Desert booming can be heard after a natural slumping
event or during a sand avalanche generated by humans
sliding down the slip face of a large dune. The sound is
remarkable because it is composed of one dominant audible
frequency (70 to 105 Hz) plus several higher harmonics.
This study challenges earlier reports that the dunes’
frequency is a function of average grain size by
demonstrating through extensive field measurements that
the booming frequency results from a natural waveguide
associated with the dune. The booming frequency is fixed
by the depth of the surficial layer of dry loose sand that is
sandwiched between two regions of higher compressional
body wave velocity. This letter presents measurements of
the booming frequencies, compressional wave velocities,
depth of surficial layer, along with an analytical prediction
of the frequency based on constructive interference of
propagating waves generated by avalanching along the dune
surface
