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Scientists may be a step closer to solving the mystery of Siberia's giant exploding craters. First spotted in the Yamal and Gydan peninsulas of Western Siberia in 2012, these massive holes, known as giant gas emission craters (GECs) can be up to 164 feet deep. They seem to appear randomly in the permafrost and are formed when powerful explosions blast soil and ice hundreds of feet into the air.

For more than a decade, researchers have been coming up with theories about the origin of these craters, ranging from meteor impacts to gas explosions. However, none of these have been able to explain why the craters are only found in this specific area and not in the permafrost elsewhere in the Arctic.

Now, research in the journal Science of the Total Environment proposes a new and more complete explanation that links the craters to specific factors unique to the two peninsulas, the vast gas reserves in this region and the effects of climate change.

"We propose that the formation of GECs is linked to the specific conditions in the area, including abundant natural gas generation and seepage and the overall limited thickness of the continuous permafrost," wrote the researchers in their paper.

Helge Hellevang, an environmental geoscientist at the University of Oslo, and his colleagues studied past research, looked at the geological data and used numerical calculations to develop a conceptual model of what is happening.

A new model for crater formation

According to their model, GECs form when gas and heat rise from deep underground. The heat melts the permafrost seal (a layer of permanently frozen ground that acts as a lid), making it thinner. Meanwhile, the gas builds up underneath it, and with nowhere to go, the pressure rises. As the climate warms, the permafrost thaws even more, making the lid thinner. Eventually, pressure becomes too great and causes an explosive collapse that creates a large crater.

Dr. Hellevang and his colleagues say their model is just a first step. The next stage will be fieldwork and computer simulations to test their model. The team also believes that there may be many more of these craters in Siberia hiding in plain sight. The reason is that they quickly fill up with water and dirt, making them look like lakes that form from thawing ice. So while GECs are a relatively recent discovery, they could have been a feature of the landscape for much longer.