South Tufa, Mono Lake Tufa State Reserve, Mono County, CA, 10/23/2010
At dawn one day in mid autumn I arrived at the south shore of Mono Lake and enjoyed this lovely sunrise over the tufa formations. This was an exceptionally short-lived sunrise, and I had to move quickly to capture its beautiful colors before they faded. Were it not for human activity Mono Lake would be much deeper and broader than it currently is and this area along with the tufa would be totally submerged. Since the 1940s however, the Los Angeles Department of Water and Power has been diverting some of the lake's tributary streams 350 miles to the south to meet the water demands of the city of Los Angeles. The reduced flow into the lake is responsible for depressing the water level and exposing the tufa that comprise the unique and otherworldly landscape here. These fantastic tufa towers are a type of limestone or calcium carbonate formed by the precipitation of minerals during the interaction of freshwater springs and alkaline lake water, back when this area was part of the lake. Mono Lake lies in a basin with no outlet to the ocean. Because the lake is the ultimate destination for all the rain and runoff from a surrounding area of about 780 square miles, its water is extremely alkaline and saline. Mono Lake is believed to have formed more than 760,000 years ago, dating back to the Long Valley eruption to the south. Sediments located below the ash layer are a clue that Mono Lake could be a remnant of a larger and older lake that once covered a significant portion of Nevada and Utah, making it one of the oldest lakes in North America.
