大地震 の 前兆 段階
Quentin Bletery1, Jean-Mathieu Nocquet1,2
1Université Côte d'Azur, IRD, CNRS, Observatoire de la Côte d'Azur, Géoazur, France.
Science (New York, N.Y.)
|July 20, 2023
まとめ
大規模な地震は,検出可能な滑り段階から始まります. グローバルGPSデータ分析では 破裂前の2時間の指数関数滑り加速が示され,地震予測の先駆的段階を示唆しています.
科学分野:
- 地理学
- 地震学
- 地震科学
背景:
- 大規模な地震の前に観測可能な前駆的スライドフェーズが存在することは,地震学における長年の議論である.
- 以前の提案された前駆的滑り観測は地震の開始と直接的な相関関係がないため,不一致に観察されています.
研究 の 目的:
- グローバル・ポジショニング・システム (GPS) の高速データを使用して,大規模な地震 (モメント・マグニチュード≥7) 前に,短期的な先駆的滑落を地球規模で探す.
- 潜在的前駆的スリップ段階の時間的特徴を調査する.
主な方法:
- 高速GPSタイムシリーズのデータ分析
- 予想される先駆的滑り方向にGPSの位移を投影する.
- 90の大きな地震の前の48時間の予測移動の合計です.
主要な成果:
- 大規模な地震の破裂前に,約2時間の一貫した先駆的滑り段階が検出されました.
- この先駆的スライドは 主要な破裂までの指数関数加速パターンを示しています
- 発見は,大きな地震が 検出可能なスライドフェーズで始まることを示しています.
結論:
- 大規模な地震は 滑り前の段階から始まるようです
- GPSネットワークでの測定精度とデータ密度の向上により,この先駆的滑落の検出とモニタリングが改善されます.
- この発見は地震の早期警告システムを 発展させる可能性を秘めています
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