New Ocean being Formed in Africa

PenguinRadio writes "The San Francisco Chronicle is reporting on a 37-mile long fissure that split open in September in the Afar desert in Ethiopia that could be the start of a new ocean forming. The fissure, which grew 8 meters wide in 3 weeks following an earthquake on Sept 14, is now splitting at about 0.8 inches per year, would eventually lead to Ethiopia eastern portions becoming an island in a million years or so. The findings were presented at the American Geophysical Union meeting taking place in San Francisco this week. The BBC reports that formation of a ocean basin is the first step toward developing an ocean, but that it will be millions of years before that could occur."

Comments

Photo at the BBC

[geeber]

BBC article

Re:Photo at the BBC

[Poisonous Drool]

Perhaps you meant to link to the enlarged image:

http://news.bbc.co.uk/1/shared/spl/hi/pop_ups/05/s ci_nat_enl_1134158277/html/1.stm

A little info on what's going to happen

[Anonymous Coward]

In East Africa, spreading processes have already torn Saudi Arabia away from the rest of the African continent, forming the Red Sea. The actively splitting African Plate and the Arabian Plate meet in what geologists call a triple junction, where the Red Sea meets the Gulf of Aden. A new spreading center may be developing under Africa along the East African Rift Zone. When the continental crust stretches beyond its limits, tension cracks begin to appear on the Earth's surface. Magma rises and squeezes through the widening cracks, sometimes to erupt and form volcanoes. The rising magma, whether or not it erupts, puts more pressure on the crust to produce additional fractures and, ultimately, the rift zone.

East Africa may be the site of the Earth's next major ocean. Plate interactions in the region provide scientists an opportunity to study first hand how the Atlantic may have begun to form about 200 million years ago. Geologists believe that, if spreading continues, the three plates that meet at the edge of the present-day African continent will separate completely, allowing the Indian Ocean to flood the area and making the easternmost corner of Africa (the Horn of Africa) a large island.

From Understanding Plate Motions

Old news ...

[Anonymous Coward]

The Afar region has been stretching apart, in the process of forming a new ocean, for the last 10 or 20 million years. Stretching rates in various parts of the rift vary from 6 to 12mm per year. Parts of the Afar region are already >100m below sea level and filled with salt deposits, and the area is faulted extensively, with many tilted blocks of older material and extensive volcanoes (e.g., Erte Ale) related to the stretching (imagine the effect if you stretched a piece of candy with a brittle crust). So, the headline isn't really news at all.

The new part is the establishment and growth of such an obvious fissure where one did not exist before. The new one is fascinating, but only the latest example of a process that has been ongoing for a long time, and which will probably continue for millions of years more before the ocean eventually invades.

Science extrapolating out....are you sure?

[billnad]

So let me get this straight. There was an earthquake that opened a crack in the earth three months ago and now the scientists involved can tell, after only three months that there will be a sustained widening of this crack by less than one inch per year. After one million years of this exact widening of one inch a year there will be a new ocean created.

Maybe it is hjust me but most real scientific fact going out a million years would likely be based on more than a three month snapshot of data.

They're wrong

[amightywind]

The Afar area is a triple junction where upwelling magma is driving 3 continental crust apart - the Arabian plate, West Africa and East Africa. The plates crack in 120 deg pieces because the configuration relieves plate extensional stress with minimal displacement. What typically happens when the basin expands is that one of arms is abandoned, again for thermodynamic reasons. Spreading along a single great circle requires less membrane deformation of the outer crust than spreading along 3. The principle of least action at work. In this case the active arms of the triple junction are the Red Sea and the East Indian ocean which are sites of rapid spreading of oceanic crust. Th East Africa Rift is clearly spread more slowly than the active arms and will fail. The North Sea, Mississipi delta, Camaroon rift, Connecticut Valley, etc are examples of rift valleys and failed arm abandonment during the opening of ocean basins. Sure, volcanism and rifting can still occur in the failed arm. The extensional faults that define these areas assures this. We see this in Afar, and deeper in the African rift. Camaroon is another example. The triple function there opened 120 Mya and it is still active. But is will never form a wide ocean basin. Afar tectonics are still a very interesting phenomen.

Another article with MORE PICTURES

[scalveg]

http://www.volcano.si.edu/world/volcano.cfm?vnum=0 201-113&volpage=var

Speaking as an amateur geologist, I think I can safely use the geophysical jargon and say, "MAN that is FREAKY!"