Geochemical characterization of seafloor sediment porewater as a rapid response to methane seepage and its biogeochemical processes to document methane seepage characteristics. In this study, methane seepage and geochemical indicators in porewater were investigated for five stations in “Haima” Cold Seep in the South China Sea. The results showed that the methane release in different stations was quite different, with the methane diffusion flux ranged from 0.3 to 168.3 μmol/(m²·a). However, there were some similarities in the geochemical indicators for every station. Correlation analysis indicated that methane seepage was positively correlated with depth and PO43-, and negatively correlated with TS, K+, Na+, Mg2+, Mn2+, Fe3+, and NO2-. The PCA cluster analysis results were similar to the classification of habitat characteristics observed during sampling. Therefore, it may be possible to provide an indication of methane leakage through habitat characteristics in future studies.
Keywords cold seep, methane seepage, sediment, geochemical characteristics