Putin hails 'pragmatism and common sense' as he launches US-Russian oil project in Kara Sea, which has Saudi-scale potential.

Blocks of soil and ice thrown hundreds of metres from epicentre of the funnel at the Yamal peninsula.

Findings pave the way for a 1.2 million square kilometre claim to the UN on hydrocarbon drilling rights.

Pipes are built over bulging and unstable Arctic pingos prone to violent eruptions caused by 'thawing methane gas', as seen twice on the Yamal peninsula this year.

A new study of some of the world's most remote islands show there are dramatic climate changes since detailed research by Soviet scientists 55 years ago.

Satellites show giant hole ringed by 20 'baby craters'.

Haunting beauty of massive hole as scientists examine frozen lake formed after giant blowout.

Concern from scientists over potential danger to gas production facilities in region vital for energy supplies.

Reindeer herders find more craters in the far north in a deepening puzzle for scientists. 

Mysterious 'gigantic' hole in remote region spotted by helicopters over gas-rich Yamal peninsula.