We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Estimation of the global inventory of methane hydrates in marine sediments using transfer functions.
- Authors
Piñero, E.; Marquardt, M.; Hensen, C.; Haeckel, M.; Wallmann, K.
- Abstract
The accumulation of gas hydrates in marine sediments is essentially controlled by the accumulation of particulate organic carbon (POCar) which is microbially converted into methane, the thickness of the gas hydrate stability zone (GHSZ) where methane can be trapped, and the delivery of methane from deep-seated sediments by ascending pore fluids and gas into the GHSZ. Recently, Marquardt et al. (2010) developed a transfer function to predict the gas hydrate inventory in diffusion-controlled geological systems based on POCar and GHSZ. We present a new parameterization of this function and apply it to global datasets of bathymetry, heat flow, seafloor temperature and organic carbon accumulation estimating a global mass of only 91 Gt of carbon (GtC) stored in marine methane hydrates. Seepage of methane-rich fluids is known to have a pronounced effect on gas hydrate accumulation. Therefore, we carried out a set of systematic model runs with the transport-reaction code in order to derive an extended transfer function explicitly considering upward fluid advection. Using averaged fluid velocities for active and passive margins, which were derived from mass balance considerations, this extended transfer function predicts the formation of gas hydrates along the continental margins worldwide. Different scenarios were investigated resulting in a global mass of sub-seafloor gas hydrates of 400-1100 GtC. Overall, our systematic approach allows to clearly and quantitatively distinguish between the effect of biogenic methane generation from POC and fluid advection on the accumulation of gas hydrate and hence, provides a simple prognostic tool for the estimation of large-scale and global gas hydrate inventories in marine sediments.
- Subjects
ESTIMATION theory; METHANE hydrates; MARINE sediments; TRANSFER functions; GAS hydrates; CARBON compounds; THICKNESS measurement
- Publication
Biogeosciences Discussions, 2012, Vol 9, Issue 1, p581
- ISSN
1810-6277
- Publication type
Article
- DOI
10.5194/bgd-9-581-2012