Application of a seismic network to baleen whale call detection and localization in the Panama basin – a Bryde’s whale example

Tary, Jean-Baptiste; Peirce, Christine; Hobbs, Richard; Bonilla Walker, Felipe; De La Hoz, Camilo; Bird, Anna; Alberto Vargas, Carlos

Abstract

Baleen whales use sounds of various characteristics for different tasks and interactions. This study focuses on recordings from the Costa Rica Rift, in the Eastern Tropical Pacific Ocean, made by 25 ocean-bottom seismographs and a vertical array of 12 hydrophones between January and February 2015. The whale calls observed are of two kinds: more commonly, repetitive 4–5 s–long signals separated into two frequency bands centered at ∼20 and ∼36 Hz; less commonly, a series of ∼0.5 to 1.0 s–long, lower amplitude signals with frequencies between 80 and 160 Hz. These characteristics are similar to calls attributed to Bryde's whales which are occasionally sighted in this region. In this study, the repetitive calls are detected using both the short-term average/long-term average approach and a network empirical subspace detector. In total, 188 and 1891 calls are obtained for each method, demonstrating the value of the subspace detector for highly similar signals. These signals are first localized using a non-linear grid search algorithm and then further relocalized using the double-difference technique. The high-resolution localizations reveal the presence of at least seven whales during the recording period, often crossing the instrument network from southwest to northeast.

Citation

Tary, J., Peirce, C., Hobbs, R., Bonilla Walker, F., De La Hoz, C., Bird, A., & Alberto Vargas, C. (2024). Application of a seismic network to baleen whale call detection and localization in the Panama basin – a Bryde’s whale example. The Journal of the Acoustical Society of America, 155, 2075–2086. https://doi.org/10.1121/10.0025290

• Journal Article Type: Article
• Acceptance Date: Feb 26, 2024
• Online Publication Date: Mar 13, 2024
• Publication Date: Mar 13, 2024
• Deposit Date: Feb 28, 2024
• Publicly Available Date: Mar 14, 2024
• Journal: The Journal of the Acoustical Society of America
• Print ISSN: 0001-4966
• Publisher: Acoustical Society of America
• Peer Reviewed: Peer Reviewed
• Volume: 155
• Pages: 2075–2086
• DOI: https://doi.org/10.1121/10.0025290
• Public URL: https://durham-repository.worktribe.com/output/2288793