Pacific plate motion change caused the Hawaiian-Emperor Bend

• Published in: Nature communications 2017-06, Vol.8 (1), p.15660-15660, Article 15660
• Main Authors: Torsvik, Trond H., Doubrovine, Pavel V., Steinberger, Bernhard, Gaina, Carmen, Spakman, Wim, Domeier, Mathew
• Format: Article
• Language: English
• Subjects: 704/2151/210; 704/2151/412; 704/2151/508; 704/2151/562; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms15660

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.