Occasionally you can see in nature is a curious phenomenon — ice circles. They appear in the slow flowing rivers and are perfectly smooth, slowly rotating circles of ice.
These circles are formed by water currents, arising in the river. Caught in a piece of ice over to rotate. During rotation of the edge of the piece of worn down the surrounding ice, and may soon get a perfect circle.
Most often, this phenomenon is observed in Scandinavia and North America, but also saw it in Germany, England and Russia. First ice circles recorded in 1895 at the American Mianus River.
Typically, ice circles are more than four meters in diameter. The largest such circle was spotted on the lake and had a diameter of four kilometers.
Category: Natural anomalies