Vol. 18, issue 05-06, article # 19

Abstract:

We have investigated decomposition of methane hydrates in the World Ocean that may occur due to the secular change in the surface temperature of the ocean. Several scenarios of warming or cooling of the surface water are considered. It is supposed that the temperature of the ocean surface changes by 1 to 1.5 degree for 50 years. The climatic model of the ocean thermohydrodynamics, complemented with the heat conduction equation for the bottom sediment and the transport equation for dissolved methane, is integrated over a period of 2000 to 8000 years. The transport of dissolved methane from methane hydrates buried under the bottom at a depth from 100 to 300 m is simulated. The obtained methane flows into the atmosphere, comparable with the available estimates, vary from 1.0 to 10 Tg/year, depending on the warming scenarios. The time of beginning of possible decomposition of the methane hydrates varies from 70 to 1 000 years depending on the scenario parameters.