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Langmuir streaks on Quake Lake, Montana
Langmuir steaks on the surface of Quake Lake, Montana. These streaks form during moderate winds when parallel cells with helical water currents are set in motion. When two adjoining cells converge and downwell, the foam is left on the surface. Quake Lake, near Yellowstone National Park, formed on 17 August 1959 when a 7.5 Richter Scale earthquake caused a massive landslide that blocked the Madison River in Montana. The lake that formed is 60-m (197 ft) deep and 10-km (6 mi) long. Photo, July 2004.