Spatial-temporal variations of the gas hydrate stability zone and hydrate accumulation models in the Dongsha region, China

It is of great significance to study the spatial-temporal variations thickness gas hydrate stability zone (GHSZ) understand decomposition, migration, accumulation and dissipation hydrate, corresponding relationship between bottom-simulating reflectors (BSRs) distribution heterogeneous hydrate. We selected Dongsha region in South China Sea (SCS) as research object calculate variation GHSZ since 10 Ma, analyzed main factors affecting GHSZ, discussed dynamic processes proposed an model region. The results show that thicknesses area were 0 m 100 from 5.11 relatively higher bottom water temperature (BWT) was key factor leading thinner during this period. From 5.11-0 gradually increased but showed several fluctuations due changes geothermal gradient, seawater depth, BWT, other factors. decrease BWT thickening Ma. are 110 415 at present. present spatial features following characteristics. deep canyon thick, with generally 225 m, while areas thin, m. Based on characteristics two models proposed: a double-BSRs thinning multilayer single or multiple BSRs.