Scientists reveal mystery around Earth’s largest star sand dunes. Here’s what they found

The researchers, in a groundbreaking investigation, have finally found the estimated age of the largest sand dunes in the world.

As reported by the BBC, these dunes known as ‘Star dunes’ or ‘pyramid dunes’ have been named on the basis of their distinctive shapes and have hundreds of metres of height. 

These deserts are spread across lands which includes sand seas of Africa, Arabia, China, and North America and are also found on the surface of Mars and Saturn.

Prof Geoff Duller of the Department of Geography and Earth Sciences at Aberystwyth said, ”They are extraordinary things, one of the natural wonders of the world. From the ground, they look like pyramids but from the air, you see a peak and radiating off it in three or four directions these arms make them look like stars.”

Now, in a first, the researchers have found the estimated age of one such star dune, known as Lala Lallia in Morocco.

 A technique, known as luminescence, was used to find out the age of the star dune. The method was used to calculate when the grains of sand were exposed to daylight last time. 

To carry out the study, the team of researchers from the United Kingdom, travelled to the southeast of Morocco, to examine the 100-metre-high and 700-metre-wide Lala Lallia. 

The researchers found the that dune’s base was nearly 13,000 years old, however, the structure’s upper part was formed in the last 1,000 years or so, as reported in The Guardian. 

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It took more than 900 years for the dune to get formed and it grew by 6,400 metric tonnes every year. After the dune’s initial formation, its growth stopped for nearly 8,000 years and then again quickly expanded in the last several thousand years.

According to the researchers, the recent findings support the theory that the formation of the star dune was accompanied by a change in wind direction.

Explaining the formation of star dunes, Birkbeck University’s and fellow study co-author Charlie Bristow said, “Star dunes are formed in areas with complex wind regimes, which means winds blowing from different directions, and net sand accumulation, points within the desert where big piles of sand can be blown around to form giant dunes. They form extraordinary and awe-inspiring landscapes… From the ground, they can be intimidating, mobile mountains of sand.”

(With inputs from agencies)