日本地球惑星科学連合2023年大会

講演情報

[J] オンラインポスター発表

セッション記号 S (固体地球科学) » S-VC 火山学

[S-VC34] 海域火山

2023年5月23日(火) 13:45 〜 15:15 オンラインポスターZoom会場 (3) (オンラインポスター)

コンビーナ:田村 芳彦(海洋研究開発機構 海域地震火山部門)、藤田 英輔(防災科学技術研究所 火山防災研究部門)、前野 深(東京大学地震研究所)、小野 重明(国立研究開発法人海洋研究開発機構)

現地ポスター発表開催日時 (2023/5/24 17:15-18:45)

13:45 〜 15:15

[SVC34-P10] フンガ火山海底部から採取された岩石

*佐藤 智紀1田村 芳彦1、常 青1、Richard Wysoczanski2、Kevin Mackay2 (1.国立研究開発法人海洋研究開発機構、2.National Institute of Water & Atmospheric Research Ltd)

キーワード:フンガ火山、海底火山、ドレッジ

A catastrophic eruption occurred at Hunga volcano on January 15, 2022. This volcano is a large submarine volcano located in the Tonga-Kermadec arc, 65 km north of Tongatapu Island, the capital of Tonga. Part of the caldera rim forms islands at the top of the volcano (Hunga Tonga and Hunga Ha'apai). Older lava collected from the islands are basaltic andesite to andesite [1], but the submarine section has not been previously studied. Recent pyroclastics from the volcano are andesitic in composition [1, 2]. Nishinoshima in the Izu-Ogasawara arc also erupts andesitic magma, and its shape as a submarine volcano is similar. There are several similarities between the two volcanoes. Therefore, the study of Hunga volcano may provide important insights for predicting and preparing for future eruptions of submarine volcanoes in the Izu-Ogasawara arc as well as other similar submarine volcanoes worldwide.
JAMSTEC and NIWA (National Institute of Water and Atmospheric Research Limited) made a Cooperative Research Agreement to collaborate in performing research on the magmatic evolution process of Hunga volcano. The cooperative studies will show the genesis of magmas of this submarine volcano by studying the dredged rocks. NIWA conducted a research cruise 3 months after the 2022 eruption (TAN 2206) and collected a variety of rock samples (lava, pumice, and scoria) from 8 sites (320-1,400 mbsl) on the seafloor around the Hunga volcano. Here we present a summary of the dredge and preliminary results of chemical compositions of the submarine samples as well as bathymetric maps of the edifice.

[1] Brenna et al. (2022) https://doi.org/10.1016/j.lithos.2022.106614
[2] Cronin et al. (2022) https://doi.org/10.5194/egusphere-egu22-13584