地震研究

利用云南东川地区10个宽频带流动台站的连续波形数据,采用基于深度学习的自动震相拾取方法和震相关联技术,对2020年东川ML4.2地震序列分别进行绝对定位和相对定位,获得了该地震序列的高精度地震定位结果,得到东川ML4.2地震序列的212个余震事件,约为中国地震台网目录给出的余震数目的5倍,丰富了ML≤3.0余震; 精定位结果表明东川ML4.2主震震源深度为5.19 km,余震震源深度集中在3～6 km,余震序列分布长轴呈NNE向展布; 此次地震发生在小江断裂带西支,发震构造与乌龙拉分盆地的构造演化有关。

Selecting the continuous waveform data from 10 temporary broadband seismic stations in Dongchuan,Yunnan Province,and using the automatic seismic phase detection and correlation based on deep learning,we conduct absolute and relative locations of the July 8th,2020 Dongchuan ML4.2 earthquake sequence,and obtain high-resolution results:the ML4.2 earthquake sequence contains 212 events,about five times of the events from the catalogue of China Earthquake Networks Center,enriching the ML<3.0 aftershocks.The focal depth of the ML4.2 mainshock is 5.19 km and the aftershock sequence concentrates in the depth of 3—6 km.The Long axis of the aftershock zone is in the NNE direction.The earthquake sequence occurs in the west branch of the Xiaojiang Fault Zone and its seismogenic structure may be related with the tectonic evolution of the pull-apart Wulong Basin.

引言
1 数据与研究方法
2 结果与讨论
3 结论

图1 东川ML4.2地震附近区域构造和本文所用台站分布图<br/>Fig.1 Tectonic background of the Dongchuan ML4.2 earthquake and the distribution of seismic stations in the vicinity

图1 东川ML4.2地震附近区域构造和本文所用台站分布图
Fig.1 Tectonic background of the Dongchuan ML4.2 earthquake and the distribution of seismic stations in the vicinity

图2 本文数据处理流程和方法<br/>Fig.2 Data-processing flow and the methods adopted in the study

图2 本文数据处理流程和方法
Fig.2 Data-processing flow and the methods adopted in the study

图3 参与定位的P波(a)和S波(b)走时分布图<br/>Fig.3 Travel-time curves of P-wave(a)and S-wave(b)serving the earthquake location

图3 参与定位的P波(a)和S波(b)走时分布图
Fig.3 Travel-time curves of P-wave(a)and S-wave(b)serving the earthquake location

图4 初始和 VELEST更新后的一维速度模型<br/>Fig.4 Initial 1-D velocity model and updated VELEST 1-D velocity model

图4 初始和 VELEST更新后的一维速度模型
Fig.4 Initial 1-D velocity model and updated VELEST 1-D velocity model

图5 绝对定位和相对定位地震分布图<br/>Fig.5 Epicenters distribution from the absolute location and the relative location

图5 绝对定位和相对定位地震分布图
Fig.5 Epicenters distribution from the absolute location and the relative location

图6 本文地震精定位结果与中国地震台网目录地震分布对比图<br/>Fig.6 Comparison of epicenters obtained in this study with the epicenters from the CENC catalogue

图6 本文地震精定位结果与中国地震台网目录地震分布对比图
Fig.6 Comparison of epicenters obtained in this study with the epicenters from the CENC catalogue

图7 东川ML4.2地震序列空间分布和发震构造<br/>Fig.7 Spatial distribution of the Dongchuan ML4.2 earthquake sequence and its seismogenic structure

图7 东川ML4.2地震序列空间分布和发震构造
Fig.7 Spatial distribution of the Dongchuan ML4.2 earthquake sequence and its seismogenic structure

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备注

引言

1 数据与研究方法

2 结果与讨论

3 结论

期刊信息