WHAT HAPPENS IN GAS HYDRATE-BEARING SEDIMENTS DURING/AFTER MASSIVE GAS EMISSION INTO WATER COLUMN IN THE SEA OF OKHOTSK?

Abstract

e propose a scenario to explain occurrence of two kinds of chimneys in gas hydrate-bearing sediments: (1) As warm fluid with gas is migrating upward into seafloor along the fault, the area around the fault become non-gas hydrate stability condition around the fault. Gas/fluid migrating along the fault saturates diffusely into adjacent sedimentary layers, which forms relatively wide ER chimney with enhanced reflection along the fault. (2) After stoppage of warm fluid supply, the ER chimney comes back under gas hydrate stability condition as inner temperature decreases. Thus gas in the chimney is converted into gas hydrates. Focused saturation of gas hydrates along the fault makes the narrow WO chimney. (3) New ER chimney is formed at the sites where gas/fluid is migrating upward along other path.