Raiders of the Lost Lake
During the rainy season, which lasts from January to April, the world's largest salt flat -- Salar de Uyuni, in Bolivia -- turns into the world's largest mirror, reflecting heaven on Earth. Here a 4x4 car drives across the desert.
The rare cacti (Echinopsis tarijensis) sit in profile on Isla Inkahuasi with star trails in the sky during a long night exposure.
A rock formation, better known as the Stone Tree, lies in the middle of the Siloli desert and volcanic region of Potosi in southwestern Bolivia, on the Andes mountain range, near the Chilean border.
Tours are headed by guides who traverse the region without any roads to access geographic areas, such as lagoons, salt mines, rock formations and volcanoes. The region is known for its unpredictable climate and temperature changes, often providing snow in a small 1 kilometer area.
Reflection of Tunupa volcano and four-wheels drive trek across Salar de Uyuni, Bolivia.
Laguna Colorada at the Eduardo Avaroa Andean Fauna National Reserve, with James' flamingos. The salt lake contains borax islands, whose white color contrasts with the reddish color of its waters, which is caused by red sediments and pigmentation of some algae.
Massimo Borchi/Atlantide Phototravel/Corbis
A hotel in the southwest Bolivian desert. Elevation is 3,653 meters (nearly 12,000 feet).
During the rainy season, Salar De Uyuni becomes saturated with over several centimeters water.
A lake larger that Lake Superior once brought life to an area of south-central Africa that now hosts only a salty desert. The long-gone Lake Makgadikgadi filled in a huge expanse of northern Botswana near the wildlife paradise of the Okavango Delta, the world’s largest inland river delta.
In its prime, the 90,000 square kilometer (35,000 sq. mi.) lake would have boasted the second largest surface area of any inland body of water after the Caspian Sea.
Prehistoric Africans must have been perplexed when the lake drained away thousands of years ago. Rich fishing and hunting grounds shriveled as the water evaporated or escaped into the Zambezi River.
Nineteenth century European explorers noted the ancient shorelines etched on surrounding hillsides and realized that a massive lake once filled the area. But they didn’t know exactly how large the lake was or what had caused its demise.
More recent geological sleuthing revealed the rise and fall of Lake Makgadikgadi.
The mega lake fluctuated in size between approximately 1.8 million years ago to possibly as recently as 8,500 years ago, until it finally disappeared, Joel Podgorski of the Institute of Geophysics in Zurich, Switzerland told Discovery News. Podgorski’s study of the lake’s ancient boundaries will be published in the October issue of Geology.
Podgorski used magnetic imaging of the lost lake region to determine its ancient shorelines. His study also found a massive lost inland delta, or mega-fan, beneath the vanished lake. A biological paradise, similar to the modern Okavango Delta, may have first been drowned by the mega-lake, then dessicated when the water drained.
Populations of animals in the two small lakes remaining in the Makgadikgadi region may be remnants of the ancient lake’s ecosystem.
“Molecular dating of catfish and crocodiles points to paleo-Lake Makgadikgadi having existed as a connection between now separate populations of these species,” said Podgorski. “One could presume that the lake hosted a sizable wildlife population much as the nearby Okavango Delta does today,” said Podgorski.
Shifts in the Earth’s crust eventually caused the rivers that fed Lake Makgadikgadi to change course. The lower Zambezi River captured the water that once flowed into the mega-lake.
As recently as 1952, earthquakes have altered the flow of rivers in the region. A magnitude 6.7 quake in ’52 changed the water flow in part of the Okavango Delta.
Geologic activity also flattened out the ground beneath the lost lake, making it shallower and hastening its evaporation.
The lake dried up and left behind one of the world’s largest salt pans. A salt pan consists of the minerals left behind after a body of water evaporates. The Salar de Uyuni in southern Bolivia is one example. The Black Rock Desert in Nevada, home to the Burning Man festival, is an example of an ancient lake that dried up leaving only alkali flats, a desert ecosystem similar to a salt pan.
IMAGE: Kubu Island, Makgadikgadi Salt Pans (Stefan Huchler, Wikimedia Commons)