One of the world's weirdest lakes stands out in scarlet in new NASA images.
Lake Natron in northern Tanzania is an incredibly alkaline body of water. Its pH is as high as 10.5 — not quite as caustic as ammonia, but similar to the laxative Milk of Magnesia. The reason for this bizarre chemistry is the volcanic geology surrounding Lake Natron. The minerals and salts produced by volcanic processes — particularly sodium carbonate — push Lake Natron's water far above water's typical pH of around 7, which is neutral on the 0 to 14 pH scale.
Many animals can't survive in water that alkaline, but the lake is home to flocks of flamingos and other birds as well as tilapia fish. When the lake's animals die, their bodies are sometimes preserved by the sodium carbonate minerals that are responsible for the water's strange chemistry. Ancient Egyptians used sodium carbonate and other naturally occurring salts, known as natron, in their mummification practices. [Photos: Lake Natron Gives Up Its Dead]