Scientists have come up with a new explanation for giant explosion craters that seem to appear randomly in the permafrost of Siberia.
An expedition member stands at the edge of a newly formed explosion crater on the Yamal Peninsula. Photo: Reuters
The strange craters that first appeared in 2012 in remote areas of Siberia have puzzled researchers. They can be as large as 65 feet wide and as deep as 150 feet, sending large chunks of rock and soil flying hundreds of feet. Some reports said the explosions could be heard as far as 60 miles away. Scientists now believe that hot natural gas leaking from underground reserves may have caused the explosions, Business Insider reported on January 15. The discovery could explain why the craters only appear in certain parts of Siberia.
The region is known for its vast underground reserves of natural gas, according to study leader Helge Hellevang, a professor of environmental geoscience at the University of Oslo in Norway. The permafrost retains much of the organic material. As temperatures rise, the soil thaws, allowing the coating to decompose. That process releases methane gas.
So scientists speculate that methane gas leaking from the frozen ground is behind the crater explosion. This is the same process that leads to thermokarst, lakes that form in areas where frozen ground melts and contains flammable methane bubbles. But that doesn’t explain why the craters are so localized. So far, researchers have identified only eight craters, all of which are located in the specific region of the Yamal and Gydan peninsulas in western Siberia in northern Russia. Thermokarst lakes, on the other hand, occur in a variety of locations, including Canada.
Hellevang and his colleagues hypothesize that hot gases leak through certain geological faults and accumulate beneath the frozen soil, heating the frozen soil from below. The hot gas plume contributes to thawing the frozen soil, making it weaker and more prone to collapse. According to Hellevang, the explosion could only occur if the frozen soil was thin and weak enough to break.
At the same time, rising temperatures melted the frozen soil on top. This created the perfect conditions for gas to escape suddenly, triggering an explosion or a pressure collapse mechanism. The process of creating a crater. Western Siberia is rich in gas deposits, consistent with the hypothesis of Hellevang et al.
According to the team's model, many craters could form and disappear as nearby water and soil fill in the void. "This is a very remote area, so we don't know the true number. If you look at satellite images of the Yamal Peninsula, there are thousands of these circular disks. Most or all of them could be thermokarst, but they could also be pre-existing craters," Hellenvang said.
An Khang (According to Business Insider )
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