The Role of Methane Hydrate in Ocean Carbon Chemistry and Biogeochemical Cycling

Abstract

The microbiological role in the production of methane and the formation and stability of methane hydrates is critical to our understanding of ocean carbon cycling and global warming, and has important ramifications for sources of alternative energy, and the global economy. The methane hydrate reservoir vastly exceeds other carbon energy reservoirs (Kvenvolden, 1988). The amount of methane that is present in the ocean floor depends on the distribution of hydrates and the methane content. The estimated range of ocean gas hydrates is 26.4 to 139.1 × 10¹⁵ m3 (Gornitz and Fung, 1994). The maximum content in 1 m3 of hydrate is calculated to be 164 m3 methane and 0.8 m3 water (Kvenvolden et al., 1993; Max and Lowrie, 1997). Variability in hydrate methane content is controlled by geothermal gradients, methane and other hydrocarbon gas contents and by the rate of biological formation. Currently only the sketchiest details of the ocean carbon cycle in the sediment and water column are understood. This is a primary emerging research topic in ocean science.