A comprehensive catalog of hydroacoustic sources using the International Monitoring System network

As part of the Comprehensive Nuclear-Test-Ban Treaty, six hydrophone stations of the International Monitoring System transmit continuous data in real time. These stations have recorded low-frequency underwater acoustic waves propagating in the SOund Fixing And Ranging channel for decades. Automated processing of this large data volume is desirable, particularly to discriminate records by source type. However, no catalog currently exists. We present a methodology based on a rule-based expert system to establish such a catalog, covering seven source types: earthquakes, volcanic activity, cryospheric activity, whales, vessels, airguns, and chemical explosions. The catalog consists of 49 452 events from moored hydrophone stations, with an assignment error of less than 1%. Because the process is interpretable and reproducible, the catalog can be readily expanded to incorporate additional inputs. This catalog can be used to identify and analyze specific source types in greater detail.