溶融は,アキシアル火山の下の石層-アステノスフィアの境界に沿って集中している
G M Kent1,2, A F Arnulf3,4, S C Singh5
1Nevada Seismological Laboratory, University of Nevada, Reno, Reno, NV, USA. gkent@unr.edu.
Nature
|April 24, 2025
まとめ
アクシアル火山の下にある石層とアステノスフィアの境界線 (LAB) は,マグマを表面に導いて,フンネルの形をしている. この発見により,マグマの吸収が 火山系を形成し,噴火に影響を及ぼすことが明らかになりました
科学分野:
- 地理学
- 火山学
- 構造学
背景:
- リトスフィア-アステノスフィアの境界線 (LAB) は,浸透性の障壁として機能し,マントルの融解を海洋の拡散中心に導きます.
- 以前の地震研究は,LABで浅い軸性マグマレンズ (AML) を特定したが,より深いLABの構造は不明であった.
研究 の 目的:
- Axial火山の下の地殻に LABの3次元構造をイメージする
- ホットスポット・リッジの交差点でのマグマリズムを集中させ,火山のプロセスを制御するLABの役割を理解する.
主な方法:
- LABの構造を視覚化するために3Dの地震反射画像を使用しました.
- 地震データを分析し LABの幾何学とマグマ活動との関係をマッピングしました.
主要な成果:
- Axial火山の下の地殻に 5~6キロの長さがある 状の LAB が発見されました
- LABはマグマ吸収フロントと一致し,ホットスポットと中海のリッジの両方からマグマを集中させることを実証しました.
- 溶けた物体が存在する"マグマ領域"の上限としてLABを特定しました.
結論:
- 状の地殻LABは,マグマリズム,噴火制御,熱水活動,およびアクシアル火山の溶岩化学に焦点を当てています.
- 熱制御されたマグマの吸収は,アイスランドのような他の火山系で一般的なプロセスである可能性を示唆しています.
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