5 November 2009

Volcanic activity could split Africa

Cosmos Online
Volcanic activity may split Africa in two, creating a new ocean. This is due to a geological crack which has appeared in northeastern Ethiopia, say experts.
Rift

The vast rift has appeared in Afar, Ethiopia. Credit: University of Rochester

SYDNEY: Volcanic activity may split the African continent in two, creating a new ocean, say experts. This is due to a recent geological crack which has appeared in northeastern Ethiopia.

The 60-kilometre split in the desolate Afar region – the result of two volcanic eruptions in September 2005 – has enabled scientists to further examine the Earth’s tectonic movements, said a paper published this week in Geophysical Research Letters.

“The significance of the finding is that a huge magnetic deformation can happen within a few days, like in [the] oceans,” said lead author Atalay Ayele, a professor at Addis Ababa University in Ethiopia.

Natural laboratory

Faults and fissures, which normally occur deep down on the ocean floor, are the main processes by which continents gradually break off from each other.
Africa underwent a similar phase when it split from America millions of years ago.

“Normally, such phenomena happens beneath the ocean, which is inaccessible, expensive and very difficult to make experiments. But in Afar, it’s quite a natural laboratory for us to carry those out,” Ayele explained.

“The whole point of this study is to learn whether what’s happening in Ethiopia is like what’s happening at the bottom of the ocean, where it’s almost impossible for us to go,” agreed co-author Cindy Ebinger at the University of Rochester in New York, USA. “Ethiopia would essentially be a unique and superb ocean-ridge laboratory for us.”

The team, who have been undertaking studies since the eruptions, said the event indicated what was likely to happen to the continent in the future.

Ocean’s slow formation

“The ocean’s formation is happening slowly, likely to take a few million years. It will stretch from the Afar depression (straddling Ethiopia, Eritrea and Djibouti) down to Mozambique,” Ayele said.

“This work is a breakthrough in our understanding of continental rifting leading to the creation of new ocean basins,” commented Ken Macdonald, of the Department of Earth Science at the University of California, Santa Barbara.

“For the first time they demonstrate that activity on one rift segment can trigger a major episode of magma injection and associated deformation on a neighbouring segment. Careful study… will continue to provide extraordinary opportunities for learning about continental rifts and mid-ocean ridges,” he added.

The Afar region, known for its salt mines and active volcanoes, is one of the lowest and hottest places on the planet.

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With AFP.
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