On March 28th, 2009, at 19: 1 1, an earthquake of magnitude 4.2 occurred in Yuanping City, Xinzhou City, Shanxi Province (latitude 38.9, east longitude1/2.9). The earthquake lasted about 3 to 5 seconds, and Taiyuan, Xinzhou, Dingxiang, Yuanping and Daixian all claimed to have different degrees of earthquake sensation. The epicenter was located in Yuanping City, Xinzhou City, Shanxi Province, southwest of Daixian County18km (194), northeast of Yuanping County, 26km (43), northwest of Wutai County, 37km (303), southwest of Fan Shi, 46km (356) and northeast of Taiyuan.
Up to 2 1: 50 * * *, there were 49 aftershocks, with the maximum magnitude of 1.3. The earthquakes in Baishi Township, Sulong Town, Zhongyang Township, Shangzhuang Township and Jiaokou Township in Daixian County of Yuanping City were strong, and the earthquakes in Xinzhou, Shuozhou, Datong, Taiyuan and Yangquan were strong, but no disaster reports were made. 1 165438 (the fifth day of October 22nd of the Qing Emperor Kangxi) On June 22nd, an earthquake of magnitude 7 occurred in Yuanping, Shanxi.
Datong, Daixian, Xinzhou, Taiyuan, Pingyao, Linfen and Yuncheng have always been strong earthquake-prone areas, located in the Shanxi Rift Valley on the eastern edge of Ordos block. The latter is a fault zone formed by a series of graben or semi-graben fault basins (such as Datong basin, Ding Xin basin, Lingqiu basin, Taiyuan basin, Linfen basin and Yuncheng basin). ), and each fault basin is basically an asymmetric subsidence basin with one side deep and one side shallow. GPS survey shows that the extension rate of Shanxi Rift Valley is about 4 mm/year. There have been many strong earthquakes in the history of Shanxi Rift Valley. For example, in May12, the Datong earthquake of magnitude 7.5, the seismogenic fault was a 90-kilometer-long, NE-oriented, and the dip angle was 40-75? The normal fault is called Huanghualiang-Shanzizao fault, and the coseismic offset is about 2.3 meters. Two earthquakes of magnitude 6.5 occurred in Datong Basin at 1022 and 1305 respectively. 198910 June 18 Xujiabao Township, Datong Basin (39.37? n， 1 13.43？ E) An earthquake with magnitude of 6. 1 occurred, and the occurrence of the seismogenic fault was (204,74), and the lateral angle of the slip vector was 10 NE, which was a right-handed strike-slip fault with slight normal fault components.