Prof. Luis Matias is an Associate Professor at the Sciences Faculty of the Lisbon University and a Senior Researcher at the Instituto Dom Luiz. His main research area is Seismology and the application of passive and active methods to Seismotectonics and the knowledge of the deep structure of passive margins. One of the tools used is OBS (Ocean Bottom Seismometers) that record opportunistically whale vocalizations. Profiting from a high-quality dataset recorded in the Gulf of Cadiz (Southwest Portugal) Prof. Matias developed in the last 10 years methods to identify and locate fin whale vocalizations using the 4 channels recorded by a single OBS. The results have already been applied to fin whale call density estimation and were validated against active seismic recordings and fin whale vocalizations in the Azores where signal triangulation could be applied also. This work has been partially supported by the “Cheap DECAF” project funded by ONR (2011 – 2014). Since October 2018 he is coordinating the Portuguese 3-year funded project AWARENESS: Assessing vocal behavior of fin whales for robust density estimation from passive acoustics.