近日,兰州交通大学李伟团队研究了基于InSAR测量的2023年鸡石山Mw6.0级地震同震形变与滑动分布。2025年7月8日,《大地测量与地球动力学》杂志发表了这一成果。
2023年12月18日,甘肃省临夏州积石山县发生MW6.0地震。研究组利用Sentinel-1A卫星雷达观测获取了2023年积石山地震的同震形变场,并以此作为约束反演了发震断层的几何展布和精细滑动分布。结果表明,此次地震表现为逆冲运动特征。同震滑动分布结果显示,本次地震最大滑动量为0.3米。库仑应力分布显示,拉脊山断裂南缘整段、拉脊山断裂北缘NWW向段及其震中以南的NNW向段、西秦岭断裂北缘以及道塘河-临夏断裂震中东段均处于应力加载状态,表明这些区域的地震潜势危险性有所增加。
研究组探讨了地震的发震特征及断层的活动趋势。推测认为,积石山地震是区域断裂构造与构造应力共同作用的结果。基于地震数据、大地测量以及其他地质地球物理资料的观测,研究组认为该地震是在青藏高原东北向扩展的驱动机制下,局部应力使地壳薄弱区域活化所致。综合多方面因素考虑,此次地震的发震断层更可能为北东倾向,发生在属于积石山断裂带东缘的隐伏断层上。
附:英文原文
Title: Coseismic deformation and slip distribution of the 2023 Jishishan Mw6.0 earthquake based on InSAR measurements
Author: Wei Li a b c d f
Issue&Volume: 2025/07/08
Abstract: A MW6.0 earthquake struck Jishishan County in Linxia Prefecture, Gansu Province, on December 18, 2023. In this research, Sentinel-1A satellite radar observations were used to obtain the field of coseismic deformation of the Jishishan earthquake in 2023, and the geometric and fine slip distribution of the seismogenic fault were inverted using this as a constraint. The results show that the earthquake is characterized by thrust movement. The coseismic slip distribution results show that the maximum slip of this earthquake is 0.3 m. The Coulomb stress distribution shows that the whole section of the southern edge of Lajishan fault, the NWW trending segment of the northern edge of Lajishan fault and its NNW trending segment to the south of the epicenter, the northern edge of the West Qinling fault and the segment to the east of the epicenter of the Daotanghe Linxia fault are under stress loading, which indicates an increase in the potential risk of earthquakes. This research discussed the seismogenic characteristics of earthquakes and the tendency of faults. We speculate that the Jishishan earthquake is the result of the joint action of regional faults and tectonic stress. Based on the observation of seismic data, geodesy, and other geological and geophysical data, we believe that the earthquake was caused by the activation of weak areas under the crust by the local stress from the driving mechanism of the northeast expansion of Qinghai-Xizang Plateau. The seismogenic fault of this earthquake is more likely to be northeast dipping under the comprehensive consideration of various factors, which occurred on the concealed fault belonging to the eastern edge of the Jishishan fault zone.
DOI: 10.1016/j.geog.2025.04.009
Source: https://www.sciencedirect.com/science/article/pii/S1674984725000485
Geodesy and Geodynamics:《大地测量与地球动力学》,创刊于2010年。隶属于爱思唯尔出版集团,最新IF:2.4
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