Looked wikipedia. "An unusual natural phenomenon, ice disks occur in slowly moving water in cold climates and can vary in size, with circles more than 15 metre

Looked wikipedia. "An unusual natural phenomenon, ice disks occur in slowly moving water in cold climates and can vary in size, with circles more than 15 metres (49 ft) in diameter..." There has been few more of them around the world. https://en.wikipedia.org/wiki/Ice_circle https://en.wikipedia.org/wiki/Ice_circle