Hot pulses from deep within the Earth are slowly tearing a giant crack through Africa

Beneath the African continent, powerful plumes of molten rock are slowly reshaping the land from below. Scientists studying this massive geological event have uncovered new clues about what lies below the surface and how these forces shape the planet. Their work reveals that powerful surges of molten rock, called mantle upwellings, pulse upward beneath a key region in East Africa. These pulses are reshaping the landscape, fueling volcanoes, and preparing the way for a new ocean to form.

The research focuses on a region called Afar, located in northeastern Africa. It's one of the only places on Earth where three giant cracks, or rifts, in the Earth's surface meet. These rifts stretch across Ethiopia and beyond, and over time, they are splitting the land apart. Underneath these rifts, a large column of hot rock from deep inside the planet rises like a heartbeat, pushing toward the surface.

A team of researchers from the University of Southampton has found that this hot plume beneath Afar does not rise smoothly. Instead, it pulses, sending waves of partially molten rock upward at intervals. These pulses carry unique chemical markers, which the team identified by analyzing over 130 rock samples from recent volcanoes across the region.

“We found that the mantle beneath Afar is not uniform or stationary – it pulses, and these pulses carry distinct chemical signatures,” said Dr. Emma Watts, who led the study while at the University of Southampton. “These ascending pulses of partially molten mantle are channelled by the rifting plates above.”

This finding matters because it shows how the movement of tectonic plates – the massive slabs of Earth's outer shell – directly influences what happens deep below. When plates stretch and thin, they allow the mantle to rise more easily. In places where the plates are spreading apart more quickly, such as the Red Sea Rift, the pulses move faster and more regularly. In areas with slower movement, like the Main Ethiopian Rift, the pulses are less frequent and spread farther apart.

Professor Tom Gernon of the University of Southampton, a co-author of the study, explained, “The chemical striping suggests the plume is pulsing, like a heartbeat. These pulses appear to behave differently depending on the thickness of the plate, and how fast it’s pulling apart.”

The rising mantle does more than just flow. It brings heat and pressure to the surface, where it causes volcanoes to form and earthquakes to strike. The way these upwellings move and shift helps explain why certain places experience more volcanic and seismic activity than others.

The Afar region gives scientists a rare window into how continents break apart. Over millions of years, as the rifts grow, they stretch and thin the land like warm putty. Eventually, these stretches reach a breaking point and begin to form new ocean basins. That’s what is slowly happening in East Africa right now.

Researchers say the process is controlled from below by the mantle upwelling. This flow of molten rock from Earth’s interior shapes the surface above. But until now, scientists didn’t fully understand the structure of this deep plume or how it changes over time.

To investigate, the team collected rock samples from across the triple junction where the three rift zones meet. They analyzed the chemical makeup of the volcanic rocks, then combined that data with earlier research and advanced computer models. The results point to a single, uneven plume feeding all three rifts. The plume shows repeating bands of chemical signals, similar to barcodes, that stretch across the rift zones.

The spacing between these bands isn’t random. In places where the tectonic plates pull apart faster, the bands are closer together. Where movement is slower, the bands spread out more. This pattern supports the idea that mantle material flows more efficiently through thinner, faster-moving parts of Earth’s crust.

Dr. Watts explained the significance: “That’s important for how we think about the interaction between Earth’s interior and its surface.”

Dr. Derek Keir, another co-author from the University of Southampton and the University of Florence, said: “We have found that the evolution of deep mantle upwellings is intimately tied to the motion of the plates above. This has profound implications for how we interpret surface volcanism, earthquake activity, and the process of continental breakup.”

Understanding this link helps scientists predict where volcanoes and earthquakes are likely to occur. It also helps explain how continents slowly pull apart and form new oceans. Over time, the Afar region could become a wide ocean basin, just like the Atlantic or Indian Ocean.

Dr. Keir added, “The work shows that deep mantle upwellings can flow beneath the base of tectonic plates and help to focus volcanic activity to where the tectonic plate is thinnest. Follow-on research includes understanding how and at what rate mantle flow occurs beneath plates.”

Dr. Watts pointed out how vital teamwork was to the study: “Working with researchers with different expertise across institutions, as we did for this project, is essential to unravelling the processes that happen under Earth’s surface and relate it to recent volcanism.”

She added, “Without using a variety of techniques, it is hard to see the full picture, like putting a puzzle together when you don’t have all the pieces.”

This research shows that the Earth’s interior is not still or simple. It is dynamic, shifting, and shaped by forces both deep below and high above. The pulses rising from the mantle under Afar tell a story about how Earth changes, not just over centuries but over millions of years.

The discovery of this pulsing mantle opens new questions about how Earth's layers interact. Why do the pulses happen in regular waves? How exactly do they trigger volcanoes at the surface? And how fast is this future ocean growing beneath East Africa?

By collecting more data and building even better models, scientists hope to answer those questions. For now, the pulsing heart of Earth beneath Afar continues to beat, slowly shaping the planet’s future one volcanic surge at a time.

Research findings are available online in the journal Nature Geoscience.

Note: The article above provided above by The Brighter Side of News.

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