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WONDERS OF NATURE
Sahara Desert. Nature miracle
A truly endless sea of sand, stone and clay scorched by the sun, revived only by rare green spots of oases and a single river - this is what the Sahara is. The gigantic scale of this largest desert in the world is simply amazing. Its territory occupies almost eight million square kilometers - it is larger than Australia and only slightly smaller than Brazil. Its hot expanses stretch for five thousand kilometers from the Atlantic to the Red Sea.
Nowhere else on Earth is there such a huge waterless space. There are places in the interior of the Sahara where it doesn't rain for years. So, in the oasis of In-Salah, in the heart of the desert, for eleven years, from 1903 to 1913, it rained only once - in 1910, and only eight millimeters of rain fell. These days, the Sahara is not so difficult to access. From the city of Algiers on a good highway to the desert can be reached in one day. Through the picturesque gorge of El Kantara - "Gateway to the Sahara" - the traveler finds himself in places that by their landscape do not at all resemble the "sandy sea" he expected with golden waves of dunes. To the left and right of the road, which runs along a rocky and clay plain, small rocks rise, to which the wind and sand have given the intricate outlines of fairy-tale castles and towers. Sandy deserts - ergs - occupy less than a quarter of the entire territory of the Sahara, the rest falls on the share of rocky plains, as well as clayey areas cracked from the scorching heat and salt-white depressions-salt marshes, generating deceptive mirages in the unsteady haze of heated air. In general, the Sahara is a vast plateau, table, the flat character of which is broken only by the depressions of the Nile and Niger valleys and Lake Chad. On this plain, only in three places do truly high, albeit small in area, mountain ranges rise. These are the Ahaggar and Tibesti highlands and the Darfur plateau, rising more than three kilometers above sea level. The mountainous, gorge-cut, absolutely dry landscapes of Ahaggar are often compared to lunar landscapes. But under the natural rocky canopies, archaeologists have discovered here a whole art gallery of the Stone Age. The rock paintings of ancient people depicted elephants and hippos, crocodiles and giraffes, rivers with floating boats and people harvesting ... All this suggests that the climate of the Sahara used to be more humid, and savannahs were once located on most of the current desert . Now they are found only on the slopes of the Tibesti highlands and the flat, elevated plains of Darfur, where for a month or two a year, while it rains, real rivers even flow through the gorges, and abundant springs feed the oases with water all year round. In the rest of the Sahara, precipitation is less than two hundred and fifty millimeters per year. Geographers call such areas arid regions. They are unsuitable for agriculture, and herds of sheep and camels can only be driven over them in search of scarce food. Here are the hottest places on our planet. For example, in Libya there are areas where the heat reaches fifty-eight degrees! And in some areas of Ethiopia, even the average annual temperature does not fall below plus thirty-five. The sun governs all life in the Sahara. Its radiation, taking into account rare cloudiness, low air humidity and lack of vegetation, reaches very high values. The daily temperatures here are characterized by large jumps. The difference between day and night temperatures reaches thirty degrees! Sometimes frosts occur at night in February, and on Ahaggar or Tibesti the temperature can drop to minus eighteen degrees. Of all the atmospheric phenomena, the traveler endures prolonged storms the hardest in the Sahara. The desert wind, hot and dry, causes hardship even when it is transparent, but it is even more difficult for travelers when it carries dust or fine grains of sand. Dust storms are more common than sandstorms. The Sahara is perhaps the dustiest place on earth. These storms look from afar like fires quickly covering everything around, clouds of smoke from which rise high into the sky. With furious force they rush through the plains and mountains, blowing dust from the destroyed rocks on their way. Storms in the Sahara have extraordinary strength. The wind speed sometimes reaches fifty meters per second (remember that thirty meters per second is already a hurricane!). Caravaneers say that sometimes heavy camel saddles are carried away by the wind for two hundred meters, and stones, the size of a chicken egg, roll along the ground like peas. Quite often, tornadoes occur when the very heated air from the earth heated by the sun rapidly rises, capturing fine dust and carrying it high into the sky. Therefore, such whirlwinds are visible from afar, which, as a rule, allows the rider to save his life by evading a meeting with the “desert genie,” as the Bedouins call the tornado. A gray column rises into the air to the very clouds. Pilots met dust devils sometimes at a height of one and a half kilometers. It happens that the wind carries Saharan dust across the Mediterranean Sea to Southern Europe. On the vast Saharan plains, the wind almost always blows. It is estimated that there are only six calm days in the desert for a hundred days. Especially notorious are the hot winds of the Northern Sahara, which can destroy the entire crop in the oasis in a few hours. These winds - sirocco - blow more often in early summer. In Egypt, such a wind is called khamsin (literally - "fifty"), since it usually blows for fifty days after the vernal equinox. During his almost two-month rampage, the window glass, not closed by the shutters, becomes dull - this is how grains of sand carried by the wind scratch it. And when there is calm in the Sahara and the air is filled with dust, there is a "dry fog" known to all travelers. At the same time, visibility completely disappears, and the sun seems to be a dull spot and does not give a shadow. Even wild animals lose their bearings at such moments. They say that there was a case when, during the "dry fog", usually very shy gazelles calmly walked in a caravan, walking between people and camels. Sahara likes to be reminded of herself unexpectedly. It happens that the caravan sets off when nothing foretells bad weather. The air is still clean and calm, but some strange heaviness is already spreading in it. Gradually, the sky on the horizon begins to turn pink, then takes on a purple hue. It is somewhere far away that the wind has picked up and drives the red sands of the desert towards the caravan. Soon, the cloudy sun barely breaks through the rapidly rushing sandy clouds. It becomes