A recent study published in Nature Geoscience sheds light on a remarkable geological process unfolding beneath the Afar region of Africa. Scientists have discovered a rhythmic, heartbeat-like pulse deep within the Earth’s crust, driven by molten magma rising from the mantle. This discovery, which was made by a team led by geologist Emma Watts, provides fresh insight into the dynamic interactions between the Earth’s interior and surface, particularly in the Afar Triple Junction where three tectonic plates are slowly pulling apart. As these tectonic plates continue to shift, they are laying the groundwork for the creation of a new ocean basin—a monumental shift in the planet’s geological structure.

The research offers vital clues to the processes that drive the breakup of continents, volcanic activity, and earthquake dynamics, all of which have profound implications for how we understand the constantly evolving Earth. By analyzing volcanic rocks from the region, scientists were able to detect distinct chemical signatures, which they believe are a result of the mantle’s pulsing movements beneath the surface. This groundbreaking discovery could change the way we view deep mantle dynamics and its effects on Earth’s tectonic activity.

Understanding the Pulse Beneath Afar

At the heart of this research is the observation that the mantle beneath the Afar region is not a uniform, static mass, as previously thought. Instead, it is dynamic and pulses with distinct chemical signatures. “We found that the mantle beneath Afar is not uniform or stationary – it pulses, and these pulses carry distinct chemical signatures,” says Emma Watts, who was involved in the study. The study’s findings suggest that these pulses, which are partially molten materials from the Earth’s mantle, are channeled through the rifting plates above.

This pulse-like activity plays a critical role in the tectonic processes occurring in the Afar region. The rifting plates, as they slowly tear apart, allow molten magma to surge upwards, creating volcanic activity and reshaping the Earth’s crust. Understanding how the mantle pulses could have broader implications for interpreting volcanic behavior and earthquake dynamics in other regions. “These ascending pulses of partially molten mantle are channeled by the rifting plates above. That’s important for how we think about the interaction between Earth’s interior and its surface,” Watts explains.

A tectonic map of the Afar rift system. (Val Rime/Wikimedia Commons.)

The Formation of a New Ocean Basin

The Afar Triple Junction is a geological hotspot where the Arabian, Nubian, and Somalian plates meet. Over time, the continental crust in this region will become increasingly thinner, and eventually, the surface will drop below sea level, forming a new ocean basin. This tectonic activity is part of a long-term process of continental breakup, which is currently in its early stages. The region is a natural laboratory for studying how new ocean basins are formed and how tectonic plates interact during the breakup process.

The study also highlights how mantle plumes can shape the dynamics of tectonic plates. The upwelling of mantle material beneath the plates is believed to play a role in how quickly and efficiently these rifts open. As the mantle material rises, it affects the plates above it, influencing the speed at which they separate and the intensity of volcanic activity in the region.

The Heartbeat of the Earth

One of the most striking elements of the research is the idea that the mantle’s movements resemble a heartbeat. Geologist Tom Gernon from the University of Southampton comments, “The chemical striping suggests the plume is pulsing, like a heartbeat.” The mantle’s pulse can be seen in the way the chemical signatures in volcanic rocks repeat across the region, with distinct bands that suggest periodic surges of molten material. This pulsing behavior is not uniform across the entire region; instead, it is influenced by the thickness of the tectonic plates above and the rate at which they are moving apart.

In faster-spreading rifts, like the one along the Red Sea, the pulses travel more efficiently and regularly, almost like a pulse through a narrow artery. This insight could change the way scientists think about mantle plumes and the forces that shape volcanic and tectonic activity. It suggests that mantle upwellings could be more closely tied to the dynamics of the plates above than previously thought.

A diagram of the plume, channeled by the three rifts. (Watts et al., Nat. Geosci., 2025)

Implications for Volcanism, Earthquakes, and Continental Breakup

The discovery of rhythmic pulses beneath the Afar region has profound implications for how we interpret various geological phenomena, including surface volcanism, earthquake activity, and the process of continental breakup. Derek Keir, a geophysicist at the University of Southampton, states, “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 how mantle material flows beneath tectonic plates will help researchers predict future volcanic eruptions and earthquakes, as well as gain a deeper understanding of how continents break apart over time.

The study also suggests that mantle plumes are not simply rising vertically but can flow beneath the base of tectonic plates, focusing volcanic activity where the plates are thinnest. This finding could help predict where future volcanic eruptions will occur and how intense they might be. “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,” Keir adds. This discovery opens new avenues for studying the dynamic interactions between the Earth’s mantle and its tectonic plates.