Siberian media reported the discovery of a 50-meter deep crater in the Arctic tundra that suddenly opened up. Craters like these have been found since 2014, and scientists believe they may be a result of cryogenic eruptions—in other words, ice volcanoes.
According to the Siberian Times, a TV crew from station Vesti Yamal observed the massive crater by chance while traveling from an assignment. The crater is one of several on the Yamal and Taymyr peninsulas in Siberia, and these geological phenomena have been subjects of research for years.
One research group led by Lomosnosov Moscow State University geologist Andrey Bychkov proposed that the first discovered crater in the region was caused by an ice volcano eruption. In 2018, they published a paper in the journal Scientific Reports to explain the origin of what they dubbed the “spectacular crater.”
Bychkov said in an email that cryovolcanism is a known phenomenon on other planets, but prior to their study, ice volcanoes were not believed to exist on Earth. However, he found that a cryogenic eruption would adequately explain how the crater was formed.
At the time, others theorized that the crater may have been caused by a meteorite impact or deep migration of gas under the Earth’s surface.
In the paper, the authors describe how an ice-cored hill called a pingo would have exploded to produce the crater. First, a talik—an area of unfrozen ground surrounded by permafrost—forms underneath a thaw lake, a process lasting thousands of years. The top of the talik freezes over while methane and carbon dioxide builds up inside its core. The pneumatic pressure pushing up on the frozen top of the talik produces a pingo that eventually bursts.
Bychkov said that all but one of these explosions have happened in remote locations. People recorded smoke and loud sounds in the one instance that a crater formed near human habitation. According to Bychkov, these craters don't remain gaping holes in the Earth forever; water eventually fills these craters, producing round lakes that are widespread in the Arctic.
“There are thousands of round lakes; they may have been craters,” he said.
The explosions of pingos into craters also seem to be associated with unusually warm summers. The heat, according to Earther, likely weakened the Siberian permafrost, facilitating the explosion of methane from the pingo. Bychkov said we still do not know exactly how these warm temperatures affect cryovolcanism, though.
For Bychkov, it’s not the craters themselves that fascinate him; rather, it’s the ecology and composition of the taliks, ecosystems that have been shut off from the rest of the world for millennia.
“The most interesting thing is the life in the talik,” Bychkov said. “It is a closed world with evolution separated from oxygen for thousands of years. Special microbes can live at low temperatures and produce gases, which provide cryovolcanism. This world has not been explored.”