difficult to breathe, it seems that the sand has displaced the air and filled everything around. Hurricane winds rush at speeds up to hundreds of kilometers per hour. Sand burns, chokes, knocks down. Such a storm sometimes lasts a week, and woe to those whom it caught on the way. But if the weather is calm in the Sahara and the sky is not covered with wind-blown dust, it is difficult to find a more beautiful sight than a sunset in the desert. Perhaps only the aurora borealis makes a greater impression on the traveler. The sky in the rays of the setting sun each time strikes with a new combination of shades - it is both blood-red and pink-pearl, imperceptibly merging with pale blue. All this is piled up on the horizon in several floors, it burns and sparkles, growing into some kind of bizarre, fabulous forms, and then gradually fades away. Then, almost instantly, an absolutely black night sets in, the darkness of which even the bright southern stars cannot dispel. Of course, the most desirable and most picturesque places in the Sahara are the oases. The Algerian oasis of El Ouedd lies in the golden yellow sands of the Great East Erg. An asphalt highway connects it with the outside world, but it only appears as such on the map. In many places, the wide roadbed is thoroughly covered with sand. A good two-thirds of the telegraph poles are buried in it, and teams of workers with shovels and whisks are constantly raking drifts, first in one area, then in another. After all, the wind blows here all year round. And even a weak breeze, tearing off the tops of sandy dune hills, steadily moves sandy waves from place to place. With a strong wind, traffic on the roads of the desert sometimes stops completely, and not for one day. Like all oases of the Sahara, El Ouedd is surrounded by a palm grove. Date palms are the basis of life for the locals. In other oases, in order to give them water to drink, irrigation systems are arranged, but in El Ouedd it is easier. In the dry bed of the river flowing through the oasis, they dig deep funnel holes and plant palm trees in them. Water always flows under the bed at a depth of five or six meters, so that the roots of palm trees planted in this way easily reach the level of the underground stream, and they do not need irrigation. In each funnel grows from fifty to one hundred palm trees. The sinkholes are arranged in rows along the channel, and they are all threatened by a common enemy - sand. To prevent the slopes from sliding, the edges of the funnels are strengthened with wattle from palm branches, but the sand still seeps down. You have to take it all year round on donkeys or carry it on yourself in baskets. In the summer, in the heat, this hard work can only be done at night, by the light of torches or in the glow of the full moon. Water wells are also dug in these funnels. It is enough for drinking and for watering gardens. Camel droppings serve as fertilizer. Dates and camel milk are the main food of fellah farmers. A valuable nutmeg variety of dates is sold and even exported to Europe. The capital of the Algerian Sahara - the oasis of Ouargla - differs from other oases in that it has ... a real lake. This tiny town in the middle of the desert has a reservoir of four hundred hectares, huge by local standards. It was formed from water discharged from palm plantations after irrigation. Water is always supplied to the fields and date groves in excess, otherwise evaporation will lead to the accumulation of salts in the soil. Excess water, along with salts, is discharged into a depression next to the oasis. This is how artificial lakes appear in the Sahara. True, most of them are not as large as in Ouargla, and do not withstand a deadly struggle with sand and sun. Most often, these are just swampy depressions, the surface of which is covered with a dense, transparent, like glass, layer of salt. But oases in the Sahara are rare, and one has to get from one "island of life" to another along the endless roads of the desert, overcoming the heat of the sun, hot wind, dust and ... the temptation to turn off the road. Such a temptation often arises among travelers both on ancient caravan trails and on modern paved highways in these inhospitable lands. When the desired outlines of an oasis appear on the horizon in front of a traveler exhausted by a long journey, the Arab guide only shakes his head negatively. He knows that there are still tens of kilometers to the oasis under the scorching sun, and what the traveler sees "with his own eyes" is just a mirage. This optical illusion sometimes misleads even experienced people. Experienced travelers who have passed through the sands on more than one expeditionary route and have studied the desert for more than one year have also become victims of mirages. When you see palm groves and a lake, white clay houses and a mosque with a high minaret at a short distance, it is hard to make yourself believe that in reality they are several hundred kilometers away. Experienced caravan guides sometimes fell under the power of a mirage. One day, sixty people and ninety camels died in the desert, following a mirage that carried them sixty kilometers away from the well. In ancient times, travelers, in order to make sure whether it was a mirage in front of them or reality, kindled a fire. If even a small breeze blew in the desert, then the smoke creeping along the ground quickly dispersed the mirage. For many caravan routes, maps have been drawn up, which indicate places where mirages are often found. These maps even mark what exactly is seen in one place or another: wells, oases, palm groves, mountain ranges, and so on. And yet, in our time, when two modern highways ran through the great desert from north to south, when multi-colored autocaravans of the Paris-Dakar rally rush through it every year, and artesian wells drilled along the roads allow, in case of anything, to walk to the nearest source of water, the Sahara gradually passes to be that fatal place that European travelers feared more than the Arctic snows and the Amazonian jungle. Increasingly, inquisitive tourists, fed up with beach idleness and contemplation of the ruins of Carthage and other picturesque ruins, go by car or on a camel into the depths of this unique region of the planet to inhale a sip of the night wind on the slopes of Ahaggar, hear the rustle of palm crowns in the green coolness of the oasis, see the graceful run gazelles and admire the colors of the Sahara sunsets. And next to their caravan, the mysterious guardians of the peace of this hot, but beautiful land, dusty-gray, whirled by the wind, "desert genies" are running along the roadside with a quiet rustle. Author: B.Wagner
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