Current Slip and Strain Rate Distribution Along the Ganzi-Yushu-Xianshuihe Fault System Based on InSAR and GPS Observations
Current Slip and Strain Rate Distribution Along the Ganzi-Yushu-Xianshuihe Fault System Based on InSAR and GPS Observations
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基于InSAR和GPS观测的甘孜-玉树-鲜水河断裂带沿线水流滑移和应变率分布
DOI：
10.3389/feart.2022.821761
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发表时间：
2022-02
期刊：
影响因子：
--
通讯作者：
Xiaoxue Xu
中科院分区：
文献类型：
--
作者：
Wenting Zhang;Lingyun Ji;Liangyu Zhu;Chuanjin Liu;Fengyun Jiang;Xiaoxue Xu
甘孜-玉树-鲜水河断裂是位于青藏高原东侧的一条大型走滑断裂，近年来地震活动频繁。然而，尽管这一断层带来了地震风险，但缺乏关于当前滑动率的高分辨率大地测量结果。利用2014年至2020年的4轨上升和5轨下降Sentinel-A/B SAR干涉合成孔径雷达（干涉合成孔径雷达）数据，以高分辨率获得整个GYXSF在雷达视线（LOS）内的当前滑移率。综合利用干涉合成孔径雷达和全球定位系统（GPS）数据，计算了高分辨率的三维形变场和应变率场。我们还使用螺旋位错模型计算了断层平行方向上20 km间隔处的电流滑动速率。我们研究的主要发现如下。(1)甘孜-玉树断裂的现今滑动速率是分段的：甘孜-玉树断裂（GYF）的滑动速率从北西向东南逐渐增加，从1.01 ~ 1.66 mm/a;鲜水河断裂（XSF）的滑动速率从北西向东南逐渐增加，从1.85 ~ 1.12 mm/a。(2)沿GYXSF存在不可忽略的震后变形沿着，我们的最佳拟合结果表明，GYF约100 km长的路段在2010年玉树6.9级地震后的4-10年内经历了震后后滑，（3）应变速率在GYF区分散，而在XSF区集中在断层上。在GYXSF以北的次级断层上也有可测量的应变率，这意味着这些次级断层的地震危险性不容忽视。(4)连续变形模型和块状模型分别是解释GYF和XSF观测和变形特征的最佳模型。
The Ganzi-Yushu-Xianshuihe fault (GYXSF), a large strike-slip fault located on the east side of the Tibetan Plateau, has seen high seismic activity in recent years. However, despite the earthquake risk posed by this fault, there is a lack of high-resolution geodetic survey results regarding the current slip rate. We have used 4-track ascending and 5-track descending Sentinel-A/B SAR Interferometric Synthetic Aperture Radar (InSAR) data from 2014 to 2020, to obtain the current slip rate of the entire GYXSF within the radar’s line of sight (LOS), with high resolution. Both InSAR and published Global Positioning System (GPS) data were integrated to calculate a high-resolution three-dimensional deformation field and strain rate field of the GYXSF. We have also used the screw dislocation model to calculate current slip rates in the fault-parallel direction at 20 km intervals. The key findings of our study are as follows. (1) The current slip rate of the GYXSF is segmental: the slip rate of the Ganzi-Yushu fault (GYF) gradually increases from ∼1 to ∼6 mm/yr from the north-west to the southeast, while the slip rate of the Xianshuihe fault (XSF) increases from ∼8.5 to ∼12 mm/yr from the north-west to the southeast. (2) There are non-negligible post-earthquake deformations along the GYXSF, and our best fitting results show that an approximately 100 km long section of the GYF has undergone post-seismic after-slip in the 4–10 years since the 2010 Yushu M 6.9 earthquake, with a maximum creep of ∼2.2 mm/yr (3) The strain rate is dispersed in the GYF region but concentrated on the fault in the XSF region. There is also a measurable strain rate on secondary faults north of the GYXSF, implying the seismic hazard of these secondary faults cannot be ignored. (4) The continuous deformation and block-like models are the best models to explain the observations and deformation characteristics of the GYF and XSF, respectively.
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影响因子：
3.9
作者：
Jiang Guoyan;Xu Xiwei;Chen Guihua;Liu Yajing;Fukahata Yukitoshi;Wang Hua;Yu Guihua;Tan Xibin;Xu Caijun
通讯作者：
Xu Caijun
影响因子：
5.2
作者：
Hua Wang;Tim J. Wright;Juliet Biggs
通讯作者：
Hua Wang;Tim J. Wright;Juliet Biggs
DOI：
--
发表时间：
2008
期刊：
Seismology and Geology
影响因子：
--
作者：
Chen Gui-hua
通讯作者：
Chen Gui-hua
影响因子：
5.2
作者：
R. Walters;R. Holley;B. Parsons;T. Wright
通讯作者：
R. Walters;R. Holley;B. Parsons;T. Wright
影响因子：
16.6
作者：
通讯作者：
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