沈殿板の超低速度層は,メキシコ南部の静かな地震と一致しています
Teh-Ru Alex Song1, Donald V Helmberger, Michael R Brudzinski
1Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road N.W., Washington, DC 20015, USA. asong@ciw.edu
まとめ
大規模な地震は,閉じられた潜流ゾーンで発生します. メキシコの超低速度層 (USL) は,静かな地震 (スロースリップイベント) と相関し,過渡的な摩擦地帯を明らかにします.
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
- プレート・テクトニクス (プレート・テクトニクス)
背景:
- 大規模な地震は,板のインターフェイスがロックされている浅い潜水潜水地帯で発生します.
- 静かな地震 (スロースリップイベント) は,これらのロックされたゾーンのダウンディップエッジで発見され,地震サイクルに影響を与えます.
研究 の 目的:
- 超低速層 (USL) とメキシコ南部におけるスロースリップ現象の発生との関係を調査する.
- プレート界面での過渡的な摩擦行動におけるUSLの役割を理解する.
主な方法:
- 地元で観察された,改造されたSP到着者の分析.
- 潜水板の頂上をサンプリングするテレシズミック下部反射の解釈.
- メキシコ南部の超低速層 (USL) の空間地図作成.
主要な成果:
- 超低速度層 (USL) は空間的に変化し,厚さは3~5kmで,S波の速度は2.0~2.7km/sである.
- 特定されたほとんどのスロースリップパッチは,空間的にUSLの存在と一致しています.
- スロースリップイベントの境界線は,USLの欠如と一致しています.
結論:
- USLの存在と空間的な範囲は,スロースリップイベントの発生における重要な要因です.
- USLは,プレート界面での過渡的な摩擦行動のゾーンを線引きし,地震活動に影響を与えます.
- USLの分布を理解することは,潜水地帯における地震サイクルを理解する上で鍵となる.
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