And many other questions remain: If a sinkhole erupted material, why is the hole's border so round and even? Would there be enough gas to fuel such an eruption, and where did such gas come from?
This part of Siberia contains deep gas fields, and it also contains a lot of small lakes, which formed between 4,000 and 10,000 years ago when the climate was warmer, Romanovsky said. Perhaps these odd holes developed in the same way that sinkholes did, but later expanded.
Domes of natural gas also exist in the United States, located east ofthe Sagavanirktok River in Alaska's North Slope Borough.
The development of permafrost sinkholes could be one indication of global warming, Romanovsky. "If so, we will probably see this happen more often now."
More From LiveScience:
In Photos: Stunning Sinkhole Gallery 12 Strangest Sights on Google Earth 7 Huge Misconceptions about Aliens Original article on Live Science.
Copyright 2014 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.