Field result of marine controlled source electromagnetic survey for gas hydrates in northern South China Sea

Marine controlled-source electromagnetic (CSEM) sounding can be used to address the problem of imaging conductive sedimentary sequences underlying resistive layers. We conducted a marine CSEM sounding at Hydrate Ridge in the northern South China Sea, in 2015. Electromagnetic fields transmitted by a towed horizontal electric dipole source in deep sea were measured by a linear array of six seafloor receivers, positioned 500 m apart. Furthermore, to illustrate some of the important issues like the gas hydrate distribution and the depth in the region, we tried two type of data process method like fast flourier transform, single frequency sinusoidal wave fitting in order to get the highest signal noise ratio. We have produced the original calculations like 1D result to provide a preliminary survey of potential hydrate distribution in this region. Resistivity results are compared with seismic reflectors collected in the area. Results are presented in simple form separated by apparent resistivity pseudo sections, which produce an approximate image of lateral resistivity variations across the study region.