The lake, the largest source of fresh water in the world for its volume, seems to have some warm whirlpools that flow clockwise under the ice. The striking ice rings on the surface of Lake Baikal are caused by these jets of water under the ice crust.
However, the center of the eddies typically presents less strong currents, which explains why the centers of these rings still retain exceptionally thick ice.
An international team of researchers from France, Russia and Mongolia drilled holes in the ice and placed sensors in the water below.
The sensors estimated that the temperature of the water in the eddies was 1 to 2 degrees Celsius warmer than the surrounding water, while the eddies themselves are known for their lens shape, something that rarely occurs in the lakes, but is frequent in the oceans.
Lake Baikal is not the only place where there are ice rings of this type: the nearby Ubsugul lake in Mongolia, and Lake Telétskoye in Russia, also have them, said Alexei Kuráyev, assistant professor at the Laboratory of Studies in Space Geophysics and Oceanography (LEGOS) of the Federal University of Toulouse, France.
Scientists have tried to determine how ice rings actually formed for a long time. According to one of the most widespread theories, methane bubbles rising from the bottom of the lake were responsible for the appearance of these rings. But Kuráyev’s team discarded the idea, noting that some of these ice rings originated in the shallowest areas of the lake, in areas with no known gas emissions.
The Ice Rings Community
The thickness of ice allows people to pass regularly above the surface of the lake during the winter months.
“It is obvious,” said Kuráyev, explaining that it is a very long lake, and if one wants to go from one place to another, one must travel about 400 kilometers one way and another 400 kilometers back. “But the trip through the ice is about 40 kilometers, so the choice is obvious,” he claimed.
However, the rings can be truly dangerous due to the thickness of the ice and its size that is difficult to detect. These areas represent a danger to heavy cars, which can sink.
Kuráyev and his colleagues, or the Community of the Ice Rings, as they jokingly refer to themselves, perform the work of recognizing the rings and inform the national park service and the Russian Ministry of Emergencies about their findings. The researchers also update their website with satellite images of the new ice ring locations.