Tanzania's Great Rift Valley Lakes & Mountains

As if the dry season is attempting its final life sapping effort to suffocate us before the rains come, an apocalyptic dust storm is sweeping across the southern shore of Lake Natron. Agitated by the dark, threatening thunderstorm, the dust is diffusing the afternoon rays of sun giving Oldonyo Lengai an eerie glow as the dust slowly envelopes the volcano.

Driving from Amboseli to Lake Natron the other day, I took a cross-country route through the plains between four prominent volcanoes. The volcanic dust, like talcum powder enveloped the vehicle billowing into the car through every space possible. Building cumulonimbus clouds inspired graphic dust devils on the barren landscape. Zebra, Fringe-eared oryx, Grant’s gazelle, Thomson’s gazelle and giraffe stood in the shade of the few Acacia trees resting in the heat of the day.

Lake Natron, where we’re headed is the largest of the Great Rift Valley’s soda lakes and is also the most caustic lake in the world. It is extremely shallow, no more than 3 meters deep. Lying at 610m above sea level it also gets extremely warm and water temperatures regularly reach 40C (60C recorded), combined with a pH of 9-10, it’s surprising that life can actually flourish. Microorganisms that love the salt give it amazing shades of red, greens and crystal white.

Lesser Flamingos use this lake as an important breeding ground, protecting their eggs and hatchlings by building little mounds in the water far enough away from the shore that predators have to seriously think about venturing out. They also specialize in feeding on the algae- Spirulina that blooms in these waters. There’s also an endemic fish- the Magadi Tilapia that concentrate in the hot springs that feed into the lake.

A year ago, travelling with Nick Brandt on safari, we drove to Natron in search of calcified birds. We scoured the shores picking up a variety of birds including hornbills, flamingoes, starlings, doves, bee-eaters, mouse-birds, and Quelea that had been mummified by the salts in the water. The small invertebrates, fish, and bats that stood frozen in their death pose were fascinating. Click to see his photos of what we found.

A mixture of Sodium bi-carbonate (baking soda) and Sodium carbonate is called Natron, and is the same substance that was mined in Wadi el Natron in Egypt 5000 years ago by the Egyptians when they began mummifying their pharaohs. The alkali salt loves water and absorbs it, drying whatever it has come in contact with. Its alkalinity is also anti-bacterial which helps to stop bacterial decay.

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A few days after we arrived here, it rained. The dust finally settled, and you could almost hear the animals breathing a sigh of relief. We drove out into the plains in front of Kitumbeine Mountain visiting all the little parasitic craters at the base of Gelai, Kerimasi and Oldonyo Lengai. The green grass already sprouting, we counted hundreds of zebra and wildebeest on the plains and spent some time just sitting and watching. In the evening we drove up Lengai as far as the track goes and sat watching the afternoon light sending moving shadows through the valleys and ridges, reflecting Shompole in the lake. 

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