断続的な実験室地震が動的に弱まる断層の穴に
V Rubino1, N Lapusta2,3, A J Rosakis4
1Graduate Aerospace Laboratories, California Institute of Technology, Pasadena, CA, USA. vito.rubino@caltech.edu.
Nature
|June 1, 2022
まとめ
地震は断層の滑り方として発生します. 実験室での実験では 動的な断裂は 断続的な滑り方によって 滑り方によって 摩擦が強くなり 滑り方によって 弱くなり 地震の危険性が生じます
科学分野:
- 地理学
- 地震科学
- ロック・メカニクス
背景:
- 大規模な地震は,滑り込み中に形成された粒状の物質である断層の滑り込みによるものです.
- 断層摩擦は地震の核形成,伝播,地震に不可欠です.
- 実験室での自発的な地震の進行を研究することは,サンプルサイズとイメージングの制限のために困難です.
研究 の 目的:
- 研究室での実験で,断層の摩擦が自発的な地震破裂の進行にどのように影響するかを調査する.
- 細い岩の裂け目における複雑な滑りプロセスと摩擦の進化を理解する.
主な方法:
- 細い岩石の断層地帯での動的破裂の拡散をシミュレートする実験室での実験.
- 摩擦の進化,滑り率,およびシーアー加熱および膨張/圧縮などの関連プロセスの分析.
主要な成果:
- 突発的に広がる動的破裂は,細い岩石の滑り方において,複雑で断続的な滑り方を示します.
- 摩擦は低滑り率で強化され,破裂停止を引き起こします.
- 摩擦はより高い滑り率で急速に弱まり (フラッシュ加熱と一致する),地震の再核化を可能にします.
結論:
- 断層の摩擦は基本的に滑り率と関連するプロセスに依存します.
- 断層の弱まりは,安定した断層地域を通って地震の破裂を容易にする.
- 発見は地震の危険性を理解し評価する上で重要な意味を持つ.
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