Development research on new method for resistivity imaging using artificial electric noise caused by DC-railway leakage current

为了发展利用人工电噪声进行地下电阻率成像的新方法，通过对现有多点同时观测的电磁资料的仔细分析，揭示了直流铁路漏电流的特征，阐明了利用漏电流作为有源源时应注意的问题。在仔细的研究过程中，我们获得了2007年诺托坂东地震震源区周围的三维电阻率图像。

In order to develop new method for underground resistivity imaging using artificial electric noise, which should be removed in ordinary electromagnetic surveys, caused by DC-railway leakage current, werevealed the characteristics of the DC-railway leakage currents by careful scrutiny of existingmultipoint and simultaneous observed electromagnetic data and clarified the issues in case of using leakage currents as active sources. In process of the careful scrutiny, weobtained three-dimensional resistivity image around the focal region of the 2007 Noto Hanto earthquake.