Three-dimensional anthropogenic underwater noise modeling in an Arctic fjord for acoustic risk assessment.

Sea-ice covering is drastically declining in the Arctic, opening new maritime routes and thus introducing underwater noise pollution in nearly pristine acoustic environments. Evaluating underwater noise pollution requires good acoustic propagation modeling to predict sound exposure levels. However, underwater noise modeling for acoustic risk assessments has often been carried out using simplistic propagation models, which approximate a 3D propagation in several planes (Nx2D), instead of using full 3D propagation models. However, Nx2D propagation models are impractical for winding geography and steep bathymetry as found in Arctic fjords. The purpose of this study is to estimate disturbance and masking effects on Arctic animal species from shipping noises, modeled through a traditional Nx2D BELLHOP model and a full 3D BELLHOP model. Classical Nx2D propagation modeling largely underestimates the anthropogenic noise footprint in Arctic fjords compared to using a full 3D propagation model.