Latest news with #tectonic
The Independent
15 hours ago
- Science
- The Independent
The deep Earth discovery that could put a new ocean where a continent is
Scientists have detected rhythmic surges of molten mantle rock, described as similar to a heartbeat, deep beneath the African continent. These upward-surging pulses of hot mantle could eventually lead to the continent tearing apart and the formation of a new ocean over millions of years. Evidence for this phenomenon was found in the Afar region of Ethiopia, a triple junction where three tectonic rifts converge. Emma Watson, lead scientist of the study published in journal Nature Geoscience, explained that the mantle beneath Afar is not static but pulses, with these ascending molten channels being guided by the overriding rifting plates. The research highlights how deep mantle upwellings are linked to plate motion, influencing surface volcanism, earthquake activity, and the process of continental breakup. Something is 'pulsing' beneath the Earth, scientists say – and could tear a continent apart
Times
15 hours ago
- Science
- Times
How a plume of magma threatens to one day rip east Africa apart
Africa is being torn apart by a pulsing plume of magma rising from deep within the Earth that is set to slice off the continent's east coast to form a new ocean, researchers have found. A new ocean basin will gradually form in a low-lying region of Ethiopia and, in several million years' time, scientists believe this will develop into a vast crack running from northern Ethiopia down to the middle of Mozambique. This could result in a 3,200-mile stretch of the east African coast, extending several hundred miles inland, splitting from the rest of the continent as the tectonic plate stretches, thins and eventually ruptures 'almost like soft plasticine'. This would leave a narrow ocean between continental Africa and a vast new island made up of present-day Somalia and large parts of what are now Ethiopia, Kenya, Tanzania and Mozambique. The Afar region of Ethiopia is a rare area where three tectonic rifts converge: the Main Ethiopian, Red Sea and Gulf of Aden rifts. Geologists had suspected that a 'hot upwelling' of molten mantle, often known as a plume, was rising up from between 620 and 1,700 miles deep, shooting upwards and melting the continental crust, weakening and thinning it. Researchers from the University of Southampton collected more than 130 samples of volcanic rock from the Afar region and Main Ethiopian Rift. They used modelling to understand the structure of the crust and mantle in the area. They found that beneath the Afar region there was an asymmetrical plume coming up out of the mantle, with patterns that differed in each of the three rifts. 'We found that the mantle beneath Afar is not uniform or stationary — it pulses, and these pulses carry distinct chemical signatures,' said Dr Emma Watts, lead author of the study who is now at Swansea University. 'These ascending pulses of partially molten mantle are channelled by the rifting plates above.' The results suggest the plume is 'pulsing like a heartbeat', said Tom Gernon, a professor of Earth science at Southampton. 'These pulses appear to behave differently depending on the thickness of the plate, and how fast it's pulling apart. In faster-spreading rifts like the Red Sea, the pulses travel more efficiently and regularly like a pulse through a narrow artery.' When a hot plume of magma rises from deep within the Earth it flows beneath the base of the tectonic plates and helps to 'focus volcanic activity to where the tectonic plate is thinnest'. 'This has profound implications for how we interpret surface volcanism, earthquake activity and the process of continental break up,' said Dr Derek Keir, a co-author of the study, which is published in the journal Nature Geoscience. Gernon said that part of the Afar region was about 120 metres below sea level and had been flooded by the sea several times in the past, including 80,000 years ago, as shown by salt deposits in the area. 'The formation of a fully developed ocean and mid-ocean ridge — that is, a plate tectonic feature where new ocean crust is created — in this region is likely to take several million years,' he said.
