Geologists have ringside seats for an ocean's birth

A new sea forming in Africa

By Lucy Sherriff • Get more from this author

Posted in Science, 20th July 2006 08:36 GMT

A rift that opened in Africa after a massive earthquake last September could be the beginning of a new Ocean, scientists say. The crack in the ground appeared along a fault line in the Afar desert in Ethiopia.

The crack is heading for the Red Sea. If it makes it that far, it would carve a new ocean that would separate Eritrea and part of Ethiopia (both of which lie on the Arabian plate) from the rest of the continent, creating a new island.

Satellite data collected since the quake shows that the rift is widening at an unprecedented rate, according to reports. It is sixty kilometres long and by October it was already eight metres wide in some places. These observations are reported in Nature.

The Rift Valley is a very geologically active region, thanks to the separation of the Arabian and Nubian tectonic plates. As the plates slide away from each other, the crust of the Earth is stretched and thinned to the point where cracks appear.

In this case, as the crust fractured, approximately 2.5 cubic kilometres of magma from nearby volcanoes flooded into the rift, forming fresh continental crust. That is enough to cover the area inside the M25 to a depth of about a yard, the BBC reports.

The research team, a collaboration between scientists in the UK and in Ethiopia, used both field measurements and satellite images from the European Space Agency's Envisat spacecraft to build a precise map of the changes. It is the first event of this kind to have occurred since the satellite technology became available.

If the crack does represent the birth of a new ocean (and it may not - it could all just settle down again), it will be about a million years before it is wet enough.

Which should give any local Noahs plenty of time to build their Arks. ®

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