Researchers Unearth the Reason Behind Mysterious Giant Craters in Siberia
Mysterious Siberian Craters
Giant craters found in Russia's permafrost-covered Yamal and Gydan peninsulas have been confusing scientists for almost a decade. In 2014, they began appearing out of nowhere and since then multiple of them have been spotted in the area by civilians and experts, IFL Science reported. A recent study published in Geophysical Research Letters has proposed osmosis as the reason behind the formation of the craters and considers the region's geology and climate change, as the main reasons. For experts, these craters are reminders that alteration in the environment could have explosive implications.
Craters Exist Only In Specific Regions
Eight giant craters around 160 feet deep, have been located in the Siberian permafrost over the last decade, Live Science reported. These craters specifically appeared in Russia's northern Yamal and Gydan peninsulas and are not known to exist elsewhere in the Arctic. Around the crater's edge, the surface is torn and features a grey jumble of ice and clods of permafrost, BBC reported. There are some roots of plants appearing around certain craters, that have been scorched.
Past Theories
Scientists in the past have come up with various theories regarding the craters, Live Science reported. One of the most discussed theories was that the craters were formed as a result of historic lakes rising from under the permafrost. Multiple experts rejected the proposition because many craters were formed on surfaces where historic lakes did not exist. Other theories range from meteor impacts to natural gas explosions, but none could be backed up by proper evidence.
Surface Warming
Ana Morgado, a chemical engineer at the University of Cambridge, and her colleagues concluded in the study, that the craters were formed because of surface warming. The experts also noted unusually high levels of methane around the craters, which implied that greenhouse gases were being released from the holes. As per scientists, the phenomenon of surface warming gave way to rapid pressure change in the underground, which eventually led to the powerful release of methane gas. "There are very, very specific conditions that allow for this phenomenon to happen," Morgado explained. "We’re talking about a very niche geological space."
Osmosis Causing Explosion
The scientists already knew that the craters came into being because of explosions, IFL Science reported. "There are only two ways you can get an explosion," said Julyan Cartwright, a geophysicist at the Spanish National Research Council. "Either a chemical reaction happens, and you have an explosion, like dynamite blowing up, or you pump up your bicycle tire until it blows up – that’s physics." Researchers in their study pinpointed osmosis as the process that caused the explosion. Osmosis is a methodology by which a fluid moves to equalize the concentration of substances dissolved in it. Normally, the permafrost of the Yamal Peninsula should act as the osmotic barrier, but climate change has altered its features considerably, making it inept for this function.
Rising Temperatures
The average temperature rise in the Yamal and Gydan peninsulas has caused the active layer of permafrost to melt and expand downwards, clashing with the cryopeg layer due to osmotic pressure. The layer does not have enough space to hold the extra water, leading to an increase in pressure. This pressure facilitates cracks that travel up to the surface, and results in a sudden drop in pressure at depth. The instant pressure change damages the methane hydrate placed below the cyropegs, causing methane gas to be released, during the explosion. As per researchers, the underlying processes required for these explosions would need decades to complete. "This might be a very infrequently occurring phenomenon," Morgado said. "But the amount of methane that’s being released could have quite a big impact on global warming."