首页|2022年门源Ms6.9地震的同震滑动分布:联合InSAR、GPS和地表位错的贝叶斯建模

2022年门源Ms6.9地震的同震滑动分布:联合InSAR、GPS和地表位错的贝叶斯建模

Coseismic slip distribution of the 2022 Menyuan Ms6.9:Bayesian modeling based on joint InSAR,GPS and surface dislocation observations

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2022年1月8日青海省门源Ms6.9地震发生于托莱山断裂东段和冷龙岭断裂西段的交汇部位,其运动学特征关系到青藏高原北缘的动力学行为,同时也是区域地震危险性评估中的基础数据.本研究针对该地震,综合InSAR和GPS观测的同震位移场,以及野外地质调查的同震位错数据,采用贝叶斯反演方法,构建同震滑动分布,断层模型采用三角网格更好地刻画断层的不规则几何形态.结果显示,本次左旋走滑型地震的主要滑动发生在冷龙岭断裂西段,深度范围约2～6 km,计算的地震矩为0.95×1019N·m,对应矩震级Mw6.65.利用多数据的联合反演解析出,沿走向存在两个滑动集中区,东侧的最大滑动达约4.8 m.震间亏损能量和库仑应力分析表明,托莱山断裂和冷龙岭断裂仍存在未来发震潜能;该地震造成的应力变化,对长期地震空区金强河—毛毛山段落有加载作用,因此,该段未来地震危险性值得关注.
On 8 January 2022,a Ms6.9 earthquake shook Menyuan County in Qinghai Province,Western China.The epicenter was located at the intersection of the eastern segment of Tuolaishan fault and the western segment of Lenglongling fault.Its kinematic characteristics are related to the dynamic behavior of the northern margin of the Qinghai-Tibet Plateau,constituting fundamental data for regional seismic hazard assessment.In this study,the coseismic slip model is constructed based on the InSAR,GPS coseismic deformation field and field coseismic dislocation observations,using Bayesian inversion method.Triangular dislocations are utilized to enhance the construction of an irregular fault geometric model.The results show that the main slip asperity of this left-lateral strike-slip earthquake concentrated on the west part of the Lenglongling fault,at depths ranging from about 2 km to 6 km.The optimal slip model yielded a released seismic moment of 0.95×1019 N·m,corresponding to Mw6.65.The joint inversion of multiple datasets shows that there are two distinct slip patterns along the strike,with a maximum slip of about 4.8 m within the east slip pattern.The interseismic deficit moment and Coulomb stress analysis indicate that the Tuolaishan fault and Lenglongling fault still have future earthquake potential.The static Coulomb stress change caused by the earthquake has a loading effect on the long-term seismic gap of Jinqianghe-Maomaoshan section,so the future seismic risk is worth paying attention to.

2022 Menyuan earthquakeCoseismic slip distributionMulti-data joint inversionBayesian methodLenglongling fault zone

路珍、王丽凤、黄伟亮、刘传金

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中国地震局第二监测中心,西安 710054

中国地震局地质研究所,地震动力学国家重点实验室,北京 100029

长安大学地质工程与测绘学院,西部矿产资源与地质工程教育部重点实验室,西安 710054

2022年门源地震 同震滑动分布 多数据联合反演 贝叶斯方法 冷龙岭断裂

国家自然科学基金国家自然科学基金国家自然科学基金地震动力学国家重点实验室开放基金陕西省自然科学基础研究计划

420410064180406442072243LED2018B012021JM-600

2024

10.6038/cjg2023R0124

地球物理学报
中国地球物理学会 中国科学院地质与地球物理研究所

地球物理学报

CSTPCD北大核心
影响因子：3.703
ISSN：0001-5733
年,卷(期)：2024.67(5)
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