Baleen whale localization using a dual-line towed hydrophone array during seismic reflection surveys

Abstract

Three dimensional seismic reflection surveys use multiple towed hydrophone arrays for imaging the structure beneath the seafloor. Since most of the energy from seismic reflection surveys is low frequency, their impact on Baleen whales may be particularly significant. To better mitigate against this potential impact, safety radii are established based on the criteria defined by the National Marine Fisheries Service. Marine mammal observers use visual and acoustic techniques to monitor safety radii during each experiment. However, additional acoustic monitoring, in particular locating marine mammals, could demonstrate the effectiveness of the observations, and improve knowledge of animal responses to seismic experiments. In a previous study (Abadi et al., 2014), data from a single towed seismic array was used to locate Baleen whales during a seismic survey. Here, this method is expanded to a pair of towed arrays and the locations are compared with an alternative method. The experimental data utilized in this presentation are from the seismic experiment conducted by the R/V Marcus G. Langseth near Alaska in summer 2011. Results from both the simulation and experiment are shown and data from the marine mammal observers conducted simultaneously with the experiment are used to verify the analysis. [Sponsored by NSF.]