Beneath the Pacific’s quiet surface, where the ocean floor is pockmarked by thousands of hidden mountains, a new model is rewriting the story of how Earth builds its undersea world. For decades, scientists have puzzled over the origins of over 40,000 seamounts—vast underwater mountains that never breach the waves. While the Hawaiian–Emperor chain offered a textbook example of volcanic hotspots driven by deep mantle plumes, that model only explained about 50 of the world’s seamount chains. The rest remained a mystery—until now.
A breakthrough study led by Professor Liu Lijun at the Institute of Geology and Geophysics (IGG) of the Chinese Academy of Sciences has reconstructed the 3D evolution of Earth’s mantle over the past 270 million years, revealing a unified mechanism behind even the most scattered seamounts. Using high-resolution simulations and unprecedented computational power, the team traced how deep mantle plumes—originating near the core-mantle boundary—interact with tectonic plates to create vast zones of volcanic activity far beyond classical hotspot zones.
The key lies in the asthenosphere, the soft, flowing layer of the upper mantle. When mantle plumes rise from the edges of large, dense structures called LLSVPs (Large Low-Shear-Velocity Provinces), they don’t just produce single volcanic chains. Instead, they deposit immense heat beneath young oceanic plates, creating widespread thermal anomalies. In the Western Pacific, for example, these anomalies align precisely with clusters of isolated seamounts—evidence that the region became a long-lived “seamount brewing zone.” The simulations show that plumes can also split as they rise, generating secondary plumes that seed additional volcanic activity across broad areas.
Remarkably, the heat from these plumes lingers for millions of years, slowly migrating with mantle flow and continuing to fuel volcanic eruptions far from the original plume center. The study found a strong linear correlation between the modeled temperatures of these residual anomalies and the actual elevations of seamounts—confirming their thermal origin. This dynamic process explains both the linear chains and the seemingly random clusters that dot the ocean floor.
Published in Nature Geoscience on June 10, 2026, this research not only resolves a long-standing geological puzzle but also opens new windows into Earth’s deep-time dynamics. By linking surface features to deep mantle behavior over hundreds of millions of years, it offers a more complete picture of how our planet shapes itself from within. As computational models grow more sophisticated, scientists may soon be able to forecast ancient volcanic events with the same precision we use to read Earth’s fossil record—revealing, one thermal pulse at a time, the hidden rhythms of a living planet.