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Credit: K. Roberts

It should come as no surprise that Lake Winnipeg freezes over in the winter. This picture shows fractures in clear ice, approximately 15 cm thick, near shore on Lake Winnipeg (at Victoria Beach). Large sheets of ice are subject to cracking due to stresses from changing water levels, differential wind and weight. Cracks in the ice tend to propagate in straight lines along surfaces in the crystal structure. Here the displacement of the ice along the newer, diagonal fracture can be seen by the break in the older crack. These fractures result from the ice being compressed and sheared. If the ice had instead been pulled apart a band of newer ice would appear in the space between the older pieces. Stronger compression forces can pile up ridges of smashed and broken ice pieces.

UVic / SEOS / Climate Group / About Front Page Picture / Lake Winnipeg Ice Fractures Last updated: Tuesday, 01-Feb-2011 10:09:10 PST
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