These holes are large, so whatever caused them was very large as well. As of this article from Listverse points out, there is no proof about what caused them and how they were made.
Mysterious Holes In The Forests Of Siberia
Although many Internet sites have recently reported on mysteriously appearing holes in Russia, there are three particular holes in northern Siberia that are particularly interesting.
The theories to explain them include aliens or beings from the inner Earth, a meteorite strike, a simple prank, or a buildup of natural gas that exploded. The natural gas theory seemed to make some sense based on eyewitness and investigative reports.
People have seen strange flashes and smoke rising from the locations of the holes. Investigators also noted that earth and debris lay around the outside of the holes as if something had pushed this material out from below.
The holes themselves are like cone-shaped tunnels that go straight down approximately 100 meters (330 ft). This is confusing to investigators. One researcher said, “It is not like this is the work of men, but [it] also doesn’t look like natural formation.”
There is also disagreement on when these holes appeared. Some reports state that they formed around 2013. Others point to vegetation that has grown within the holes to suggest that they are at least several years older than that.
The investigations continue—as do the rumors about what caused these holes. Global warming is one of the latest theories.
Are we really sure we want to know the answer ? Do we really need to find out the origin of these strange holes in the ground ? I can't help but wonder !
Coffee out on the damp patio this morning !