A subduction and mantle plume origin for Samoan volcanism

Vincent Strak*, Wouter P. Schellart

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review


The origin of Samoan volcanism in the southwest Pacific remains enigmatic. Whether mantle melting is solely caused by a mantle plume is questionable because some volcanism, here referred to as non-hotspot volcanism, defies the plume model and its linear age-progression trend. Indeed, non-hotspot volcanism occurred as far as 740 km west of the predicted Samoan hotspot after 5 Ma. Here we use fully-dynamic laboratory subduction models and a tectonic reconstruction to show that the nearby Tonga-Kermadec-Hikurangi (TKH) subduction zone induces a broad mantle upwelling around the northern slab edge that coincides with the non-hotspot volcanic activity after 5 Ma. Using published potential mantle temperatures for the ambient mantle and Samoan mantle plume, we find that two geodynamic processes can explain mantle melting responsible for intraplate volcanism in the Samoan region. We propose that before 5 Ma, the volcanism is consistent with the plume model, whereas afterwards non-hotspot volcanism resulted from interaction between the Subduction-Induced Mantle Upwelling (SIMU) and Samoan mantle plume material that propagated west from the hotspot due to the toroidal component of slab rollback-induced mantle flow. In this geodynamic scenario, the SIMU drives decompression melting in the westward-swept plume material, thus producing the non-hotpot volcanism.

Original languageEnglish
Article number10424
Pages (from-to)1-12
Number of pages12
JournalScientific Reports
Publication statusPublished - 11 Jul 2018


We thank Bernhard Steinberger and an anonymous reviewer for their constructive comments that allowed us to improve the manuscript. We also thank João Duarte and Zhihao Chen for their helpful assistance in the lab. WPS acknowledges support from the Australian Research Council through Discovery grant DP120102983 and Future Fellowship FT110100560, and from the Dutch Science Foundation (NWO) through Vici Fellowship 016. VICI.170.110.

FundersFunder number
Australian Research CouncilFT110100560, DP120102983
Nederlandse Organisatie voor Wetenschappelijk Onderzoek


    Dive into the research topics of 'A subduction and mantle plume origin for Samoan volcanism'. Together they form a unique fingerprint.

    Cite this