考虑激电效应的二维大地电磁测深正演

2D magnetotelluric forward modeling with induced polarization

通常情况下地下岩矿石在通电的情况下,不仅表现出电磁效应,还表现出激电效应,在激电效应强烈的地区两者难以分离。笔者通过对均匀半空间中两种极化体的正演模拟,分析Cole--Cole模型参数对极化体的影响规律。模型正演结果表明:激电效应的存在会使视电阻率值增大,不同激电参数对视电阻率产生的影响不同,其中极化率对视电阻率的影响最大;极化率越大,视电阻率越大。

Under the common condition of electricity,the underground rocks show not only the electromagnetic effect,but also the excitation effect,which are difficult to separate in the areas where the excitation effect is strong. Through the forward modeling of two polarization bodies in uniform half space,the influence of parameters of polarization in the Cole--Cole model on the polarization bodies is analyzed. The forward model shows that existing of induced polarization increases the apparent resistivity,and the effects of different excitation parameters on apparent resistivity are different,of which the polarizability has the greatest influence on the apparent resistivity. The greater the polarizability,the greater the apparent resistivity.