龙门山断裂带精细速度结构成像研究

项目名称： 龙门山断裂带精细速度结构成像研究

项目编号： No.41274060

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 陈九辉

作者单位： 中国地震局地质研究所

项目金额： 70万元

中文摘要： 龙门山断裂带的精细速度结构探测结果对理解青藏高原东缘动力学和2008年汶川地震的孕震、发生过程至关重要，是确认青藏高原东缘动力学模型的重要依据。本研究将发展适用于断裂带精细速度结构的三维地震环境噪声短周期面波频散反演方法，并利用在横跨龙门山断裂带布设的密集流动地震台阵记录到的近震走时资料和短周期环境噪声面波资料，结合双差层析成像方法反演龙门山断裂带中上地壳精细速度结构，探讨青藏高原东缘地壳变形特征、汶川地震的孕震构造和可能的孕震机制。

中文关键词： 龙门山断裂带；速度结构；汶川地震；环境噪声；三维反演

英文摘要： Fine velocity structure of the Longmenshan fault zone provides key constraints not only for understanding the dynamic process of the occurrence of the 2008 Wenchuan earthquake, but also for validating the models of the geodynamic process on the eastern border of the Tibetan Plateau. In this study, we will develop a 3D inversion scheme that fits the need for the fine velocity structure in the fault zone like the Longmenshan. The inversion method aims at short period surface wave obtained from cross-correlation of seismic ambient noise and based on 3D FD or FEM wavefield simulation method. We will further use this method along with double- difference traveltime tomography to study the fine upper and middle crust velocity structure, on the dataset we have obtained after the Wenchuan earthquake. Then we will try to discuss the genesis and occureance process of the 2008 Wenchuan earthquake and validate the geodynamic models in the region of the eastern Tibetan Plateau.

英文关键词： Longmenshan Fault Zone；Velocity Structure；Wenchuan earthquake；seismic ambient noise；3D inversion