PROJECT DETAILS ONLY - NO DATA. Since 20 September, 2005, an ~120 km-long segment of the Red Sea rift system in Ethiopia has been rocked by 31 earthquakes detected on seismometers worldwide. Ashes emanating from long, open fissures at the surface have blanketed a much wider area, displacing ~50,000 people and their livestock. Colleagues from Addis Ababa University report new fault scarps, and new displacements along existing fault scarps; these faults provide direct measures of rates of crustal deformation that can only be inferred from routine monitoring. The active rupture zone is much larger than has been associated with other historic sequences in the Afar depression, and other continental rift zones worldwide, suggesting this linked tectonic-volcanic crisis is a major event. Thus, the Boina seismo-volcanic crisis provides a superb opportunity to record directly the processes of continental breakup leading to the formation of a new ocean basin. Routine seismic, volcanic, and geodetic monitoring provides information on the time-averaged deformation, but misses the sometimes catastrophic discrete events that achieve the tectonic processes. This proposal aims to: 1) establish a seismic monitoring network to measure aftershock sequences and lava movement within the plate; 2) investigate reports of new eruptions and measure gas emissions from vents along the length of the rupturing segment and compare them with earlier baseline measurements from Afar; and 3) use space-based radar images acquired prior to, during, and after the crisis to measure the magnitude and extent of deformation across the region. Simple elastic modelling of seismic and radar interferometry results will allow us to estimate the proportion of tectonic vs magmatic deformation associated with continental rupture. Additionally, our measurements will provide a firm basis for hazard mitigation for the Ethiopian government coping with this catastrophe, supplementing the sparse infrastructure established by our Ethiopian colleagues.
