Experimental Validation of the Electrokinetic Theory and Development of Seismoelectric Interferometry by Cross-Correlation

Figure 13

The geometry of the 1D numerical experiment. Positions 𝑥_𝐴 and 𝑥_𝐵 represent the receiver positions, denoted by the top-down triangles. The upper boundary is called 𝑥₁ and the lower boundary 𝑥₂, located at 𝑥=−150m and 𝑥=650m, respectively. The positions of the interfaces are visualized by the red bars. FS denotes the free-surface, whereas 𝐼𝐹1 and 𝐼𝐹2 correspond to the first and second subsurface interfaces, respectively. Furthermore, schematic ray paths of events in the seismoelectric Green’s function 𝐺^𝐸,𝑓(𝑥_𝐵,𝑥_𝐴,𝑡) are shown. The black arrows represent shear wave ray paths, whereas the green arrows depict electromagnetic ray paths. The labels correspond to the labelled events in Figures 14 and 15, where 𝑑 denotes the direct event and 𝑑𝑔 its source-side ghost, which are both coseismic field responses, 1 represents the interface response of the most shallow interface and 1𝑔 its source-side ghost, 2 corresponds to the interface response of the second, deeper interface and event 2𝑔 represents again its source-side ghost.