Editor's Summary
20 July 2006
A continent divided
Occurring mainly over a week in September 2005, a 60-km-long section of the Afar depression in Ethiopia was torn apart by the injection of over 2 cubic kilometres of molten rock into the plate: an 8-metre-wide gap appeared at the surface. Satellite radar imagery reveals that a series of fissures opened, the rift shoulders rose, and the ground surface dropped above the molten rock. A similarly large rift took place in Krafla in Iceland 25 years ago, but in a series of events over a ten year period. The Afar incident suggests that magma intrusion into a dyke, rather than faulting of the crust, may be responsible for the segmentation of continental rifts.
News and Views: Plate tectonics: Magma does the splits
A minor volcanic eruption in Ethiopia was the main visible clue to a massive injection of magma along the Afar rift last year. Such inconspicuous processes could have been crucial in early continental break-up.
Freysteinn Sigmundsson
doi:10.1038/442251a
Letter: Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode
Tim J. Wright, Cindy Ebinger, Juliet Biggs, Atalay Ayele, Gezahegn Yirgu, Derek Keir and Anna Stork
doi:10.1038/nature04978
First paragraph | Full Text | PDF (421K) | Supplementary information
