Sahara

• The Sahara is a desert that covers most of North Africa and is approximately the same size as China.

Geography

• Area:
  • The Sahara starts from the Atlantic Coast, and continues across North Africa to the Red Sea, occasionally reaching the Mediterranean Sea.
• Interior:
  • It is a desert area in the Interior, separating the North African Coastal Nations from the Central African Countries below it.
• Southern Limit:
  • The southern limit of the Sahara is the Sahel, an East-West band of Tropical Savanna produced by an annual summer Rainfall.

Terrain

• Sand dunes
  • The terrain consists of Sand dunes which can reach a height of 590 feet (180 m).
  • Great Sand Sea
    • This is the Sahara Desert from the Qattara Depression in western Egypt to eastern Libya, but only 7% of its area consists of Dunes.
    • The Dunes cover an area about 185 miles (300km) by 400 miles (650 km).
  • Erg of Bilma
    • This is a Sand Sea in the Fezzan located in Niger.
• Rocky Plateaux
• Fezzan
  • The Fezzan is an area of the Sahara, located in southern Libya and Niger.
• Maghreb
  • The Maghreb is a term used to describe modern Morocco, Algeria, Tunisia, and Libya, but not Egypt.
• Qattara Depression
  • The Qattara Depression is one of several Depressions.
  • It is below sea level, with its lowest point at 436 ft (133m) below sea level, and is located in the northwest of Egypt, forming part of the Western Desert.
• Mountain Ranges
  • There are Mountain Ranges, the Saharan Atlas Mountains and the Tibesti Mountains in southern Libya and northern Chad.
  • The highest point in the Tibesti and the Sahara is Mount Emi Koussi with a height of 11,302 ft (3,445m).
•  Rivers
  • There is only one river which continues to flow all year round through the Sahara, which is the Nile. Other rivers exist but they are only seasonal.
• Oases
  • Siwa Oasis
  • Guelta d'Archei

The Earth’s Tilt

• The Sahara goes through long cycles of no rainfall to mild rainfall, due to the Earth’s Axis being tilted, which varies between 22° to 24.5 ° every 41,000 years.
• Around 7,000 BCE the Sahara received more Sun when the tilt was stronger, which caused a greater heating, and so drew moist Monsoon winds into the interior, causing Rainfall.
• By 4,000 BCE the tilt had lessened, the monsoons had withdrawn and the Sahara had returned to being a Desert.

Weather

• Rainfall:
  • Half the Sahara receives less than 20mm of Rainfall per annum.
  • The other half receives up to 100 mm of Rainfall per annum.
  • Rainfall occurs as very brief but concentrated downpours.
• Snow
  • The Algerian Saharan Desert has occasionally received snowfall, although it quickly melts.
  • The Tahat Peak in Southern Algeria receives snow every three years.
  • The Peaks of the Tibesti Mountains which are over 8,200 ft (2,500m), receive snow on average every seven years.
• Sandstorms
  • Sandstorms occur in the Sahara Desert and in other desert regions including the Arabian Peninsular. They are known as a Haboob.
  • The Sandstorm is characterised by its sudden onset, appearing as a wall of solid clouds, where the sun becomes obscured, visibility drops to a few feet or metres, and high winds arise.
  • The leading edge of the sandstorm can be a wall of sand up to one mile (1.6km) high. Heavy objects can be picked up in the high winds and dropped.

Garamantes

• The Garamantes occupied the region below Tripolitana, and controlled all the Trans Saharan Caravan Routes to the Central African Kingdoms.
  • In 19 BCE Septimius Flaccus invaded the Garamantes.
  • In 50 CE Suetonius Paulinus invaded the Garamantes again and converted the Kingdom into a Roman Client Kingdom which lasted until the Third Century CE. He used a Roman Camel Corps to cross the Sahara.

Camel Caravans

• These crossed the Sahara along the trade routes between the Mediterranean and the Sahel African Kingdoms.
• The main routes went from Libya and Egypt and Carthage, which became the main Port for the Routes from the Sahel.

1. ‘The Way of the Forty’
   • Darb el-Arba Caravan Route meaning ‘the Way of the Forty’, took 40 days from Kobbei in Darfur, Sudan, via the Kharga Oasis and Wadi Howar in the Libyan Desert and into Egypt.
   • The Romans built a chain of mud brick Forts to protect the Route.
2. Timbuctu to Morocco and Algeria
   • From Mali in Africa, a Medieval Salt Road from Timbuctu ran across the Sahara to Morocco until the 1950’s.
   • It ran to Algeria via Tuat.
   • Thousands of Camels were deployed in the caravan.
3. Tripoli to Lake Chad
   • From Tripoli in Libya, via Murzuk to Lake Chad, in southeastern Chad.
   • This route operated during the Roman Period.
4. Benghazi to Wadir
   • From Benghasi in Libya, via Kufra to Wadai in southwestern Chad.
5. Tunis to Kano
   • A Medieval Route ran from Tunis via Ghat, the Mountains of Air to Kano in Nigeria.

Other Camel Caravan Routes

1. King's Highway in the Levant
   • The Camel was used in Camel Caravans along the King's Highway beween the Euphrates in Mesopotamia and Egypt.
2. Incense Road in Arabia
   • Camel Caravans ran the Incense Road from Yemen to the Levant Coast, the Incense Road.

The Sahara Desert