Noise of underwater explosions in the North Sea. A comparison of experimental data and model predictions

An analysis is presented of sound measurements performed near two detonations unexploded ordnance (UXO) in the North Sea, at distances ranging from 1.5 to 12 km. The charge masses were 325 and 140 kg TNT equivalent. objective was improve accuracy model predictions area where UXO affect harbour porpoises Sea. For predictions, an explosion emission combined with a shallow-water propagation model. prediction previously validated for up 2 reported here allowed validation distance measured levels spectra are well explained by calculations. results depend strongly on sea sediment layering. high-frequency components appears be affected primarily silty top layer, while low-frequency also deeper sandy layers. Measured calculated noise used determine permanent-threshold-shift effect (Phocoena phocoena). Values 6 km found detonations.