分散音響センサによって画像化された地震アスペリティの割れ目
Jiaxuan Li1, Taeho Kim2, Nadia Lapusta3,2
1Seismological Laboratory, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA. jxli@caltech.edu.
Nature
|August 2, 2023
まとめ
高周波地震計は 地震の破裂の詳細を明らかにします 光ファイバーケーブルを用いた分散型音響センサーは 断層の強さをイメージし,地震のダイナミクスを理解するのに不可欠です.
科学分野:
- 地震学
- 地震の断裂の動態
- 地理学
背景:
- メガスラスト地震の断裂シグネチャーは周波数依存を示しますが,高周波の放射器は十分に理解されていません.
- 地殻の地震で 高周波の放射を観測するのは 密度の高い地震配列がないと 難しいことです
研究 の 目的:
- 分散音響センシング (DAS) を使用して高周波地震破裂ラジエータをイメージします.
- 地震の破裂の振る舞いを調節する断層アスペリティの役割を調査する.
主な方法:
- 100キロのダーク・ファイバー・オプティック・ケーブルを 1万チャンネルの地震計として使った
- 高周波地震データを取得するための分散音響センシング (DAS) 技術を採用しています.
- 画像解析の結果と長時間瞬間放出データと動的破裂シミュレーションを比較した.
主要な成果:
- Antelope Valley 6.0地震の4つの高頻度のサブイベントを成功裏に画像化しました.
- これらのサブイベントは 断層の断層として特定されました
- 断裂の進行を促すことが示された.
結論:
- 断層アスペリティは地震の破裂行動を大きく変化させる.
- DAS技術は,既存のファイバーネットワークを使用して,中規模な地震を研究するための新しい方法を提供します.
- ダイナミックな断裂モデリングと統合することで,地震の断裂過程の理解を深めることができます.
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