一种简单的大地电磁阻抗张量畸变分解方法

A SIMPLE DECOMPOSITION METHOD OF DISTORTION IN MAGNETOTELLURIC IMPEDANCE TENSOR

提出了一种简单的大地电磁阻抗张量畸变分解方法 .引入 3d/2d模型 ,使得全畸变的大地电磁阻抗张量被简化 .通过对比Swift旋转和Bahr分解后的资料 ,用联系二者的畸变矩阵表示浅层三维电性异常体对区域二维构造的局部畸变影响 .通过研究畸变张量矩阵 ,并对其进行分解 ,可将局部三维电性不均匀体产生的畸变与区域构造分离开来 ,从而了解区域构造的维数特征和局部畸变类型及其对区域构造的影响 .最后 ,应用 3个测点的实际资料 ,对这种简单的畸变分解方法进行了检验 .结果表明 ,该方法简单且应用方便 。

The necessity of establishing a 3d/2d model is discussed. Owing to introducing the model, the full electric and magnetic field galvanic distortion tensor is simplified. The effects of a surface 3 d conductivity anomaly on a regional 2 d structure is derived by comparing data through Swift rotation with data through Bahr decomposition, then is expressed by a distortion matrix. The effect of a local anomaly can be separated from a regional structure by researching and decomposing the distortion tensor matrix. So it is available to find out the regional structure dimensionality, classification of the local structure and the effect of it on the regional structure. Eventually, the simple distortion decomposition method is tested through three sites of practical data.