The first massive crater was discovered in northern Siberia in the middle of last month. The hole, which was found by reindeer herders, was approximately 260 feet (80 meters) wide.
It drew world-wide press attention, not least because it was discovered in the Yamal Peninsula, otherwise known as 'The End of the World'.
Since the discovery of the first chasm, two further holes have been found. One in the Taz district was reportedly around 50ft. Another in the Taymyr Peninsula was between 200 and 330-feet.
Another scientist, Chris Fogwill of the University of New South Wales, in Australia, has suggested the first hole was created when a pingo - an earth-covered mound that forms in Arctic and subarctic regions - collapsed. A number of other scientists have supported this position.
Researchers dispatched to investigate the first formation have taken soil and water samples to determine when the hole was formed.
Yamal holds some of Russia’s largest gas reserves and the crater appeared less than 20 miles from the biggest gas field, Bovanenkovo.
Mikhail Lapsui, a deputy of the regional parliament, said local residents in the area first became aware of the new opening in September 2013.
He told the newspaper: “I flew by helicopter to inspect this funnel on Saturday 19 July. Its diameter is about 15 metres. There is also ground outside, as if it was thrown as a result of an underground explosion.”
Vladimir Romanovsky, meanwhile, told LiveScience that the development of permafrost sinkholes could be related to global warming.