Researchers from Norway and Russia have found significant amount of the greenhouse gas methane is leaking from an area of the Arctic seabed off the northern coast of Siberia.

According to the team’s report in the Journal of Geophysical Research: Biogeosciences, the melting of permafrost on the seafloor of the Kara Sea is releasing previously-sequestered methane.

“The thawing of permafrost on the ocean floor is an ongoing process, likely to be exaggerated by the global warming of the world´s oceans,” said study author Alexey Portnov at Centre for Arctic Gas Hydrate, Climate and Environment (CAGE) at The Arctic University of Norway.

Permafrost is considered soil that has been permanently frozen for at least two years and is usually much thicker on land where temperatures can stay far below the freezing point for months on end.

“Bottom water temperature is usually close to or above zero. Theoretically, therefore, we could never have thick permafrost under the sea,” Portnov explained.

He added that 20,000 years ago, during the last ice age, the sea level dropped nearly 400 feet.

“It means that today´s shallow shelf area was […]