地磁場逆転のダイナミック類似性について
Jean-Pierre Valet1, Alexandre Fournier, Vincent Courtillot
1Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, UMR 7154 CNRS, 1 rue Jussieu, 75238 Paris Cedex 05, France. valet@ipgp.fr
Nature
|October 6, 2012
まとめ
地磁場逆転は1億8000万年以上にわたって一貫した動態を有し,前駆体,極性スイッチ,リバウンドの3つの段階を特徴としています. これらの急速な出来事は,二極でないフィールドの出現と世俗的な変化を明らかにします.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- パレオマグネティズム (古磁気学) とは
- ジオダイナミクスは地力学です.
背景:
- 逆転時の地磁場の性質とダイナミクスは,未だに十分に理解されていない.
- 逆転は,弱まった軸二極とより顕著な非二極場によって特徴付けられます.
- 火山と堆積物の記録は,地磁場の振る舞いに異なる洞察を提供している.
研究 の 目的:
- 地磁場逆転の共通の動的特性を調査する.
- 逆転プロセスが地質学的時間尺度で一貫しているかどうかを判断する.
- 地磁場逆転の段階的なモデルを提案する.
主な方法:
- 地磁気逆転の十の詳細な火山記録の分析.
- 共通の期間を仮定して,これらのレコードをマッチングします.
- 発見と堆積物記録の比較.
主要な成果:
- 逆転の火山記録は,共通の動的特徴を示し,一致させることができます.
- 地磁気逆転プロセスは,少なくとも1億8千万年前から一貫しています.
- 逆転について,3段階のモデル (先行イベント,180°の極性スイッチ,リバウンド) が提案されています.
結論:
- 地磁場逆転は,地質時間における一貫した動態と期間を示しています.
- 逆転プロセスは,非二極フィールドが支配する明確な前駆的およびリバウンドフェーズを含む.
- 急速な極性スイッチフェーズ (<1,000年) は,通常の世俗的変動とは異なるメカニズムを含んでいる可能性があります.
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