title: Non-Fickian diffusion and the accumulation of methane bubbles in deep-water sediments.
abstract: In the absence of fractures, methane bubbles in deep-water sediments can be immovably trapped within a porous matrix by surface tension. The dominant mechanism of transfer of gas mass therefore becomes the diffusion of gas molecules through porewater. The accurate description of this process requires non-Fickian diffusion to be accounted for, including both thermal diffusion and gravitational action. We evaluate the diffusive flux of aqueous methane considering non-Fickian diffusion and predict the existence of extensive bubble mass accumulation zones within deep-water sediments. The limitation on the hydrate deposit capacity is revealed; too weak deposits cannot reach the base of the hydrate stability zone and form any bubbly horizon.
authors.affiliation: Department of Mathematics, University of Leicester, LE1 7RH, Leicester, UK, Denis.Goldobin@gmail.com.
authors.forename: D S
authors.initials: DS
authors.lastname: Goldobin
authors.forename: N V
authors.initials: NV
authors.lastname: Brilliantov
authors.forename: J
authors.initials: J
authors.lastname: Levesley
authors.forename: M A
authors.initials: MA
authors.lastname: Lovell
authors.forename: C A
authors.initials: CA
authors.lastname: Rochelle
authors.forename: P D
authors.initials: PD
authors.lastname: Jackson
authors.forename: A M
authors.initials: AM
authors.lastname: Haywood
authors.forename: S J
authors.initials: SJ
authors.lastname: Hunter
authors.forename: J G
authors.initials: JG
authors.lastname: Rees