THE FATE OF GAS MIGRATION PATHS IN GAS HYDRATE-BEARING SEDIMENT IN THE SEA OF OKHOTSK

Abstract

Many active gas and fluid venting sites at the seafloor and gas flares in the water column have been detected in the Sea of Okhotsk where massive gas hydrate deposits have been found (Ginsburg et al., 1993

Matveeva et al, 2003, Biebow et al. 2003). In the NE continental margin off Sakhalin Island, we simultaneously collected both high-resolution seismic and hydroacoustic data along the survey lines to examine fine-scale seismic structures of gas hydrate-bearing sediments and ongoing gas-emission features in the water column, respectively. Correlation of those two data sets enables us uniquely to investigate migration paths of methane in gas hydrate-bearing sediments directly associated with ongoing methane releases into the water column. We present here a model of the evolution of the gas chimney during and after large-scale gas release occurs in the water column.