Sand dunes can sing, and they do it loudly!

Sand dunes can sing, and they do it loudly!

Imagine traveling across wide empty desert dunes when suddenly a loud low-pitch rumble and a roar fill the air. How would you explain it?  Early explorer Marco Polo suspected evil spirits were at play. Charles Darwin stated that he could not explain it. I haven’t yet experienced singing sand myself, but I’ll follow the expert instructions with hope next time at a sand dune. 

If the conditions are right, desert dunes can sing or hum. It sounds like the lower notes on a cello played again and again. Others describe it as “dozens of drums played at the same time.” You can hear the natural sound phenomenon up to 10 km/6 miles away.

Dunes at different locations sing in different tunes

Researchers recording dunes found that a Moroccan dune sang a low G-sharp, while an Omani dune let out nine different tones. Looking at grain size, the Moroccan grains were similar in size and shape, while the Omani sands differed. Drier sand grains gave a deeper sound than damp ones.
Scientists still investigate and debate the exact science of how dunes sing. The tune depends on grain size, shape, and temperature. The squeak that some sand makes when walking on it is something else. I’ll save that for another post. 

Singing dunes are rare. There are only about 40 sites worldwide. Agreed is that sand avalanching, set off by wind or by someone walking near the top of the dune, sets off the sound. The loud noise is the sound of sand grains bumping into each other. The human ear can not detect one single sand grain bumping into another. But a billion grains colliding together will roar. Strength in numbers!

If you’re close to a dune and want to hear it sing, do as the researchers: 1. Climb up to the top of a dune on a dry day.
2. Once at the top, sit down and spread your legs wide as if stretching after exercising.
3. Start scooting down, trying to create a small sand avalanche.
Your best chance is at a dune well known for singing, but who knows, you might find an unknown singing site. Of course, you can always pick a favorite song and sing it yourself if you don’t!