This paper studied the shear-wave splitting of 5 portable stations in Dali-Yongping to the west of Red River fault which was set up under the project China Array Phase I from 2011 to 2013, obtaining 18, 14, 7, 9 and 5 shear-wave splitting results for these 5 portable stations, respectively. Applying “Over-Normalization” correction method with more precise shear wave path, 3 anisotropic layers with different anisotropic strength are found above 10 km depth in the upper crust. The second anisotropic layer’s anisotropy is weakest with thickness of 2?2.4 km. The first anisotropic layer’s anisotropy is stronger with thickness of 4.1?5.0 km. The third anisotropic layer’s anisotropy is strongest. This multilayered anisotropy characteristic is coincide with the magnetotellurics results in this area. Combining low velocity anomaly, low resistivity and low Q value in western Yunnan, the strongest anisotropy in the third anisotropic layer is caused by rich cracks and upward transferring heat flow which is created by the upwelling of mantle material.

对中国地震科学台阵探测项目一期于2011—2013年布设在红河断裂以西大理永平地区的5个流动台站进行横波分裂研究, 分别得到18, 14, 7, 9 和5个横波分裂参数测量结果, 并使用更精确的实际横波路径, 通过过量归一化方法进行改正, 研究该区域各向异性分层特征。结果显示, 研究区上地壳10 km深度之上存在各向异性强度大小相间的3层各向异性层, 其中第2层各向异性强度最小, 厚度为2~2.4 km; 第1层各向异性强度稍强, 厚度为4.1~5.0 km; 第3层各向异性强度最强。各向异性分层特征与前人在该区域的大地电磁测深结果吻合。结合滇西地区地壳中的低速异常、低电阻率和低Q值现象, 认为第3层的强各向异性是地幔物质上涌造成裂隙发育以及热流上传所致。