The sand dunes scattered in the Kumtag Desert in Dunhuang city make a distinctive sound when the wind blows through them.
Singing Sand Dunes in Dunhuang City. Photo: Lonely Planet
The singing dunes vary in size, with the tallest reaching 1,715 meters. Up close, they even have rich colors, ranging from yellow and white to green and black. While not unique to Dunhuang, the singing dunes in this region lie along the Silk Road, a vital trade route between Central Asia and Europe that continued for 1,500 years from the 2nd century BC.
The quality of the sand grains is just one of the factors that make a dune sing. Composed of a range of fine to medium sized grains, the size of the grains allows them to move and interact better. Combined with their shape, this creates a different resonance and frequency. Rounder, smoother grains produce a better sound. The shape of the dune also contributes to the sound. The slope of the dune affects how well the grains interact. Additionally, the right wind conditions are needed to blow the grains enough to produce sound. In strong winds, dunes produce a loud rumble, but in light winds, the sound is more melodious.
The surrounding structure also plays a role in generating and amplifying the sound, as hills create air currents that concentrate the wind in specific areas around the dune. When the wind blows the sand grains, friction occurs, causing the sand to vibrate, creating sound. Air holes between the sand grains can act as resonators, amplifying the sound. Arid climates are another factor in sound production. That’s why singing dunes are found in desert environments. Low humidity increases the friction between the sand grains, creating sound as they rub against each other. The combination of sand grain vibration, resonance, and air holes leads to the characteristic sound of a dune.
In addition to Dunhuang, singing dunes have been found in Inner Mongolia, Xinjiang, Gansu, and Ningxia. Similar dunes are found in Namibia’s Namib Desert and California’s Mojave Desert. Researchers closely monitor the dunes for signs of erosion and traffic. Despite the large number of tourists, the desert winds blow through the dunes every night, erasing all footprints, leaving the dunes pristine.
An Khang (By IFL Science )
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