Scientists Uncover Likely Cause of Explosive Craters in Siberian Permafrost
Over the past decade, more than 20 large craters have mysteriously appeared in the permafrost of Siberia’s Yamal and Gydan Peninsulas, intriguing scientists and sparking theories ranging from meteor strikes to alien interference, CNN reports.
These massive craters, some hundreds of feet wide, formed suddenly, marked by violent ejections of soil and ice. The latest crater was discovered in August, and researchers now believe they have uncovered the forces behind these explosive events.
A recent study led by scientists from the University of Cambridge points to a complex interplay between regional geology and climate change. Scientists already agreed that the craters are likely caused by methane gas trapped under the tundra, which builds up pressure and eventually explodes. However, this new research provides fresh insights into the precise mechanisms that trigger such eruptions.
According to the study, the craters form as warmer temperatures driven by climate change cause surface soil to thaw, allowing water to seep down and increase pressure in a specific geological layer. Underneath Siberia’s thick permafrost lie methane hydrates, which are solid methane deposits trapped by ice. Sandwiched between these hydrates and the surface permafrost are pockets of salty, unfrozen water, known as cryopegs. When additional water from the thawing surface enters the cryopeg layer, it creates extra pressure that fractures the ground above, causing a sudden release of methane gas and an explosive blowout.
Ana Morgado, a chemical engineer and one of the study’s authors, likened the process to the buildup of air in a tire. She explained that as cracks in the ground rapidly reduce pressure in the cryopeg, the methane hydrates below destabilize, leading to an explosive release of gas. This gradual buildup of pressure and its eventual release may take decades, suggesting that the current wave of craters is linked to long-term warming in the Arctic.
However, not all scientists are convinced that this study has fully cracked the mystery. Evgeny Chuvilin, a research scientist at Moscow’s Skolkovo Institute of Science and Technology, expressed skepticism, noting that Siberia’s dense, ice-rich permafrost might prevent water from the surface from reaching the cryopeg layer. Chuvilin’s own research suggests that methane collects closer to the permafrost surface, creating high-pressure pockets that eventually burst through the ground. He believes that additional research is needed to capture the full complexity of these eruptions.
Lauren Schurmeier, a geophysicist at the University of Hawaii, agrees that while the theory is plausible, it may not account for all gas sources contributing to the explosions. Both scientists believe climate change is a key factor, and Schurmeier emphasizes that these craters are most likely to appear after unusually warm summers—a trend that could increase as the Arctic continues to warm.
Experts warn that these eruptions may have repercussions beyond the local environment. Each explosion releases methane, a greenhouse gas far more potent than carbon dioxide in its short-term heat-trapping ability. Though each crater contributes only a small amount to global emissions, they are nonetheless a stark signal of the Arctic’s rapid transformation.
As temperatures continue to rise, the frequency of such explosive events could increase, posing risks to nearby communities and infrastructure, particularly oil and gas facilities. Researchers, including Vasily Bogoyavlensky of the Russian Academy of Sciences, are monitoring Siberian mounds, which may serve as indicators of impending explosions. While predicting the exact timing of these events remains challenging, tracking these mounds can help prioritize regions for closer observation.
