Scientists reveal how mantle currents feed volcanic islands remotely

Fragment of the lowermost continental mantle (Image: Prof Tom Gernon/University of Southampton)

Scientists have uncovered a hidden link between continents and ocean volcanoes. They found continental materials buried deep below remote volcanic islands. This discovery redefines how Earth's deep mantle recycles its own crust.

New Insights into Mantle and Continental Roots

Researchers discovered that deep mantle “waves” scrape material from beneath continents. These fragments travel sideways under oceans, feeding volcanic islands far from tectonic boundaries.

Published in Nature Geoscience, this study was led by Prof. Thomas Gernon with teams from GFZ Potsdam. Collaborators include University of Potsdam, Queen’s University Canada and Swansea University.

A Hidden Flow Beneath the Surface

The study reveals continents leave deep scars when they split apart. A mantle wave forms more than one hundred kilometres below ground. This wave scrapes ancient material from the continent's crystalline roots. The fragments drift sideways through the mantle beneath the ocean floor.

Feeding Volcanoes Across Vast Distances

The stripped continental matter moves thousands of kilometres through time. It slowly fuels volcanic eruptions across oceanic islands and seamounts. These volcanoes carry chemical traces matching continental mantle signatures. It proves that ocean islands can rise from continental remnants below.

A New Mechanism Beyond Mantle Plumes

Earlier theories relied on plumes or recycled sediments from subduction zones. But many volcanic regions are too cool for such plume activity.

This new model shows the mantle remains active after rifting ends. It keeps shifting, reorganizing and transporting continental material long after separation.

Echoes from Gondwana’s Breakup

Geochemical evidence from the Indian Ocean confirms the hidden process. Enriched materials appeared soon after the supercontinent Gondwana broke apart. As time passed, the signal weakened with the mantle's slowing motion. These findings change how scientists understand Earth's inner workings and its development.