Brown University researchers have worked with the city to set up the camera that takes a photo of the formation in the Presumpscot River every minute, allowing for some pretty neat time lapse footage as well.
The disc may have gotten even bigger after the weekend storm and bitter cold temperatures that followed. The social media sensation has been spinning for over a week, but recent ice buildup between the disc and shore may now be freezing it in place and preventing rotation.
Polar scientist Chris Horvat says the ice disc helps his team study how pieces of sea ice move and break up.
According to WBZ-TV (CBS Boston) Chief Meteorologist Eric Fisher, the rotation of the ice was driven by the current of the river and the temperature changes in the water underneath the ice. That created a vortex that causes it to spin.
“The shore in this case acts almost like a grinding wheel where the ice hits the coast and it starts to shave off and it creates this perfect pizza shape of the ice disc floating in the water,” he said.
Last week, the disc stopped spinning when it got stuck to the riverbank but a man on a paddleboard set it free with an ice pick, the Portland Press Herald reported.
Another ice disc was spotted last week in Maine’s Baxter State Park.