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１９９６年３月２８日田湾地震序列是四川二滩水库地震遥测台网自１９９２年１月正式运行以来，发生在库区的规模最大的一次地震序列，主震震级ＭＬ＝４．０，持续时间近２月，后续余震３３个，其中震级在３．０级以上的余震３个。因该序列地震位于二滩台网监控范围以外，为改善观测台站的分布条件，本文综合使用了二滩水库地震遥测台网，西昌地震遥测台网和四川区域台网约２５个台站的观测资料，利用工业爆破和天然地震资料，计算了该区域的Ｐ波和Ｓ波地壳分层速度模型。以此模型为基础，再采用参考时间平均值法和数值性能极好的单纯形空间迭代寻优的定位方法，修定了该序列的震源位置，得到精度一般小于０．３ｋｍ，最大不超过０．５ｋｍ的极为精确的位置参数（震中经度、震中纬度和震源深度），以到时曲线为准，对解的精度进行了检验。最后，利用定位结果，对田湾序列中ＭＬ≥３．０的４次地震使用Ｐ波初动方向求解了震源机制。结果表明，田湾地震序列非常集中地分布在雅砻江库区及近旁的断层交汇和地形特殊的两个片区。主震及３个大于３．０级的余震都集中发生在田湾断层上，该处的震源深度在１１ｋｍ的深度上呈现出优势层位的分布，该处震中走向横切雅砻江库区。该序列中的地震起初与金河一带南北?
The sequence of the Tianwan earthquake on March 28, 1996 was the largest one in the reservoir area since the formal operation of the Ertan reservoir seismic telemetry network in January 1992. The magnitude of the main shock is ML = 4.0 and the duration Nearly two months later, there were 33 aftershocks followed by 3 aftershocks of magnitude 3.0 or above. Because the sequence of earthquakes lies outside the monitoring range of the Ertan network, in order to improve the distribution of the observational stations, this paper uses a combination of Ertan reservoir telemetry network, Xichang earthquake telemetry network and about 25 stations in Sichuan regional network Observed data, using the industrial blasting and natural seismic data, calculated the P-wave and S-wave crustal velocity model. Based on this model, the location of hypocenters of the sequence is revised by using reference time averaging method and the numerical method of iterative optimization of simplex spaces with excellent numerical performance. The accuracy is generally less than 0.3km and the maximum is less than 0 Accurate position parameters (epicenter, epicentral latitude and focal depth) for a distance of .5 km are tested against the arrival time curve and the accuracy of the solution is tested. Finally, using the localization results, the focal mechanism was solved using the P-wave initial direction for the four earthquakes with ML ≥ 3.0 in the Tianwan sequence. The results show that the sequence of Tianwan earthquake is very concentrated in the convergence of faults and the special topography in the Yalong River reservoir area. The main shocks and three aftershocks greater than 3.0 concentrated on the Tianwan fault, where the depth of focal depth shows the distribution of dominant strata at the depth of 11km. The epicenter of this earthquake transverses the Yalong River reservoir area . The sequence of earthquakes initially with the North and South Jinhe?