How was the desert formed?
the desert is, so to speak, a climatological facies of the surface. The only condition for form a desert it is drought: little rain, rapid, rare and short-lived rains. The climatological regions have slow passages between them.
It has long been known that the Sahara has not always been a desert. Several thousand years ago, from – 9000 BC, it was even a very green and humid region, where elephants, giraffes or hippos lived, as evidenced by prehistoric cave paintings.
the desert : definition It is a region of the globe characterized by a rainfall of less than 200 and often even 100 millimeters per year and where the population density is very low due to climatic conditions, according to the dictionary.
These traces, dated 110 years ago, testify to a time when the Sahara was very different from today. Indeed, the current desert was then covered with tropical vegetation and rivers: the Sahara was ” green “.
The recent history of the desertification of the Sahara has just been reconstructed thanks to sediments deposited at the bottom of a Chadian lake. The process spanned several thousand years. Larger than Australia with its 8 million square kilometres, the Sahara has not always been the largest hot desert on the planet.
Of the 8 or 9 million km2 of desert in the Sahara, the equivalent of the combined area of Australia and New Zealand, an area of about 2.8 million km2 (31% of the total area) receives average annual precipitation less than or equal to 10 mm and nearly 1.5…
This geographical area has been subject to glacial/interglacial cycles for 2.7 million years, changing from verdant to desert every year. About 40,000 years ago, there were large lakes in the Sahara, then populated by semi-nomads. 18,000 years ago, the Sahara was hyperarid.
Rich in many mineral resources that have helped bring some countries into globalization, the Sahara desert still contains large quantities of hydrocarbons that today arouse much desire.