Degrading Offshore Permafrost and Arctic Hydrates as a Source of Methane on the Arctic Shelf

Collaborative research between UGA and U. Alaska - funded by NSF, Arctic Natural Sciences.

The Arctic Ocean contains a huge amount of organic carbon buried within seabed sediments. These sediments are annually (“offshore” permafrost) or seasonally frozen, representing a substantial reservoir of potentially labile organic carbon. Global warming in the Arctic region is predicted to be substantial, and possibly rapid, in next few decades. Upon permafrost melting, the old carbon stored therein will be reintroduced into the modern carbon biogeochemical cycle, possibly acting as a strong source of methane to the overlying water and potentially the atmosphere. Additionally, extremely large amounts of more ancient (Pleistocene) methane are trapped as gas hydrates within and beneath the permafrost.

This project aims to elucidate the present and future methane flux potential of sediments and permafrost on the Arctic Shelf. As a result of global warming, seafloor permafrost may experience a pronounced change in thermal regime. Increased temperature may affect permafrost in several ways, ultimately leading to its degradation and enhanced CH4 release.

The project will combine field data and modeling to advance the understanding of the coupled physical-geological-biological-chemical Arctic system by elucidating the impact of global warming on methane dynamics. In particular, the current and potential capacity of sediments and permafrost to act as a methane source to the overlying water column and atmosphere will be quantified.