Siberia – land of permafrost, (possibly) Yetis and… gigantic holes? Two weeks ago, a 70-foot deep crater was discovered in Siberia’s Yamal Peninsula with no explanation. Now, the Siberian Times reports, two additional holes have been found: Another in Yamal, and a third in the Taymyr Peninsula, to the east of Yamal in the Kransoyark region. They have diameters of 15 and four meters, respectively. Again, science is unsure as to their cause.

“According to local residents, the hole formed on 27 September 2013. Observers give several versions. According to the first, initially at the place was smoking, and then there was a bright flash. In the second version, a celestial body fell there,” said member of the regional parliament Mikhail Lapsui.

That pretty well sums up the theories for how these holes keep appearing. Onlookers speculate that they might be the result of artillery fire, meteorites, pranks or even aliens. One of the more sound theories proposes that the melting of permafrost due to climate change causes a buildup of methane gas, which eventually explodes. No scientists have stepped in to confirm this as an official theory, however.

The third and smallest crater – in the Taymyr Peninsula – was discovered accidentally. Local herders from the village of Nosok nearly fell into the hole while herding their livestock.

There is no word as to what lies at the bottom of these new holes. The first hole, discovered last month, is said to have an icy lake at the bottom.

“Undoubtedly, we need to study all such formations. It is necessary to be able to predict their occurrence. Each new funnel provides additional information for scientists,” said Marina Leibman, Chief Scientist of the Earth Cryosphere Institute.

Image credit: Siberian Times