SHIPPING AND SEISMIC EXPLORATION CONTRIBUTORS TO NOISE IN THE NORTHERN NORWEGIAN SEA: TRENDS AND RECENT MEASUREMENTS

Abstract

A major contribution to low-frequency ambient noise in the shallow ocean is the noise due to shipping activity. This paper presents a study of temporal and spatial distribution of maritime activities including shipping, fishing and seismic exploration activity in the northern Norwegian Sea. The initial study covers data from the period 2006-2009. The overall motivation is to develop a prediction models for low-frequency ambient noise levels. The study has examined ship traffic and coastal fishery activity based on data from the Automatic Identification System. Regional and seasonal variations in shipping and fishing activity and their correlations have been analyzed. The number of seismic exploration vessels is relatively small compared to fishing and other vessels, thus seismic exploration is treated as individual events, not by density. An example of measured noise from a seismic exploration vessel is presented. The present study illustrates that with ships separated into two categories, fishing vessels and other vessels, densities show distinctively different seasonal and geographic patterns. Further work, including correlation with measured acoustic data, is needed to investigate the relevance of the findings in predicting ambient noise in this geographic region.