A mounting number of vast craters have scarred the depths of Siberia in recent years, caused by explosive gases bubbling beneath the surface and violently breaking through the permafrost above. Now, we may know what caused them. Just as many suspected, a new study has indicated the culprit is most likely the warming temperatures in the Russian Arctic being cooked up by the climate crisis.

The gaping craters of northwestern Siberia first came to worldwide attention in 2014 when a 40-meter (131 foot) wide hole in Yamal emerged amidst a violent explosion. Since then, at least 20 more craters have been documented and studied. One of the most recent was a 20-meter-wide (65 foot) hole that appeared in the central part of Yamal back in August 2020, known as C17 (pictured above). 

Internet cranks initially suggested the craters might have been created by apocalyptic asteroids or aliens, but it quickly became apparent the holes were appearing in permafrost-topped areas sitting above deposits of natural gas. The sudden onset of the emerging craters, however, was startling. Some suspected climate change, while others pointed the finger at the region's prolific fossil fuel extraction.

In a new study published in GeoSciences, scientists at Skolkovo Institute of Science and Technology in Moscow have shown that the craters are likely a product of climate change. Through studying the permafrost and local geology around the newbie crater C17, the team showed that warming temperatures — which are particularly pronounced in the Earth’s Arctic region — help to decay the permafrost and ground ice, making these craters all the more likely. 

Below the ground, methane builds up within the cavities in and around the permafrost, gradually mounting in pressure like a shaken-up soda bottle. With warming temperatures, the permafrost “ceiling” of the cavity starts to thaw and degrade, raising its risk of collapse. Furthermore, the thawing permafrost will release its own methane trapped inside, contributing to the pressure build-up. Warming temperatures also allow intra-permafrost gas-water fluids to circulate more rapidly in degrading permafrost, further weakening the ceilings over the gas pools.

Once the ceiling becomes weak enough, it will succumb to the mounting pressure of the gas below and — BOOM! — a colossal explosion occurs, leaving behind a shower of debris and a deep crater. 

The study essentially confirms what many researchers initially surmised. The new paper, however, does contain some relatively promising news for the rest of Eurasia and North American. According to their findings, the explosive craters are due to the unique cryological and geological make-up of northern West Siberia, suggesting they are less likely to occur elsewhere in the Arctic. 

“The craters form under a certain combination of cryological and geological conditions, in gas-saturated permafrost that encloses thick massive ground ice and cryopegs… in the presence of large gas fields and related ascending gas-water fluids. Such conditions exist currently in some areas of northern West Siberia (Yamal and Gydan peninsulas), but this combination of factors does not always occur elsewhere in the Arctic. Therefore, explosive gas release is not a ubiquitous phenomenon in the permafrost of Eurasia and North America,” the study concludes.

With that crumb of positive news in mind, let's not distract from the fact that parts of the planet are now literally exploding as a result of climate change.