Inland Sea Foam on Great Salt Lake

December 07, 2015

GSL Foam

PhotographerRay Boren
Summary Author: Ray Boren

Looking very much like bubble bath suds, white pillows of wind-born foam occasionally appear, and even take flight as buoyant globs, along the shores of Utah’s Great Salt Lake.

The photographs featured above illustrate two foam encounters within days of each other on the big, briny lake’s south and north shores. In the top photo taken on November 2, 2015, the Sun is setting through a break beyond what is otherwise a substantial rain-cloud deck overhead. A brisk zephyr is prompting the gathering foam to crowd in jiggly, elongated puffs against a curve of the drought-exposed lake bed, near where historic but now vanished Saltair Resort once stood, west of Salt Lake City. The bottom photo, taken on November 13, shows impressive stretches of foam piled along the lake’s northern Rozel Bay, site of artist Robert Smithson’s iconic earthwork sculpture “Spiral Jetty,” where the exposed, salt-crusted lakebed testifies to the Western U.S. drought’s depleting effect.

One of the world’s largest terminal or endorheic lakes, Great Salt Lake is typically three to five times saltier than the ocean. One supposition, then, might be that its high salt content is the prime cause of the sea foam phenomenon here. However, the Utah Geological Survey’s J. Wallace Gwynn has noted that this is not strictly so. While dissolving salts can play a role, foam requires a surfactant, usually decaying organic matter such as algae. He writes that the foam generator on Great Salt Lake is probably phytoplankton, in this case, salt-loving Dunaliella viridis. Algae naturally exude surfactants, which are also produced as they die and decay. Stirred by windstorms and waves, fluffy foam is whipped up from such compounds on Earth’s oceans — and on a certain salty inland sea.

Photo Details: Top - Camera: NIKON D3200; Lens: AF-S DX VR Zoom-Nikkor 18-55mm f/3.5-5.6G; Focal Length: 18mm (35mm equivalent: 27mm); Aperture: ƒ/6.3; Exposure Time: 0.050 s (1/20); ISO equiv: 400. Bottom - same except: Aperture: ƒ/11.0; Exposure Time: 0.0020 s (1/500); ISO equiv: 140.