7. The Desert's Singing Dunes
The occurrence of "singing," or "booming," dunes is among the most odd events in the Namib Desert. These dunes generate a powerful, resonant humming sound under particular conditions that is audible miles away. When the wind moves sand particles down the slip face of the dune, this acoustic phenomena results from vibrations producing sound waves. Sand particle size and sand grain movement speed determine the sound frequency. One of the most unusual natural concerts in the desert, scientists have found that only some dunes with the proper sand composition and moisture content may create this enigmatic music.
