Scientists have identified two massive thermochemical formations at Earth’s core-mantle boundary that refine understanding of the planet’s interior architecture. Using advanced seismic modeling techniques, researchers mapped dome-like structures that may extend up to about 1,000 kilometers above the core-mantle boundary—comparable to roughly 100 times Mount Everest’s height—and spanning thousands of kilometers laterally.
The findings, published in Nature in January 2025, are based on the QS4L3 model, a global three-dimensional seismic attenuation model that helps distinguish temperature variations from compositional differences within Earth’s mantle.
The Breakthrough Behind the Discovery
The research team associated with Utrecht University, including Professor Arwen Deuss and first author Sujania Talavera-Soza, spent years refining seismic models and assembling global earthquake data. Their innovation involved analyzing whole-Earth oscillations during large earthquakes—known as normal-mode oscillations—to resolve structures that previous models could not clearly characterize.
By jointly considering wave velocity and attenuation, scientists improved separation of thermal effects from compositional anomalies, clarifying the nature of continent-scale structures at Earth’s deepest mantle boundary that had long remained enigmatic.
These structures, formally known as Large Low Shear Velocity Provinces (LLSVPs), are commonly referred to as Tuzo (beneath Africa) and Jason (beneath the central Pacific).
They are thought to interact with and possibly anchor mantle plumes associated with volcanic hotspots including Hawaii, Iceland, and Réunion, and they influence mantle flow patterns that inform models of mantle convection and Earth’s long-term geodynamic evolution.
Ripple Effects Across Science and Industry
Research institutions worldwide are actively integrating the new attenuation model into existing seismic and geodynamic studies to better constrain the deep mantle. Geophysicists, volcanologists, and planetary scientists are combining seismic datasets and updating global mantle models, and funding bodies in several regions are increasing support for deep-Earth research using normal modes, body waves, and satellite geodesy.
The study encourages expanded deployments of seismic stations, ocean-bottom seismometers, and complementary observations, including gravity data, to refine how these long-lived anomalies interact with the broader mantle system.
The implications may extend beyond academia. Companies developing seismic sensors, modeling software, and subsurface imaging technologies could benefit from increased demand as deep-Earth models become more detailed.
Resource industries, including oil, gas, and mining, are interested in how improved understanding of mantle convection, slab recycling, and deep compositional reservoirs might sharpen large-scale geodynamic frameworks that underpin exploration strategies, even though the LLSVPs themselves are far deeper than economically accessible deposits.
Public Engagement and Educational Transformation
Educational publishers, museums, and science centers are beginning to incorporate modern views of the deep mantle—such as LLSVPs and plume-generation zones—into curricula and exhibits. Planetariums and science outreach programs are developing visualizations and virtual experiences of Earth’s interior, using results from seismic tomography and attenuation studies to communicate the scale and invisibility of these deep structures to the public.
Interest in geology, geophysics, and Earth-system science is supported by the growing availability of high-impact visual material derived from global seismic models and whole-Earth oscillation data.
These developments also contribute to broader cultural conversations about Earth’s origins and deep time. The realization that some of the planet’s largest structures lie entirely hidden in the lowermost mantle fosters renewed curiosity about how internal processes shape surface environments over billions of years, informing discussions about environmental change, planetary habitability, and the evolution of rocky planets like Mars and Venus.
Looking Forward
Scientists plan to further refine seismic attenuation models and integrate them with velocity, density, and mineral-physics constraints to investigate how LLSVPs influence hotspots, plume generation, and plate-tectonic cycles. International teams are preparing new analyses of normal modes, expanded seismic networks, and joint inversions with gravity and geodynamic modeling to deepen understanding of these regions.
Researchers are also exploring how variations in grain size and composition in LLSVPs contribute to inferred high viscosities and long-term stability, distinguishing them from surrounding, colder, small-grain-size regions associated with subducted slabs.
These hidden, continent-sized structures represent a major focus in modern Earth science. Rising perhaps up to about 1,000 kilometers above the core-mantle boundary and likely persisting for at least hundreds of millions of years, if not longer, they are considered among the largest and most stable features inside Earth, with evidence suggesting that, unlike much of the surrounding mantle, they have remained quasi-stationary over very long timescales.
As research progresses, evolving models of Tuzo and Jason will continue to influence geology, planetary science, education, certain industries, and collective understanding of the dynamic world beneath Earth’s surface.