby TG and SLH sites. At YJG, we obtain a lower slip rate of 4.4 ± 0.5 mm/yr, most likely because the parallel Zheduotang fault shares the slip rate at this longitude, therefore suggesting a ∼5 mm/yr slip rate along the Zheduotang fault. The ∼10 mm/yr late Quaternary rate along the Xianshuihe fault is higher than that along the Ganzi fault to the NW (6–8 mm/yr). This appears to be linked to the existence of the Longriba fault system that separates the Longmenshan and Bayan Har blocks north of the Xianshuihe fault system. A higher slip rate along the short (∼60 km) and discontinuous Selaha fault compared to that along the long (∼300 km) and linear Ganzi fault suggests a high hazard for a M > 6 earthquake in the Kangding area in the near future, which could devastate that densely populated city. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110042
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Key Laboratory of Continental Dynamics, Institute of Geology, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Rd, Beijing, 100037, China; ISTerre, Université Grenoble Alpes, Grenoble, F-38400, France; Laboratoire de géologie de Lyon, Université de Lyon 1, ENS de Lyon, CNRS, UMR 5276 LGL-TPE, Villeurbanne, F-69622, France
Recommended Citation:
Bai M.,Chevalier M.-L.,Pan J.,et al. Southeastward increase of the late Quaternary slip-rate of the Xianshuihe fault, eastern Tibet. Geodynamic and seismic hazard implications[J]. Earth and Planetary Science Letters,2018-01-01,485