Something is ‘pulsing' beneath the Earth, scientists say – and it could tear a continent apart

Independent

2 days ago

Scientists have detected deep pulses in the Earth beneath Africa – and it could tear the continent apart.
The pulses are made up of molten mantle rock surging in rhythm, the researchers say. The plume of hot mantle is surging upwards in pulses that are like a heartbeat, they say.
Eventually, the continent will be torn apart and a new ocean will be formed.
That will take place over millions of years, as the tectonic plates are ripped apart at rift zones like those in the Afar region in Ethiopia. That is where scientists found the evidence of the unexpected behaviour.
'We found that the mantle beneath Afar is not uniform or stationary – it pulses, and these pulses carry distinct chemical signatures,' said Emma Watson, the scientist who led the study.
'These ascending pulses of partially molten mantle are channelled by the rifting plates above. That's important for how we think about the interaction between Earth's interior and its surface.'
In the research, scientists gathered samples from the Afar region, where three tectonic rifts meet. Scientists have long thought that mantle was being pushed up making the crust extend, eventually giving birth to a new ocean basin, but did not know how it was happening.
To better understand that process, they took those samples and combined them with existing data and models to understand the plume beneath the surface of the Earth.
They showed that there is one asymmetric plume beneath the surface.
'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,' said Derek Keir, a co-author.
'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,'
The work is described in a new paper, 'Mantle upwelling at Afar triple junction shaped by overriding plate dynamics', published in the journal Nature Geoscience.