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Deadly lake turns animals into statues
Lake Natron Gives Up Its Dead
ACCORDING to Dante, the Styx is not just a river but a vast, deathly swamp filling the entire fifth circle of hell. Perhaps the staff of New Scientist will see it when our time comes but, until then, Lake Natron in northern Tanzania does a pretty good job of illustrating Dante's vision.
Unless you are an alkaline tilapia (Alcolapia alcalica) – an extremophile fish adapted to the harsh conditions – it is not the best place to live. Temperatures in the lake can reach 60 °C, and its alkalinity is between pH 9 and pH 10.5.
The lake takes its name from natron, a naturally occurring compound made mainly of sodium carbonate, with a bit of baking soda (sodium bicarbonate) thrown in. Here, this has come from volcanic ash, accumulated from the Great Rift valley. Animals that become immersed in the water die and are calcified.
Photographer Nick Brandt, who has a long association with east Africa – he directed the video for Michael Jackson's Earth Song there in 1995 – took a detour from his usual work when he discovered perfectly preserved birds and bats on the shoreline. "I could not help but photograph them," he says. "No one knows for certain exactly how they die, but it appears that the extreme reflective nature of the lake's surface confuses them, and like birds crashing into plate glass windows, they crash into the lake."
When salt islands form in the lake, lesser flamingos take the opportunity to nest – but it is a risky business, as this calcified bird illustrates. The animals are all arranged in poses by the photographer. Above, on the right we have a sea eagle and on the left a dove, in what is surely the most horrific depiction of the "bird of peace" since Picasso's Guernica.
Brandt's new collection of photos featuring animals in east Africa, Across the Ravaged Land, is published by Abrams Books.
The Ol Doinyo Lengai, "Mountain of God" in the Maasai language, is an active volcano located in the Gregory Rift, south of Lake Natron within the Arusha Region of Tanzania. Part of the volcanic system of the East African Rift, it uniquely produces natrocarbonatite lava.
Ol Doinyo Lengai is unique among active volcanoes in that it produces natrocarbonatite lava, a unique occurrence of volcanic carbonatite. A few older extinct carbonatite volcanoes are located nearby, including Homa Mountain.
Whereas most lavas are rich in silicate minerals, the lava of Ol Doinyo Lengai is a carbonatite. It is rich in the rare sodium and potassium carbonates, nyerereite and gregoryite.
Due to this unusual composition, the lava erupts at relatively low temperatures of approximately 510 °C (950 °F). This temperature is so low that the molten lava appears black in sunlight, rather than having the red glow common to most lavas. It is also much more fluid than silicate lavas, often less viscous than water.
The sodium and potassium carbonate minerals of the lavas erupted at Ol Doinyo Lengai are unstable at the Earth's surface and susceptible to rapid weathering, quickly turning from black to grey in colour. The resulting volcanic landscape is different from any other in the world.
Despite some media reports, the animal didn't simply turn to stone and die after coming into contact with the lake's water. In fact, Lake Natron's alkaline waters support a thriving ecosystem of salt marshes, freshwater wetlands, flamingos and other wetland birds, tilapia and the algae on which large flocks of flamingos feed.
The photographer Nick Brandt has captured haunting images of the lake and its dead for his book titled. [Photos: Lake Natron Gives Up Its Dead]
Brandt discovered the remains of flamingos and other animals with chalky sodium carbonate deposits outlining their bodies in sharp relief. "I unexpectedly found the creatures — all manner of birds and bats — washed up along the shoreline of Lake Natron," Brandt wrote in his book. "No one knows for certain exactly how they die, but … the water has an extremely high soda and salt content, so high that it would strip the ink off my Kodak film boxes within a few seconds."
"I took these creatures as I found them on the shoreline, and then placed them in 'living' positions, bringing them back to 'life,' as it were," Brandt wrote, referring to the way he repositioned the animals. "Reanimated, alive again in death."
During breeding season, more than 2 million lesser flamingos (Phoenicopterus minor) use the shallow lake as their primary breeding ground in Africa. The flamingos' nests are built on small islands that form in the lake during the dry season.
Lake Natron is one of two alkaline lakes in that area of East Africa; the other is Lake Bahi. Both are terminal lakes that do not drain out to any river or sea; they are fed by hot springs and small rivers. As shallow lakes in a hot climate, their water temperatures can reach as high as 106 degrees Fahrenheit (41 degrees Celsius).
The serenity of Lake Natron — and its flamingo population — are threatened by a proposed hydroelectric power plant on the Ewaso Ngiro River, the main river feeding the lake. As isolated as the lake is (it wasn't even discovered by Europeans until 1954), there are no protections in place for the lake or its threatened flamingo population.
INTERACTION WITH MASAI
The road that leads from the Serengeti in Natron is one of the best places to meet the real Masai. Unlike the Maasai to be found along the main streets of the Ngorongoro these are not waiting for you. Each, woman, old, warrior and child is following his day, and unless you're not to intervene tend to be rather reserved, adults watching you silently from a few meters away, the children shyly trying to touch you. Do not try to sell you anything for sure, maybe they could ask your guide ask if you can take a small step.
Sources: www.newscientist.com/article/mg2192...ml#.UsDUYfTuKqg
www.livescience.com/40135-photograp...ake-natron.html
http://en.wikipedia.org/wiki/Ol_Doinyo_Lengai
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Deadly lake turns animals into statues1 Gennaio 2014 |
