Deep, cylindrical craters in the permafrost of Siberia have puzzled researchers since they were discovered a decade ago. Researchers now propose that the distinctive structures are caused by a build-up of hot gas beneath the permafrost. Warming Arctic temperatures might then weaken the permafrost so much that the gas explodes through its surface.
“Climate change is likely the triggering factor, but it happens there because you have the thinning of the permafrost due to the gas,” says Helge Hellevang at the…