December 27, 2005
Big News Network

Addis Ababa — A continental rifting process that normally takes millions of years to form has developed over a span of seven weeks in the Afar region of Ethiopia. It was a close study, using radar interferometry, of an earth rupture developing into a rare axial rift zone -- a possible future ocean basin.

Scientists from Ethiopia and Britain made four expeditions to the Da'ure locality in the Afar Depression between mid-September and early October to collect geophysical and geological data, said Atalay Ayele of the Geophysical Observatory of the Addis Ababa University (AAU). It started with a series of quakes that were first recorded Sep 14 in Da'ure, an area in the lowlands of western Ethiopia that stretches from the central part of the country to the Dahlak Islands of Eritrea in the Red Sea.

The volcanic activity, recorded at N 12.651 degrees longitude and E 40.519 degrees latitude, spewed ash for three continuous days and eventually numerous cracks appeared on the ground, spreading fear among the pastoral inhabitants. Unsettled by the phenomena of rumbling tremors, they approached the regional authorities to ask the federal government in Addis Ababa to look into it. The government asked experts in the field at the AAU to investigate the phenomena, and if need be ask for assistance from universities abroad, which is where the British scientist got involved.

"We were thus involved in a collaborative undertaking with earth scientists from Britain to undertake further study to collect data in and around the Da'ure locality," said Atalay. An image of the locality taken by a NASA satellite orbiting the earth showed that an area of 60 km had developed an eight-metre opening. "This was a fast opening rate within a span of about two months, from Sep 14 to early November, an exciting event in scientific terms," said Atalay.

"Compare this to the very slow movement of the plate tectonic affecting the crust of the earth in the Afar region, which is about 17 mm per year," he explained. Cindy Binger of Royal Holloway, University of London, presented the findings at the fall meeting of the American Geophysical Union in San Francisco. Atalay said there were no immediate concerns about the Afar region, noting that it would take a couple of million years before the area turns into an ocean basin.

For scientists researching the phenomena, the Afar region is a natural laboratory where the transition between oceanic rift and continental rift is visible on land. Such transition is also evident in Iceland. "The events we witnessed in Afar for about seven weeks have enabled us to look into the possible, faster rate of rifting in the region," said Atalay. "What we saw was a microcosm of a process of an earth split that takes millions of years to evolve into an ocean basin," he declared.

http://feeds.bignewsnetwork.com/redir.php?jid=f8b3ec5b5495447b&cat=c08dd24cec417021