Characteristics of hydroacoustic sources of natural and anthropogenic origin

We report on a review of multiple sources and source characteristics of hydroacoustic signals recorded at the six hydrophone stations of the International Monitoring System for verifying compliance with the Comprehensive Nuclear-Test-Ban Treaty.  We present a comprehensive list of hydroacoustic sources as well as their general waveform shape and individual spectral source characteristic, i.e. the time duration, source intensity, frequency content and signal variation.

We identify and investigate numerous natural sources like earthquakes, volcanoes, icebergs and marine mammals as well as anthropogenic sources like explosions, airgun surveys and shipping activity. We show selected example events and associated references, collected in the course of the joint research project "Metrology for low frequency sound and vibration - 19ENV03 Infra-AUV". We further use freely available recordings from e.g. seismic stations for cross-validation purposes.

This overview provides the basis for an open-access systematic source classification, where only few, fragmentary event catalogues are available up to now and in situ identification of sources and calibration of instruments are difficult and complex. This work is applicable to future activities in automatic source detectors and event catalogs, sensor calibration activities using remote excitation sources and data comparison with other hydroacoustic measurements. We invite the scientific community to discuss useful source labels for such a compilation and useful datasets for comparison and validation.