西南印度洋中脊龙旂热液区（49°39’E）是超慢速扩张洋中脊上发现首个活动热液喷口的地方，也是我国开展海底多金属硫化物资源勘探及走向深海大洋的重点研究区域。前期具备余弦函数分布特征的65,634对三维走时残差数据，为该区开展创新性的地震波各向异性研究提供了坚实数据基础。本项目拟在前期研究基础上，利用65,634对主动源走时残差及最新采集的被动源地震数据，通过采用纵波方位各向异性和横波分裂联合分析的方法，重点研究地壳和地幔各向异性特征，并结合三维速度模型与区域地质背景资料，对获得的快波方向和快、慢波到时差参数进行深入分析，阐明地壳内裂隙分布、应力场变化和地幔流动特征，揭示龙旂热液区的热液循环机制、岩石圈形变和深部动力学过程等科学问题。本项目不仅为超慢速扩张洋中脊的热液系统研究做出实质性的贡献，而且为我国今后海底多金属硫化物资源勘探提供重要依据，对科学与资源均具有深远的研究意义。

Dragon Flag hydrothermal field (49°39’E) where the first active hydrothermal vents on the ultraslow-spreading mid-ocean ridge were discovered, is located on Southwest Indian Ridge, and it is a key areas for exploration of seafloor polymetallic sulfide resources and studying to the deep ocean for China. The 65,634 three-dimensional travel-time residuals which show cosine relationship with azimuths, provide solid data base for innovative seismic anisotropy research here. The proposed project will carry out seismic anisotropic study by means of azimuthal seismic anisotropy technique and shear wave splitting, based on OBS data generated by the active (airguns) and passive (earthquakes) sources. Combined with three-dimensional velocity model and regional geological background data, the crustal cracks distribution, stress variation and mantle flow will be depicted by deep analysis for anisotropic parameters of fast wave direction and travel-time difference between fast wave and slow wave, and then hydrothermal circulation mechanism, lithospheric deformation and deep dynamics process etc will be revealed. It will not only make great contribution for hydrothermal circulation mechanism on ultra-slow spreading ridges, but also provide fundamental data for the exploration and development of seafloor polymetallic sulfide resources. This research has profound significances for both science and resources.