Singing sand

From Wikipedia, the free encyclopedia

It has been suggested that Singing Sand Dunes be merged into this article or section. (Discuss)

Singing Sand Dune
Location	Altyn-Emel National Park, Almaty Province, Kazakhstan
Coordinates	43°51′53″N 78°34′0″E / 43.86472, 78.56667

Singing sand, whistling sand or barking sand is sand that produces sounds of either high or low frequency under pressure. The sound emission is usually triggered by wind passing over dunes or by walking on the sand. The sound is generated by shear stress.

Certain conditions have to come together to create singing sand:

1. The sand grains have to be round and between 0.1 and 0.5 mm in diameter
2. The sand has to contain silica
3. The sand needs to be a certain humidity

The most common frequency emitted seems to be close to 450 Hz.

Importantly, there are still scientific controversies on the details of the singing sand mechanism (see references). It has been proposed that the sound frequency is controlled by the shear rate. Others have suggested that the frequency of vibration is related to the thickness of the dry surface layer of sand. The sound waves bounce back and forth between the surface of the dune and the surface of the moist layer creating a resonance that increases the sound's volume.

Other sounds that can be emitted by sand have been described as "roaring" or "booming".

Examples of singing sand dunes include California's Kelso Dunes and Eureka Dunes, sugar sand beaches and Warren Dunes in southwestern Michigan, Sand Mountain in Nevada, the Booming Dunes in the Namib Desert, Africa, Porth Oer (also known as Whistling Sands) near Aberdaron in Wales, Indiana Dunes in Indiana, in some beaches in Hawaii, and Singing Beach in Manchester-by-the-Sea, Massachusetts.

[edit] See also

• Singing Sand Dunes
• Bouncing stones

[edit] External links

• Booming sand

[edit] References