It’s summer in Siberia and that has scientists thinking about sinkholes … specifically, the huge mysterious craters that were discovered last year and have triggered sharp debates on their causes. A team of researchers recently gave up a weekend of barbecuing yak to make an expedition to some of the largest craters to check on their status … and what they found surprised them.

Led by Professor Vasily Bogoyavlensky from the Oil and Gas Research Institute, the team went to Yamal (the name means End of the Earth) in northern Russia where the first craters were discovered. They were surprised to find that the largest, known as B-1, is no longer just a hole but is now a swimming hole. The water level is within 10 meters of the edge of the crater, which new measurements show is 60 meters deep – much deeper than they expected. Sure, you would expect to find water in an area where it’s summer and snow is melting, but the researchers were stunned by how fast it filled. Bogoyavlensky says he expects it to be a lake in 10 years.

The professor also found what he believes to be evidence that the crater was the result of an eruption, not due to a collapse, meteors, UFOs, missile testing or giant sandworms. A pingo or dirt-covered mound of ice had formed there in a spot above intersecting faults. As climate change caused the pingo to melt underground, Bogoyavlensky explains what he thinks happened next:

Through the cracks, natural gas got into the melting ice core, filled it and the pingo erupted. It was also heated by a stream of warmth coming from the bowels of the earth through the cracks … It’s a very interesting process, which we have never observed before.

The blowout from the explosion could account for the 30 or so smaller craters surrounding B-1. That sounds like a winner, Professor, except for one thing … your own instruments did not detect any abnormal gas levels at the site! Not only that, crater B-2, just 20 km away, is already a lake and looked nothing like B-1, except for being a hole. Any other ideas?

As with any loyal government worker, Professor Bogoyavlensky said the craters were “quite shocking” but “At the moment we do not see any reason for panic.”

Maybe the professor should pay a visit to Vorkuta, located in Russia’s Komi Republic. While they don’t have any craters, the town had a heavy snowfall on July 5th.

A midsummer yak barbecue called on account of snow? Now THAT’S a reason to panic.