A Russian TV crew flying over the Siberian tundra this summer spotted a massive crater 30 meters (100 feet) deep and 20 meters wide — striking in its size, symmetry and the explosive force of nature that it must have taken to have created it.Scientists are not sure exactly how the huge hole, which is at least the ninth spotted in the region since 2013, formed. Initial theories floated when the first crater was discovered near an oil and gas field in the Yamal Peninsula in northwest Siberia included a meteorite impact, a UFO landing and the collapse of a secret underground military storage facility. While scientists now believe the giant hole is linked to an explosive buildup of methane gas — which could be an unsettling result of warming temperatures in the region — there is still a lot the researchers don’t know.

“Right now, there is no single accepted theory on how these complex phenomena are formed,” said Evgeny Chuvilin, lead research scientist at the Skolkovo Institute of Science and Technology’s Center for Hydrocarbon Recovery,who has visited the site of the newest crater to study its features.”It is possible they have been forming for years, but it is hard to estimate the numbers. Since craters usually appear in uninhabited and largely pristine areas of the Arctic, there is often no one to see and report them,” Chuvilin said.”Even now, craters are mostly found by accident during routine, non-scientific helicopter flights or by reindeer herders and hunters.”

Permafrost, which amounts to two-thirds of the Russian territory, is a huge natural reservoir of methane, a potent greenhouse gas, and recent hot summers, including in 2020, in the region may have played a role in creating these craters.

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