Ice Wreaths

December 23, 2010

Ice circles 
Photographer: Jan Koeman; Jan's Website
Summary Author: Jan Koeman; Jim Foster

Winter arrived early in Europe this year. Several significant storms and cold snaps have created snowy landscapes and caused lakes and ponds to freeze. On the photo above, a series of wreaths formed on a drainage ditch following four consecutive nights of sub freezing conditions at Kattendijke, The Netherlands. I've never before witnesses these curious ring features. In the middle of each ring, a weak spot or fracture was evident. It's likely that water was extruded upward through these partially frozen surfaces and then refroze as the temperatures dropped well below freezing. As this occurred on successive nights, the thickness of the rings and the linear crack in the foreground noticeably increased. Perhaps the porosity or density of the snow covering the ditch played a role in the circular shapes as well -- constant porosity and therefore near constant shape. Photo taken on December 3, 2010.

Photo details: Camera Maker: Canon; Camera Model: Canon PowerShot G11; Image Date: 2010-12-03 ; 15:10:44 +0100; Focal Length: 6.1mm; Aperture: f/5.0; Exposure Time: 0.0013 s (1/800); ISO equiv: 80; Exposure Bias: -0.33 EV; Metering Mode: Matrix; Exposure Mode: Manual; White Balance: Auto; Flash Fired: No (Manual); Color Space: sRGB.