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Fog from the cold ocean gives Namib Desert life, and it may be the oldest desert on Earth

the gist

The Namib is a coastal desert stretching more than 2,000 kilometres along the Atlantic coasts of Angola, Namibia and northwest South Africa. It has been arid or semi-arid for roughly 55 to 80 million years, which makes it possibly the oldest desert in the world. Its coastal sand seas include dunes around 300 metres high, the second tallest in the world after those in China's Badain Jaran Desert. Rain is almost absent here, with some areas getting just 2 millimetres a year. Much of its moisture instead comes from fog, which rolls in from the ocean on more than 180 days a year in coastal areas.

how it works

Cold water from the Benguela Current flows up the southwest African coast. Where it meets warm air from the Hadley cell, the moist air cools and condenses into a dense fog belt. Plants, beetles and lichens use this fog as their main water source, collecting droplets on their surfaces.

so what

The Namib shows how life can persist without rain, which matters for understanding deserts and the limits of life on Earth. Its age and endemic species make it a major site for studying long-term evolution in arid conditions. Much of the desert is protected under Namibia's constitution.

fun fact

The Skeleton Coast, part of the Namib's shoreline, has more than a thousand shipwrecks lying along it.

more on this

Adapted from Wikipedia, the free encyclopedia · CC BY-SA 4.0

Image: Wikimedia Commons