(Newser) – More mysterious craters have been spotted in Siberia, and researchers are starting to sound more than a little alarmed about the phenomenon. Vasily Bogoyavlensky, deputy director of Russia's Oil and Gas Research Institute, says at least seven suspicious craters have now been spotted—five of them in a region known as the "end of the world"—and a satellite image shows one of them has at least 20 water-filled "baby craters" around it. "I would compare this with mushrooms: When you find one mushroom, be sure there are [a] few more around. I suppose there could be 20 to 30 craters more," he tells the Siberian Times. He's calling for urgent research "to prevent possible disasters" that could affect cities and oil industry infrastructure in the region.

Bogoyavlensky and other experts believe gas emissions, possibly linked to climate change, are causing the holes to appear and suspect there are many more to be found, reports NBC News. "The processes that are causing them to form likely occur over a wide area of the continuous permafrost in this part of Siberia," the chief of the US Geological Survey's Gas Hydrates Project tells the Huffington Post. She hasn't researched the holes firsthand, but she agrees they demand further study "to determine the processes that cause their formation, how they evolve with time, and whether it is possible to predict where new ones will occur." Bogoyavlensky plans an upcoming expedition to the craters (only one of them has been studied in depth thus far) and intends to install seismic stations in the region. (Another Siberian find: Ivan the Terrible's sword.)

