Methane profiles along the continental margin off Svalbard ...

• Published in: Nonlinear Processes in Geophysics
• Main Authors: Mau, Susan, Römer, Miriam, Torres, Marta E, Bussmann, Ingeborg, Pape, Thomas, Damm, Ellen, Geprägs, Patrizia, Wintersteller, Paul, Hsu, Chieh-Wei, Loher, Markus, Bohrmann, Gerhard
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2017
• Subjects: Center for Marine Environmental Sciences MARUM; Arctic; Bjørnøya; Damm; Hornsund; Ingeborg; Svalbard; Kongsfjord*; Kongsfjorden
• Online Access: https://dx.doi.org/10.1594/pangaea.874434; https://doi.pangaea.de/10.1594/PANGAEA.874434

Numerous articles have recently reported on gas seepage offshore Svalbard, because the gas emission from these Arctic sediments was thought to result from gas hydrate dissociation, possibly triggered by anthropogenic ocean warming. We report on findings of a much broader seepage area, extending from 74° to 79°, where more than a thousand gas discharge sites were imaged as acoustic flares. The gas discharge occurs in water depths at and shallower than the upper edge of the gas hydrate stability zone and generates a dissolved methane plume that is hundreds of kilometer in length. Data collected in the summer of 2015 revealed that 0.02?7.7% of the dissolved methane was aerobically oxidized by microbes and a minor fraction (0.07%) was transferred to the atmosphere during periods of low wind speeds. Most flares were detected in the vicinity of the Hornsund Fracture Zone, leading us to postulate that the gas ascends along this fracture zone. The methane discharges on bathymetric highs characterized by sonic hard ... : Supplement to: Mau, Susan; Römer, Miriam; Torres, Marta E; Bussmann, Ingeborg; Pape, Thomas; Damm, Ellen; Geprägs, Patrizia; Wintersteller, Paul; Hsu, Chieh-Wei; Loher, Markus; Bohrmann, Gerhard (2017): Widespread methane seepage along the continental margin off Svalbard - from Bjørnøya to Kongsfjorden. Scientific Reports, 7, 42997 ...