Singing Sand Dunes Explained

nat geo ^ | October 31, 2012 | Shannon Fischer

[BenLurkin]

When Marco Polo heard it in China, he suspected evil spirits. When residents of Copiapo, Chile, heard it emanating from a sandy hill, they dubbed the peak El Bramador, for its roars and bellows.

Scientists today call it "singing sand," but they're all referring to the same thing: As sand grains shuffle down the slopes of certain sand dunes, they produce a deep, groaning hum that reverberates for miles.

But how these dunes produce this "music" remains a much debated mystery. Another vexing question is why different dunes sing different tunes—and how can some even sing more than one note at a time?

A trio of Parisian biophysicists think they know the answer. It's not necessarily the motion of the sandy ocean that determines the pitch of the note—it's the size of the grains, though why the size matters is still unknown.

The researchers first tracked down a pair of singing dunes, one in Morocco, the other in Oman. Working literally by the seat of their pants, they scooted feet-first down the hills to trigger the avalanches. They found that, while the Moroccan hill moaned at a steady 105 Hz—or a low G sharp—the Omani dunes sang a nine-note blare that ranged from 90 to 150 Hz.

[Defiant]

How do i get a research grant like that, so i can travel the world and slide down sand dunes?

[martin_fierro]

As sand grains shuffle down the slopes of certain sand dunes, they produce a deep, groaning hum that reverberates for miles.

My puns have that effect.

[Dr. Bogus Pachysandra]

I hate playing in G#!
Scooted down the Sleeping Bear Sand Dunes many times,,,, never heard a note!

[uglybiker]

...though why the size matters is still unknown.

Ask your girlfriend.

[Harold Shea]

The scooting there is probably better than at

Indiana Dunes..I must have done it wrong and

the wife just shook her head at me

Love those places

[mikrofon]

I can't explain the singers they get there...

[rfp1234]

Reminds me of the Singing Bush from “The Three Amigos”.
(When Steve Martin was still funny.)

[Dr. Bogus Pachysandra]

The Sleeping Bear Sand Dunes are amazing, and the Glen Lake, Michigan area is a wonderful place to vacation! When I was a kid, they had a car service that gave you a tour of the Dunes. 1954 , red and white Olds convertibles with balloon tires.

[Uncle Chip]

Yep — heard a lot of songs and lost a lot of money at those Sand Dunes??? And I didn’t have to go to Chile to do it either.