'Singing' sand observed at a U.S. national park, listen here
Researchers estimate that there are only 30 sand dunes in the world that have the right grain size and dry conditions to create this phenomenon.
Great Sand Dunes National Park and Preserve in southern Colorado is home to the tallest sand dunes in North America, some of which are over 700 metres in height.
An impressive phenomenon was recently captured by the National Park Service - millions of grains of sand tumbled down and created a haunting ‘song.’
Scientists have dubbed this occurrence as ‘singing’ sand, which happens when sand grains tumble down the slopes of certain sand dunes, typically during an avalanche process.
“An audible vibration can develop when sufficient amounts of sand avalanche and compress the air within the moving sand,” says the National Park Service.
“Just as our own voices are made by air moving through vibrating vocal chords, a humming sound is made at Great Sand Dunes as air is pushed through millions of tumbling sand grains during an avalanche. Avalanches occur naturally during storms, but can also be created by people pushing sand down a dune face.”
Alpine tundra, forests, massive dunes, grasslands, and wetlands are all protected as elements of the Great Sand Dunes natural system. Credit: National Park Service
Researchers from the University of France found that the size of the sand grains creates the sound, as opposed to the motion of the sand falling, as reported by CBC. While the sound of one or a few grains colliding would be inaudible, millions of collisions create the sound that can be heard from several kilometres away.
“Singing sand dunes are rare — it's estimated that there are approximately 30 dunes around the world that have the right grain size and dry conditions — each with its own distinctive pitch,” the researchers state.
