音频大地电磁法对断层分辨能力的正演模拟

音频大地电磁(AMT)法是寻找断裂带裂隙水的有效方法。本文通过多个模型的正演模拟,并在分析不同模型正演响应的TM模式Bostick一维反演断面特征的基础上,探讨了点距、点位、第四系低阻层对AMT法TM模式数据定位断层的影响以及AMT法TM模式数据对断层的位置、倾向、倾角、发育深度、破碎程度等特征的分辨能力。研究表明:在点位和点距布设合理的情况下,AMT法TM模式数据对断层倾向、发育平面位置的推断是可靠的;第四系覆盖层更似低通滤波器,减弱了AMT法TM模式数据对断层的刻画能力,尤其影响了对浅部断层的识别,其反演结果可揭示断层发育深度;受静态和纵向分辨率的影响,AMT法TM模式数据无力估计小型断层的倾角和纵向上破碎的差异性。

Forward modeling for fault resolution capability of AMT method

AMT is an effective way to find fault crevice water.In this paper,through several forward models,on the basis of analysis the response of TM mode Bostick?section?features in different models 1D inversion,probed into the influence as point location,dot pitch and Quaternary cover on locate fault?and the resolution capability on fault location,orientation,inclination,developmental?depth,degree of fragmentation and other?characteristics of TM mode.Studies have shown that:?in the case of reasonable point location and dot pitch,the inference of fault?orientation,developmental?plane position from TM mode is reliable.The quaternary cover?is more like?a low-pass filter,weakened the capability of depict fault,especially affect?the identification?of?shallow?faults,the?inversion?results can?reveal?the depth of?fault.By the affect of static and vertical resolution,TM mode is unable to estimate the small faults differences of inclination and vertical broken.