An inhospitable expanse of barren emptiness stretches like a pale ribbon along Africa’s south-western coastline; the Namib. This is no ordinary desert, however, where relentless sun beats down on burning sands, for every ten days or so fog rolls in from the sea and swathes the area in impenetrable mist.
Chill sea winds gust across the vast eerie wastes of the great Namib Desert. On confronting this barren expanse of ghostly, mid-shrouded sand dunes in the 1850s, the Swedish explorer Charles Andersson wrote: “A place fitter to represent the infernal regions could scarcely in searching the world around be found. A shudder, amounting almost to fear, came over me when its frightful desolation first broke upon my view. Death would be preferable to banishment in such a country.”
This curious, fogbound wilderness is one of the oldest and driest desert deserts on Earth. Stretching for some 1300 miles (2100km) along the Atlantic coast of Namibia from the Angolan border in the north to the Orange River in the south it ranges in width from 100 miles (160km) at some points to less than 6 miles (10km) at others.
The Kuiseb River, which flows into the Atlantic at Walvis Bay, divides the Namib Desert in two. To the south lies an immense sea of land, where rippling dunes and troughs, known graphically as streets, alternate in regular parallel lines. The ancient gravel terraces beneath the dunes conceal a spectacular trove of buried treasure – the largest single deposit of gem diamonds in the world.
Before the dunes were formed around a million years ago, the rushing waters of the Orange River carried a rich mixture of jewels and muddy gravel from Kimberley region in South Africa to the sea. As the gravel settled on the seabed, the glistening gems were swept north by coastal currents and deposited along the Namib shore, where they were eventually swallowed by mud and silt from the Orange River valley.
To the north of the Kuiseb River the landscape is characterized by rocky gravel plains. These in turn are bounded to the west by treacherous coastal waters that have earned this remote seaward stretch of desert the macabre name Skeleton Coast, the place ‘where ships and men come ashore to die’.
Although less than 1in (25mm) of rain falls along this desert coastline each year, the region’s unique source of moisture – its mists and fogs – supports a variety of small animals. Every ten days or so, as warm moist air from the Atlantic blows over the cold Benguela current dense night fog is generated. This fog rolls inland shrouding the coast and much of the desert in swirling damp cloud. Beetles, termites, wasps, spiders and lizards depend on the fog for water and each creature displays remarkable evolutionary ingenuity in extracting the moisture it needs.
A the white mists approach, headstander beetles stagger up the windward side of coastal dunes and adopt the ungainly stance that has given them their name: they balance upside-down with their heads between their legs and their backs condenses, and the water that collects trickles down into their parched mouths. Button and darkling beetles, by contrast, dig minute parallel furrows in the sand at right angles to the direction of the wind. The descending mist condenses on the exposed individual grains of sand which the beetles then suck dry. Beetles also feed on organic debris trapped in the dunes.
Members of the lizard family derive their moisture from these small insects, with clown dune crickets and darkling beetles providing succulent feasts. The nocturnal gecko, in addition, has evolved an exceptionally long, flexible tongue with which it licks the dew from the surface of its own eyes to ‘top up’ its moisture supply. The lizard’s greatest foe is the sidewinding sand viper, which skims across the dunes, leaving parallel tracks at a 45° angle to the direction of its own movement. When hunting, the snake buries its body in the sand: only its eyes protrude, scouring the surface for unsuspecting prey. Lizards that venture too close are injected with venom and devoured whole.
Larger animals have difficulty adapting to life in the desert. They require more water than is usually available and the intense heat of the sun can warm their blood to a temperature so high that it destroys their brains. The Gemsbok, however, has adapted to the heat by remarkable means: it simply stops sweating when deprived of water, and its hot blood is cooled through a capillary system in its nose before entering its brain.
The extraordinary Welwitchsia, a desert plant resembling a giant radish, grows on the gravel plains north of the Kuiseb River. Unique to Namib, this bizarre species can survive for up to 2000 years. The plant has just two leathery strap-like leaves that curl and trail along the ground but the leaves of individual specimens are frequently shredded to ribbons by the relentless desert winds.
As the rolling fog condenses on the plant’s surface, it takes in moisture through the pores in its leaves. It can also absorb any water that seeps into the ground through a network of small rootlets. The Welwitchsia’s central root, which can measure up to 10ft (3m) long, serves as its larder, storing food and water to provide sustenance in times of drought.
Rustling hulls of ancient vessels bear silent witness to the raging storms, howling gales and treacherous currents that for centuries have claimed the lives of countless mariners along the aptly named Skeleton Coast. The sands shift continually to bury and then reveal fragments of human bone and the wrecked remains of long-lost ships washed up along the shoreline.