Until a few years ago, the cause of ice circles eluded scientists. The circles first cropped up in Russia and were later observed in Scandinavia, Canada, and parts of the United States.
In 2009, astronauts on the International Space Station reported seeing giant ice rings — about 2.7 miles in diameter — in Lake Baikal in Siberia. Ecologists believed the rotating discs could be attributed to warm water underneath the ice that melts the surface into a circle. LiveScience explains: "Methane emissions can create a rising mass of warm water that begins swirling in a circular pattern because of the Coriolis force, or the phenomenon caused by the Earth's rotation that also helps create cyclones."
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