First observation of direct methane emission to the atmosphere from the subglacial domain of the Greenland Ice Sheet

• Published in: Scientific Reports
• Main Authors: Christiansen, Jesper Riis, Jorgensen, Christian Juncher
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: WESTERN MARGIN; BENEATH; CO2; THAW; OXIDATION; FEEDBACK; GLACIER; FLUXES; Arctic; Greenland; glacier; greenlandic; Ice Sheet
• Online Access: https://pure.au.dk/portal/da/publications/first-observation-of-direct-methane-emission-to-the-atmosphere-from-the-subglacial-domain-of-the-greenland-ice-sheet(2ca42a93-84c8-45de-a52a-0bd55773b030).html; https://doi.org/10.1038/s41598-018-35054-7; https://pure.au.dk/ws/files/137049256/s41598_018_35054_7.pdf

During a 2016 field expedition to the West Greenland Ice Sheet, a striking observation of significantly elevated CH4 concentrations of up to 15 times the background atmospheric concentration were measured directly in the air expelled with meltwater at a subglacial discharge point from the Greenland Ice Sheet. The range of hourly subglacial CH4 flux rate through the discharge point was estimated to be 3.1 to 134 g CH4 hr(-1). These measurements are the first observations of direct emissions of CH4 from the subglacial environment under the Greenlandic Ice Sheet to the atmosphere and indicate a novel emission pathway of CH4 that is currently a non-quantified component of the Arctic CH4 budget.