Ice circles in a lake
Jan 28, 2019 19:34:21 #
It was wet, drizzly, very heavy overcast, and about 35F this afternoon, but I went down to a local lake anyway to do some reading. I expected to see a portion of the lake frozen and other portions open water.
To get to the parking lot you must cross a causeway running north/south. When I crossed the causeway I observed on the west/left side what I expected to see – some ice and open water. However, on the right/east side I observed a lot of ice circles, something I had only seen in books and movies.
The side with the ice circles is the smaller, most up-stream, and most in-land portion of the lake. On the west side of the causeway the lake is much wider and a lot more open. The only way water gets from the smaller east side to the larger west side is under the causeway, which is visible in pictures 2 and 6.
I did not notice these circles rotating. It may simply be that they rotated so slowly it was imperceptible without an intervalometer to aid in that determination. Pictures 6 & 7 are of interest because they show formation of these circles.
The space between the circles was all water, but likely just above freezing.
All pictures taken with an IPhone 7 from shore, and about 7-8 feet above lake level. Some PP was done in PSE 14 to adjust light/contrast a bit. I saved the images so you can download,
For scale/visual reference, the portion of the green buoy that is visible in pictures 2, 4, 5, & 6 is about 3 – 4 above the water level.
If anyone has any more or better information about ice circles that form in such conditions please feel free to share with it in this post.
Basic information I found about ice circles is as follows. (Note – The following information is taken from https://en.wikipedia.org/wiki/Ice_circle . I removed footnotes, underlining, bolding, and hyperlinks to certain words, locations, or publications for ease of reading. For full text of article see: https://en.wikipedia.org/wiki/Ice_circle.)
“Ice discs, ice circles, ice pans, or ice crepes are a natural phenomenon that occur in slow moving water in cold climates.
Ice circles are thin and circular slabs of ice that rotate slowly in the water. It is believed that they form in eddy currents. It has been shown that existing ice discs can maintain their rotation due to melting.
An unusual natural phenomenon, ice disks occur in slow moving water in cold climates and can vary in size, with circles more than 15 metres (49 ft) in diameter observed. Ice Circle of Vana-Vigala in Estonia is reported to have had a diameter of over 20 meters, whilst one approximately 298 feet (91 meters) in diameter appeared in Westbrook, Maine in January 2019.
Ice discs form on the outer bends in a river where the accelerating water creates a force called 'rotational shear', which breaks off a chunk of ice and twists it around. As the disc rotates, it grinds against surrounding ice — smoothing into a circle. A relatively uncommon phenomenon, one of the earliest recordings is of a slowly revolving disc spotted on the Mianus River and reported in an 1895 edition of Scientific American.”
Enjoy!
To get to the parking lot you must cross a causeway running north/south. When I crossed the causeway I observed on the west/left side what I expected to see – some ice and open water. However, on the right/east side I observed a lot of ice circles, something I had only seen in books and movies.
The side with the ice circles is the smaller, most up-stream, and most in-land portion of the lake. On the west side of the causeway the lake is much wider and a lot more open. The only way water gets from the smaller east side to the larger west side is under the causeway, which is visible in pictures 2 and 6.
I did not notice these circles rotating. It may simply be that they rotated so slowly it was imperceptible without an intervalometer to aid in that determination. Pictures 6 & 7 are of interest because they show formation of these circles.
The space between the circles was all water, but likely just above freezing.
All pictures taken with an IPhone 7 from shore, and about 7-8 feet above lake level. Some PP was done in PSE 14 to adjust light/contrast a bit. I saved the images so you can download,
For scale/visual reference, the portion of the green buoy that is visible in pictures 2, 4, 5, & 6 is about 3 – 4 above the water level.
If anyone has any more or better information about ice circles that form in such conditions please feel free to share with it in this post.
Basic information I found about ice circles is as follows. (Note – The following information is taken from https://en.wikipedia.org/wiki/Ice_circle . I removed footnotes, underlining, bolding, and hyperlinks to certain words, locations, or publications for ease of reading. For full text of article see: https://en.wikipedia.org/wiki/Ice_circle.)
“Ice discs, ice circles, ice pans, or ice crepes are a natural phenomenon that occur in slow moving water in cold climates.
Ice circles are thin and circular slabs of ice that rotate slowly in the water. It is believed that they form in eddy currents. It has been shown that existing ice discs can maintain their rotation due to melting.
An unusual natural phenomenon, ice disks occur in slow moving water in cold climates and can vary in size, with circles more than 15 metres (49 ft) in diameter observed. Ice Circle of Vana-Vigala in Estonia is reported to have had a diameter of over 20 meters, whilst one approximately 298 feet (91 meters) in diameter appeared in Westbrook, Maine in January 2019.
Ice discs form on the outer bends in a river where the accelerating water creates a force called 'rotational shear', which breaks off a chunk of ice and twists it around. As the disc rotates, it grinds against surrounding ice — smoothing into a circle. A relatively uncommon phenomenon, one of the earliest recordings is of a slowly revolving disc spotted on the Mianus River and reported in an 1895 edition of Scientific American.”
Enjoy!
Jan 28, 2019 20:15:18 #
Cool thing to see! Saw some of these on a science or weather show on tv. Lucky You!
Jan 28, 2019 20:42:02 #
Jan 28, 2019 20:49:58 #
Jan 29, 2019 10:08:50 #
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