It is the shape of a tadpole but is no baby in the world of sinkholes.
A crater so large and deep it is known as the ‘mouth to hell’ is still expanding, with locals claiming to hear strange booms coming from its depths.
The Batagay megaslump, to give the official name, began as a small crack in the 1960s, and since then has grown to become a behemoth, growing at a rate of at least ten metres every year, and potentially up to 30 metres.
It is the shape of a tadpole but is no baby in the world of sinkholes, with over 35 million cubic meters of soil lost from the area in north eastern Siberia, Russia, since the 1990s.
The reason for its relentless growth is that permafrost is melting due to climate change, making the ground around it much less stable.
It is also the reason that sinkholes are becoming more widespread around the world, sometimes because of melting ice and sometimes because of wetter and more extreme weather.
The crater in the Yana Uplands of northern Yakutia is contributing to climate change, too, as it releases carbon previously locked in the ground as it continues to grow.
People have been fascinating by it for years, both for scientific reasons and for its weird and potentially terrifying nature.
As it expands, the crater exposes areas of ground buried for thousands of years since the last ice age, so can tell us a lot about the geology of the area and how it developed over time.
Several preserved remains of animals have been revealed as the crater enlarged, including fossilised remains of mammoths, horses, and musk ox.
The Batagay megaslump is not the only giant crater to be known as the ‘mouth of hell’. There is also a fiery pit in Turkmenistan which has been burning since the 1980s.
Engineers ingnited methane in the Darvaza gas crater intending for it to burn off and make the area safer, but it never stopped – and now lights up the Karakum Desert, where the 70-metre hole of fire has even become a tourist attraction.
That hellmouth was manmade, but the one in Russia is a natural pit – although it was humans who changed the climate making it possible.
Writing in Permafrost and Periglacial Processes last year, Julian Murton said that the Russian crater will ‘probably stabilise eventually’ due to reaching the limits of the topography surrounding, even though it is rapidly growing at present.
But it will be years to decades before this happens, and there is still the possibility it could start eating up the landscape again after that.
He said the slump was ‘exceptional’ both for the insights it could provide, and for the example it gave of how sensitive ice-rich permafrost is to abrupt thawing as a result of terrain disturbance.
‘Slump growth probably accelerated due to climate warming and wetting,’ he said.
