Seepage from an arctic shallow marine gas hydrate reservoir is insensitive to momentary ocean warming

• Published in: Nature Communications
• Main Authors: Hong, Wei-Li, Torres, Marta E., Carroll, JoLynn, Crémière, Antoine, Panieri, Giuliana, Yao, Haoyi, Serov, Pavel
• Language: unknown
• Published: 2023
• Subjects: 54 ENVIRONMENTAL SCIENCES; Arctic; Storfjordrenna; Spitsbergen
• Online Access: http://www.osti.gov/servlets/purl/1374892; https://www.osti.gov/biblio/1374892; https://doi.org/10.1038/ncomms15745

Arctic gas hydrate reservoirs located in shallow water and proximal to the sediment-water interface are thought to be sensitive to bottom water warming that may trigger gas hydrate dissociation and the release of methane. Here, we evaluate bottom water temperature as a potential driver for hydrate dissociation and methane release from a recently discovered, gas-hydrate-bearing system south of Spitsbergen (Storfjordrenna, ~380m water depth). Modelling of the non-steady-state porewater profiles and observations of distinct layers of methane-derived authigenic carbonate nodules in the sediments indicate centurial to millennial methane emissions in the region. The results of temperature modelling suggest limited impact of short-term warming on gas hydrates deeper than a few metres in the sediments. We conclude that the ongoing and past methane emission episodes at the investigated sites are likely due to the episodic ventilation of deep reservoirs rather than warming-induced gas hydrate dissociation in this shallow water seep site.