The Mountains Beneath Earth Dwarf Everest by 100 Times

Scientists just released something that quietly rewrites the scale of everything we thought we knew about Earth’s interior. Published on January 22, 2025, in Nature, a new study presents the first complete 3D map of how the entire mantle absorbs seismic energy. What it reveals is staggering: two colossal structures buried deep beneath Africa and the Pacific Ocean, each rising roughly 1,000 kilometers from the base of the mantle. Mount Everest, at 8.8 kilometers tall, doesn’t even register by comparison.

This isn’t a distant theoretical finding. It reframes what Earth is, how it works, and why the ground beneath your feet is far stranger than any mountain range above it.

What Most People Believe About Earth’s Extremes

Ask anyone to name Earth’s most dramatic geological feature, and Everest comes up almost instantly. At 8,849 meters above sea level, it’s the tallest point on the planet’s surface. It dominates geography textbooks, bucket lists, and the cultural imagination of exploration.

The assumption runs deep: the most extreme structures on Earth are the ones we can see. Mountain ranges, ocean trenches, volcanic arcs. These are the landmarks that define geological scale in the public mind.

There’s also a quieter assumption underneath that: Earth’s interior is relatively uniform. Hot, dense, and largely featureless beyond the basic layers of crust, mantle, and core. Most people picture something like a hard-boiled egg, just much hotter.

The First Crack: Ocean Rock at the Top of Everest

Before we get to what’s underground, consider what’s already strange about Everest itself. The very summit of the world’s highest mountain is composed of marine limestone. Fossils of ocean-dwelling creatures sit at 8,849 meters above sea level, embedded in rock that was once part of a seafloor. Everest was once at the bottom of the Tethys Sea, and tectonic forces pushed it skyward over tens of millions of years.

That fact alone should calibrate our intuitions. The surface of Earth is not static. It folds, subducts, and rises. What looks permanent is just slow-motion chaos.

If the surface can hide that kind of history, what might the deep interior be concealing? The answer, it turns out, is structures so large they make the surface geology look like wrinkles on a bedsheet.

The Scale Comparison That Changes Everything

What the New 3D Mantle Map Actually Found

The research team, led by Sujania Talavera-Soza at Utrecht University, analyzed 104 large earthquakes recorded between 1975 and 2018. Collaborators included Laura Cobden, Ulrich H. Faul from MIT, and Arwen Deuss from Vassar College. Together, they built a global model called QS4L3, the first 3D map of seismic attenuation across the entire mantle.

Seismic attenuation measures how much a seismic wave is absorbed or weakened as it travels through rock. Hotter, softer, or partially molten material absorbs more energy. Cooler, rigid rock lets waves pass through cleanly. By mapping these differences globally, the team could identify regions of dramatically different composition and temperature deep inside the Earth.

What emerged were two enormous anomalies: the Large Low-Seismic-Velocity Provinces, or LLSVPs. One sits beneath Africa. One sits beneath the Pacific Ocean. Both are hotter than the surrounding mantle, both absorb seismic waves differently, and both rise approximately 1,000 kilometers from the core-mantle boundary, which itself sits roughly 1,800 miles beneath Earth’s surface.

The LLSVPs together outline roughly a quarter of the entire zone where the mantle meets the outer core. These are not small anomalies. They are continental-scale features at the very base of the planet’s rocky interior.

Why the Pacific Ring of High Attenuation Matters Too

The LLSVPs weren’t the only discovery. The new QS4L3 model also revealed a broad ring of high seismic attenuation encircling the Pacific in the lower mantle. High attenuation means more energy is being absorbed, which points to hotter, softer, or compositionally distinct rock.