1303年山西洪洞8级地震震源断层研究

发布时间：2018-11-01 17:17

【摘要】：1303年在山西洪洞附近发生的8级巨大地震,是中国根据现存较为详细的文献记载史料所确定的最早的一次8级地震。这次地震距今已有700多年的历史,而地震所在区域至今仍有持续不断的小地震活动。本文根据地震破裂区1981年至2013年的中小地震精定位地震目录,采用震源断层面拟合方法,反演得到了1303年山西洪洞地震的震源断层面参数:走向19.3°、倾角88.5°、滑动角-170.0°。断层面长75.5km,宽26.2km,深度为地下11.12~37.35km。将地震破裂区的地震精确定位资料以近东西向的洪洞断裂为界划分为地震北段和地震南段,分段进行地震震源断层拟合,反演得到洪洞地震北段震源断层面参数:走向13.7°、倾角76.6°、滑动角-157.6°。断层面长32.7km,宽21.7km,深度为地下11.97~32.86km;南段震源断层面参数:走向20.3°、倾角87.1°、滑动角-154.6°。断层面长45.9km,宽16.6km,深度为地下9.32km~25.50km。无论是分段还是不分段,反演得到的洪洞地震震源断层均是右倾的近直立断层,属于右旋走向滑动性质。分段计算得到的地震北段震源断层深度比南段更深,将反演得到的震源断层与临汾盆地深部构造最新研究成果进行了分析对比,北段震源断层深度及倾角大小与深地震剖面推测得到的深大断裂几乎相同。震源断层在地表的投影与洪洞地震的高烈度区能够较好地对应。
[Abstract]:The magnitude 8 earthquake near Hongdong in Shanxi Province in 1303 was the earliest earthquake of M 8 in China according to the historical data recorded in detail. The earthquake has a history of more than 700 years. Based on the detailed catalogue of earthquakes located in the rupture region from 1981 to 2013, the focal fault plane fitting method is used to invert the source fault plane parameters of the 1303 Hongdong earthquake in Shanxi Province: strike 19.3 掳, dip angle 88.5 掳. The slip angle is 170.0 掳. The fault plane is 75.5 km long and 26.2km wide. The depth of the fault is 11.12g 37.35km. The seismic accurate location data of the seismic rupture area are divided into the northern segment and the southern segment of the earthquake by dividing the near-east-west Hongdong fault as the boundary. The seismic focal fault fitting is carried out in sections, and the source fault plane parameters of the northern segment of the Hongdong earthquake are obtained by inversion: the strike is 13.7 掳. The inclination angle is 76.6 掳and the slip angle is -157.6 掳. The fault plane is 32.7km long and 21.7km wide, and the depth is 11.97km 32.86km.The source fault plane parameters of the southern segment are as follows: strike 20.3 掳, dip angle 87.1 掳, slip angle -154.6 掳. The fault plane is 45.9km long and 16.6 km wide, and the depth is 9.32km ~ (-1) (25.50km). Whether it is segmented or not, the source faults of Hongdong earthquake obtained by inversion are nearly vertical faults with right inclination, which belong to the nature of right-lateral strike sliding. The depth of the source fault in the northern segment of the earthquake is deeper than that in the south segment. The inversion of the source fault is compared with the latest research results of the deep structure of the Linfen basin. The depth and dip of the source fault in the northern segment are almost the same as those of the deep large fault predicted by the deep seismic profile. The projection of the focal fault on the surface can well correspond to the high intensity area of the Hongdong earthquake.
【作者单位】：河北省地震局;中国地震局地球物理勘探中心;
【基金】：国家自然科学基金(41274113) 河北省地震科技星火计划面上项目联合资助
【分类号】：P315.33

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