Using unprecedented computational power and model resolution, a research team led by Prof. LIU Lijun at IGGCAS, reconstructed the dynamic evolution of Earth’s interior over the past 270 million years. Based on these simulations, the team analyzed the spatiotemporal behavior of deep-rooted mantle plumes and their role in generating volcanism within ocean basins. Their results suggest that both linear hotspot chains and scattered seamounts originate from residual asthenospheric heat supplied by mantle plumes rising from the core-mantle boundary. This study provides a unified explanation for the formation of different types of seamounts and was published online in Nature Geoscience on June 10th.
Recent studies have revealed that more than 40,000 seamounts are distributed across the world’s oceanic plates and occur in nearly all ocean basins. According to the classical hotspot hypothesis, hot mantle plumes rising from the core-mantle boundary induce partial melting beneath moving tectonic plates, producing volcanic chains such as the Hawaiian Islands. However, only about 50 seamount chains conform to the classical hotspot model. This striking discrepancy between the number of recognized hotspots and the abundance and spatial distribution of global seamounts raises a fundamental scientific question: are all seamounts generated by hotspot and mantle plume activity? If so, how can such a limited number of hotspots explain the widespread occurrence of seamounts throughout the global oceans?
Several hypotheses have been proposed to explain seamount formation, including sub-lithospheric small-scale convection, edge-driven convection, shear-driven upwelling, slab-flexure-induced rupture, and secondary plumes. Notably, most of these models downplay or exclude the role of deep-rooted mantle plumes. In addition, many remain largely conceptual and descriptive, with limited links to the actual evolution of the deep mantle.
The IGGCAS research team employed a newly refined high-resolution global data-assimilation model that successfully reproduces not only most present-day hotspots and their underlying thermal structure within the asthenosphere, but also the spatiotemporal evolution of deep mantle plumes associated with major hotspots such as Hawaii (Fig. 1). The 4D model reveals that the formation and evolution of both linear, well-organized seamount chains and isolated scattered seamounts are closely associated with asthenospheric thermal anomalies generated by mantle plumes originating from the core-mantle boundary (Fig. 2).
Fig. 1: Comparison between the modeled present-day 3D mantle plume structure and geological observations. The upper surface shows continental topography, while white regions show continental shelves, seamounts, island arcs, and other geological features. Orange isosurfaces represent mantle plumes, while gray isosurfaces indicate subducting slabs deeper than 300 km.
Taking the Pacific plate as an example, during the early stages of mantle plume ascent, large amounts of plume-derived heat accumulate beneath the young Pacific lithosphere, forming extensive asthenospheric thermal anomalies. These anomalies exhibit a clear spatiotemporal correspondence with scattered seamounts in the Western Pacific Seamount Province. During subsequent evolution, mantle plumes may split either from their lower-mantle roots or within the mantle transition zone, generating secondary mantle plumes. This process further increases the number of modeled hotspots and creates favorable conditions for the formation of additional seamount chains.
The hot material associated with these plumes can persist within the asthenosphere over geological timescales, gradually migrating and dispersing under the influence of mantle convection. Modeled temperatures of these residual thermal anomalies show a significant linear correlation with observed seamount elevations at corresponding locations (Fig. 2). These results suggest that asthenospheric thermal anomalies can generate numerous small and scattered seamounts, confirming that such thermally anomalous regions serve as “seamount brewing zones”.
Fig. 2: Significant spatiotemporal correlations between mantle plume-induced asthenospheric thermal anomalies and observed seamount occurrences. (a–f) Background colors denote asthenospheric temperature anomalies at different evolutionary stages. Green dots mark the paleo-emplacement locations of observed seamounts. (g) Locations and elevations of all identified seamounts. (h) Relationship between observed seamount elevations and modeled present-day thermal anomalies directly beneath each seamount. The red line represents the mean thermal anomaly, and the black line denotes the linear regression fit. (i) Probability distribution of modeled thermal anomalies for different seamount-elevation classes.
This study employs a high-resolution global model of subduction and mantle plume evolution to successfully reconstruct the evolutionary history of deep mantle plumes and the spatiotemporal distribution of asthenospheric thermal anomalies, offering a new explanation for the origin of intraplate seamounts. Its major significance lies in identifying a unified deep-Earth dynamic mechanism responsible for the formation of widely distributed seamounts, thereby extending and refining the classical mantle plume model.
Publication information:DOI: 10.1038/s41561-026-02006-0.
Contact:
Professor LIU Lijun
E-mail: ljliu@mail.iggcas.ac.cn
IGGCAS, State Key Laboratory of Lithospheric and Environmental Coevolution
