Modeling Acoustical Pressure and Particle Acceleration Close to Marine Seismic Airguns and Airgun Arrays

Comparisons are made of sound pressure and particle acceleration predicted by two methods in the vicinity of two arrays of marine-seismic airguns. Data describing the array properties and the environmental conditions are taken from test cases designed to facilitate intermodel comparison.The two propagation approaches, one based on method of...

International Airgun Modeling Workshop: Validation of Source Signature and Sound Propagation Models - Dublin (Ireland), July 16, 2016 - Problem Description

Computer models can be used to predict the sound field near an airgun or airgun array. The accuracy of such predictions can be assessed either by a process of verification (comparison with alternative theoretical solution to the same computational problem) or by validation (comparison with measurement). A set of verification test problems is...

Source specific sound mapping: Spatial, temporal and spectral distribution of sound in the Dutch North Sea

Effective measures for protecting and preserving the marine environment require an understanding of the potential impact of anthropogenic sound on marine life. A crucial component is a proper assessment of the anthropogenic soundscape: which sounds are present where, when and how strong? We provide an extensive case study modelling the spatial,...

Mapping underwater sound in the Dutch part of the North Sea

The European Union requires member states to achieve or maintain good environmental status for their marine territorial waters and explicitly mentions potentially adverse effects of underwater sound. In this study, we focused on producing maps of underwater sound from various natural and anthropogenic origins in the Dutch North Sea. The source...

The effect of sound speed profile on shallow water shipping sound maps

Sound mapping over large areas can be computationally expensive because of the large number of sources and large source-receiver separations involved. In order to facilitate computation, a simplifying assumption sometimes made is to neglect the sound speed gradient in shallow water. The accuracy of this assumption is investigated for ship...

Definition and results of test cases for shipping sound maps

The SONIC (Suppression Of underwater Noise Induced by Cavitation) and AQUO (Achieve QUieter Oceans by shipping noise footprint reduction) projects were awarded within the European Seventh Framework Program to develop tools to investigate and mitigate the effects of underwater sound generated by shipping activities on marine life. Model generated...

Assessing the Impact of Underwater Clearance of Unexploded Ordnance on Harbour Porpoises (Phocoena phocoena) in the Southern North Sea

(UXO) are still present in the North Sea. UXO are frequently accidentally encountered by fishermen and dredging vessels. Out of concern for human safety and to avoid damage to equipment and infrastructure from uncontrolled explosions, most reported UXO found in the Dutch Continental Shelf (DCS) are detonated in a controlled way. These underwater...

A fast algorithm for the computation of incoherent propagation loss for variable water depth: A validation study

Accurate and fast estimation of propagation loss (PL) is needed for simulations of sonar or acoustic communication performance, and for environmental risk assessment. Accurate calculation of PL in range dependent and lossy waveguides can require computationally expensive wave theory techniques . In this work, a new propagation model is...

A depth-dependent formula for shallow water propagation

In shallow water propagation, the sound field depends on the proximity of the receiver to the sea surface, the seabed, the source depth, and the complementary source depth. While normal mode theory can predict this depth dependence, it can be computationally intensive. In this work, an analytical solution is derived in terms of the Faddeeva...

Sound maps of the Dutch North Sea for natural and anthropogenic sound sources

Regulations for protecting and preserving the marine environment (e.g. in the USA and EU) often require investigating the potential effect of anthropogenic sound on marine life. The origin of underwater sound can be natural as well as anthropogenic. To assess the potential importance of various types of sounds, we constructed sound maps for the...

Ship sound mapping in the North Sea

There is an increasing concern that anthropogenic underwater noise may have a negative impact on marine life. Governmental authorities are introducing regulations to address this problem. The European Commission, for instance, has adopted the Marine Strategy Framework Directive requiring EU Member States to achieve or maintain Good Environmental...

Mapping underwater noise for the Dutch part of North Sea (abstract)

The EU’s Marine Strategy Framework Directive (MSFD) requires member states (MS) to achieve or maintain Good Environmental Status (GES) by 2020. Specifically, the wording of Descriptor 11 requires “underwater noise to be at levels that do not adversely affect the marine environment”. The MSFD further requires monitoring of “trends in the ambient...

Propagation loss model comparisons on selected scenarios from the Weston memorial workshop

The accurate and stable calculation of underwater acoustic propagation is needed for applications such as sonar performance prediction, noise mapping and acoustic communication. In this work, some widely used acoustic propagation models, based on different methods such as normal mode, ray tracing, parabolic equation and flux theory are tested on...

Insights into the Calculation of Metrics for Transient Sounds in Shallow Water

Concern about possible impact of human activity on marine life has led to regulation in the USA [1,2] and the EU [3].The EU’s Marine Strategy Framework Directive [3] requires member states to achieve Good Environmental Status (GES) by 2020. Descriptor 11 of GES is “Introduction of energy, including underwater noise, is at levels that do not...