Analysis of International Monitoring System hydrophone triplet data: Identifying the August 2021 eruption at Fukutoku-Okanoba, 24.3°N Bonin Arc

[摘要] Fukutoku-Okanoba is an active submarine volcano in the southern Bonin Arc, located 5 km northeast of Minami-Io¯to¯ in the Volcano Islands archipelago (Fig. 1A, B). Eruptive activity at the volcano, which shoals to depths of less than 30 m below sea level, has been reported on multiple occasions throughout recent years, including intermittent observations of discolored seawater, floating debris, and explosive degassing (e.g., [1,2]). Dziak and Fox [3] note detections of harmonic tremor from a nearby location between 1998 and 2001, which may have been associated with activity at Fukutoku-Okanoba. On 12 August 2021, the volcano entered a phase of cataclysmic activity that was first detected by the Himawari-8 geostationary satellite in the form of a rapidly expanding subaerial plume, triggering the issuance of an eruption notice by the Tokyo Volcano Ash Advisory Center [4]. Reports of Surtseyan-style activity have since included phreatomagmatic explosions, vigorous degassing, and the ejection of material from a central vent, around which an approximately 1-km wide, horse-shoe shaped island has formed.

[学科分类] 声学和超声波

[关键词] Submarine eruption;Fukutoku-Okanoba;Wake Island;CTBTO;IMS;SOFAR