Change of Gas Hydrate Reservoir in Southern South China Sea from the Last Glacial Maximum to Present and Its Effect on Environment

Abstract

There has been a big change of the sea level and seabed water temperature since the Last Glacial Maximum (LGM) in southern South China Sea. In order to study the change of the thickness of gas hydrate stable zone and its effect on environment, 35 spots from four key areas in the southern South China Sea were selected to calculate it based on relative equation and program. The results show that the thickness of the gas hydrate stable zone are 262m and 233m, the methane resource quantity are 2.69 x 10(13) m(3) and 2.39 x 10(13) m(3), and the gas hydrate resource quantity are 1.64 x 10(11) m(3) and 1.46 x 10(11) m(3) in LGM and at present, respectively, indicating the thickness of the stable zone has reduced by 29m, i.e. 12 percent on average and 3.0 x 10(12) m(3) methane was released since LGM. This released methane should have greatly affected the environment and even terminated the ice age.