SEGJ Technical Conference

2.5 dimensional numerical simulation for applicability of marine ellectromagnetic sounding in submarine massive sulphide exploration

Abstract Recently, electromagnetic method is widely used for shallow subsurface exploration. In this paper, we propose a new controlled-source electromagnetic method using two AUVs for the exploration of submarine massive sulphides. A numerical simulation code for 2.5-D electromagnetic field in the frequency domain was developed in order to estimate electromagnetic responses in possible conductivity structures. As a result, we confirmed that electric field on the seafloor is very sensitive to the location of buried conductive zone. We also confirmed that the intensity of received electric field decrease near the seafloor in an area wider than the horizontal extent of the buried conductive zone, when the controlled-source is located above the conductive zone. This is because electric field is attenuated due to an electric current in the conductive zone. The result also shows that the new controlled-source electromagnetic method we propose is realizable.