Important news has emerged on the studies investigating the formation of the mysterious craters that appeared, starting from the summer of 2012, on the vast desolate lands of the Siberian tundra, in Russian territory.
A study proposes a new explanation for giant exploding craters that seem to appear randomly in Siberian permafrost. These craters, first spotted in 2012, appeared in the permafrost of Siberia, leaving scientists perplexed.
Some are truly remarkable, reaching more than 50 meters deep and 20 meters wide, and ejecting pieces of debris hundreds of meters away. Some reports suggest that the explosions can be heard 100 km away.
Hot gas from underground reserves
Now scientists suggest that hot natural gas escaping from underground reserves may be behind the explosions. The findings could explain why craters appear only in specific areas of Siberia.
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The area is known for its vast underground reserves of natural gas, he told BusinessInsider the lead author of the study Helge Hellevang, professor of environmental geosciences at the University of Oslo, Norway.
“When climate change or a warming atmosphere weakens the other part of the permafrost, then these explosions occur, only in Siberia”.
Permafrost traps a lot of organic material. When the temperature rises, it melts, allowing the material to decompose. This process releases methane. So scientists had naturally proposed that behind the craters there was methane seeping from the permafrost itself.
What’s happening in the area?
This is in particular the process that is believed to lead to thermokarsts, that is, lakes that appear in areas where the permafrost is melting, which boil with methane and can catch fire. However, this does not explain why the so-called explosive craters are so localized.
Only eight such craters have been identified so far, all within a very specific area: in the Arctic peninsulas of Yamal and Gydan, in western Siberia.
Exploding lakes, in contrast, are seen in a wide variety of areas where permafrost is found, including Canada. From the study of these scientists it would emerge how Hot natural gas, seeping through some kind of geological fault, is accumulating under the frozen layer of ground and warming the permafrost from below.
The hot gas plumes would help melt the permafrost from the bottom, making it weaker and more likely to collapse. These explosions can only happen if the permafrost is thin and weak enough to break.
At the same time, rising temperatures melt the top layer of permafrost. This creates the perfect conditions for the gas to suddenly release, triggering an explosion or “mechanical collapse” caused by the gas under pressure. This creates the crater, they suggest Hellevang and colleagues.
According to the study, the area is rich in natural gas reserves, it is no coincidence that it is one of the largest oil provinces in the world. According to the scientist’s model, many of these craters could have formed and then disappeared as nearby water and soil filled the void.
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Furthermore, from satellite images, we can see how the area of the Yamal peninsula is characterized by many round depressions. Most or all of them could have been thermokarst, but potentially they could also be craters that formed previously.
A serious threat to the climate?
While the idea is sound, more evidence will be needed to show that these gas reserves are accumulating beneath the permafrost, he said Lauren Schurmeier, Earth scientist at the University of Hawaii who studies the topic. However, if the hypothesis proves correct, this could lead to problems for climate models.
Natural gas is full of methane, a very powerful greenhouse gas. This could mean that the craters behave like huge chimneys through which the substance could be suddenly released into the atmosphere, he said Thomas Birchall of the University Center in Svalbard, Norway, explaining that it would discharge “a lot of methane in a very short time”.
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If this phenomenon only exists in a very limited area, it is possible that the impact on a global scale will be minimal. While there is likely to be a large amount of methane stored in underground reserves, it is unclear how much of it could escape.
“I think what we need to do is first understand how much methane is naturally escaping from these types of systems, and then compare that to how much methane is actually within the permafrost for organic matter,” he said Hellenvang. “Then we can have a more realistic budget on how much can be released due to atmospheric warming or climate change,” says the scientist.
