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-CG 固体地球科学複合領域・一般

[S-CG52] 海洋底地球科学

2023年5月24日(水) 13:45 〜 15:15 オンラインポスターZoom会場 (6) (オンラインポスター)

コンビーナ:沖野 郷子(東京大学大気海洋研究所)、田所 敬一(名古屋大学地震火山研究センター)

現地ポスター発表開催日時 (2023/5/23 17:15-18:45)

13:45 〜 15:15

[SCG52-P18] 海底音響反射強度データのピークフィット解析に基づく南鳥島周辺マンガンノジュールの分布様態の解明

*佐々木 航1安川 和孝1中村 謙太郎1、町田 嗣樹 2 (1.東京大学大学院工学系研究科システム創成学専攻、2.千葉工業大学次世代海洋資源研究センター)

キーワード:クリティカルメタル、マンガンノジュール、音響反射強度探査、ピークフィット解析、南鳥島

Ferromanganese nodules are attracting worldwide attention as a promising source of industrially critical metals including cobalt, nickel, or copper. Thus, various research for their development are being conducted by many countries. In 2016, a wide distribution of dense ferromanganese nodule fields was discovered in the Japanese exclusive economic zone (EEZ) around Minamitorishima Island, which provides us a new expectation for the potential domestic resource for the metals that are essential for carbon-neutral technologies.
Our previous study established a new visualization method for the distribution of ferromanganese nodules using the acoustic backscatter intensity of the seafloor [1]. In the study, the acoustic backscatter intensity data obtained by a multi-narrow beam echo sounder during several cruises were processed and integrated into a unified dataset. The analysis of the histogram of the comprehensive data provided a threshold corresponding to a dense ferromanganese nodules distribution in the studied area. However, the relationship between some obvious peaks in the histogram of the acoustic intensity data and the actual seafloor facies has not yet been investigated.
In this study, we first decomposed the acoustic intensity data histogram into three distinct peaks by a peak-fitting analysis, and then investigated how these peaks correspond to the actual seafloor surface features observed by the SHINKAI 6500. In the presentation, we will discuss the relationship between each peak and the distribution mode of ferromanganese nodules on the seafloor around Minamitorishima Island.