アイスランドにおける光ファイバージオデシーによる再発的な堤防侵入の分単位スケールダイナミクス
Jiaxuan Li1,2, Ettore Biondi1, Elías Rafn Heimisson3
1Seismological Laboratory, California Institute of Technology, Pasadena, CA, USA.
まとめ
低周波分散音響センシング (LFDAS) を使用した光ファイバージオデシーは,アイスランドのグリンダビク近くの火山堤入りを追跡しました. この方法は,噴火の予測と危険性評価のために高解像度,ほぼリアルタイムのデータを提供します.
科学分野:
- 地理学
- 火山学
- 地震学
背景:
- 火山の近くのマグマの動態を理解するには,継続的な地質測定が不可欠です.
- ダイク侵入の高空間時間解像度は,火山のモニタリングにおける重要な課題です.
研究 の 目的:
- 堤防の侵入を追跡するためにLFDASを使用して光ファイバージオデシを導入し,検証する.
- 火山の変形現象を分単位で解明する
主な方法:
- 通信用光ファイバーケーブルに沿った低周波分散音響センサー (LFDAS) を利用した.
- LFDASのストレスのデータにジオデシック・インバーション・テクニックを適用した.
- アイスランドのグリンダビークの近くの堤防の侵入を監視した.
主要な成果:
- 9つの堤防の侵入を成功裏に追跡した. そのうちの6つは裂け目の噴火につながった.
- 噴火開始15分から22分前に推定された堤防の容積率はピークに達した.
- 高解像度変形イメージングのための密度の高いストレインメーター配列としてのLFDASの能力を実証しました.
結論:
- 繊維光学ジオデシーは,地表の変形をほぼリアルタイムで画像化するための強力なツールを提供します.
- LFDASは,噴火の予測と危険性評価を改善するために,マグマの進化に関する重要な洞察を提供します.
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