The discovery of eight massive, 160-foot-deep craters in Siberia’s permafrost has puzzled scientists for over a decade. However, a new theory proposed in a preprint paper sheds light on their formation, focusing on Russia’s Yamal and Gydan peninsulas where these unique craters are found.
The prevailing theory suggests that these “giant escape craters” (GECs) may have formed in locations where historic lakes once existed, bubbling with natural gas from the permafrost. As these lakes dried up, the exposed ground froze, sealing gas vents. Over time, gas buildup led to explosive releases, creating the large craters. However, this theory doesn’t fully explain why the craters are found in diverse geological settings across the peninsulas.
Researchers now highlight the specific conditions of Yamal and Gydan, where permafrost varies in thickness, trapping ancient marine sediments rich in methane. The heat from natural gas reserves below the permafrost melts it from within, creating gas pockets. Climate change-induced permafrost thawing, especially in thinner areas, combined with gas pressure, may cause the remaining permafrost to collapse, triggering explosions.
This “champagne effect” theory posits that smaller craters surrounding the giant ones resulted from chunks of ice propelled during explosions, denting the ground. The researchers suggest there could be more undiscovered craters, as some may have filled with water and sediment over time.
Moreover, the release of greenhouse gases like methane during these events highlights a concerning climate feedback loop. With ongoing global warming accelerating permafrost thawing, an estimated 1,900 billion tons of stored greenhouse gases in Arctic permafrost pose significant environmental risks.
The potential for “abrupt thawing” in Arctic permafrost due to climate change could lead to a surge in greenhouse gas emissions, including methane. This underscores the urgent need for climate action to mitigate the impacts of permafrost degradation on the planet’s carbon cycle.