WESTBROOK, Maine (AP) — Maine’s rotating ice disk has begun to form again in the Presumpscot River three years after its famous first appearance in 2019. Westbrook city officials shared photos Wednesday of the formation on Facebook. Ice disks form as a result of a collection of a current and vortex underneath the ice. Ice sheets begin to spin and then shape into symmetrical circles. But ice disks this large rarely form in locations like Westbrook. A 100-yard-wide formation appeared in the river for the first time three years ago and brought international attention to Westbrook before it dissipated with the advent of warmer weather.