Hydrate formation in porous media with upward-migrating methane and its implications for the evolution of deep-sea...

Methane leaking from the deep seabed is a primary source of carbon and energy for various microorganisms, sustaining the evolution and productivity of cold seep ecosystems. However, the dynamics of methane hydrate formation under methane seepage conditions and potential impacts on the evolution of cold seep ecosystems remain unclear. This study investigated the dynamic formation characteristics of gas hydrates within cold seep sediments by simulating the methane leakage process. Using magnetic resonance imaging (MRI) to monitor the methane hydrate formation process by detecting the distribution of ¹H in pore water, we aimed to determine the influence of various parameters on hydrate formation. Our experimental results demonstrated that high flow rates and pressures combined with low temperatures would accelerate the formation of methane hydrates and effectively promote the conversion of leaked methane into solid hydrates. Our findings suggest that methane hydrate formation within cold seep sediments may regulate the availability and flux of methane for microbial activities within cold seep environments, thus influencing local biogeochemical processes and ecosystem dynamics. This study advances our understanding of the transformation of leaked methane into solid hydrate within cold seep sediments, highlighting its importance in the dynamic evolution of cold seep ecosystems and its impact on the oceanic carbon cycle.