【摘要】 根据历史地震资料的重新考证和野外调查,认为现行地震目录所给出的公元前186年甘肃武都地震的参数不确切,应做如下修正:其重破坏区位于武都县桔柑乡—舟曲县坪定乡之间,震中位于武都县两河口附近,震级为7~7(1/4)级,烈度达Ⅸ~Ⅹ度.这次地震重破坏区长轴方向为北西西向,大致与该区的迭部—白龙江断裂带中东段走向相吻合,时间上与探槽揭露的该断裂段最晚一次古地震事件的年代(83±46)BC之前可以对比.该断裂段至今仍保存有部分地震形变带的遗迹.综合分析认为,公元前186年武都7~7(1/4)级地震的发震构造应为迭部-白龙江断裂带的中东段.更多还原

【Abstract】 On the basis of the textual research on the historical earthquake data and the field investigation of Wudu earthquake occurred in 186 B.C., we suggest that the earthquake parameters drawn from the present earthquake catalogs are not definite and amendments should be made. The heavily-damaged area of this earthquake should be located between Jugan Township of Wudu County and Pingding Township of Zhouqu County. Its epicenter should be in the vicinity of Lianghekou in Wudu County with a magnitude of about 7~7.25 and an intensity of about Ⅸ~Ⅹ. The major axis direction of the heavily-damaged area should be in the WNW direction that is approximately consistent with the strike of the middle-east segment of Diebu-Bailongjiang active fault zone, and the origin time should match up to that of the latest palaeo-earthquake event (before 83±46 B.C.) obtained by the trench investigation. Certain seismic rupture evidences are still preserved on this fault segment. Therefore, we propose on the basis of comprehensive analysis that the causative structure of the M7~7.25 Wudu earthquake in 186 B.C. should be in the middle-east segment of Diebu-Bailongjiang active fault zone.更多还原