Sahara
The age of the Sahara
Category: Ecology
Updated June 1, 2013
The Sahara stretches from the Atlantic Ocean to the Red Sea over a length of 5200 km and a width of 1500 km or 9,000,000 km2 of desert. The Sahara is permanently altered by erosion brulants winds, it is devoid of vegetation. Maximum temperatures in the hottest regions in the world, exceeding 50 ° C. The record temperature was recorded in the Sahara, with 58 ° C in Al Azizia in Libya. The fossil dune formations in Chad by researchers at the CNRS in February 2006 (Science magazine), has determined the age of the Sahara, the largest desert in the world. It would not be older than 86,000 years, as was believed, but at least 7 million years. According to the CNRS, there is a few thousand years, to the site of the current Sahara, ruled a humid climate where there were many rivers and lakes, including Lake Mega-Chad.
The Sahara desert is currently in a period but other desert earlier episodes were recorded, the oldest dating back 86,000 years.
note: The word Sahara is of Arabic origin (al-kubra, "The Greatest Desert"). The largest desert in the world occupies about 10% of the African continent.
Image: Satellite image of the largest desert in the world, the Sahara (9,000,000 km2) extending largely in Morocco, Algeria, Tunisia, Libya, Egypt, Mauritania, Mali, Niger , Chad and Sudan (see Google maps).
sahara Satellite View
Geography Sahara
The age of the Sahara
Category: Ecology
Updated June 1, 2013
The Sahara stretches from the Atlantic Ocean to the Red Sea over a length of 5200 km and a width of 1500 km or 9,000,000 km2 of desert. The Sahara is permanently altered by erosion brulants winds, it is devoid of vegetation. Maximum temperatures in the hottest regions in the world, exceeding 50 ° C. The record temperature was recorded in the Sahara, with 58 ° C in Al Azizia in Libya. The fossil dune formations in Chad by researchers at the CNRS in February 2006 (Science magazine), has determined the age of the Sahara, the largest desert in the world. It would not be older than 86,000 years, as was believed, but at least 7 million years. According to the CNRS, there is a few thousand years, to the site of the current Sahara, ruled a humid climate where there were many rivers and lakes, including Lake Mega-Chad.
The Sahara desert is currently in a period but other desert earlier episodes were recorded, the oldest dating back 86,000 years.
note: The word Sahara is of Arabic origin (al-kubra, "The Greatest Desert"). The largest desert in the world occupies about 10% of the African continent.
Image: Satellite image of the largest desert in the world, the Sahara (9,000,000 km2) extending largely in Morocco, Algeria, Tunisia, Libya, Egypt, Mauritania, Mali, Niger , Chad and Sudan (see Google maps).
sahara Satellite View
Geography Sahara
Ergs are massive big dune, they occupy about 20% of the surface of the Sahara. They evolve with the prevailing winds.
The regs are flat expanses, rocky and are the most common landscape of the Sahara. The reg Tanezrouft which means "land of thirst" is in Algeria.
Dayas are limited extension bowls, deep usually clay where water trickling can accumulate. These are areas of vegetation that are found mostly north of the Sahara.
Sebkhas form temporary salt marshes. The water comes from temporary sources. The sebkha of Chott el Jerid, covers 5,000 square kilometers.
Hamadas are tabular rocky plateaus smoothed by wind erosion. When covered sandstone, they are appointed as tassilis Tassili Ajjer in Algeria.
Jebel means all other reliefs.
Saharan oasis, only a thousandth of the surface of the Sahara. Oases are often located on the river bed or at the foot of the great mountains.
Guelta is a body of water with no visible flow. They are discovered in the form of ponds in the wadi beds, or in the hollows of rock formations protected from sun exposure.
The wadis are temporary streams, most of the time they are dry.
The Tenere, or "desert" is the central part of the Sahara.
Image: Dunes, cliffs and mountains in the Tadrart Acacus, in the southwest of Libya into the Sahara.
desert libya
The country's thirst
Tanezrouft is a Sahara region straddles Algeria and Mali, west of the Hoggar and extends 500 km, Reggane on the border of Mali.
Tanezrouft is considered an absolute desert because of its extreme aridity. This vast plain avoided by caravans, has no water source. In the 20th century, they found the mummified remains of a caravan of 1,800 camels and 1,500 men. His first official crossing camel is awarded by a European captain Cortier in 1913.
This stunning view from space Basin Tanezrouft, the "Land of Thirst" tells us about one of the most arid regions of the Algerian Sahara. On the picture against the basin Tanezrouft shows her dark sandstone hills, traces its white salt and rocky plateaus. At the top right of the image, Erg Mehedjibat seems like a bed of small yellow dunes. Rainfall is very low and erratic in the Sahara and most regions receive on average less than 130 mm of rain per year. Tanezrouft can take several years without receiving rain.
Despite its aridity, the region is home Tanezrouft however both cities and Taoudeni Taghaza famous for their mining rock salt and Tuareg caravans are trading at the annual Azalaï.
note: The caravans of camels carrying the famous salt plates across the desert, and the shipments they form are called Azalaï in Tamasheq.
Image: The Japanese satellite ALOS (Advanced Land Observation Satellite) took this image with a resolution of 10 meters, 24 June 2009 using his camera AVNIR-2 (Advanced Visible and Near Infrared Radiometer Type-2) designed to map the land surface and vegetation.
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