Bulk analysis of underwater sound spectra from vibratory pile driving of cylindrical steel piles in coastal waters

Abstract

Vibratory pile driving is a common means of pile installation in both near-shore and offshore environments. Spectral knowledge of the noise produced by this activity is crucial in modeling and assessing the impacts to aquatic species. With the goal of providing generic representative spectra to better inform propagation modeling and related impacts, approximately 80 near-pile measurements of vibratory pile driving of cylindrical steel piles from more than 19 hydroacoustic reports were analyzed. Included pile diameters range from 24–48 inches and all measurements were of activities in U.S. coastal waters. Results include representative spectra based on the mean and median spectra binned by pile size and the presence of noise mitigation systems, an examination of the variation in the data, marine mammal hearing group weighted spectra, broadband sound pressure levels, and comparisons with general knowledge of vibratory pile driving spectra characteristics in previous literature. Finally, data availability and larger efforts aimed at a comprehensive underwater pile driving acoustic spectral database are discussed.