直接的な地震波に先立つ弾性重力信号の観測とモデリング
Martin Vallée1, Jean Paul Ampuero2, Kévin Juhel3
1Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, CNRS, France. vallee@ipgp.fr.
Science (New York, N.Y.)
|December 2, 2017
まとめ
初期の地震の信号は 地震波ではなく 重力の変化で検出されました この新しい方法は,ブロードバンド地震計を使用して大規模な地震の速度の推定を可能にします.
科学分野:
- 地震学
- 地理学
- 重力測定法
背景:
- 地震の早期警告システムは通常,地震波 (P波) に依存しています.
- 重力場の変化は 光の速さで発生し 地震波に先行します
- 地震による重力の乱れを 以前の検出は 十分正確ではなかった.
研究 の 目的:
- 初期の地震の信号として重力の乱れの可能性を調査する.
- 地震分析のための重力の変化と関連する動きを正確にモデル化します.
- 地震の大きさを 素早く判定するために これらの信号の利用を 探求する.
主な方法:
- ブロードバンド地震計を使って 微妙な重力の乱れを検知する
- 2011年の東北地震 (マグニチュード9.1) のデータを分析する.
- 重力変化と重力誘発運動の両方をモデル化するための新しい形式主義を開発しました.
主要な成果:
- 東北地震の震源から1000〜2000kmの広帯域地震計によって重力波が効果的に観測された.
- 新しいモデリング手法で 素早く発する 弾性重力信号を正確に捉えました
- この発見は,これらの信号を地震分析に使用する可能性を示しています.
結論:
- 地震のダイナミクスを理解するための 新しい道を開くのです
- この研究により,大きな地震の分間尺度の決定の可能性が生まれます.
- 重力波分析は地震の早期発見と特徴づけを大幅に改善します
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