16:30 〜 16:45
[SVC28-10] A recent episode of submarine volcanic activity in the South Sandwich Arc – Insights from International Monitoring System hydroacoustic data
★Invited Papers
キーワード：Submarine volcanism, Hydroacoustics, South Sandwich Arc, IMS, CTBTO
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. In addition to radionuclide, seismic, and infrasound monitoring stations, the IMS also includes eleven hydroacoustic receiver sites: Five land-based, high-frequency seismometers and six bottom-moored hydrophone triplet stations, the latter of which are typically deployed near remote ocean islands and at the depth of the Sound-Fixing-and-Ranging (SOFAR) channel where low-frequency acoustic energy propagates most efficiently.
Here, we present a recent example for the civil and scientific application of IMS hydroacoustic data. On 24 April 2022, IMS stations detected a cluster of impulsive, seismo-acoustic events in the South Sandwich Arc, a volcanically active chain of remote islands and seamounts in the South Atlantic Ocean. Preliminary results from automated and interactive analysis of hydrophone and T phase station data suggest that these events, which occurred over a period of less than two hours and which were preceded by at least two hour-long episodes of low-level tremor, are likely volcanic in nature, and originated at or near one of several recently discovered seamounts offshore Candlemas and Saunders Island. To the knowledge of the authors, these observations constitute the first known detection of submarine volcanic activity in the South Sandwich Arc in about half a century.
Our findings are consistent with waveform data gathered by non-IMS stations and further highlight the potential of the IMS hydroacoustic network for detecting and studying submarine volcanic activity in some of the most remote regions on the planet.
Here, we present a recent example for the civil and scientific application of IMS hydroacoustic data. On 24 April 2022, IMS stations detected a cluster of impulsive, seismo-acoustic events in the South Sandwich Arc, a volcanically active chain of remote islands and seamounts in the South Atlantic Ocean. Preliminary results from automated and interactive analysis of hydrophone and T phase station data suggest that these events, which occurred over a period of less than two hours and which were preceded by at least two hour-long episodes of low-level tremor, are likely volcanic in nature, and originated at or near one of several recently discovered seamounts offshore Candlemas and Saunders Island. To the knowledge of the authors, these observations constitute the first known detection of submarine volcanic activity in the South Sandwich Arc in about half a century.
Our findings are consistent with waveform data gathered by non-IMS stations and further highlight the potential of the IMS hydroacoustic network for detecting and studying submarine volcanic activity in some of the most remote regions on the planet.