Some very interesting images in this article. It is believed to be methane but could be anything at this point. A little bit strange that they “suddenly” appearing now.
>>> “Such funnels are believed to be caused by the build up of methane gas in pockets of thawing permafrost under the surface.”
siberiantimes.com/other/others/news/giant-new-50-metre-deep-crater-opens-up-in-arctic-tundra/