Friday, 14 March 2008
After reading about the phenomenon many times, I finally heard it: singing sand!
I found this recording on Sound of the seismic, a site made by John N Louie. Here can also other interesting sounds be heard, with their technical explanation. The text that was given with this singing sand was this:
“On Oct. 4, 1999 a crew from the UNR Geological Sciences program met Dr. Franco Nori of the University of Michigan, Dr. Nick Lancaster of the Desert Research Institute, and documentary filmmaker Brando Quilici at Sand Mountain about 90 minutes east of Reno. Dr. Nori had written an article for the Sept. 1997 Scientific American about booming and squeaking sand dunes; Dr. Lancaster had spent time tracking sand-dune movements in sub-Saharan Africa. Brando Quilici was preparing a segment on Sand Mountain for a video titled Burning Sands, which played on the Discovery Channel in 2000. Louie’s professional seismic recording equipment was in repair at the time, so he recorded two geophones wired into the sound input of his laptop (as shown for about 1 second in Burning Sands). The left channel of the recording below is from a horizontal geophone (sensitive to horizontal particle motion) at the base of the dune’s slip face. The right channel is from a vertical geophone at the dune crest. This recording in not speeded up, and you can hear the crew conversing, through the geophones.
The recording begins with Dr. Nori plowing sand down the slip face near the crest (strong in the right ear), and proceeds as he sleds down the face past the lower geophone 100 feet away (strong in the left ear). Starting at about 45 seconds into the recording you will hear the booming strongly. It is a strong resonance at about 70 Hz frequency. Good headphones or a subwoofer are necessary to hear this low frequency well.”
This small sound clip does not satisfy me completely, of course. If you read some of the descriptions of what can be heard in the desert, like here for example, you want at least a greatest hits CD of Singing Sand.
Here is today’s soundtrack, The Four Dimensions with Sand surfing.