1993年のパークフィールドの非地震的な一時的な出来事に関連した地震散布器の移動
Fenglin Niu1, Paul G Silver, Robert M Nadeau
1Department of Earth Science, MS-126, Rice University, 6100 Main Street, Houston, Texas 77005, USA. niu@rice.edu
Nature
|December 5, 2003
まとめ
科学者は,繰り返されるマイクロ地震からの地震データを用いて,断層地帯の構造の変化を観察しました. これらの変化は,無地震的トランジントと関連しており,約3kmの深さの断裂内での液体の再分配を示唆しています.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- 地震学 地震学とは
- 地震科学 地震科学 地震科学
背景:
- 断層地帯の動態を理解することは,地震の予測に不可欠です.
- 地震の深さで時間変化による変形を検出することは,大変な課題でした.
- 実験室での研究は,地殻の骨折における構造変化の地震検出性を示唆しています.
研究 の 目的:
- 断層圏内の観測可能な構造変化の証拠を提供するため.
- 繰り返される微小地震の地震図における時間的変動を調査する.
- 地震分散運動と無地震変形現象を相関させるため.
主な方法:
- サンアンドレアス断層 (1987年-1997年) で発生した小規模地震の繰り返しによる地震画像の分析.
- 断層圏内の地震分散体の位置.
- 散射器の動きを,文書化されている無地震的トランジエントと比較.
主要な成果:
- マイクロ地震地震図で,系統的な時間的変動が観察されました.
- 散乱部位で約10メートルのシフトが,深さ3kmで検出されました.
- Scatterer運動は,空間的にも時間的にも,無地震的な一時的な出来事と一致しました.
結論:
- 断層圏内の構造の変化は,地震的に観測できます.
- 観測された分散運動は,骨折におけるストレス誘発された液体の再分配による可能性が高い.
- これらの発見は,断層の行動や地震の過程についての理解を深める.
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