Glacial Loss and Methane Release from Catchments near Kongsfjorden

Vast amounts of methane, a potent greenhouse gas (GHG), are stored in subsurface sediments in the Arctic. The estimated size of these reservoirs varies greatly between studies, but it is widely agreed that a release of even a small fraction could contribute significantly to global GHG concentrations. Glaciers and permafrost provide sufficiently high pressures and low temperatures to entrap methane in the form of stable hydrates, preventing the gas from being leaked to the atmosphere. Climate-sensitive glacial retreat can dissociate these stores while also exposing areas of glacial forefields where permafrost aggradation has not yet developed. These regions may provide pathways for subsurface methane to reach the atmosphere through subglacial and groundwater upwelling. Anoxic environments are required for microbial production of methane. Sub- or anoxic conditions have been found to occur in subglacial drainage pathways and thus upwelling sites have been associated with considerable methane release during melt season. These conditions have been shown to support the production of contemporary biogenic methane through microbially-mediated methanogenesis, but may also support the migration of geological methane sourced from subsurface reserves (shale gas or coal bed methane). Through a spatial survey of glacial forefields throughout Spitsbergen, this project aims to describe the relationship between glacier retreat and the development of methane-containing subglacial and groundwater upwelling sites. Geochemical analysis of fluid outflows at each site will be used to investigate the origin, potential flow paths and fate of methane in proglacial areas. Currently, due to COVID restrictions, only sites throughout Nordenskiöld Land have been sampled. Additional sites in the Kongsfjorden region will generate the geologically diverse dataset required to investigate the relationship between bedrock geology and the physical and biogeochemical processes governing methane release.