19–23 Jun 2023
Hofburg Palace & Online
Europe/Vienna timezone

Hydroacoustic SignalsConverted at Coastal International Monitoring System Stations

20 Jun 2023, 09:00


Board: 21
E-poster T1.4 Multi-Discipline Studies of the Earth’s Subsystems Lightning talks: P1.3, P1.4, P5.2


Paulina Bittner (CTBTO Preparatory Commission)


The hydroacoustic International Monitoring System (IMS) network was designed to detect underwater nuclear explosions. Two types of stations belong to this network. Six of them record signals with hydrophone triplets placed in the Sound Fixing and Ranging (SOFAR) channel. Remaining five are T phase, seismic stations which detect hydroacoustic signal converted to seismic wave at a steep shore slope. T phase stations measure arrival time but, unlike in case of hydrophone stations, do not provide other detection parameters (i.e. azimuth estimate). Analysts consider correlation with signals at other stations or observations for similar events to include T phase station detections in event solutions. Hydroacoustic signals generated by large magnitude seismic events are also observed at coastal seismic or infrasound IMS stations, which are configured to measure detection parameters, i.e. azimuth, or slowness. Correct identification of such signals will help analysts to include them in International Data Centre bulletins. Investigation of these additional hydroacoustic data will also allow to estimate whether detection parameters can increase confidence in correct associations of T phase station detections.

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Currently the main contribution of T phase stations is to constrain solution of locally recorded events by using recorded seismic signals. We believe that results of this study may help to improve T phase station contribution, which comprise half of the IMS hydroacoustic network.

E-mail [email protected]

Primary author

Paulina Bittner (CTBTO Preparatory Commission)


Mr Moulay Ali Kasmi (CTBTO Preparatory Commission) Mr Sherif Ali (CTBTO Preparatory Commission) Ms Marcela Villarroel (CTBTO Preparatory Commission) Ms Ivana Jukic (CTBTO Preparatory Commission)

Presentation materials