1989年のマキューリー・リッジ大地震の遅い前駆者のテレシスミック検出
まとめ
マグニチュード7.6の地震に相当する遅い変形先駆者は,1989年のマッキャリー・リッジ地震に先行した. このゆっくりとしたイベントが主要な衝撃を引き起こし,海洋上のマントルの複合破裂過程を示唆した.
科学分野:
- 地震学 地震学とは
- 地震の物理学 地震の物理学
- 地質物理学 地質物理学とは地質物理学です.
背景:
- 1989年のマッキャリー・リッジ地震 (Mw 8.2) は,大規模な地震事件でした.
- 地震の前兆を理解することは,地震の危険性評価に不可欠です.
研究 の 目的:
- 1989年のマッキャリー・リッジ地震の低周波地震スペクトルを調査するために.
- メインショックに先立つ潜在的な前駆的な現象を特定する.
主な方法:
- 1989年のマッキャリー・リッジ地震からの低周波地震スペクトル (<6mHz) の分析.
- 地震を,ゆっくりと変形する複合的な出来事としてモデル化する.
主要な成果:
- 観測された振幅の増加と相遅延の減少が6mHz未満であることは,短期的な遅い前駆体であることを示している.
- 遅い前駆体は,約3×10^20Nm (Mw 7.6) のモメントを放出しました.
- 先駆者は,おそらく主要な破裂を開始し,複合イベントを示唆しました.
結論:
- 1989年のマッキャリー・リッジ地震は,重要なゆっくりとした変形イベントが先行した.
- この遅い前身は,海洋上のマントルで,主要な破裂地帯の下から発生した.
- 地震は,ゆっくりとした変形エピソードから始まり,伝統的な破裂モデルに挑戦することができます.
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