ARSF project ET07/04: The Hararo Rift Segment in the Afar Triple Junction, and geohazards in the Afar capital, Semara. Led by: Dr. Tim Wright, School of Earth and Environment, University of Leeds, Leeds, UK. Location: Afar Province, Ethiopia.

The Afar region in Northern Ethiopia sits on a tectonic triple junction above a hot spot in the Earth mantle, where the Arabian, Nubian (African) and Somalian plates pull apart. The plate boundary zones are segmented into ~60-km-long rift segments, similar to those seen at mid-ocean ridges. Such structures are usually inaccessible to remote sensing techniques as they are covered by 2.5 km of water. In September 2005, the Dabbahu rift segment, on the Arabia-Nubia boundary, underwent a major rifting episode – 2.5 km3 of magma was injected into a volcanic dyke along the entire segment, which pushed the plates apart by up to 8 metres. The Hararo rift segment lies immediately to the south of the Dabbahu segment and is geologically and structurally very similar. We proposed a survey that characterised the style of previous volcanic and tectonic events on the Hararo segment, which has no historic record of activity. These data was compared to similar data sets from the Dabbahu segment (January 2008) and Krafla (Summer 2007) in Iceland. We used the data sets to determine likelihood of a major rifting episode on the Hararo segment, on which the regional capital, Semara, was being constructed.