These mysterious circles in Namibia have kept scientists wondering for half a century – NRK Trøndelag

Dronebilde av bil som kjører gjennom naturreservatet kalt NamibRand i Afrika.

The Namib Desert is located in the western part of Namibia in Africa. It is considered the oldest in the world. At least 80 million years old.

As part of this desert, a little far away, you find Very special Terrain.

Here, grass grows, which more or less clings to the sand with the help of the little rain that the area provides.

But it is not the grass itself that creates the surprising – it is rather the shape of the landscape.

Small and large circles are found very close to each other in the sand. Together, these make up a completely distinct style.

mysterious circles

The sheer growth of grass in this area is impressive.

And very mysterious.

The landscape is marked by millions of strange circles. Each of them is devoid of grass or other plants.

The diameter ranges from 2-10 meters, and the circles are separated by about 10 meters.

Why is it like that?

This question has occupied researchers for nearly half a century.

Scientists examined dead grass from mysterious circles in the Namib Desert.

Among other things, researchers examined dead grass from places around mysterious circles in the Namib Desert.

Photo: Dr. Stefan Getzen

Two well-known theories

For a long time, scientists have tried to demystify circles in Namibia. So far, two different theories have been considered:

One assumes that the rings are formed by The White Termite. Whereas the other theory is that the lawn organizes itself in this way, in order to make the best possible use of the available water.

Previous studies have given both theories a basis. But in 2016 something changed.

Then similar circles were discovered in Australia. But here scientists could not find a link to termites.

Now a new study Published in October this yeargiving more answers.

The grass died after ten days

In the new study, researchers examined grass and land in the Namib Desert before and after periods of rainfall.

They installed sensors to measure humidity.

The researchers then analyzed the differences in waterproofing between the inside and outside the circuits. They did this in several places.

The results showed that after about ten days of the rainy period, the grass inside the circles began to die. There must be little growth there at all.

After 20 days everything is dead.

But the grass outside was green and lush.

Researcher and co-author of the new study, Sönke Holch, downloaded grass data from the desert in February 2021.

Researcher and co-author of the new study, Sönke Holch, downloaded grass data from the desert in February 2021.

Photo: Dr. Stefan Getzen

important discovery

To understand what happened, the researchers examined the roots of the grass, among other things. Then they discovered something important.

Dr. Stefan Getzen and colleagues found that termites were excluded.

Explain why:

The lack of grass in the circles cannot be explained by termites. There is no biomass that insects can eat. We can prove that insects are not to blame, as the grass inside the circles dies immediately after it rains.

say that In a press release.

Less than ten millimeters of rain falls annually in the Namib Desert, which means there is very little life left in the area.

Incredible example

Moreover, the German researcher explains that the results are in agreement with previous studies: Water in the soil spread out quickly and horizontally in the sand, even at longer distances.

This is a great example ofecohydrological response.” Barren circles are created lockers This helps keep weeds at bay.

The findings may also have broader significance. They can contribute to a better understanding of similar ecosystems.

This kind of self-regulation appears to protect plants from drying out. And it’s a growing problem, explains Stefan Getzen.

By Bond Robertson

"Organizer. Social media geek. General communicator. Bacon scholar. Proud pop culture trailblazer."