The Sahara Desert is the most famous desert in the world. However, it is she who keeps many secrets that scientists are trying to uncover.
This information was reported by Ukr.media, reports URA-Inform.
Who would have thought — but about six thousand years ago the Sahara was green and blooming.
Sand in the Sahara is distributed unevenly. In large areas, a layer of sand accumulates to a few centimeters. But most people associate the Sahara Desert with dunes. And there is much more sand in them and it goes deeper.
Dunes account for only 15% of the desert territory. The sand depth of most dunes ranges from 20 to 50 meters. The largest record-breaking dune stretches 300 meters deep.
Beneath the sand layer there are predominantly three types of surfaces: clay, lime-gypsum layers, pebbles and rocks. The soil layers here are scarce. The harsh climate with sharp temperature changes destroys rocks, gradually turning them into new sand.
Where does sand come from in deserts
Magic dunes, golden hills and mysterious oxams — it's a huge mass of sand. At the same time, Sahara — one of the most dangerous places on Earth. The air temperature in the desert can reach +50 degrees. Add to this the lack of water and food. It is very difficult to survive here.
Sand — it is sedimentary rock that has been reduced to a loose mixture of grains of sand. Sand grains are not all the same; they have many different sizes and shapes. Sand is formed from rocks by the action of wind, water and temperature changes.
Small mineral particles such as quartz, feldspars and mica are separated from the rocks and carried by the wind. Therefore, sand in the Sahara can change its color from white to red or even black, depending on the composition of the minerals.
The wind carrying sand lifts it from the surface of the soil and transports it over long distances. In desert regions, strong winds often blow, which pick up sand and transport it to new places.
As a result of such processes, dunes are formed — sandy hills stretching towards the prevailing winds. Sand dunes can reach enormous sizes — up to several hundred meters in height and up to tens of kilometers in length.
The dunes are constantly moving and changing their shape due to the wind that blows from different directions.
Recall that it was previously reported that the strangest volcano on Earth: scientists have shown that it erupts instead of lava (video).
