60 Fun Facts About Sahara

Roughly what area does the Sahara cover, in square kilometres?

That makes it the third-largest desert overall, behind only the cold deserts of Antarctica and the Arctic.

The name Sahara is a broken plural of a word from which language?

Sahra means desert, so 'Sahara Desert' is really 'Deserts Desert'.

The Sahara stretches from the Atlantic in the west to which sea in the east?

To the north it meets the Mediterranean, and the landscape only softens into coastal plain along the Atlantic.

What is the name of the belt of semi-arid savanna that bounds the Sahara to the south?

It runs right across Africa from east to west and has a short summer rainy season.

The Sahara covers about what share of the African continent?

Include every area getting under 250 mm of rain a year and it would swell to 11 million square kilometres.

In Saharan geography, what is a hamada?

Sand seas are ergs, gravel plains are reg, dry valleys are wadis and salt flats are chotts.

Many Saharan sand dunes rise to more than what height?

Only a fraction of the desert is dune field; most of it is rock and gravel.

The Tibesti Mountains, home to the Sahara's highest peak, rise mainly in the north of which country?

The peak is Emi Koussi, a shield volcano topped by two nested calderas.

Emi Koussi, the highest mountain in the Sahara, is what kind of peak?

It reaches 3,415 metres and there is still fumarole and hot-spring activity on its flanks.

The Richat Structure, nicknamed the Eye of the Sahara, is roughly how wide?

Its concentric rings expose the oldest rock at the centre and Ordovician sandstone at the edges.

What kind of geological feature is the Richat Structure?

An igneous intrusion pushed up the overlying layers, which were then worn down into rings.

Which part of the Sahara is called the sunniest, driest and most nearly rainless place on Earth?

Descending air under the subtropical ridge is strongest over the eastern part of the desert.

The eastern Sahara's 4,300 hours of bright sunshine a year is roughly what share of daylight hours?

The figure has been recorded at Aswan and Luxor in Upper Egypt and at Wadi Halfa in the Nubian Desert.

Which place is the only rival to Bou Bernous's record 47 °C mean monthly maximum temperature?

Bou Bernous is a remote town in the Algerian desert at 378 metres above sea level.

A record sand temperature of 83.5 °C was measured in which city?

Ground temperatures of 72 °C and 75 °C have been recorded in Mauritania and northern Chad.

On average, Saharan nights are how much cooler than the days?

The swing is smallest on the humid coasts and largest in the dry southern interior; winter nights can dip below freezing.

Over a wide area of the eastern Sahara, the long-term mean annual rainfall is roughly how much?

Meanwhile potential evaporation runs from 2,500 mm to more than 6,000 mm a year, the highest anywhere on Earth.

Sahara snow was recorded in 1979 and 2016 at the town of Ain Sefra, in which country?

The town sits at the edge of the Saharan Atlas, high enough for winter cold to reach it.

Under the Köppen system, most of the Sahara has which climate code?

B is dry, W is desert and h is hot; the subtropical ridge is the main reason it applies over such a huge area.

The pressure ridge over the Sahara is the eastern extension of which Atlantic system?

Its subsidence nearly reaches the ground in the coolest part of the year.

Botanists mark the northern limit of the Sahara by the northern limit of cultivation of which crop?

It also matches the southern edge of esparto grass and the 100 mm rainfall line.

What drives the Sahara's roughly 20,000-year swing between desert and savanna?

The wobble shifts the North African monsoon north or south, switching the rain on and off.

The Sahara is in a dry phase; in roughly how many years should it turn green again?

The idea that orbital changes drive monsoon strength was formally tested by John Kutzbach in 1981.

Lake Chad is the remnant of a Saharan paleolake that covered roughly how much area at its largest?

Lake Mega-Chad was the biggest of four great Saharan lakes of the African humid period.

Fog from which cool ocean current waters the lichens and succulents of the Atlantic coastal desert?

That narrow strip covers about 39,900 square kilometres of southern Morocco and Mauritania.

The Tanezrouft, one of the Sahara's most arid regions with no vegetation at all, is what kind of terrain?

It runs south from Reggane in Algeria towards the Adrar des Ifoghas in northern Mali.

The Sahara's flora comprises roughly how many species of vascular plants?

About a quarter are endemic, and about half are shared with the deserts of Arabia.

The fennec fox's most distinctive feature is what?

The ears shed heat and pick up prey moving underground; it is the smallest of all foxes.

The addax, which can go nearly a year without drinking, is also known as what?

Its spiral horns earn it a second nickname, the screwhorn antelope; it is critically endangered.

Roughly how many mature Saharan cheetahs are thought to remain?

They are unusually pale, avoid the sun from April to October and flee any human presence.

Which reptile, surprisingly, survives in small populations in the Ennedi Plateau of Chad?

Over 30,000 Saharan petroglyphs show river animals from the days when the desert was wet.

