Sahara Desert
We all know that Sahara is the World's largest hot desert and the third biggest desert. The first two biggest deserts are Antarctica (14 million square kilometers) and Arctic (13.9 million square kilometers). Above three are the top 3 deserts in the world. Area of Sahara desert is 9.2 million square kilometers. The area of desert may expand or contract due to seasonal changes. According to researcher’s estimation, the Sahara area has increased to 10% compared to last century.
Sahara Desert facts
1) The name Sahara means "desert" derived from the Arabic word Sahara.
2) Sahara Desert covers the North Africa of the African continent. The massive Sahara desert is bordered by Atlas Mountains and Mediterranean Sea in north, Sahel in south, Atlantic ocean in the west and Red sea in the east.
3) Sahara region is very vast and it comprises of the Western Sahara, Saharan Atlas, the Ténéré desert, Adrar des Iforas, Hoggar Mountains, the Red Sea hills, the Tibesti Mountains, the central Ahaggar Mountains, the Libyan Desert, and the Aïr Mountains.
4) Sahara covers many parts of 11 countries; they are Algeria, Egypt, Chad, Tunisia, Mali, Mauritania, Morocco, Niger, Western Sahara, Sudan and Libya.
5) 6000 years ago the great Sahara desert was covered in grasslands. It received good rainfall but due to change in the orientation of earth's axis (which causes weather patterns) the grasslands got transformed to the hottest desert on earth. This cycle happens once in 20,000 years. Due to the tile of earth's axis, monsoon activity reduced leading to the formation of desert.
6) Sahara desert as we know is mainly covered rocks and large sand area (sand dunes called ergs). Many sand dunes reach over a height of 180m. Apart from sand dunes, the desert has dry valleys, mountains, dry lakes, oases, salt flats, rocky plateaus (Hamadas) and gravel plains. A 40 km-diameter circular Richat structure is called Eye of the Sahara; the structure has rocks of igneous deposits and sedimentary layers.
7) A shield Volcano (largest volcanoes (in terms of area) formed by spread of overflowing low viscosity lava, they generally don’t erupt) called Emi Koussi is the highest peak in the Sahara (3,415 meters high) is located in the Tibesti range. The lowest region is called Qattara Depression (133 m below sea level), located in Egypt.
8) Sahara has 2 rivers (the Nile and the Niger) and more than 20 lakes among which lake Chad is the only freshwater lake.
9) The world tallest sand dunes lies in Isaouane-n-Tifernine Sand Sea located in Algeria; it is around 450 m high. The sand sea Chigaga in Morocco has sand tunes reaching 300 m high. One of the toughest regions in Sahara is Tanezrouft. It is one of the hottest and driest regions of the Sahara Desert. It has literally no vegetation with very rare living beings.
10) Sahara population of people is about 2.5 million who are either nomads or permanent inhabitants. Dinosaur (Mansourasaurus shahinae) fossils have been found in Sahara Desert.
Sahara desert climate
Sahara is characterized by two climatic conditions. In the north it is has a dry subtropical climate and in the south it has a dry tropical climate. Sahara Desert is well known for its extreme temperature conditions. Sahara desert is the World's hot low – latitude desert. Sahara desert temperature at summer can range from 38°C to 46°C; this is due to lack of vegetation, position of sun and very low relative humidity. The highest recorded temperature is 58°C at El Azizia, a town in Libya; it was recorded in 1922; while the previous highest temperature ever recorded on earth is 57°C at Death Valley, California in 1913.
In Sahara, it is not extremely cold at night, the temperature at night is around 13°C to 20°C but still Sahara desert at night especially winter nights can drop below freezing point in high altitude regions that can reach up to - 6 °C. Extremely low temperature of −15 °C have been recorded in the Tibesti Mountains, Even Snow fall was recorded twice in Sahara (1979 and 2016, in Algeria). Many Saharan mountain ranges get snow regularly. In 2018, Ain Sefra, Algeria received snowfall up to 40 cm. Sahara desert rainfall is very very low, unreliable, and highly unpredictable. Overall, Sahara receives zero to 100 mm rainfall per year, an average rainfall of 3 inches per year.
Sahara desert Animals
Sahara is home to a variety of wildlife; it has 70 species of Mammals, 90 flying species, 100 species of reptiles and various arthropod species (invertebrate animals with exoskeleton, segmented body and jointed appendages).
Fox species like fennec fox, pale fox and Rüppell's fox, Gazelles such as dorcas gazelle, rhim gazelle and dama gazelle, many other animals like monitor lizards, death stalker scorpion (it’s venom contains agitoxin and scyllatoxin ), highly venomous sand viper, addax, cheetah, Dromedarycamels, goats, ostrich, hyrax, African wild dogs, Saharan silver ant (fastest ant species on earth), African silver bill and black-faced fire finch. Even desert crocodiles are found in Mauritania and the Ennedi Plateau. Catfish and chromides are found in Oasis, cobras and pygmy crocodiles in the Tibesti Mountains.
Sahara desert Plants
Vegetation in Sahara is scarce due to very little or no rainfall at all, but still it supports 500 species of plants and 1000 species of trees; date palm cultivation can be seen at northern Sahara. 2800 species of tracheophytes (plants with vascular tissues to conduct water and nutrients) are able to survive in extreme conditions of Sahara. Sahara plants include acacia trees, palms, succulents, spiny shrubs, and grasses have long roots and thick stems to find and conserve water.
Plants such as Laperrine's Olive Tree, Doum Palm Tree, cypress, mastic, oleander, Sahara Love grass, Wild Desert Gourd, Nitraria Retusa, Date Palm Tree, Desert Thyme (used in cooking), Tobacco Tree, Tamarisk Shrub, Ephedra Alata (used for medical purposes) are found in Sahara, Salt-tolerant plants called halophytes also have its place in Sahara.
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