Pacific plate motion change caused the Hawaiian-Emperor Bend.
Pacific plate motion change caused the Hawaiian-Emperor Bend.
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DOI：
10.1038/ncomms15660
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发表时间：
2017-06-05
影响因子：
16.6
通讯作者：
Domeier M
中科院分区：
文献类型：
--
作者：
Torsvik TH;Doubrovine PV;Steinberger B;Gaina C;Spakman W;Domeier M
太平洋西北部夏威夷-帝王链明显的60°弯曲被不同地解释为始新世太平洋板块运动的突然变化(∼47 Ma)的结果，或者是弯曲形成前夏威夷热点的快速南移，或者是这两种原因的结合。皇帝海山的古地磁数据对夏威夷热点漂移的约束不明确，但地幔流动模拟表明，在80-47 Ma之间，该热点向南漂移4-9°。在这里，我们证明了热点南移不是夏威夷-帝王弯曲(Heb)形成的唯一或主要机制。虽然热点南移导致了今天观察到的皇帝海山更偏北的位置，但如果不引起太平洋板块运动方向在47 Ma左右的显著变化，就不能解释Heb的形成。夏威夷-帝王链有一个60°的弯曲，这被解释为太平洋板块在47 Ma运动或夏威夷热点漂移的结果。在这里，作者指出热点漂移不是弯曲形成的主要机制，但涉及到∼47 Ma时太平洋板块运动方向的变化。
A conspicuous 60° bend of the Hawaiian-Emperor Chain in the north-western Pacific Ocean has variously been interpreted as the result of an abrupt Pacific plate motion change in the Eocene (∼47 Ma), a rapid southward drift of the Hawaiian hotspot before the formation of the bend, or a combination of these two causes. Palaeomagnetic data from the Emperor Seamounts prove ambiguous for constraining the Hawaiian hotspot drift, but mantle flow modelling suggests that the hotspot drifted 4–9° south between 80 and 47 Ma. Here we demonstrate that southward hotspot drift cannot be a sole or dominant mechanism for formation of the Hawaiian-Emperor Bend (HEB). While southward hotspot drift has resulted in more northerly positions of the Emperor Seamounts as they are observed today, formation of the HEB cannot be explained without invoking a prominent change in the direction of Pacific plate motion around 47 Ma. The Hawaiian-Emperor Chain has a 60° bend that has been interpreted as the result of Pacific plate motion at 47 Ma or drift of the Hawaiian hotspot. Here, the authors show that hotspot drift cannot be the dominant mechanism for bend formation, but involves a change in the direction of Pacific plate motion at ∼47 Ma.