mojo
02-20-2002, 11:10 PM
http://news.independent.co.uk/world/africa/story.jsp?story=134317
Super-plume of molten rock could split African continent
By Cahal Milmo
20 February 2002
A vast sea of molten rock underneath Africa is creating a giant geological pressure cooker that could rise up and split the continent, research by British academics has found.
The bubble of mantle rock, known as a "super-plume", could lead to a new ocean dividing east Africa, running for 1,200 miles along the Great Rift Valley from the Red Sea to Malawi. Geologists from three British universities made the discovery during a study in Ethiopia in which they took measurements of volcanic activity and drew up a picture of movements underneath the Earth's crust.
Project Eagle, the first survey of its kind, found the Great Rift Valley, a giant faultline that already includes some of the world's most active volcanoes, is behaving like an ocean-forming ridge. Magma rising to the surface could force the two sides of the fault apart, initially at the far end of the Red Sea in northern Ethiopia but spreading down through Kenya and Tanzania.
The super-plume may be responsible for recent activity in the line of volcanoes along the Rift Valley, which includes Mount Nyiragongo where an eruption last month caused thousands to flee their homes in the Congolese town of Goma.
Scientists believe further eruptions are possible in the Rift, putting hundreds of thousands more people at risk of lethal explosions and lava flows.
The scenario of an entire continental schism is far from imminent – the whole process would take 100 million years – but geologists say the creation of a new sea has already begun. Professor Peter Maguire, of Leicester University, which is taking part in the study along with Royal Holloway College and Leeds University, said: "We are on the transition from continental to oceanic rifting. The continent in the northern part of Ethiopia is separating and there will be an ocean penetrating down into east Africa."
Martin Redfern, a geologist who has made a programme for the BBC World Service about the study, said the northern extremity of the rift in Ethiopia's Denakil desert was splitting apart at a rate of about 2 centimetres a year.
He said: "At that rate, you would see a new ocean formed by a widening Red Sea in a matter of hundreds of thousands of years – in geological terms, that is a twinkling of an eye. What is unclear is whether the conditions will be in existence to make the Rift widen further to split the African continent."
Project Eagle – Ethiopian Afar Geophysical Lithospheric Experiment – is trying find out whether those circumstances could change, as well as monitoring short-term volcanic activity.
Dr Cindy Ebinger, of Royal Holloway College, said: "There has never been a study to monitor volcanoes in the Rift. The lava has more silica in it and is resistant to flow, so these explosive eruptions can cause death and damage to a large region."
Super-plume of molten rock could split African continent
By Cahal Milmo
20 February 2002
A vast sea of molten rock underneath Africa is creating a giant geological pressure cooker that could rise up and split the continent, research by British academics has found.
The bubble of mantle rock, known as a "super-plume", could lead to a new ocean dividing east Africa, running for 1,200 miles along the Great Rift Valley from the Red Sea to Malawi. Geologists from three British universities made the discovery during a study in Ethiopia in which they took measurements of volcanic activity and drew up a picture of movements underneath the Earth's crust.
Project Eagle, the first survey of its kind, found the Great Rift Valley, a giant faultline that already includes some of the world's most active volcanoes, is behaving like an ocean-forming ridge. Magma rising to the surface could force the two sides of the fault apart, initially at the far end of the Red Sea in northern Ethiopia but spreading down through Kenya and Tanzania.
The super-plume may be responsible for recent activity in the line of volcanoes along the Rift Valley, which includes Mount Nyiragongo where an eruption last month caused thousands to flee their homes in the Congolese town of Goma.
Scientists believe further eruptions are possible in the Rift, putting hundreds of thousands more people at risk of lethal explosions and lava flows.
The scenario of an entire continental schism is far from imminent – the whole process would take 100 million years – but geologists say the creation of a new sea has already begun. Professor Peter Maguire, of Leicester University, which is taking part in the study along with Royal Holloway College and Leeds University, said: "We are on the transition from continental to oceanic rifting. The continent in the northern part of Ethiopia is separating and there will be an ocean penetrating down into east Africa."
Martin Redfern, a geologist who has made a programme for the BBC World Service about the study, said the northern extremity of the rift in Ethiopia's Denakil desert was splitting apart at a rate of about 2 centimetres a year.
He said: "At that rate, you would see a new ocean formed by a widening Red Sea in a matter of hundreds of thousands of years – in geological terms, that is a twinkling of an eye. What is unclear is whether the conditions will be in existence to make the Rift widen further to split the African continent."
Project Eagle – Ethiopian Afar Geophysical Lithospheric Experiment – is trying find out whether those circumstances could change, as well as monitoring short-term volcanic activity.
Dr Cindy Ebinger, of Royal Holloway College, said: "There has never been a study to monitor volcanoes in the Rift. The lava has more silica in it and is resistant to flow, so these explosive eruptions can cause death and damage to a large region."