Washington, D.C., Oct. 27, 2015 -- Avalanching sand from dune faces in Death Valley National Park and the Mojave Desert can trigger loud, rumbling "booming" or short bursts of "burping" sounds -- behaving as a perfectly tuned musical instrument.
This sound is persistent and the dunes "sing" in frequencies ranging from 70 to 105 Hertz, with higher harmonics. Prior to the onset of a nearly monotone booming, burps of sound of smaller amplitude occur over a significantly broader span of frequencies.