2019年リッジクレスト地震の地震配列付近の断層に関連した表面変形

Xiaohua Xu¹, David T Sandwell², Lauren A Ward³

¹Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA. xix016@ucsd.edu.

Science (New York, N.Y.)

|October 30, 2020

まとめ

衛星レーダーは2019年のリッジクレスト地震の近くで何百もの新しい地殻破裂を明らかにしました. 多くの断層は予期せぬ逆転を示しプレッシャーが既存の断層に滑り込んでいることを示唆しています

科学分野:

地理学
構造学
リモートセンシング

背景:

精密な地震リスクモデルには地殻のストレスの分布を理解しミリメートルスケールの変形を検出する必要があります
衛星レーダー干渉計 (InSAR) は,広範囲の表面変形を監視するために不可欠です.

研究の目的:

2019年のリッジクレスト地震の後の地殻のストレスのパターンと断裂の行動を分析する.
新しく発見された骨折の進行および逆行移転の背後にあるメカニズムの調査.

主な方法:

線形ストレスの濃度 (骨折) を特定し,マッピングするために衛星レーダー観測を利用した.
169の骨折の位置と幅を記録し分析した.
物理モデルを開発し,観察された断裂の移転パターンを説明しました.

主要な成果:

2019年のリッジクレスト地震の周辺で,これまでに地図化されていない数百の線形ストレス濃度が特定されました.
大抵の断層はプレッシャーに合わせて進んだ移転を示しています
重要な数の断層は逆行的な移転を示した. 支配的な構造的ストレスとは対照的に.

結論:

この研究では,地殻の骨折で観察された進行と逆行の移転を説明するモデルを提示しています.
重要な意味は,多くの既にある断層の摩擦の滑りによって,重要な構造的負荷が収納されているということです.
この発見は地震の危険性モデリングと断層システムの行動を理解する上で大きな意味を持っています.

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