Every time a wave breaks on shore (or ice) part of it flows back into the lake, the rest gets frozen as a fresh layer, like tree rings. If winds are strong enough and waves big enough, the water sprays over the top of the ice, freezing, and thus builds up thicker and thicker. At the leading edge the ice can be 10 to 15 feet thick.
Digital Infrared images taken with a Sony F828 camera.
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