喜马拉雅主逆冲断层闭锁程度与滑动亏损特征研究

发布时间：2018-07-12 08:21

本文选题：尼泊尔地震 + 速度场融合　；参考：《武汉大学学报(信息科学版)》2017年12期

【摘要】：基于融合的GPS速度场结果,使用DEFNODE负位错反演程序估算了喜马拉雅主逆冲断层(the main Himalayan thrust,MHT)的闭锁程度和滑动亏损空间分布,并结合剖面结果分析了断层远、近场的运动特征。结果表明,MHT的闭锁深度基本达到18~24km,断层面闭锁宽度达到102~136km,两次历史大地震破裂区域之间的未破裂段落和未发生大地震的段落闭锁深度更深,闭锁断层面更宽,2015年尼泊尔Mw7.8大地震就发生在两次大地震破裂区域之间的段落;MHT总滑动亏损速率和垂直断层挤压滑动亏损速率自东向西逐渐减小,平行断层右旋滑动亏损速率则基本上自东向西逐渐增加;MHT 3条剖面拟合结果也反映出其存在很强的闭锁。根据估算的此次Mw7.8地震的复发周期230年和最近500多年发生的大地震分布,认为MHT整条段落尤其是尼泊尔西部与印度接壤处和可能还没有破裂的不丹地区依然有发生8级大地震的危险。
[Abstract]:Based on the results of the fusion (the main velocity field, the spatial distribution of the locking degree and sliding deficit of the main Himalayan thrust fault (the main Himalayan thrustine) is estimated by using DEFNODE negative dislocation inversion program, and the movement characteristics of the far and near faults are analyzed based on the profile results. The results show that the interlocking depth of MHT is about 18 ~ 24km, the width of fault plane latchup is 1022136km, and the depth of interlocking between the unruptured section and the section without large earthquake is deeper. Since the 2015 Mw7.8 earthquake in Nepal occurred between the rupture regions of two major earthquakes, the total slip deficit rate of MHT and the compression slip deficit rate of vertical faults gradually decreased from east to west. The parallel fault right-lateral slip depletion rate increases gradually from east to west, and the fitting results of MHT3 section also show that there is a strong latchup. According to the estimated recurrence period of the Mw7.8 earthquake for 230 years and the distribution of large earthquakes that occurred in the last 500 years, It is believed that the entire MHT paragraph, especially in the western part of Nepal bordering India and possibly unbroken Bhutan, is still in danger of a magnitude 8 earthquake.
【作者单位】：中国地震局地质研究所地震动力学国家重点实验室;中国地震台网中心;中国地震局地震预测研究所中国地震局地震预测重点实验室;中国地震局第一监测中心;
【基金】：地震科技星火计划项目(XH15049Y) 国家自然科学基金(41330314,41274008) 2015年度震情跟踪专项工作任务(2015010201)~~
【分类号】：P315.2

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