Yet another mysterious crater has been discovered on Siberia’s Yamal Peninsula—18 miles from its larger twin. The Moscow Times reports that Nent reindeer herders made the find. Anna Kurchatova with the Sub-Arctic Scientific Research Centre said, “Global warming, causing an alarming melt in the under-soil ice, released gas causing an effect like the popping of a champagne bottle cork.” Methane seeping from warming (and decaying) organic matter is thawing the permafrost, resulting in the ominous-looking craters or—perhaps more accurately—holes. Permafrost is soil that remains frozen, near or below 0-degrees C, for at least two years.
The global-warming hypothesis is ever-growing among scientists investigating the mystery (so-called because they don't yet know with certainty what's occurring), and it's possible more "craters" will pop up—preferably, far from populated regions.