噴火による板の薄めによる火山活動と長期の地震性
Raffaele Bonadio1, Sergei Lebedev2,3, David Chew4
1Department of Earth Sciences, Bullard Laboratories, University of Cambridge, Cambridge, UK. rb2075@cam.ac.uk.
Nature communications
|August 22, 2025
まとめ
マントルの羽根は,地球の石層を侵食することによって,表面の上昇と大きな火山地帯 (LIP) を引き起こします. この研究は,イギリスとアイルランドの下の薄い石層を明らかにし,それをアイスランド・プームと現在の地震性に関連付けています.
科学分野:
- 地理学
- 構造学
- 地力学
背景:
- マントルの羽根は,表面の上昇と大きな火山地帯 (LIP) を引き起こすと理論化されています.
- LIPのマグマ中心の分散分布は横方向の羽根流を示唆しているが,直接的な証拠は限られている.
- 北大西洋火山地帯は,マントルの羽根に関連したLIPの重要な例です.
研究 の 目的:
- マントルの羽根,石層構造,およびLIP形成の関係を調査する.
- アイスランド・プームに関連したイギリス・アイルランド地域における石層の厚さの変動をマッピングする.
- リトスフィアの構造と羽根の衝撃と現在の地震パターンを相関させる
主な方法:
- 詳細な画像を撮影するために 豊富な地震データを利用しました
- プレート厚さのマッピングに 先進的な地震温度測定技術を適用した.
- 地質学的,地震学的観測と相関する地質学的データ.
主要な成果:
- イギリスとアイルランドの地域では,これまで知られていなかったプレート厚さの変化が確認されました.
- ~60 Myr 古い上昇/マグマティズムと現在薄い石層との間での体系的な相関を示した.
- イギリスとアイルランドの現在の地震性は,薄い石層の領域と厚さの対比に沿って局所化されていることが示されました.
結論:
- アイスランド・プームは,イギリス・アイルランド地域の石層を侵食し,解圧融解を引き起こし,その後の上昇とマグマティズムを引き起こした.
- マントルの羽根は 岩層に永続的な機械的異質性をもたらした.
- この異質性は,この地域の変形,地震,地震のリスクの長期分布に影響します.
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