5 / 2025-07-05 11:09:30
Variation in the on-fault coseismic offset associated with the 2008 Mw 7.9 Wenchuan earthquake in eastern Tibetan Plateau and its implications for active thrust fault deformation
2008 Wenchuan earthquake,Longmenshan fault,surface rupture,thrust fault
摘要待审
Hu Wang / Southwest Jiaotong University
The characteristics of coseismic surface ruptures associated with large earthquakes are important for understanding fault deformation mechanisms and seismic rupture behaviour. We revealed that the variation in the coseismic vertical offset at a short wavelength scale produced by the 2008 Wenchuan Mw 7.9 earthquake occurred in the Longmen Shan fault zone along the eastern Tibetan Plateau. Field investigations, including topographic surveys, trenching, and geophysical surveys, revealed that the coseismic vertical offset gradient ranged from ∼5 to ∼24 m/km at the Shenxigou site, whereas the corresponding amount reached ∼100 m/km at the Pingxi site. Both sites show a strong relationship between the coseismic vertical offset and near-surface sediment. Furthermore, we used a two-dimensional discrete element numerical simulation to reveal that sediment properties, including strength and thickness, are the first-order contributors to the along-strike high-frequency coseismic offset variation within tens of metres. Moreover, we suggest that near-surface sediment might directly affect off-fault deformation, which then affects fault deformation patterns and offset amounts. These results have significant implications for understanding the spatial heterogeneity of coseismic deformation as well as for probabilistic seismic hazard analysis for active thrust faults.
重要日期
  • 会议日期

    08月23日

    2025

    08月26日

    2025

  • 07月10日 2025

    初稿截稿日期

  • 08月26日 2025

    注册截止日期

主办单位
Southwest Jiaotong University, China (SWJTU)
International Consortium on Geo-disaster Reduction (ICGdR)
UNESCO Chair on Geoenvironmental Disaster Reduction
承办单位
Southwest Jiaotong University, China (SWJTU)
International Consortium on Geo-disaster Reduction (ICGdR)
UNESCO Chair on Geoenvironmental Disaster Reduction
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