在云南南部地区布设了一条孟连一罗平的北东向大地电磁测深剖面,以开展该地区的深部电性结构探测和孕震环境探查.沿该剖面进行了114个大地电磁测深点的观测,经过对观测资料的远参考Robust处理、定性分析和二维反演,得到了沿该剖面地壳、上地幔电性结构模型,从模型的电性结构特征进一步探讨了剖面穿过的3个地震区的深部地震孕育环境.研究结果表明:沿剖面的地壳上地幔电性结构反映出与区域地质构造资料基本一致的构造特征;该区的三个强震带地球深部都存在壳内低阻体,地震发生在电阻率梯度带上;断裂带的两侧块体介质的电阻率差异是强震活动带重要的深部背景.
Magnetotelluric sounding profile was carried out at 114 sites from northeast to southwest in the southern area of Yunnan Province for the exploration of seismogenic environment in deep earth. An electrical structure model of crust and upper mantle was obtained after Robust processing, Qualitative Analysis and two dimension inversion of the observation data. Three strong earthquake belts are distributed along the profile. The deep seismogenic structure shows that: (1) the electrical structure of crust and upper mantle along the profile is broadly consistent with the regional geological data; (2) all of the strong earthquake belts along the profile from Menglian to Luoping have low resistance area and resistivity gradient zone; (3) resistivity difference between two sides of deep fault is the important background of strong earthquake belts.