Permafrost Mystery: scientists explore Yamal Sinkhole (Trailer)

The appearance of giant craters in Siberia sparked dozens of wild theories about their origins, from meteorites to UFOs. An RT Doc crew travelled to the region to try to find explanations for the geological mystery.
Mysterious giant craters have started to appear in Siberia, some say they're a new phenomenon others that they have existed since the dawn of time. This riddle of nature attracted RT Doc to the land of the nomadic Nenets. Our team met visiting scientists and locals, in search of answers either from research data or ancient legend.
The natives dismiss scientific explanations for the sinkholes preferring to believe the craters are a “connection to another world.” Anyone who lives there, including the nomads who roam the tundra must hear the voice of the Earth. So they believe that something extraordinary happened, and that the reason behind it is supernatural.
Science on the other hand offers a much more prosaic explanation, pointing to the fact that the sinkholes have appeared in a gas-rich region.
However, there is one mystery that not even the scientists can answer: the holes are perfectly round. What’s more, dozens of smaller sinkholes have been found around giant ones.