Daily Mail
17 hours ago
- Science
- Daily Mail
Africa is tearing in HALF: Scientists detect deep Earth pulses beneath Ethiopia - in ominous sign that the entire continent could rupture
We know that all of the world's continents are constantly moving. But one of them has already begun a dramatic transformation. Scientists say a massive crack has started ripping through Africa, from the north east to the south. The experts uncovered evidence of rhythmic surges of molten rock rising from deep within the Earth's surface, beneath Ethiopia. These pulses are gradually tearing the continent apart and forming a new ocean – although it's happening so slowly it's basically imperceptible. 'The split will eventually go all the way down Africa,' lead author Dr Emma Watts, a geochemist at Swansea University, told MailOnline. 'It has already begun and is happening now but at a slow rate – 5-16 mm per year – in the north of the rift. 'Regarding timescales, this process of Africa being torn apart will take several million years before it is completed.' Dr Watts and colleagues point to the Gulf of Aden, a relatively narrow body of water separating Africa in the south and Yemen in the north. Like a small tear in a piece of clothing, the gradual separation event could start at the Gulf of Aden and gradually spread downwards. As it does so, it would split through the middle of enormous bodies of water in East Africa, such as Lake Malawi and Lake Turkana. By the time the split is complete, several million years from now, Africa would be made up of two landmasses. There would be the larger landmass in the west featuring most of the 54 modern-day African countries, such as Egypt, Algeria, Nigeria, Ghana and Nambia. Meanwhile, the smaller landmass to the east will include Somalia, Kenya, Tanzania, Mozambique and a large portion of Ethiopia. 'The smaller part that breaks away towards the east will be approximately 1 million square miles in area,' Dr Watts told MailOnline. 'And the remaining larger landmass will be just over 10 million square miles.' The layers of Earth Crust: To a depth of up to 43 miles (70km), this is the outermost layer of the Earth, covering both ocean and land areas. Mantle: Going down to 1,795 miles (2,890km) with the lower mantle, this is the planet's thickest layer and made of silicate rocks richer in iron and magnesium than the crust overhead. Outer core: Running to a depth of 3,200 miles (5,150km), this region is made of liquid iron and nickel with trace lighter elements. Inner core: Going down to a depth of 3,958 miles (6,370km) at the very centre of Earth, this region is thought to be made of solid iron and nickel. For the study, the team collected more than 130 volcanic rock samples from across the Afar region. In this region, three tectonic plates converge (the Main Ethiopian Rift, the Red Sea Rift and the Gulf of Aden Rift), making it a hotbed of volcanic activity. The experts used these samples, plus existing data and advanced statistical modelling, to investigate the structure of the Earth's crust and the mantle below it. The mantle, the planet's thickest layer, is predominantly a solid rock but behaves like a viscous fluid. 'We found that the mantle beneath Afar is not uniform or stationary – it pulses,' said Dr Watts. 'These ascending pulses of partially molten mantle are channelled by the rifting plates above.' Over millions of years, as tectonic plates are pulled apart at rift zones like Afar, they stretch and thin – almost like soft plasticine – until they rupture, marking the birth of a new ocean. Geologists have long suspected that a hot upwelling of mantle, but until now, little was known about the structure of this upwelling, or how it behaves beneath rifting plates. The team say the pulses appear to behave differently depending on the thickness of the plate, and how fast it's pulling apart. The findings, published in Nature Geoscience, show that the mantle plume beneath the Afar region is not static, but dynamic and responsive to the tectonic plate above it. 'We have found that the evolution of deep mantle upwellings is intimately tied to the motion of the plates above,' said co-author Dr Derek Keir, associate professor in earth science at the University of Southampton and the University of Florence. 'This has profound implications for how we interpret surface volcanism, earthquake activity, and the process of continental breakup. '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 Earth is moving under our feet: Tectonic plates move through the mantle and produce Earthquakes as they scrape against each other Tectonic plates are composed of Earth's crust and the uppermost portion of the mantle. Below is the asthenosphere: the warm, viscous conveyor belt of rock on which tectonic plates ride. Earthquakes typically occur at the boundaries of tectonic plates, where one plate dips below another, thrusts another upward, or where plate edges scrape alongside each other. Earthquakes rarely occur in the middle of plates, but they can happen when ancient faults or rifts far below the surface reactivate.
