Booming sand dunes
Oh my goodness, such a wonderful and amazing sound! (I found out about this from one of those YouTube accidents that happen when you travel out from the right hand side of YT.)
Sand dunes that sing, or roar or boom. Incredible!
Here is a first introduction to this amazing phenomenon. (The whole site, “Sonic Tourism” is worth exploring.)
According to Wiki, there are certain preconditions necessary for dunes to make such sounds:
- The sand grains have to be round and between 0.1 and 0.5 mm in diameter.
- The sand has to contain silica.
- The sand needs to be at a certain humidity.
Apparently, also according to Wiki, the most common frequency is around 450 Hz. (Wiki also provides a list of locations where you can find dunes that make this sound.)
Here is a link to the National Geographic that talks about the ideas that various researchers have about WHY this sound happens.
THIS site has several lovely videos of different singing dunes from around the world.
Here is a brief article at Physics.org on the topic. There is a link to an article in the journal Physics World, but you need a subscription to access it, as far as I can see.
This article provides a very good overview of these dunes. Apparently Marco Polo wrote about his encounters with them back in the 13th century: “[the dunes] at times fill the air with the sounds of all kinds of musical instruments, and also of drums and the clash of arms.”
This article also notes that: “In Arabic, the sound is called za’eeq al raml, or “shouting sand”, a name that aptly describes the noise’s startling loudness. Volumes can reach up to 115 decibels and be heard up to 10km away.” THAT sound I would like to hear!
Here is a great video that provides you with examples of the sounds, plus an update on the research into how this sound is created.
And here is ONE last video for your viewing enjoyment.