Scientists led by the University of Southampton have unveiled groundbreaking evidence showing rhythmic surges of molten mantle rock rising beneath Africa’s Afar region. These surges are gradually tearing the continent apart and forming a new ocean basin.
The study was published recently in Nature Geoscience. It reveals that the mantle plume under Ethiopia’s Afar behaves like a beating heart. The plume pulses molten rock upwards. This finding changes our understanding of how Earth’s interior interacts with the tectonic plates above, shaping surface geology.
THE DYNAMIC MANTLE BENEATH AFAR: MORE THAN JUST HEAT
For decades, geologists have known that the Afar region is tectonically unique. Three major rifts converge there: the Main Ethiopian Rift, the Red Sea Rift, and the Gulf of Aden Rift. These rifts are zones where the Earth’s crust is slowly pulling apart, eventually leading to ocean formation.
The new research reveals that the mantle plume beneath Afar is not a stationary blob of heat. Instead, it pulses upward in rhythmic surges. It carries distinct chemical signatures. These signatures reflect the flow of molten rock from deep inside the Earth.
Dr. Emma Watts, lead author, conducted this research at Southampton and is now at Swansea University. She explained, “The mantle beneath Afar pulses. These pulses are influenced by the rifting tectonic plates above. This pulsing is crucial for understanding Earth’s deep interior and surface evolution.”
HOW MANTLE PULSES DRIVE CONTINENTAL BREAKUP
Tectonic plates stretch and thin over millions of years at rift zones like Afar. This slow, plastic-like deformation eventually causes the crust to rupture, marking the birth of a new ocean basin.
The mantle pulses rise and interact dynamically with the stretching plates. This interaction controls where and how the plates thin and break apart. According to the study, these pulses behave differently depending on factors like plate thickness and rifting speed.
Professor Tom Gernon, co-author at Southampton, described this by comparing mantle pulses to a heartbeat. He said, “In faster-spreading rifts such as the Red Sea, pulses move more regularly. They are similar to blood flowing through a narrow artery.”
A MULTI-INSTITUTIONAL EFFORT UNLOCKING EARTH’S SECRETS
This discovery is the result of a broad collaboration. It involves ten institutions across the UK, Europe, and Africa. These institutions include Lancaster University, Universities of Florence and Pisa, GEOMAR in Germany, and Addis Ababa University.
The team analyzed over 130 volcanic rock samples collected throughout the Afar region and the Main Ethiopian Rift. Using advanced statistical modeling combined with geochemical data, they mapped the mantle plume’s structure and flow beneath the rift system.
Their results identified a single, asymmetric mantle plume beneath Afar, with repeating chemical bands across the rift arms. These “geological barcodes” reveal how mantle flow is structured beneath the continent’s surface.
LINKING MANTLE PULSES TO VOLCANISM AND EARTHQUAKES
The mantle plume’s pulsing movement profoundly impacts surface phenomena, including volcanic eruptions and earthquake activity.
Dr. Derek Keir, co-author and associate professor at the Universities of Southampton and Florence, emphasized that mantle upwellings evolve together with tectonic plate motion. This connection shapes volcanic activity and influences how continents break apart.
These pulses focus volcanic activity where the plate is thinnest. They help explain the distribution of volcanoes and seismic zones in the Afar region. Understanding this process is key to predicting volcanic hazards and assessing earthquake risk.
WHY THE AFAR REGION OFFERS A UNIQUE GEOLOGICAL WINDOW
Few places on Earth offer such clear access to processes occurring deep beneath tectonic plates. The Afar region is a geological hotspot where three rift systems meet. This makes it an ideal natural laboratory to study the birth of ocean basins.
As the African continent continues to split, Afar provides real-time evidence of how mantle dynamics drive continental breakup. This research not only sheds light on the past but also informs future models of plate tectonics and mantle convection.
Dr. Watts stated, “Without combining multiple expertise and methods, understanding this complex system would be nearly impossible. This project demonstrates how multidisciplinary science is essential for piecing together Earth’s interior puzzle.”
THE FUTURE OF RESEARCH ON MANTLE-PLATE INTERACTION
Scientists aim to explore how mantle pulses vary with changes in tectonic plate motion following this discovery. They also want to understand how quickly molten mantle flows beneath plates. This will improve predictions of geological hazards and refine models of Earth’s interior dynamics.
Further studies may also explore similar mantle pulses in other rifting zones worldwide. Researchers will assess if this heartbeat-like behavior is a universal feature of mantle plumes beneath rifting continents.
A PULSING HEART BENEATH OUR FEET
This research uncovers a fascinating aspect of Earth’s inner workings. A mantle plume pulses rhythmically. It directly shapes the surface of our planet. The Afar region in Africa stands as a dynamic landscape where continents fracture, and new oceans are born.
By linking mantle flow to tectonic plate behavior, scientists can better understand volcanic activity, earthquakes, and the grand process of continental breakup. This discovery enriches our knowledge of Earth’s geology and opens exciting avenues for future exploration.
