大地测量与地球动力学2025，Vol.45Issue(8)：823-828,857,7.DOI:10.14075/j.jgg.2024.08.415
山西南部历史地震的深部孕震环境
Deep Seismogenic Environment of Historical Earthquakes in South Shanxi
摘要
Abstract
Using the arrival time data of natural earthquakes from January 2009 to June 2023 in Shanxi and adjacent areas,the double-difference tomography method was employed to obtain the relocated catalog of the region,as well as high-resolution three-dimensional crustal velocity structure and veloc-ity ratio structure.The tectonic environment for historical earthquakes of magnitude 6 or above in this area was discussed.The two-dimensional profiles of velocity and velocity ratio versus depth for histor-ical earthquakes of magnitude 6 or above that passed through the southern part of Shanxi show that the 1303 Hongtong earthquake of magnitude 8 occurred on a gradient belt of high and low velocity a-nomalies,with a low-velocity anomaly beneath the earthquake,indicating that the ductile creep of the lower-middle crust can lead to localized stress and strain concentration in the brittle upper crust,triggering earthquakes.The earthquake is located in an area of low velocity ratio,and the Linfen basin has a low velocity ratio beneath it,with slightly higher velocity ratios on both sides of the mountainous areas,which is related to the process of crustal extension and thinning beneath the basin.Both the velocity and velocity ratio structures show that the structural characteristics beneath Luoyunshan piedmont fault are steep in the shallow part and gentle in the deep part,with the fault cutting extending to a depth of about 30 km,which is similar to the results of existing seismic reflection profiles and may be the reason for multiple earthquakes of magnitude 6 or above in this area.Most historical earthquakes in the southern part of Shanxi occurred near the gradient belt of high and low velocity ratios,which may be related to these areas being located at the boundary of the basin and mountain,where the crus-tal material composition changes more dramatically and is more likely to accumulate stress and strain,thus generating earthquakes.关键词
双差层析成像/历史地震/山西南部/P波速度/波速比Key words
double-difference tomography/historical earthquakes/south Shanxi/P wave velocity/VP/VS velocity ratio分类
天文与地球科学引用本文复制引用
王霞,宋美卿,吕坚,张娜,梁向军,郭文峰..山西南部历史地震的深部孕震环境[J].大地测量与地球动力学,2025,45(8):823-828,857,7.基金项目
地震预测开放基金(XH24004D) （XH24004D）
中国地震局震情跟踪定向工作任务(2024020101) （2024020101）
中国地震局地震科技星火计划(XH200403Y) （XH200403Y）
山西省科技厅青年基金(201901D211548) （201901D211548）
北京市自然科学基金(8232053) （8232053）
中国地震局地质所国家野外站研究课题(NORSTY2021-01,NORSTY2023-07,NORSTY2023-08). Open Fund of Earthquake Prediction,No.XH24004D （NORSTY2021-01,NORSTY2023-07,NORSTY2023-08）
The Earthquake Tracking Task of CEA,No.2024020101 （）
The Spark Program of Earthquake Technology of CEA,No.XH200403Y （）
Youth Fund of Department of Science and Technology of Shanxi Province,No.201901D211548 （）
Natural Science Foundation of Beijing,No.8232053 （）
Research Project of the National Field Sta-tion of the Institute of Geology,CEA,No.NORSTY2021-01,NORSTY2023-07,NORSTY2023-08. （）