The deathstalker, which can grow to 10 cm, is what kind of Saharan animal?

Its venom is packed with agitoxin and scyllatoxin, but the sting rarely kills a healthy adult.

For roughly how long each day is the Saharan silver ant active outside its nest?

It runs at 855 mm per second, the fastest of any ant, and uses only four of its six legs at top speed.

Which domesticated animal is the favourite of Saharan nomads for its endurance and speed?

Dromedaries and goats are the most common domestic animals in the desert.

Gobero, the Sahara's largest Stone Age graveyard, was found in 2000 by an expedition searching for what?

Paul Sereno's team found two cultures there: the tall Kiffians and the later Tenerians.

The 5,600-year-old Uan Muhuggiag child mummy is roughly how many years older than Egypt's earliest?

The boy was eviscerated, embalmed and wrapped in antelope skin, with an ostrich-eggshell necklace.

The megaliths at Nabta Playa predate Stonehenge by roughly how long?

The society behind them may have laid the groundwork for Egypt's Old Kingdom.

Tifinagh, the Tuareg script, descends from an ancient Libyan alphabet based on which people's writing?

The Phoenicians strung settlements along the North African coast between 1200 and 800 BCE.

The Garamantes built their empire around 500 BCE in the Fezzan of which modern country?

Archaeologists have found eight major towns in their territory, and a Roman bath in the capital, Garama.

Why did the Garamantes' civilization eventually collapse?

They could no longer sustain the effort of driving their tunnels ever further into the mountains.

Before the Muslim conquest, which empire ruled the Sahara's northern shores from the 5th to the 7th centuries?

By the end of 641 all of Egypt was in Muslim hands and trade across the desert intensified.

According to Ibn Battuta, an average trans-Saharan caravan numbered about how many camels?

He noted that some caravans ran to 12,000 animals.

Ibn Battuta crossed the desert in the mid-14th century via Taghaza, a settlement famous for mining what?

He went from Sijilmasa to the oasis of Oualata; salt going south was traded for gold coming north.

Timbuktu's rise as a salt, gold and ivory trade hub followed which ruler's visit around 1325?

The city lies about 20 km north of the Niger River in modern Mali.

La Compagnie Transsaharienne, established in 1927, ran what across the desert?

The French also flew Aéropostale air links over the Hoggar to Timbuktu, Bamako and Dakar.

The Tree of Ténéré, once considered the most isolated tree on Earth, met what fate in 1973?

The dead acacia now stands in a shrine at the national museum in Niamey.

After Spain left Western Sahara in 1975, which country annexed most of the territory?

It was first partitioned between two neighbours; Mauritania pulled out in 1979.

Libya's Great Man-Made River, which Gaddafi called the Eighth Wonder of the World, is what?

It pumps fossil water from the Nubian Sandstone Aquifer to Tripoli and Benghazi.

The proposed Trans-Sahara Highway would run from Algiers on the Mediterranean to Kano in which country?

Every proposed trans-African highway across the desert is only partly complete.

Which of these dinosaurs has been found as fossils in the Sahara?

Afrovenator and Jobaria came from the same rocks, laid down when the region was far wetter.

Tassili n'Ajjer, the rock-art massif listed by UNESCO in 1982, has a Berber name meaning what?

Some 15,000 engravings there show crocodiles, cattle herds and dancing humans.

Western Sahara is a major source of which mined mineral resource?

Algeria and Libya, by contrast, sit on big oil and gas fields.

In Saharan geography, what is an erg?

Gravel plains are called reg, dry valleys wadi and salt flats shatt or chott, alongside the rocky hamada plateaus.

Which national capital lies within the Sahara?

Other Saharan cities include Tamanrasset and Ghardaïa in Algeria, Timbuktu in Mali, Agadez in Niger and Faya-Largeau in Chad.

What is the primary source of the little rain that falls on the southern Sahara?

This belt of low pressure near the equator brings the brief, irregular rainy season to the Sahel and the desert's southern edge.

By roughly what date had the Sahara become as dry as it is today?

A shift in Earth's orbit cut rainfall and raised temperatures, turning the region into a barrier with settlement clustered around oases.

Which model describes species spreading across a 'Green' desert and retreating when it dries again?

In arid phases flora and fauna fall back to the Atlas Mountains, West Africa or the Nile Valley.

What human activity is proposed to have accelerated the Sahara's drying between 6000 and 2500 BCE?

Cattle herding had become a sophisticated social system by 4000 BCE, with animals traded as valued assets.

If every area with under 250 mm of annual rain were included, how big would the Sahara be?

By the usual definition it covers about 9 million square kilometres, or 31 percent of Africa.

Which Saharan people still write in Tifinagh, a descendant of the ancient Libyco-Berber alphabet?

The Libyco-Berber script itself derived from the writing of seafaring traders who settled the North African coast from 1200 BCE.