image source, Getty Images
Scientists have not reached a consensus about the origin of these formations.
- Author, Writing
- Role, BBC News World
Members of the Himba tribe in Namibia have told for generations how the dragon’s powerful exhalation left traces in the land.
Vegetation no longer grew in those semicircular marks. All that was left was bare land surrounded by grass common, found in the arid terrain of South-Eastern Africa.
In the 1970s, an environmentalist Ken Tinley He concluded that these areas of land resembled the famous mushroom rings found in Europe and named them “fairytale circles”.
According to Tinley, they may have been caused by the presence of termites.
But until today these land formations are remain a mystery. For years, scientists have debated what causes them and have not reached a consensus.
Now, new research has added another ingredient to the debate: there aren’t just fairy circles in southwest Africa or northwest Australia, as previously believed.
“From space, with the help of a model based on artificial intelligence, we found dry areas of the world hundreds of places with vegetation patterns equal to fairy circles it has never been described before,” Spanish scientist Emilio Guirado explains to BBC Mundo.
image source, E. Guirado and others
New research has found fairy circles beyond Nambia, in the Sahel, Western Sahara and the Horn of Africa.
A researcher from the University of Alicante (Spain) led a study that reveals that fairy circles are present at a minimum 15 countries from three continents.
Although their research did not focus on solving the origin of these formations, the data provided provides information that may help find an answer.
The debate of years
image source, E. Guirado and others
Fairy circles have been studied in two areas: south-west Africa and north-west Australia.
Despite their name, fairy circles are usually formations hexagonal on the ground in which no vegetation grows in its interior, but in all or most of its surroundings.
After Tinley’s investigation in the 1970s, the scientific discussion of the origin of fairy circles shifted towards two main theories.
One was raised in 2013 by a German biologist Norbert Jürgenswho concluded after decades of research that what causes the formation of fairy circles are sand termites.
According to Jürgens, these insects eat the roots of vegetation that begins to grow after rain, which leaves a pool of water in the subsoil and allows it to survive.
“Termites are social insects that control their territory, where they have water and food, and the colony defends its territory against its neighbors, sometimes very aggressively,” Jürgens explained to BBC Mundo in 2016.
The German biologist said it was a “system of competition between colonies”, a theory he was “absolutely confident” and which he assured many of his colleagues had confirmed.
Almost in parallel, a German ecologist Stephan Getzin and Israeli physicist Ehud Meron came together to investigate the fairy circles of Australia and proposed that what explains their origin is self-organization theory.
image source, Getty Images
The fairy circles were seen by the Himba people long before they were documented by scientists.
Nature, Meron explained to BBC Mundo after the study was published in 2016, copes with the lack of water with this phenomenon: “By organizing the surrounding vegetation in rings, they benefit from an additional source of water as rain on the glades in the field finds its way through different water transport mechanisms.”
“In Australia, the mechanism involves the flow of water over land, while in Namibia it involves the diffusion of stored water,” he said.
Getzin and Meron dismissed Jürgens’ theory, saying that there were no termites in the fairy circles they studied in northwestern Australia.
In this regard, Jürgens said that his colleagues did not dig far enough to find them.
What does the new research say?
The research of Emilio Guirado’s team went beyond finding the cause that fairy circles should perform atlas where these formations are located.
The scientist explained that they used two models of artificial intelligence with which they found hundreds of places with fairy circles in the arid regions of the world – which represent 41% of the earth’s surface.
image source, E. Guirado and others
Fairy circles have been detected in 15 countries on three continents.
They analyzed some “predictors”, such as climatic, soil and environmental factorsand found that fairy circles exist in those places where these variables are stable. Especially where the soil is sandy.
“We analyzed hundreds of thousands of images to discover hundreds of vegetation patterns, such as fairy circles in the world’s arid regions. This process took just over a month on a supercomputer with 4 graphics processing units (GPUs),” explains Guirado.
With the help of two artificial intelligence models, they searched 600,000 satellite images from world map services such as Google Earth, Bing Maps or Mapbox to find the highest resolution terrain images.
image source, E. Guirado and others
The study located one of the largest concentrations of fairy circles in Australia.
This helped to get a clearer picture of those dry spots on Earth where fairy circles are present.
As a result, they found 263 points on the planet where there are fairy circles, placed in 15 countries in Africa, Asia and Oceania.
Areas where they have been found include the Sahel, Western Sahara, Horn of Africa, Madagascar, Southwest Asia, and Central Australia.
When asked if his research provides any explanation for the origin of these patterns, the Spanish scientist replies that it remains unknown and neither excludes nor supports the hypotheses that have been raised.
But it is clear that this is a phenomenon of arid countries, so it would be almost impossible to see them outside them: “Theoretically, in places where there is more precipitation, the circles would close,” says Guirado.
image source, E. Guirado and others
Fairy circles in Asia were not known until now.
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