A new global gas hydrate budget based on numerical reaction-transport modeling and a novel parameterization of Holocene and Quaternary sedimentation

Burwicz, Ewa, Rüpke, Lars and Wallmann, Klaus (2011) A new global gas hydrate budget based on numerical reaction-transport modeling and a novel parameterization of Holocene and Quaternary sedimentation Proceedings of the 7th International Conference on Gas Hydrates (ICGH 2011), Edinburgh, Scotland, United Kingdom, July 17-21, 2011. HWU, Edinburgh, p. 9.

[img]
Preview
Text
ICGH7_extended_abstract.pdf - Published Version

Download (182Kb)

Abstract

This study provides new estimates for the global methane hydrate inventory based on reaction-transport modeling [1]. A multi-1D model for POC degradation, gas hydrate formation and dissolution is presented. The model contains an open three-phase system of two solid (organic carbon, gas hydrates), three dissolved (methane, sulfates, inorganic carbon) and one gaseous (free methane) compounds. The reaction module builds upon the kinetic model of POC degradation [2] which considers a down-core decrease in reactivity of organic matter and the inhibition of methane production via accumulation of metabolites in sediment pore fluids.
Global input grids have been compiled from a variety of oceanographic, geological and geophysical data sets including a parameterization of sedimentation rates in terms of water depth (Holocene) and distance to continents (Quaternary).The world's total gas hydrate inventory is estimated at 1.74 x 1013 m3 – ~2 x 1015 m3 CH4 (STP) or, equivalently, 8.3 – ~900 Gt of methane carbon. The first value refers to the present day conditions using the relatively low Holocene sedimentation rates; the second value corresponds to a scenario of higher Quaternary sedimentation rates along continental margins. This increase in the POC input could be explained by re-deposition process at the continental rise and slope due to erosion of continental shelf sediments during glacial times.
Our results show that in-situ POC degradation is at present not an efficient hydrate forming process. Significant hydrate deposits are more likely to have formed at times of higher sedimentation during the Quaternary or/and as a consequence of active upward fluid transport.

Document Type: Book chapter
Keywords: Meereswissenschaften; Physical Oceanography; Meeresgeologie; Geology; Gas hydrates, global budget, numerical modeling, reaction-transport model
Research affiliation: OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-MG Marine Geosystems
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-JRG-B3 Seabed Resources
Refereed: No
Date Deposited: 23 Jan 2012 08:38
Last Modified: 06 Jul 2012 14:53
URI: http://eprints.uni-kiel.de/id/eprint/13518

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...