Modelling noise from wind, rain and distant shipping in scenarios of varying complexity

Passive sonars attempt to detect sound radiated by vessels of interest. This detection takes place against a background of noise, with important sources of noise including distant shipping, rain falling on the sea surface and breaking waves and bursting bubbles associated with sea-surface waves. The estimation of these noises is therefore an...

Underwater noise measurements in the North Sea in and near the Princess Amalia Wind Farm in operation

Reykjanes ambient noise reflection interferometry

We present results from the application of ambient noise seismic interferometry (ANSI) to data that were recorded continuously in 2014 and 2015 at Iceland’s peninsula Reykjanes. The objective of this study is the retrieval of reflected body waves (P-waves) that provide high-resolution velocity-versus-depth as well as subsurface structural...

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...

Periodic changes in ambient noise: Possible causes and implications for long term prediction

Periodic changes in ambient noise have been observed on various timescales. Available long term measurements of periodic noise fluctuations are reviewed, with particular emphasis on those exhibiting periodicity appearing to coincide with that of the Sun. Evidence is offered supporting the suggestion that such fluctuations can be caused by...

Results of a monitoring pilot with a permanent buried multicomponent seismic array at Ketzin

To monitor the migration of the injected CO2 in the Ketzin project (Germany) a permanently buried multi-component seismic array has been installed in August 2009. Since then the array has been continuously recording passive seismic data. Additionally an active seismic survey resulting in a 230 m long 2D seismic line roughly passing over the...

Rating environmental noise on the basis of noise maps within the framework of the Environmental Noise Directive

In order to evaluate the need for noise measures as well as the improvement that can be obtained with different measures, there is a need for a system that rates environmental noise on the basis of noise maps. Based on empirical exposure-response relationships, a rating system and a stepwise procedure for its implementation have been developed....

Rating environmental noise on the basis of noise maps

A system that rates noise on the basis of noise maps has been developed which is based on empirical exposure-response relationships, so that effects in the community will be lower if the system gives a better rating. It is consistent with noise metrics and effect endpoint chosen in the EU, i.e., it uses L</field>den and L</field>night and...

Sub-bottom profiling with ambient noise measured on a drifting vertical array

The angle and frequency dependent reflective properties of the seabed can be determined from beam-steered ambient noise measurements on a vertical array of hydrophones. From the up-to-down ratio the beam-smeared modulus square of the plane wave reflection coefficient is obtained. Geo-acoustic parameters can be inverted by matching the measured...

A high frequency transient detector suitable for monitoring marine mammal activity

As part of a program to study the effect of man-made noise on marine mammals an EARS Acoustic Recording System) buoy was deployed in the Ligurian sea. The EARS buoy was deployed at a position with a high probability of marine mammal activity at a depth of around 950 m. It was operating for almost 19 days and collected acoustic data sampled at...

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