Approximately 14% of our planet’s land surface is covered in desert. Often, the desert is compared to an ocean of sand, an infinite ocean of emptiness and oblivion.
It is not possible to imagine the amount of sand in this immense sandy plain which extends to the horizon.
But it is possible to measure the depth of the sand layer by digging a hole.
The thickness of sand varies. It depends on the wind which can transport tons of sand from one place to another, forming dunes.
Therefore, the quantity of sand layer can change depending on the geographical location.
In deserts, we also find stony places called solonchaks, where there is no sand at all.
The average depth of the sandy area reaches 100 to 200 meters.
Thus, in the Sahara, the layer of sand is 150 meters, but in the Namibian desert it reaches up to 400 meters.
In the past, several areas of the deserts were fertile lands and sometimes covered with water.
But after the geomorphogenesis formations, thousands of years ago, everything changed and the fertile lands turned into desert.
Under the sands are hidden different layers composed of stones or earth which hide certain secrets.
So, in the Wadi Al-Hitan desert in Egypt, under the depth of the sand, archaeologists discovered gigantic skeletons of whales.
This means that sea creatures once swam here.
