远场记录反演2016年4月17日厄瓜多尔M_w7.8地震破裂过程

发布时间：2018-06-02 23:14

本文选题：厄瓜多尔Mw.级地震 + 远场位移记录　；参考：《地震工程与工程振动》2017年05期

【摘要】：本文选取震中距30°~90°远场40个台站垂直向P波位移记录,采用非负最小二乘法结合多时间视窗技术,反演了2016年4月17日厄瓜多尔Mw7.8级地震震源破裂过程。采用棋盘测试对数据的反演能力进行了分析,表明最佳分辨率为子断层尺寸10 km×10 km。反演结果表明:断层破裂速度约为3.2 km/s,破裂发生在深度27 km以上,有两个凹凸体。第1个凹凸体在初始破裂点附近,最大滑动量2.0 m,以逆冲错动为主,破裂持续14 s,释放14%的地震矩。第2个凹凸体在初始破裂点西南侧50 km处,最大滑动量3.4 m,为逆冲兼左旋走滑,破裂持续20 s,释放69%的地震矩。整个断层面破裂持续50 s,释放地震矩5.3×1020N·m。对反演参数的分析表明,结果对震源时间函数的形式不敏感;远场速度记录反演结果相比位移记录,有更多的子断层参与破裂,地震矩和残差都变大。
[Abstract]:In this paper, the vertical P-wave displacement records of 40 stations with a distance of 30 掳or 90 掳from the epicentre are selected and the source rupture process of the Ecuadorian earthquake (M _ S _ Mw7.8) on April 17, 2016 is inversed by using the non-negative least square method combined with the multi-time window technique. The inversion ability of the data is analyzed by chessboard test. It is shown that the best resolution is 10 km 脳 10 km of sub-fault size. The inversion results show that the rupture velocity of the fault is about 3.2 km / s, and the fracture occurs at a depth of more than 27 km with two concave and convex bodies. The first concave and convex body is located near the initial rupture point with a maximum slip of 2.0 m.The thrust fault is dominant and the rupture lasts for 14 seconds releasing 14% of the seismic moment. The second concave and convex body is about 50 km southwest of the initial rupture point, with a maximum slip of 3.4 m, which is thrust and left lateral strike-slip. The rupture lasts for 20 s and releases 69% of the seismic moment. The rupture of the whole fault plane lasts for 50 s, and the seismic moment is 5.3 脳 10 ~ (20) N 路m ~ (-1). The analysis of inversion parameters shows that the results are insensitive to the form of focal time function, and that there are more sub-faults involved in the rupture and the seismic moments and residuals become larger than the displacement records.
【作者单位】：中国地震局工程力学研究所中国地震局地震工程与工程振动重点实验室;防灾科技学院防灾工程系;
【基金】：国家自然科学基金项目(51378479) 中国地震局工程力学研究所基本科研业务费专项资助项目(2016A04) 国家重大科技专项(2013zx06002001-09)~~
【分类号】：P315

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