近日，南方科技大学陈克杰和浙江大学吴磊团队合作研究揭示，在活动褶皱冲断带中，弯曲有助于同震隆升和长期褶皱生长。该研究于2024年10月7日发表于国际一流学术期刊《地质学》杂志上。

据研究人员介绍，了解断层滑动、褶皱生长和地震之间的相互作用，对于评估地震风险和破译褶皱—冲断带长期和短期变形之间的关系至关重要。虽然断层相关的褶皱理论在以往的研究中占主导地位，但弯曲过程(以平行与地层的收缩为特征)在地震活动和褶皱发育中的作用一直被低估。

本研究基于三维地震成像数据、干涉合成孔径雷达(InSAR)分析和测井资料，研究人员对2019年3月28日发生在柴达木盆地西部(青藏高原北部)狮子沟背斜的5.0级茫崖地震进行了研究。结果发现，这次地震不是由沿已知断层的滑动引起的，而是由背斜边缘的弯曲引起的互层滑动导致的，首次证明了弯曲可能导致中等程度的地震。

这一弯曲过程不仅导致下伏断层滑动引起的同震隆升偏离褶皱峰，而且还调节了狮子沟背斜的长期几何生长过程。研究结果强调了，弯曲过程在促进活动褶皱-韵律带的短期同震滑动和长期褶皱生长方面的重要性。

附：英文原文

Title: Buckling contributes to both coseismic uplift and long-term fold growth in active fold-thrust belts

Author: Kai Huang, Kejie Chen, Lei Wu, Xuhua Shi, Guoguang Wei, Junyong Zhang, Yongshu Zhang, Qi Yao, Ancheng Xiao, Xiubin Lin, Wei Zhang, Guisen Wen, Bo Wang, Yanming Li, Hanlin Chen

Issue&Volume: 2024-10-07

Abstract: Understanding the interplay among fault slip, fold growth, and earthquakes is crucial for assessing earthquake risk and deciphering the relationship between long-term and short-term deformation in fold-thrust belts. While fault-related folding theories have dominated previous studies, the role of the buckling process—characterized by bed-parallel contraction—in seismicity and fold development has been underreported. Herein, we attempt to address this issue through an examination of the 28 March 2019 M5.0 Mangya earthquake in the Shizigou anticline, western Qaidam Basin (northern Tibetan Plateau), based on 3-D seismic imaging data, interferometric synthetic aperture radar (InSAR) analysis, and borehole loggings. We show that this earthquake was not caused by slip along known faults, but by interbed slip due to buckling in the limb of the anticline, demonstrating for the first time that buckling could result in moderate earthquakes. The buckling process not only leads to coseismic uplift deviating from the folding crest induced by slip on the underlying fault, but also modulates the long-term geometric growth of the Shizigou anticline. Our findings underscore the significance of the buckling process in contributing to short-term coseismic slip and long-term fold growth in active fold-thrust belts.

DOI: 10.1130/G52422.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G52422.1/649015/Buckling-contributes-to-both-coseismic-uplift-and