地震学:プレート内部における構造的緊張?
E Calais1, G Mattioli, C DeMets
1Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, Indiana 47907, USA. ecalais@purdue.edu
Nature
|December 16, 2005
まとめ
構造板の変形とその地震との関連を理解することは依然として課題です. 新しい研究は,米国中部に重大な変形があるとの主張に異議を唱え,現在,大きな地震の大きさの上限と再発間隔を推定することができることを示唆しています.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- テクトニクス (地質学) とは
- 地震学 地震学とは
背景:
- プレート構造の内部で変形を起こすメカニズムは完全に理解されていません.
- 大規模で稀な地震は,この板内変形と関連しています.
- 以前の研究では,米国中部で表面が著しく変形していることが示唆されていた.
研究 の 目的:
- アメリカ合衆国中部における重要な表面変形の可能性を調査する.
- プレート境界に匹敵する変形速度に関する主張の妥当性を評価する.
- プレート内地域における地震の可能性の理解を深めること.
主な方法:
- 地検データの独立した統計分析.
- 以前の変形研究で使用されたデータセットの再評価.
- 変形速度の比較分析. 変形速度の比較分析.
主要な成果:
- 3つの独立した分析で統計的に有意な表面変形は検出されなかった.
- データは,米国中部のプレート境界と比較できる変形速度の主張を支持しません.
- この研究は,プレート内変形に関する以前の発見に異議を唱える.
結論:
- 現在のデータでは,米国中部の有意な変形が確認されていません.
- 大規模な地震の震度および再発間隔の上限のみを推論することができる.
- プレート内地震のプロセスを理解するためにさらなる研究が必要である.
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