方进^1,,
许才军^1,2,3,,,
温扬茂^1,2,3,
许光煜¹,
丁开华⁴,
何平⁵
1. 武汉大学测绘学院, 武汉 430079
2. 地球空间信息技术协同创新中心, 武汉 430079
3. 武汉大学地球空间环境与大地测量教育部重点实验室, 武汉 430079
4. 中国地质大学(武汉)信息工程学院, 武汉 430074
5. 中国地质大学(武汉)地球物理与空间信息学院, 武汉 430074

基金项目: 国家自然科学基金项目（41431069，41574002，41721003，41774011）联合资助


详细信息

作者简介: 方进, 男, 1994年生, 湖南岳阳人, 现为武汉大学硕士研究生, 主要从事GPS数据处理与大地测量反演研究.E-mailjfang@whu.edu.cn

通讯作者: 许才军, 男, 1964年生, 教授, 主要研究方向为大地测量与地球动力学.E-mail:cjxu@sgg.whu.edu.cn

中图分类号: P228;P315

收稿日期:2018-08-10
修回日期:2018-10-25
上线日期:2019-03-05

Coseismic slip distribution of 2015 Gorkha (Nepal) M_W7.8 earthquake determined using the Helmert variance component estimation

FANG Jin^1,,
XU CaiJun^1,2,3,,,
WEN YangMao^1,2,3,
XU GuangYu¹,
DING KaiHua⁴,
HE Ping⁵
1. School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China
2. Collaborative Innovation Center of Geospatial Technology, Wuhan 430079, China
3. Key Laboratory of Geospace Environment and Geodesy, Ministry of Education, Wuhan University, Wuhan 430079, China
4. Faculty of Information Engineering, China University of Geosciences, Wuhan 430074, China
5. Institute of Geophysics & Geomatics, China University of Geosciences, Wuhan 430074, China


More Information

Corresponding author: XU CaiJun,E-mail:cjxu@sgg.whu.edu.cn

MSC: P228;P315

--> Received Date: 10 August 2018
Revised Date: 25 October 2018
Available Online: 05 March 2019


摘要
摘要:基于三角位错的断层自动剖分方法，联合ALOS-2 InSAR和GPS同震位移数据反演了2015年尼泊尔M_W7.8地震的发震断层参数及滑动分布.反演中基于赫尔默特方差分量估计方法确定InSAR、GPS水平向与垂直向的3种观测位移数据的相对权比.反演结果显示，方差分量估计方法定权得到的最大滑动量5.5 m，大于验前方差定权给出的5.1 m的结果，同时前者显示同震破裂沿东南方向传播至接近M_W7.3最大余震区域，然后分别继续向北和东南传播约30 km，并形成一个滑动空区（slip gap），而后者的结果没有表现出这种显著的滑动空区特征.方差分量估计定权得到的滑动模型能更好地解释观测到的InSAR同震形变场，其拟合残差标准差较验前方差定权的结果减小了2.5 cm，GPS的东和北分量的残差标准差分别减小了0.4 cm和0.9 cm.与两种不同的基于矩形位错的方法相比，利用方差分量估计的三角位错断层自动剖分方法的滑动误差均值和标准差相对最小，其中均值为0.037 m，标准差为0.028 m，表明该方法得到的滑动模型具有相对更好的无偏性和有效性.
关键词: 同震滑动分布反演/
断层自动剖分/
三角位错/
方差分量估计/
2015尼泊尔地震

Abstract:The source parameters and coseismic slip distribution of the 2015 Gorkha (Nepal) M_W7.8 earthquake are inverted jointly using an automated fault discretization method based on triangular dislocation models from ALOS-2 satellite interferogram and GPS surface displacement measurements. During the inversion, the Helmert variance component estimation (HVCE) method is used to determine the relative weight ratio among ALOS-2 InSAR, GPS horizontal and vertical component. The maximum slip obtained from the automated fault discretization method with HVCE (HVCE-FR) is 5.5 m, which is larger than the result (5.1 m) from the automated fault discretization method with weight estimated by priori variance of the observations (WPV-FR). The HVCE-FR result shows that the rupture propagates along the southeast direction approaching the M_W7.3 aftershock of May 12, 2015, and continues to propagate to the north and southeast about 30 km, respectively, which is not resolved in the WPV-FR result. The optimal distributed slip model obtained from the HVCE-FR can well explain the observed InSAR coseismic deformation pattern, with the standard deviation of the fitting residual reduced by 2.5 cm compared with the WPV-FR. The standard deviation of the residuals of GPS east-and north-components are also reduced by 0.4 cm and 0.9 cm, respectively. Compared with the mean value and standard deviation of the slip error determined from two different rectangular dislocation-based methods, the results from the HVCE-FR are relatively small, with a mean value of 0.037 m and a standard deviation of 0.028 m, which indicates that the distributed slip model obtained from the HVCE-FR has relatively better unbiasedness and effectiveness than other methods.
Key words:Coseismic slip distribution inversion/
Automated fault discretization/
Triangular dislocation models/
Helmert variance component estimation/
2015 Gorkha (Nepal) earthquake



PDF全文下载地址:

http://www.geophy.cn/data/article/export-pdf?id=dqwlxb_14900