Siberia is no stranger to weird geological phenomena. Adding to the list of the area’s vast holes and craters is a bubbling tundra on the island of Belyy. Environmental researchers found a site where the Earth wobbles like a waterbed when stepped upon. Their best guess to explain the mysterious quivering is methane released by melting permafrost just below the surface.

Researchers Alexander Sokolov and Dorothee Ehrich first noticed the spot last year and were surprised to see similar occurrences this year. So far, 15 bubbling spots have been found in the area, each averaging about a meter in diameter. They found the air escaping from the bubbles contain 200 times more methane and 20 times more carbon dioxide than the typical air we breathe.

Related: Toxic methane is leaking from Siberia’s rapidly melting permafrost

Further studies need to be done, but they are estimating a recent heatwave through Europe may have something to do with the phenomena. Sokolov told the Siberian Times, “It is likely that that 10 days of extraordinary heat could have started some mechanisms, [and the] higher level of permafrost could have thawed and released a huge amount of gases.” Melting permafrost releasing methane and CO2 into the atmosphere is the last thing we need as climate change isn’t slowing down anytime soon without the added emissions. Sokolov said, “It is evident even to amateurs that this is a very serious alarm.”