2024-03-04 04:33:08
Image source: C Bristow
caption,
The star sand dunes of Lala Lallia in Morocco are 100 meters high.
4 hours ago
We finally know the age of the world’s largest and most complex sand dune. This is the first time in history.
Star dunes or pyramid dunes are named following the unique shape of the sand and can be hundreds of meters high.
sand dunes like this Found in Africa, Asia, and North America. including on Mars But experts have never clearly determined that When did these sand dunes form?
Until today, scientists have discovered that A sand dune called “Lala Lallia” located in Morocco. Originated 13,000 years ago
The star sand dunes are formed by winds hitting from two directions.
Professor Geoff Daller from Aberystwyth University which published research together with Professor Charles Bristow, from the University of Birkbeck, said knowing the age of the dunes might help scientists understand winds and climate patterns in the past.
Lala Lallia is a name from the language of the local Amazigh tribe, meaning This sand dune is located in the Erg Chebbi desert in southeastern Morocco. It has a height of 100 meters and a width of 700 meters.
The research results found that After forming early dunes, the Lala Lallia dunes stopped expanding for 8,000 years, then expanded rapidly in size over the past few millennia.
Scientists can usually pinpoint the emergence of deserts on Earth from geological history. But the Star Dune has never been determined in what period it occurred. Until today
Prof Daller explains that this may be because the dunes are very large. Until the experts didn’t notice that That’s a unique sand dune.
But “discovering the age of this sand dune It will shock many people. Because it shows how quickly giant sand dunes can form. And it moves across the desert at regarding 50 centimeters per year.”
Scientists use a technique called Determination of age by light-emitting method (luminescence dating) to determine the age of the star dunes By checking that When was the last time a grain of sand was exposed to sunlight?
Image source: C Bristow
Scientists took sand samples from the depths of the dunes. Come check it out in the laboratory. By using a dull red light. Similar to traditional compression
Prof. Daller explains that the mineral scales in the sand are like They are called “rechargeable batteries” because they store energy from natural radioactivity in the environment. within the sand crystal
The longer that part of sand is buried underground, the more likely it will be. It means that It will only be exposed to more radioactivity. This causes a higher accumulation of energy in the sand grains.
Then when the sand seeds were examined in the laboratory. It will release energy in the form of light. This allowed scientists to calculate its age.
“In our dark laboratory. We saw the light that the sand gave off. The brighter the light, It means that the sand grains are very old,” Prof. Daller said.
Other sand samples that scientists have also examined include: Star sand dunes in the US state of Colorado It is the highest sand dune in the United States. It has a height of 225 meters from its base to its highest point.
Prof. Daller explains that climbing these sand dunes It’s a very difficult job. “Because once you take two steps up, you take one step down, but it’s worth it. The pictures from the top of the sand dunes are beautiful.”
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