Hundreds of plumes of methane bubbles emanate from an area of the seabed off West Svalbard that has become 1°C warmer over the last 30 years. The paper investigates the hypothesis that the methane in the plumes is derived from hydrate dissociated by ocean warming. Numerical models were used to simulate the response of hydrate to changes in ocean temperature over time periods of 1000 years before present day. The models showed that the methane in the bubble plumes could be derived from hydrate if the hydrate was close to the seabed prior to the warming, or if gas flow is through fractures with a higher intrinsic permeability than the surrounding host rock.
The sonar image shows bubble plumes at the seabed for data collected during JR211 Research Cruise to West Svalbard, funded through an NERC research grant through the University of Southampton, the University of Birmingham and Royal Holloway, University of London.
The research was carried out while Kate was at the universities of Birmingham and Durham. Since joining Quintessa, Kate has continued her interests in the modelling of methane hydrates and is currently developing a coupled process model using QPAC.
Reference: K E Thatcher,1,2 G K Westbrook,1,3,4 S Sarkar,3 and T A Minshull3: Methane release from warming-induced hydrate dissociation in the West Svalbard continental margin: Timing, rates, and geological controls’.Journal of Geophysical Research: Solid Earth, Vol. 118, 1-17, 2013. 1University of Birmingham. 2University of Durham. 3University of Southampton. 4Géosciences Marines, Ifremer Centre de Brest.