Atlas Mountains

The Atlas Mountains topographically and politically

The Atlas (Arabic جبال الأطلس, DMG Ǧibāl al -atlas ) is a mountain range in northwest Africa extending about 2,300 miles across the states of Morocco, Algeria and Tunisia. The highest peak is 4165 meters with the Toubkal in southern Morocco. The atlas forms a distinctive dividing line between the humid climate of the far north west of Africa and the extremely dry Sahara.

3.1 The Atlas as a dividing line
3.2 snowmelt and rain

Structure

The mountains are divided into the following mountain ranges (in brackets the maximum height):

Tell Atlas or Little Atlas ( 2308 m) on the Algerian coast to the Mediterranean
Saharan Atlas (2008 m) in the south of Algeria Tellatlas
Rif or Er Rif ( 2456 m ) on the northern Moroccan coast to the Mediterranean
Middle Atlas ( 3340 m) in the center of Morocco
High Atlas ( 4165 m) just south of the center of Morocco
Anti-Atlas ( 2531 m) in the southwest of Morocco
The volcanic Jebel Siroua ( 3304 m) in the central south of Morocco

In Tunisia, however, the outlets of the Algerian Tell Atlas and Saharan Atlas mountain ranges are only to be found.

Geology

Formation

The atlas, as it appears today, must be divided into two parts to understanding, because its origin to two different geological phases took place. The first part consists only of the Anti-Atlas, which was already in the Late Paleozoic ( 300 million years ago) as the result of collisions former continents. Only in the Tertiary ( 65 million to about 1.8 million years ago) were formed all remaining mountain chains that form today the Atlas because the land masses of Europe and Africa at the southern end of the Iberian Peninsula pressed against each other. As the country auffaltete through this pressure to a mountain, it is called the Atlas of a fold mountain. The same movement formed at this time, in the present Straits of Gibraltar was closed, the Alps and the Pyrenees. It was only in the Quaternary (from about 1.8 million years ago), the African continent sparked by a weaker pressure against Europe.

Geological exceptional case for Africa

The bedrock of Africa was already in the Precambrian (from about 4.5 billion to about 550 million years ago) and is therefore equal to or older than the Atlas mountains lying in Africa today also. The Atlas is therefore a special role among the mountains of Africa, as it does not match the historical genesis rest of Africa.

Risk from earthquakes

The atlas is now plattentektonisch considered the boundary between the Eurasian plate in the north and the African plate to the south. When these two plates rubbing against one another, there may be earthquake. The town, located right in the Tellatlas Blida with today approximately 265,000 (2005) residents was twice completely destroyed by large earthquakes in the 19th century. In the past also in Algeria City Ech Cheliff with today approximately 235,000 (2005) inhabitants, about 5,000 people were killed in an earthquake measuring 7.3 on the Richter scale in 1980.

Occurrence of recyclable raw materials

The atlas is rich in natural resources whose exploitation is attractive for people. There are iron ore, lead ore, copper, cobalt, rock salt, phosphate, mercury, and some silver, limestone, coal and natural gas. With this variety of raw materials, it is an exception among the mountains of Africa, where the Sahara Mountains Ahaggar and Tibesti Mountains or Ethiopia in the east of the continent have no raw material deposits on. Only in the south of the continent there are similar to resource-rich areas.

Climate

Basically has a Mediterranean climate. Summers are therefore quite hot while it comes to heavy snowfall at not too low temperatures in winter due to the altitude. In most time of the year, at least the higher peaks with snow remain covered, but this latest melts during the summer months again. Glacier therefore do not exist.

In approximately centrally located in the Atlas highlands of the bulkhead, the average monthly temperatures are about 26 ° C in summer and 4 ° C in winter.

The atlas as a dividing line

From the north penetrate cold and humid air masses to the Atlas, while reach him through the Sahara from the south, the very hot and dry winds of the Scirocco. It thus forms a dividing line between two very different climatic areas. The southern slopes of the Sahara Atlases therefore have a completely different climate than the northern slopes of Tellatlases. The area of directed to the desert slopes has hardly on rainfall and is subject to strong, daytime temperature fluctuations. Further north you will encounter a somewhat milder climate with significantly more rainfall and less temperature fluctuations in the course of a day. In addition to the strong diurnal variations of ambient temperatures, the southern climate also has a more continental embossed character, which can be warmer the winters colder and summers.

Snowmelt and rain

Due to the Spring every year in the melting snow, and also by new precipitation at this time caused numerous streams and rivers that dry out partially after completion of snowmelt. This only temporarily water-bearing watercourses are al -wadi ( الواد - the valley ) called. Arise between the Tell Atlas and the Saharan Atlas in the highlands of bulkheads referred to as bulkhead salt lakes by rain and melt water that dry up in late summer again up to small laugh.

Flora and Fauna

Due to centuries of deforestation and grazing the forests of the Atlas are now replaced mainly by evergreen shrub plants. Today there are growing Macchiagebüsche, cork oak, Aleppo pine, cedar, juniper, some wild olive trees, and particularly in Morocco Argan trees and large areas of thyme and rosemary. There are also cacti, fig trees and various palm family. In well-watered places are also found loose stocks of acacia and jujube. Also in the flora of the region is striking how big are the differences between the northern and the southern Atlas. The quite fertile soils are used for agriculture.

The fauna is extremely diverse due to the two clashing climates. In the north there are the typical animals of the Mediterranean, such as wild boar, the time between very rarely were, or now domesticated donkey. South come before the specialized species of desert nearby region, such as gazelles, the endangered leopards and cheetahs, hyenas, desert rabbits and gerbils. In both regions, there are also small reptiles, snakes and of course many types of insects.

Colonization

All major cities of Algeria are in the northern part of the country and thus in the region of the Atlas Mountains, as in the southern part of the Sahara is extremely poor settlement conditions. The major cities of Tunisia and Morocco in the region of the mountain. The densely settled areas are adjacent to the coast to the Mediterranean. Some large cities, such as the Moroccan Marrakech with approximately 850,000 (2004) residents are at the foot of the mountains. The Algerian cities Constantine in 650 meters with approximately 500,000 ( 2005) inhabitants and especially El Djelfa in more than 1,100 meters above sea level with approximately 235,000 (2005) residents are the only cities of any significant size that really are in the mountains.

Between the smaller villages repeatedly small groups of children who are listed as " temporary settlers " in the official population statistics gathering.

Smaller settlements are abundant wherever water is in the form of Wadi available.

History and Mythology

Homer and Herodotus, the Greek poets and historians of antiquity, saw in the Atlas the western boundary of the known world.

The Arab geographers during the Islamic expansion seemed the mountainous north-west edge like an island, as it was from the sea north and south cut through the barren desert. This island riseth up according to their ideas against the Andalusian mountain land in present-day Spain, and for them he made the far west of the world. On the other hand, the former Arab geographers have extended the concept of the Atlas Mountains beyond its natural boundaries to the east addition.