‘Ghost plume' found beneath Oman harmless

Observer

4 days ago

The huge column of hot rock, known as a mantle plume or a 'ghost plume', which rises from deep inside the earth beneath Eastern Oman, has been identified by experts as harmless, not causing any volcanoes or obvious signs on the surface like other plumes around the world.
'This discovery of the long-hidden plume of magma beneath Oman's Salma Plateau is important because it shows that there may be many more hidden plumes beneath continents, quietly shaping landscapes and even plate movements without creating volcanoes,' said Harith al Kubaisy, Research Assistant at the Earthquake Monitoring Centre, Sultan Qaboos University (SQU).
Scientists explain that these ghost plumes may carry heat from deep inside the earth to the surface, affecting how the planet cools down and evolves over time. This finding changes the way we think about the Earth's inner workings, as not all plumes are visible at the surface.
'Normally, mantle plumes are detected when they melt rocks and create volcanoes, like those seen in Hawaii or Iceland. But the Dani plume, as scientists have named it, stays hidden because Oman's crust is very thick (over 100 kilometres deep), preventing the hot material from reaching the surface to form volcanoes,' he added.
First detailed in the journal Earth and Planetary Science Letters, the finding reveals a new class of deep mantle plumes that shape continents silently, without the typical signature of surface volcanoes.
While plumes typically leave a visible volcanic trail — like Hawaii's island chain—the Dani plume's evidence may have been erased by subduction activity in the nearby Makran zone. Still, researchers say this finding opens the door to discovering more 'ghost' plumes, particularly in regions with similar thick crusts, such as Africa. As seismic technologies advance, more silent subterranean forces shaping Earth's history may come to light.
Researchers from different countries used data from earthquakes around the world, collected by a network of seismic stations in Oman and the UAE, to create 3D images of the Earth's interior. These images showed a large area where seismic waves travel more slowly, indicating the rock is hotter than its surroundings. The plume rises from more than 660 kilometres underground all the way up towards the crust.
'Although there is no volcanic activity linked to the Dani plume, scientists have found other signs of its existence. The land above it is slightly higher than surrounding areas, suggesting the hot plume is pushing the ground upwards from below, which is called dynamic uplift. They also noticed special changes in deep underground layers, which occur when temperatures are higher,' Al Kubaisy said.
The study has also found that this hidden plume may have affected the movement of the Indian tectonic plate about 40 million years ago. The plume's heat and rising flow could have nudged the plate, slightly changing its direction as it moved towards Asia.