Depressurization experiment of pressure cores from the central Ulleung Basin, East Sea: Insights into gas chemistry

The constant carbon isotope separation (∼10-20‰) between CO2 in void gases and in the dissolved inorganic carbon (DIC) pool shown in cores from the Ulleung Basin, has also been observed in gas hydrate-bearing sediments elsewhere. It is important to consider this effect when using carbon isotopic data in carbon cycling models, specifically when unraveling metabolic pathways of methane generation. In situations where partial CO2 degassing of a core is suspected, we recommend the use of the carbon isotope ratio of DIC instead of the gas measurements to best delineate the methane cycling pathways in marine systems.