Whitewater acoustic sources and wavefields

Whitewater features are important and continuous sources of local acoustic noise with implications in hydrology, geophysics, and ecology. However, their sources and wavefields have received scarce formal study, and we know little about how sound generation varies spatially along hydraulic jumps or how sound characteristics vary with angle and distance from whitewater features. To address this knowledge gap, we recorded several whitewater features with dense networks of infrasound and audible-sound recorders, including the novel use of an acoustic camera for real-time visualization of audible-sound sources, and analyze them to reveal spatial characteristics of acoustic sources and radiation patterns. Analyses include new methods of noise reduction that are appropriate for river sounds and other types of low-amplitude continuous tremor. Results of this study will help inform site selection for acoustic gauging and geophysical monitoring, and will contribute to predicting effects of whitewater soundscapes on nearby wildlife and humans.