日本地球惑星科学連合2023年大会

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セッション記号 M (領域外・複数領域) » M-AG 応用地球科学

[M-AG32] CTBT IMS Technologies for Detecting Nuclear Explosion and Their Applications to Earth Science

2023年5月25日(木) 13:45 〜 15:00 201B (幕張メッセ国際会議場)

コンビーナ:Nurcan Meral Ozel(Comprehensive Nuclear-Test-Ban Treaty Organization)

14:45 〜 15:00

[MAG32-05] The hydroacoustic component of the International Monitoring System – Implications for studying submarine volcanic activity in the global ocean

*Dirk Metz1、Tiago C A Oliveira1、Mario Zampolli1、Georgios Haralabus1Nurcan Meral Özel2,3 (1.Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization, Vienna、2.Kandilli Observatory and Earthquake Research Institute, Bogazici University, Istanbul、3.Previously at: Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization, Vienna)

キーワード:Submarine volcanism, Hydroacoustics, IMS, CTBTO, SOFAR

As part of the verification regime for the Comprehensive Nuclear-Test-Ban Treaty of 1996, the objective of the International Monitoring System (IMS) is to detect nuclear explosions on land, in the atmosphere, and in the ocean. The IMS includes eleven hydroacoustic receiver sites: Five land-based, high-frequency seismometer and six hydrophone triplet stations. The latter are typically deployed near remote islands and at the depth of the Sound-Fixing-and-Ranging (SOFAR) channel, a minimum velocity layer in the oceanic water column where low-frequency sound travels most efficiently.

Here, we present an example for the civil and scientific usage of IMS hydroacoustic data: Using recordings from IMS hydrophone stations, we show that recent episodes of submarine volcanic activity, such as the 2021 eruption at Fukutoku-Okanoba or the 2022 eruption at Hunga Tonga-Hunga Ha'apai, can be detected – and studied – acoustically over source-receiver distances of thousands of kilometers. Frequently, IMS data provide unparalleled insights into underwater volcanic processes that may, otherwise, go unnoticed. Routes for the automated identification of on-going eruptions in IMS hydroacoustic data processing, some of the limitations inherent to long-range acoustic monitoring, and synergies with conventional monitoring tools such as satellite remote sensing will be discussed.

Our study highlights the potential of the IMS hydroacoustic network for remotely detecting, studying, and monitoring volcanic activity in the global ocean.