日本北東部における地震間ストレスの季節的調節は,積雪によって引き起こされる
1Division of Earth Rotation, National Astronomical Observatory, 2-12 Hoshigaoka, Mizusawa, Iwate 023-0861, Japan. heki@miz.nao.ac.jp
まとめ
日本における季節的な雪の負荷は,グローバル・ポジショニング・システム (GPS) のサイトを大幅に移動させ,地上移動の年間変動を引き起こします. この研究では,GPS測定における雪の深さの影響を定量化しています.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- ジオデシ (Geodesy) とは
- 環境科学 環境科学
背景:
- 日本北東部の連続グローバルポジショニングシステム (GPS) データは,場所の座標の明確な年間周期的な変動を明らかにしています.
- これらの変動には,最大弧正規収縮と沈沈が含まれるが,両者は3月にピークに達する.
- 日本北東部では大雪が降り,最大深さは3月に数メートルに達する.
研究 の 目的:
- 季節的な雪積載と,日本北東部のGPSサイトの観測された年間移転の関係について調査する.
- GPSデータにおける周期的な変動の原因となる雪の負荷の程度を判断する.
主な方法:
- 観測された雪の深さの比較とGPSデータから推定された負荷分布.
- 連続したGPSサイトからのタイムシリーズデータの分析.
主要な成果:
- 雪に起因する表面負荷は,毎年GPSサイトの移転の主な原因であることが判明しました.
- スノーロードは,太平洋プレート沈殿によって引き起こされる,日本北東部における長期のストレスの蓄積の調節に大きな影響を与える.
結論:
- 季節的な雪の積みと融解は,日本北東部でGPSデータで観測された年間垂直と水平の移動の主要な要因である.
- 雪の負荷はストレスの蓄積に影響するが,季節性地震の発生パターンにおけるその正確な役割は,さらなる調査を必要とする開かれた質問のままである.
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