Broadband teleseismic waveform data from 13 earthquakes recorded by 70 digital seismic stations were selected to evaluate the inhomogeneity parameters of the crustal medium in the southern Longmenshan fault zone and its adjacent regions using the teleseismic fluctuation wavefield method. Results show that a strong inhomogeneity exists beneath the study region, which can be divided into three blocks according to its structure and tectonic deformation features. These are known as the Sichuan-Qinghai Block, the Sichuan-Yunnan Block, and the Mid-Sichuan Block. The velocity fluctuation ratios of the three blocks are approximately 5.1%, 3.6%, and 5.1% in the upper crust and 5.1%, 3.8%, and 4.9% in the lower crust. The inhomogeneity correlation lengths of the three blocks are about 10.1 km, 14.0 km, and 10.7 km in the upper crust and 11.8 km, 17.0 km, and 11.8 km in the lower crust. The differences in the crustal medium inhomogeneity beneath the Sichuan-Yunnan Block, the Sichuan-Qinghai Block, and the Mid-Sichuan Block may be related to intensive tectonic movement and material flow in the crust and upper mantle.

选择了由70个数字地震台站记录的13次地震的宽带远震波形数据，采用远震波动波场法评估了龙门山断裂带南部及其邻近地区地壳介质的非均质性参数。结果表明，研究区下方存在强烈的非均质性，根据其结构和构造变形特征可将其分为三个区块。这些被称为川-青海块，川-云南块和四川中部块。三个块的速度波动率在上地壳中约为5.1％，3.6％和5.1％，在下地壳中约为5.1％，3.8％和4.9％。这三个区块的非均质性相关长度分别为上地壳10.1 km，14.0 km和10.7 km，上地壳11.8 km，17.0 km，下地壳11.8公里。川云南地块，川青地块和川中地块下的地壳介质不均匀性差异可能与地壳和上地幔的强烈构造运动和物质流有关。