GNSS和InSAR约束的2023积石山M_(S)6.2地震同震滑动分布

GNSS and InSAR derived coseismic slip distribution of the 2023 Jishishan M_(S)6.2 earthquake

2023年12月18日,甘肃省临夏州积石山县发生M_(S)6.2地震,造成了大量的人员伤亡和经济损失。为了研究该地震的发震构造,以多源观测为约束,利用GNSS和InSAR数据分别独立和联合反演其同震破裂模型;基于反演得到的模型,计算积石山地震在周边断裂上产生的同震库仑应力变化,并进一步分析其对周围地区的应力影响。结果显示:积石山地震的发震断层走向310°,倾角51°,是一次以逆冲为主兼有少量右旋走滑分量的地震,最大滑动量为56.02 cm,大致位于5 km深度处;该地震为调节拉脊山构造转换带两侧区域的应力-应变关系发挥着重要作用。地震发生后,积石山东缘断裂南段、拉脊山南缘断裂中南段、倒淌河—临夏断裂中段,以及西秦岭北缘断裂西段受到的库仑应力加载较高,这些区域未来的地震危险性需要重点关注。

On December 18,2023,an M_(S)6.2 earthquake struck Jishishan County,Linxia,Gansu,resulting in significant casualties and property losses.This study aims to investigate the seismogenic structure of the earthquake using multisource observational data.The coseismic rupture model was inverted independently and jointly using GNSS and InSAR data.Based on this model,the coseismic Coulomb stress changes on surrounding faults were calculated to analyze the stress influence caused by the M_(S)6.2 earthquake in the surrounding areas.The seismogenic fault of the Jishishan earthquake was found to have a strike of 310°and a dip angle of 51°.The fault movement was primarily characterized by thrust with a small right-lateral strike-slip component.The maximum slip occurred at a depth of approximately 5 km,with a maximum displacement of 56.02 cm.This earthquake played an important role in regulating the stress-strain relationship across the Lajishan tectonic transition zone.Post-earthquake analysis revealed that high-stress loading was observed in several fault sections:the southern section of the eastern margin fault of Jishishan,the south-central section of the southern margin fault of Lajishan,the middle section of the Daotanghe-Linxia fault,and the western section of the northern margin of the western Qinling fault.These findings indicate that the seismic hazards of these faults require close monitoring in the future.