Star dunes

Scientists unveiled the first in-depth study of a star dune, revealing the internal structure of these geological features and showing how long it took for one of them to form.

• The study reveals the internal structure and formation process of star dunes, focusing on Lala Lallia in the Sahara Desert.

About Star dune:

• Star dunes are vaguely pyramid-shaped sand formations, reaching heights of up to about 1,000 feet (300 meters).
• On the ground, star dunes resemble pyramids, but when viewed from above, a central peak is visible, extending arms in three or four directions, creating a star-like appearance.
• Star dunes constitute nearly 10% of Earth’s desert dunes, towering over other types like barchan and linear dunes.
• They are found in Africa, Asia, North America, and on Mars and Saturn’s moon Titan.
• Star dunes are formed in areas with complex wind regimes, which means winds blowing from different directions.
• They also require net sand accumulation, which is when large piles of sand can be blown around to form giant dunes.
• The largest star dunes on Earth are located in the Badain Jaran desert in western China.
• These distinct dunes are also present in various places worldwide, such as the Namib Sand Sea in Namibia, expansive sand seas in Algeria like the Grand Erg Oriental and Grand Erg Occidental, and the Rub’ al Khali in Saudi Arabia.
  • Notably, in North America, Great Sand Dunes National Park in Colorado features a series of these unique dunes.
• While many star dunes are known at present, only a single ancient one has been found preserved as sandstone in the geological record, dating to about 250 million years ago, in Scotland.

About Lala Lallia star dune:

• Lala Lallia, which translates to “highest sacred point” in the local Berber language, is located within the Sahara Desert.
• It is situated in a small sand sea named Erg Chebbi, approximately 3 miles (5 km) from the town of Merzouga, near the border with Algeria.

Ref:Source