Scientists: Fissure Could Be a New Ocean

By ANTHONY MITCHELL, Associated Press Writer
19 minutes ago

ADDIS ABABA, Ethiopia - Ethiopian, American and European researchers have observed a fissure in a desert in the remote northeast that could be the "birth of a new ocean basin," scientists said Friday.

Researchers from Britain, France, Italy and the U.S. have been observing the 37-mile long fissure since it split open in September in the Afar desert and estimate it will take a million years to fully form into an ocean, said Dereje Ayalew, who leads the team of 18 scientists studying the phenomenon.

The fissure, now 13 feet wide, formed in just three weeks after a Sept. 14 earthquake in a barren region called Boina, some 621 miles north east of the capital, Addis Ababa, said Dereje.

"We believe we have seen the birth of a new ocean basin," said Dereje of Addis Ababa University. "This is unprecedented in scientific history because we usually see the split after it has happened. But here we are watching the phenomenon."

The findings have been presented at a weeklong American Geophysical Union meeting taking place in San Francisco that ends Friday.

"It's amazing," the BBC quoted one of the Afar researchers, Cindy Ebinger of the Royal Holloway University of London, as saying in San Francisco. "It's the first large event we've seen like this in a rift zone since the advent of some of the space-based techniques we're now using, and which give us a resolution and a detail to see what's really going on and how the earth processes work."

The Ethiopian Afar Geophysical Lithospheric Experiment, involving scientists from Royal Holloway and the universities of Leicester, Leeds and Addis Ababa, is using sensitive instruments to study what is happening deep within the earth.

Dereje said that the split is the beginning of a long process, which will eventually lead to Ethiopia's eastern part tearing off from the rest of Africa, a sea forming in the gap. The Afar desert is being torn off the continent by about 0.8 inches each year.

"The crust under Afar is becoming like the crust found in the Red Sea," said Dereje, head of earth science at Addis Ababa University. "Once the crust is formed you will have water because it is a low area and the water will migrate from the Red Sea and the Gulf of Aden. It becomes a basin."

The scientists plan to set up an observatory to watch the split and see how it develops.

http://news.yahoo.com/s/ap/20051210/ap_on_sc/ethiopia_new_ocean

Ash and pumice is thrown out at a vent site at the northern tip of the 60km-long Boina tectono-magmatic segment. Open fissures run for at least 2km north and south of the vent, and probably exist along the entire length of the segment. (Image: C.Ebinger)

BBC News

Last Updated: Thursday, 8 December 2005, 23:23 GMT

Geologists witness 'ocean birth'
By Roland Pease
BBC science unit, San Francisco




Scientists say they have witnessed the possible birth of a future ocean basin growing in north-eastern Ethiopia.

The team watched an 8m rift develop in the ground in just three weeks in the Afar desert region last September.

It is one small step in a long-term split that is tearing the east of the country from the rest of Africa and should eventually create a huge sea.

The UK-Ethiopian group says it was astonished at the speed with which the 60km-long fissure system developed.

"It's the first large event we've seen like this in a rift zone since the advent of some of the space-based techniques we're now using, and which give us a resolution and a detail to see what's really going on and how the earth processes work; it's amazing," said Cindy Ebinger, from Royal Holloway University of London.

Professor Ebinger and colleagues described the event here at the American Geophysical Union Fall Meeting.

Earth forces

In the far-distant past, oceans such as the Atlantic have formed when supercontinents have torn apart.



Indeed, North America and Europe are still moving in opposite directions at about the pace fingernails grow.

Researchers have long recognised that the Afar region, an inhospitable depression in north-eastern Ethiopia, has been contorted by similar forces in recent geological time.

But the event in September is said to be unprecedented in scientific history.

It began with a large earthquake on the 14th of the month and continued with a swarm of moderate tremors.

Start and stop

"About a week into the sequence, there was a volcanic eruption," explained Dr Ebinger.




"A lot of ash was thrown up in the air, and a lot of cracks appeared in the ground; some of which were more than a metre wide.

"Using satellite techniques we can see ground deformation, and about a month after the sequence, we could see a 60km long section had opened up, and it opened up about 8m in its central part.

"It appears that we've seen the birth of an ocean basin."

The movements of September are only a small part of what would be needed to create a whole ocean - the complete process takes millions of years - and in other regions of the planet, ocean development has been started only to stall at a later time.

But the Afar event has given geologists a unique opportunity to study the rupture process at close quarters.

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