Huge gas explosions are erupting in the icy soils of Siberia, a recent phenomenon that is linked to climate change and has left gaping craters across the landscape.
These sudden gas blowouts in permafrost, a layer of frozen ground, pose a serious risk to Arctic communities and infrastructure. That’s why scientists have been trying to understand the origins of these dangerous eruptions since the discovery of the first crater, C1, in 2014.
Now, a team led by Evgeny Chuvilin, a leading research scientist at the Skoltech Center for Hydrocarbon Recovery in Moscow, has proposed a new formation model that can explain all 20 craters that have been discovered so far across Siberia’s Yamal and Gydan Peninsulas, which could help predict where they might strike next as they increase in frequency due to climate change, according to a recent study published in the journal Geosciences.
“It is a pure stroke of luck that, so far, none of the recorded explosions followed by formation of giant craters has caused loss of life or infrastructure damage,” Chuvilin said in an email. “Several craters were discovered a few miles from commercial and economic facilities. A potential explosion hazard exists in a significant part of Yamal where gas accumulates in the upper permafrost horizons.”
“The accumulation process can last years, but it can also be activated rather quickly by changes in the physical and mechanical properties of the upper permafrost layers, including changes caused by climate warming,” he added.
Chuvilin and his colleagues based much of their model on an expedition to examine a new crater, called C17, which formed about two months after it exploded in Siberia’s Yamal Peninsula during the summer of 2020. The fresh conditions at C17, which is 100 feet deep, provided new insights into the dangerous interplay that occurs between shallow surface layers warped by global warming and deeper pockets of accumulated gas.
Scientists have been raising the alarm about the effects of human-driven climate change on permafrost for decades because of its numerous deleterious consequences. The thawing of this layer deforms the ground, putting millions of people at risk from infrastructure damage, while also releasing greenhouse gases into the atmosphere, exacerbating climate change.
The new study found that in the context of the gas blowouts, the surface permafrost “caps” become weakened by this thawing process, which makes them more vulnerable to pressure from pools of methane gas that build up deep underground. This degradation of the upper permafrost also causes the subterranean “intrapermafrost” mix, which consists of cold briny water and other materials, to circulate faster, further compromising the strength of the cap above it.
At a certain point, the pressure from the gas pools reaches a tipping point that triggers the immense explosions. Given the direct link to climate change, Chuvilin and his colleagues expect these blowouts to continue in the future, though they require specific permafrost conditions that are particularly dangerous for the Yamal and Gydan regions.
“We assume that explosive gas emissions in Yamal and Gydan may continue to occur for a while, considering the thawing of permafrost due to climate warming which creates a favorable environment for explosive gas ejections from the upper permafrost layers,” Chuvilin said. “Discovery of new craters will be facilitated by close monitoring of both this dangerous natural process and the areas prone to crater formation using field surveys and satellite imagery.”
In addition to these field and satellite surveys, the team plans to conduct drilling operations near craters to get a better sense of the complex changes occurring in thawing permafrost. Such efforts could help provide another empirical test of their blowout formation model and might also explain why some gas pockets remain stable for long periods of time while others end up blasting huge holes into the ground.
Ultimately, Chuvilin and his colleagues want to figure out how to spot areas that might be prone to explosion, and develop ways to relieve underground pressures with degassing or drilling techniques.
“It is important to gather as much information as possible in order to be able to identify potentially dangerous spots where accumulated intrapermafrost gas can burst out, and find ways to prevent disastrous explosions,” Chuvilin said.
“We don’t know yet whether the explosion is triggered by a single natural or human factor or a specific combination of factors, but we hope that drilling will provide new insights that will help deal with this new geocryological hazard,” he concluded. “This is exactly what our research is about.”