Earth’s Fidget Spinner? Football Field Sized Ice Disk Forms in Middle of River
Source : https://www.news18.com
It appears that the Earth may have its own personal spinning top or a fidget spinner.
A spinning disc of ice has formed in the freezing waters of the Presumpscot River in Westbrook, Maine.
The slow-spinning disc has been drawing the attention of residents and netizens alike since it has been spotted. According to CNN, the disc is 100 yards in diameter, which is the average size of a football field. The disk also appears to be in the same spot though it reportedly changes opacity depending on the time of day and cloud coverage.
And while this is amusing people, this disc isn’t a new discovery. An illustration of a revolving ice cake on the Mianus River, USA, was published in 1995 in the Scientific American.
A 1997 paper on ‘large rotating ice discs on ice-covered rivers’, proposed a theory of how these disks are formed – the river creates a whirlpool effect around a chunk of ice, slowly eroding it until its edges were perfectly smooth and circular.
This theory was revamped in 2016, when scientists published a paper in journal Physical Review E,where they added that river currents could be a factor for creating these disks initially.
It further added that it was temperature changes in the water what kept these disks spinning. As the ice melts and sinks, it creates a vortex under the disk as cold water from the melted ice moves in a downward direction pushing warm water to the top, hence, making the disk ‘rotate.’
The faster the ice melts owing to the formation of warm water, the faster the disk rotates, the scientists claimed.