Arctic Ocean Gas Hydrate Stability in a Changing Climate

Abstract EN

Recent estimations suggest that vast amounts of methane are locked in the Arctic Ocean bottom sediments in various forms of gas hydrates.

A potential feedback from a continued warming of the Arctic region is therefore the release of methane to the atmosphere.

This study addresses the relationship between a warming of the Arctic ocean and gas hydrate stability.

We apply a theoretical model that estimates the base of the gas hydrate stability zone in the Arctic Ocean considering different bottom water warming and sea level scenarios.

We model the present day conditions adopting two different geothermal gradient values: 30 and 40°C/km.

For each geothermal gradient value, we simulate a rise and a decrease in seafloor temperature equal to 2°C and in sea level equal to 10 m.

The results show that shallow gas hydrates present in water depths less than 500 m would be strongly affected by a future rise in seafloor temperature potentially resulting in large amounts of gas released to the water column due to their dissociation.

We estimate that the area, where there could be complete gas hydrate dissociation, is about 4% of the area where there are the conditions for gas hydrates stability.