Singing sands

Mystical and magical is how Estonian tourism websites describe two sandy beaches in Estonia that make melodic sounds in the right conditions. One is Kauksi at the peipsijärv or lake Peipus, of which The Sun says, “the European beach Brits won’t have heard of”. Not unless you walk on it, perhaps, and even then.

We try out Laulasmaa beach at Lahepere (family bay) in northwestern Estonia on a grey afternoon, and not a squeak, a whistle or a sigh. It’s a good swimming beach, a rarity along the Baltic coast or Estonian lakes with their largely reed-lined and muddy shores, and I find out later my research has fallen short.

Laulasmaa beach

“The name Laulasmaa literally translates to ‘singing land’, a reference to the melodic sound created by the wind as it sweeps across the sandy dunes and through the pine forests,” says Places and Things to do.

More searching on this strange phenomenon: some dunes in certain deserts around the world are described as barking and roaring when the wind blows across them, at up to an ear-bashing 105 decibels.

Example dune sites are Altyn-Emel national park in Kazakhstan, Dunhuang at the edge of the Taklamakan desert in China, the Mojave desert in California, US, and south Sinai in Egypt. Beaches are less noisy in the wind, because there is less shifting of sand to make a sound.

On what makes the sand sing, the experts are agreed. The grains must be perfectly round, 0.1 - 0.5 millimetres in diameter, of the same size, made of silica or quartz, and have the correct humidity, ie pretty dry or close to it.

Strangely, the physics is less understood. You’d think someone would have done a university thesis on it, like the studies on why shoe-laces come undone, or why computer cables end up tied in knots.

What seems to happen is that the sand as described is tightly compacted, but not too tight. If you walk on this sand with a slight amount of moisture in it, but not too much, the sand grains move past each other on shear planes, making a distinctive sound. Wind on sand dunes compounds the effect; sand avalanching down the faces sings on a much larger scale than a single footprint.  

Back to Laulasmaa, another question is where the quartz sand comes from in a northern Estonian geology of Ordovician limestone. A small quantity of mineral impurities is the answer, together with aeons of weathering of the slightly soluble calcium and magnesium carbonate rocks.

To give the last word to Maria Rehman of Places and Things to do: “Imagine waking up to the sound of waves gently lapping against the shore, the scent of pine trees filling the air, and the serene beauty of the Baltic Sea stretching out before you.”

And, “The beaches here are pristine, with fine, white sand that stretches for miles, making it a perfect spot for a relaxing day by the sea. The surrounding pine forests are ideal for hiking and cycling, offering well-marked trails that lead you through the lush greenery and provide breathtaking views of the coastline.”