The Comprehensive Nuclear-Test-Ban Treaty’s global International Monitoring System, its core mission and its civil and scientific applications

The Comprehensive Nuclear-Test-Ban Treaty Organization’s (CTBTO) International Monitoring System (IMS) comprises 337 stations distributed around the world, recording data 24/7 and sending it in near-real time to the International Data Centre (IDC) in Vienna, where the data are processed to detect signs of nuclear tests. The four monitoring technologies in the IMS are: (i) seismology, (ii) hydroacoustics, (iii) infrasound, and (iv) radionuclide. The present state of completion of the IMS is nearing 90%, with the hydroacoustic network (6 stations with triplets of moored hydrophones suspended in the SOFAR channel and 5 near-shore seismometer stations for T-phase detection) being the first technology to be completely certified as of 2017. In addition to Treaty verification, IMS raw sensor data is available for civil and scientific studies, with hydroacoustic topics encompassing ocean acoustic propagation and tomography, submarine earthquakes and volcanism, ocean soundscapes, marine mammal acoustics and disaster response. This presentation will kick off this ASA Special Session by presenting the current status of the network, with emphasis on the hydroacoustic component and on the hydrophone stations, their sustainment and pertinent technology watch, and by reviewing highlights from data analysis of events for Treaty verification and scientific and civil applications.