The Red Lake That Petrifies Animals

Lake Natron sits in northern Tanzania, close to the Kenyan border, where the floor of the East African Rift opens into a wide, shimmering basin.

In the dry season the surface blushes pink and red, crusted with salt that fractures like shattered pottery.

It has a fearsome reputation as a place that “turns animals to stone.” The truth is stranger and more interesting.

Natron is a working chemistry set, an extreme landscape that can preserve what dies along its shores while nurturing one of Africa’s greatest bird spectacles.

Natron is unusually shallow, about 56 kilometers long and 24 kilometers wide at its fullest, yet generally less than three meters deep.

The Southern Ewaso Ng’iro River flows in from Kenya, along with more than twenty mineral-rich hot springs. Evaporation far exceeds rainfall, which concentrates salts such as natron and trona in the basin.

The result is a soda lake with alkaline water typically around pH 9 to 10.5. In the hottest periods the water and mud can reach scalding temperatures, and the chemistry favors salt-loving microorganisms that tint the lake red and orange.

To the south rises Ol Doinyo Lengai, the Maasai “Mountain of God,” the only active volcano on Earth that erupts natrocarbonatite lava.

Weathered products from this volcano feed the springs and help charge the lake with sodium carbonate. Under the sun, the surface takes on hues that look otherworldly from the air, while along the margins a brittle salt crust buckles underfoot.