Airborne LiDAR-Based Mapping of Surface Ruptures and Coseismic Slip of the 1955 Zheduotang Earthquake on the Xianshuihe Fault, East Tibet

作者：Jing Xu, Jing Liu‐Zeng, Zhaode Yuan, Wenqian Yao, Jinyu Zhang, Lingyun Ji, Zhigang Shao, Longfei Han, Zijun Wang · 发表于：Bulletin of the Seismological Society of America · 年份：2022 · DOI：10.1785/0120220012 · 被引用次数：16 · 研究领域：earthquake and tectonic studies、Geological and Geochemical Analysis、Yersinia bacterium, plague, ectoparasites research

ABSTRACT Surface ruptures and coseismic slip distributions of large earthquakes are the keys to understanding earthquake rupture processes, analyzing rupture history of associated faults, and assessing earthquake hazards. Detailed mapping of surface ruptures of large historical earthquakes is needed but is difficult in remote regions. The 1955 Ms 7.5 Zheduotang earthquake occurred in a prominent restraining bend of the central sinistral Xianshuihe fault and within a high-relief and densely vegetated mountain range. This study characterizes the 1955 earthquake surface rupture via 50 cm resolution airborne light detection and ranging (LiDAR) data, combined with field investigations. Our mapping of geomorphic features showed that relatively fresh mole tracks and fault scarps are still preserved beneath the dense vegetation cover. The 1955 earthquake ruptured at least 30 km in length, which consisted of four sections separated by stepovers or changes in the strike. Overall, the multistranded rupture was more complex than that of other historical earthquakes to the northwest along the Xianshuihe fault but consistent with its local structural setting. We collected 47 LiDAR-derived and 48 field-based left-lateral (with minor vertical) measurements. The clustering of the smallest offsets suggests that the average sinistral coseismic displacement of the 1955 earthquake was ∼2.1 m based on LiDAR-derived data and ∼1.5 m based on field measurements. This difference highlights the ambigui...