11:30 AM - 11:45 AM
[MIS09-10] Concentration anomalies of pore waters collected from shallow gas hydrate deposits in the eastern margin of the Japan Sea
Keywords:Shallow gas hydrate, Pore water
Although concentrations of chloride dissolved in pore waters are close to the seawater of ~560 mM at the sites where no or small amount of gas hydrates accumulates, those at the dense massive gas hydrate sites are often increased; reaching >1400 mM in the highly gas hydrate accumulated intervals. These high chloride intervals locate in shallower depths at the higher methane flux sites. Our results indicate that the pore water geochemistry is often modified in response to the formation dynamics of massive gas hydrates near the seafloor.
This study was conducted as a part of the shallow methane hydrate exploration project of METI.