Months after they started investigating a huge black hole in Siberia, Russian researchers say they have spotted still more suspicious-looking craters and lakes — and are calling for an urgent investigation of the phenomenon. Satellite imagery shows that one of the recently discovered craters, known as B2, is surrounded by more than 20 water-filled "baby craters," one researcher told The Siberian Times.
The Times quoted Vasily Bogyavlensky, deputy director of the Moscow-based Oil and Gas Research Institute, as saying that the craters are being mapped near Siberia's Bovanenkovo gas field. He linked their formation to gas emissions from beneath the surface, and possibly gas explosions. "Anyway, we must research this phenomenon urgently, to prevent possible disasters," he was quoted as saying.
Experts have said the craters could be associated with climate change.
Last year, Russian researchers reported heightened methane emissions at the crater sites and suggested that a long-term thaw was liberating underground reservoirs of natural gas. NASA scientist Tom Wagner told NBC News in December that the phenomenon might be caused instead by the collapse of tunnels and caves in the permafrost.
Wagner also predicted that more such craters would be found as researchers scanned through satellite imagery looking for fresh evidence.
A leading Russian expert sounded an alert over safety because one new Siberian crater, surrounded by at least 20 "baby holes", is just six miles from a major gas production plant.
He predicts up to 30 more are waiting to be discovered.
Scientsts are still baffled by the exact processes causing the craters and respected Moscow expert Professor Vasily Bogoyavlensky today called for "urgent" investigation of the new phenomenon amid safety fears.
"We know now of seven craters in the Arctic area," he told The Siberian Times - referring to the larger holes.
"Five are directly on the Yamal peninsula, one in Yamal Autonomous district, and one is on the north of the Krasnoyarsk region, near the Taimyr peninsula.
"We have exact locations for only four of them.
"The other three were spotted by reindeer herders.
It is important not to scare people, but this is a very serious problem. We must research this phenomenon urgently to prevent possible disasters
"I would compare this with mushrooms.
"When you find one mushroom, be sure there are few more around. I suppose there could be 20 to 30 craters more."
Two of the newly-discovered large craters - also known as funnels to scientists - have turned into lakes, revealed Professor Bogoyavlensky, deputy director of the Moscow-based Oil and Gas Research Institute, part of the Russian Academy of Sciences.
"It is important not to scare people, but this is a very serious problem.
"We must research this phenomenon urgently to prevent possible disasters. We cannot rule out new gas emissions in the Arctic and in some cases they can ignite."
An examination of the area using satellite images, comparing landscapes in the past with the present day, has alerted Russian experts to the prospect that the phenomenon is more widespread than first thought.
Experts are particularly interested in a crater they name B2, which just six miles to the south of the gas field at Bovanenkovo.
Old satellite imagery shows no sign of craters at the site but there now exists a lake, 100 metres by 50 metres, surrounded by 20 smaller holes filled with water.
These mini-craters are just a metre or two in diameter.
And, following the discovery of a funnel at Antipayuta, on the Yamal Peninsula, nearby residents told scientists about seeing a flash of light, possibly as a result of gas exploding.
"These questions are important for the safe operation of the northern cities and infrastructure of oil and gas complexes."
There is already scientific concern that Lake Baikal, the largest and oldest freshwater lake in the world, but well outside the Arctic Circle, could be among the places sitting on a "time bomb" ready to explode.
Scientists have previously said there is growing evidence that rising temperatures is the main catalyst triggering the blasts. Any continued increase - as is predicted by meteorologists - could create the ideal conditions for more craters to be formed.
It is thought permafrost at the sites could have one million times more methane hydrates locked inside than ordinary gas. One expert estimated that the total explosive power of the craters has been the equivalent of about 11 tonnes of TNT.
The professor revealed one picture of a Yamal lake showing signs of what he calls "degassing".
"This haze that you see on the surface shows gas seeps from the bottom of the lake to the surface," he said.
"We call this process 'degassing'."
He is not sure if this lake, too, was previously a crater "or if the lake formed from another process.
"More important is that the gases from within are actively seeping through this lake."