The nature of the mysterious circles on the ice of Lake Baikal was explained by subglacial eddies

The nature of the mysterious circles on the ice of Lake Baikal was explained by subglacial eddies
The nature of the mysterious circles on the ice of Lake Baikal was explained by subglacial eddies
Anonim

Russian scientists have suggested that the appearance of dark circles on the ice of Lake Baikal is associated with a special type of vortices that are formed due to the peculiarities of the ice relief. The press service of the Ministry of Science and Higher Education writes about this.

For the first time, the mysterious dark circles on the ice of Lake Baikal were noticed by researchers in the spring of 2003 while studying space images. It turned out that the diameter of such structures is from 4 to 10 km, most often they appear in the spring, before the destruction of the ice cover of the lake. The thickness of ice inside the ring and outside it practically does not differ and reaches a meter, and along the ring it is only 20-30 cm or less.

Scientists have found that these rings are dangerous for people and cars, especially in the area of the Nizhneye Izgolovye Peninsula, where the ice road from Ust-Barguzin to Olkhon Island passes. In this case, the circles are visible only from space.

Measurements of the speed of currents and water temperature in the area of the rings showed that an anticyclonic vortex is formed under such a structure down to the bottom of the lake. It delivers warmer deeper water to the bottom of the ice, causing it to melt from below.

Researchers at the Institute of Water Problems of the Russian Academy of Sciences (IVP RAS) suggested that these eddies are formed due to the bottom topography. This could be a new type of topographic eddy.

To test this assumption, the researchers, together with colleagues from the Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, launched two satellite radio beacons in the area of Cape Nizhneye Izgolovye. With their help, scientists have fixed a columnar structure (vertical vortex) in this area.

In the future, researchers using the ice radar found another ring that was not visible from space. Measurements of temperature and current velocities in that area confirmed the hypothesis: under the ring, researchers discovered a powerful anticyclonic vortex. It was he, according to experts, who caused the appearance of the ring. This is also confirmed by satellite data.

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