This does look like a huge gas blowout. Recall that the permafrost provides a natural sealed cap on top and that allows gas accumulation and collapse to take place underneath. A mass of gas saturated ice and gravel would contract as the water drained away and the gas buildup would become severe enough to blow out the weak seal.
There certainly plenty of smaller collapse structure in the permafrost which is why that country is so difficult to traverse. They produce aptly named kettle lakes. fill this with water and that is comiong and there would be nothing to see here except an actual rim which then would be blamed on a meteor.
Of course the bulk of the material has dropped to the bottom of the pit and it is all likely as dangerous as you wish to imagine. When this gets filled with water, it will be wise to keep everyone well away until the rim has collapsed back into the pit..
The seemingly bottomless pit was spotted by an oil-and-gas industry helicopter flying over northern Siberia — a region notorious for devastating events.
It might be Armageddon, seeing as the place where it was found is known as Yamal, meaning “the end of the world.”
The most deadly meteor impact of modern times — the Tunguska air burst — happened in the region in 1908. It flattened vast swaths of forest over a 775-square-mile area.
No such streak in the sky, explosive flash or seismic event has been recorded recently.
But this mysterious hole has nevertheless appeared.
The Siberian Times reports that startled helicopter passengers talked their pilot into loitering over the mysterious crater. Engineer Konstantin Nikolaev then filmed the hole and uploaded the footage to YouTube.
They say the hole was big enough for their helicopter — a 60-foot-long Mi8 — to have comfortably entered without touching the sides.
Rumors and realitySince the footage appeared online, the Internet has been abuzz with rumors of UFOs, secret entrances to the “hollow Earth” — as well as the more mundane weapon test sites and meteorite impact theories. “We can definitely say that it is not a meteorite,” a spokesman for Russia’s Emergencies Ministry said.
Russian scientist Anna Kurchatova, from the Sub-Arctic Scientific Research Center, believes the cause is something more logical, such as global warming.
Siberia’s frozen soil — known as permafrost — contains millions of tons of methane gas. As the surface slowly warms, this gas begins to be released — and pools into highly volatile pockets.
A mixture of water, salt and gas may have ignited an underground explosion. Another possibility is that the gas pocket may simply have built up enough pressure to pop like a Champagne cork, she said.
Search for answers
The expedition includes experts from Russia’s Center for the Study of the Arctic, and the Cryosphere Institute of the Academy of Sciences.
They will sample the soil, water and air at the scene in order to determine the nature of the hole.
The crater was found in the Yamalo-Nenets Autonomous Region, some 25 miles from the Bovanenkovo gas field. The peninsula, which sticks into Arctic waters, is the source of Russia’s vast gas export market to Europe.