地质力学学报2025，Vol.31Issue(3)：345-360,16.DOI:10.12090/j.issn.1006-6616.2025001
基于小南海地震地质灾害的历史地震参数分析
Analysis of historical seismic parameters based on geological hazards from the Xiaonanhai earthquake
摘要
Abstract
[Objective]As the largest historical seismic event in the Chongqing region,the Xiaonanhai Earthquake holds significant scientific value for deciphering seismogenic parameters to inform regional seismic hazard assessment and anti-seismic fortification standards.This study addresses the critical challenge of scarce observational data in historical earthquake research.[Methods]A novel methodology for inverting seismic parameters through characteristic earthquake relics has been developed,systematically reconstructing the historical seismic parameters of the Xiaonanhai Earthquake.The interpretation of high-precision remote sensing and field investigations of seismically induced geo-hazards reveal a dominant near-N-S spatial distribution of the landslide clusters triggered by the Xiaonanhai Earthquake,consistent with the elliptical major axis direction of historically documented felt areas.[Results]This spatial congruence suggests that the NNW-striking Yangtoushan Fault is the seismogenic fault.Detailed remote sensing analyses of landslide orientations,sliding directions,and deposit distributions demonstrate,for the first time,coherent SE-directed motion features across multiple landslide masses,indicating a southeastward coseismic rupture propagation.A comparative analysis of the spatial correlation between geo-hazards and seismogenic structures observed in the Ludian Earthquake,coupled with seismotectonic mechanisms in southeastern Chongqing,further validates the rationality of the derived seismic parameters.[Conclusion]This study innovatively identifies a"karst-tectonic"composite mechanism:Under persistent NW-SE tectonic stress,bead-like karst caves developed along the fault zone or dominant joint directions form natural weakening zones,inducing stress concentration and ultimately triggering left-lateral strike-slip motion with thrust components.This dual mechanism explains the unique seismic characteristics blending tectonic rupture and karst collapse.[Significance]The proposed"geo-morphodynamic inversion"methodology advances the reconstruction of historical earthquake parameters and provides critical insights for the evaluation of seismic risk in karst terrains.关键词
小南海地震/地质灾害/发震断层/动力学过程/地震成因机制Key words
Xiaonanhai Earthquake/geological disaster/seismogenic fault/dynamic processes/seismogenic mechanism分类
地质学引用本文复制引用
龚丽文,张怀,陈丽娟,王赞军,张秉诺,孙益星,柏昌云..基于小南海地震地质灾害的历史地震参数分析[J].地质力学学报,2025,31(3):345-360,16.基金项目
国家自然科学基金联合基金项目(U2239205) （U2239205）
重庆市教育委员会科学技术研究项目(KJQN202404711) This research is financially supported by the Joint Funds of the National Science Foundation of China(Grant No.U2239205)and the Scientific and Technological Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202404711). （KJQN202404711）
