Chinese scientists have discovered that secondary mantle plumes, which split from primary roots in the mantle, drive the formation of the world’s 40,000 seamounts. Published in Nature Geoscience, the research provides a new framework to explain why most submarine volcanoes don’t follow the traditional, limited hotspot model.
Why the traditional hotspot model failed to explain global seamounts
For decades, the conventional hotspot hypothesis suggested that high-temperature mantle plumes from the Earth’s core trigger rock melting under drifting plates. This process creates long chains of submarine volcanoes, similar to the Hawaiian Islands. However, this model only accounts for about 50 specific seamount chains.
Current surveys show over 40,000 seamounts dispersed across nearly every ocean basin. According to the study, there is a significant mismatch between the old hotspot model and the actual quantity, scale, and spatial distribution of these underwater mountains. The existing theory couldn’t explain how a few hotspots could produce such a vast, scattered number of features.
How secondary mantle plumes create new volcanic chains
The research, led by the Institute of Geology and Geophysics at the Chinese Academy of Sciences, introduces a unified framework for intraplate seamounts. Researchers found that while primary plumes originate from the core-mantle boundary, they don’t always remain single, continuous structures.
During the evolution of these plumes, they can split from the root within the lower mantle or the middle part of the mantle transition zone. This splitting generates secondary mantle plumes. These secondary plumes increase the number of shallow hotspots, providing the necessary conditions to form additional seamount chains across the globe.
In the Pacific region, for instance, the study observed that large volumes of hot plume material accumulated beneath the young Pacific plate during early upwelling stages. This created a broad thermal anomaly in the asthenosphere that facilitated complex volcanic formations.
What this means for future deep-sea resource mapping
Understanding the origin of seamounts will likely change how industries approach deep-sea exploration. Because seamounts are often linked to specific thermal activities and mantle structures, they serve as indicators for geological processes that influence the seafloor.
Future trends in oceanography will likely focus on using these plume models to map mineral-rich zones. Seamounts often host polymetallic nodules and other resources. By predicting where secondary plumes might create new or existing seafloor features, researchers can better identify potential sites for deep-sea mining and biodiversity conservation.
How supercomputing is accelerating geological timelines
The complexity of recreating 270 million years of subduction history required immense computational power. The team conducted their simulations on the new-generation Tianhe supercomputer at the National SuperComputer Center in Tianjin, China.
This development highlights a growing trend in Earth sciences: the reliance on global data assimilation models to replicate deep-earth structures. As supercomputing capabilities expand, scientists will be able to model even more granular spatiotemporal evolutions of hotspots like Hawaii. This allows for more accurate predictions of how the Earth’s crust and mantle interact over millions of years.
Comparison: Traditional vs. Expanded Mantle Models
| Feature | Conventional Hotspot Model | New Unified Framework |
|---|---|---|
| Primary Driver | Single mantle plumes from core-mantle boundary | Primary plumes plus secondary splitting plumes |
| Seamount Count | Limited (approx. 50 chains) | Extensive (over 40,000 seamounts) |
| Distribution | Linear, predictable chains | Scattered, intraplate distribution |
Frequently Asked Questions
What is a seamount?
A seamount is an underwater mountain rising from the ocean floor that does not reach the water’s surface.
Why are there so many seamounts?
According to the Chinese Academy of Sciences study, secondary mantle plumes splitting from larger roots create numerous shallow hotspots, resulting in thousands of scattered seamounts.
What was the role of the Tianhe supercomputer?
The Tianhe supercomputer was used to run complex simulations that replicated the thermal structure of the asthenosphere and the history of mantle plume evolution.
Want to stay updated on the latest breakthroughs in Earth science and deep-sea exploration? Subscribe to our newsletter or leave a comment below with your thoughts on these geological findings.