| 跨断层与GPS地壳形变数据联合反演鲜水河断裂地震危险性 |
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| 引用本文： | 尹海权,郭祥云,常明,占伟,李腊月,徐东卓.跨断层与GPS地壳形变数据联合反演鲜水河断裂地震危险性[J].地质学报,2020,94(8):2487-2499. |
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| 作者姓名： | 尹海权 郭祥云 常明 占伟 李腊月 徐东卓 |
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| 作者单位： | 1) 中国地震局第一监测中心，天津，300180;2) 中国地震局地球物理研究所，北京，100081 |
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| 基金项目： | 本文为国家重点研发计划课题(2017YFC1500501)、地震科技星火项目（XH20077Y、XH18067Y）、震情跟踪课题（2019010229）资助的成果。 |
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| 摘 要： | 为了探索GPS和跨断层地壳形变数据联合反演效果，本文以鲜水河断裂为研究对象，利用1999~2007期，2009~2013期和2013~2017期中国大陆GPS水平速度场数据，使用贝叶斯反演方法，以跨断层数据为先验条件，估算了川滇菱形块体东边界（主要为鲜水河断裂）的断层运动速率。发现增加跨断层数据后，反演图像的近场和远场速率区别更加显著，不同期次的断层活动速率表现出明显的差异。但是，本方法在震前效果并不明显，尤其是在汶川地震前部分跨断层场地的逆向走滑特征很难表现出来，对于地震预测预报也很难起到优势作用，但从反演效果上来看，可以更直观的反映断层在近场和远场上的速率差异以及地震后断层运动速率的分段特征。最终根据上述研究方法认为鲜水河断裂带在汶川地震后，经过多年的应力调整，目前左旋走滑速率已经基本恢复到震前状态，鲜水河断裂南段持续拉张趋势，川滇菱形块体的顺时针旋转作用持续加强，鲜水河断裂的道孚段和磨西段存均在一定的走滑速率亏损，应注意这两个地区的地震危险性，以及这两个地区地震危险的关联性。
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| 关 键 词： | 鲜水河断裂 跨断层 GPS 数据融合 断裂活动性 |
| 收稿时间： | 2019/10/25 0:00:00 |
| 修稿时间： | 2020/1/18 0:00:00 |
Inversion of seismic hazard of the Xianshuihe fault by cross- fault and GPS crustal deformation data |
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| YIN Haiquan,GUO Xiangyun,CHANG Ming,ZHAN Wei,LI Layue,XU Dongzhuo.Inversion of seismic hazard of the Xianshuihe fault by cross- fault and GPS crustal deformation data[J].Acta Geologica Sinica,2020,94(8):2487-2499. |
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| Authors: | YIN Haiquan GUO Xiangyun CHANG Ming ZHAN Wei LI Layue XU Dongzhuo |
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| Institution: | 1) First Crust Monitoring and Application Center, CEA, Tianjin, 300180;2) China Earthquake Administration, CEA, Beijing, 100081 |
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| Abstract: | In order to explore the joint inversion effect of GPS and cross- fault crustal deformation data, this paper takes the Xianshuihe fault as the research object. The study analyzed and contrasted the difference between joint inversion result and GPS inversion result and the deformation characteristics and seismic hazard of the Xianshuihe fault zone. The horizontal velocity data of GPS in China from 1999~2007, 2009~2013 and 2013~2017 were used, and the Bayesian inversion procedure was applied to estimate the movement rate of the Xianshuihe fault by using the cross- fault data as a priori condition. We compared individual GPS data inversion results with joint inversion results. It was found that the difference between near- field and far- field rates in the inversion image is more significant after the cross- fault data is added. The rate of fault activity varies significantly in different periods, especially during the deformation adjustment process after the Wenchuan earthquake. However, the effect of this method for pre- seismic is not obvious, especially the reverse strike- slip characteristics of part of cross- fault sites before the Wenchuan earthquake are difficult to show, and it is difficult to play a dominant role in earthquake prediction. But in general the analysis of fusion inversion analysis can be more intuitive to reflect the difference in velocity between the fault in the near and far fields. Finally, according to the above research method, after the Wenchuan earthquake, the left- lateral strike- slip rate has basically recovered to the pre- earthquake state by years of stress adjustment, and the southern section of the Xianshuihe fault continues to stretch. The clockwise rotation of the Sichuan- Yunnan block continues to strengthen. In addition, the Daofu section and the Moxi section of the Xianshuihe fault are at a certain slip- rate loss. It is necessary to pay attention to the seismic hazard and the correlation of earthquake risk in these two areas. |
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| Keywords: | The Xianshuihe Fault cross- fault GPS data fusion fault activity |
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