title: First recorded eruption of Nabro volcano, Eritrea, 2011.
abstract: We present a synthesis of diverse observations of the first recorded eruption of Nabro volcano, Eritrea, which began on 12 June 2011. While no monitoring of the volcano was in effect at the time, it has been possible to reconstruct the nature and evolution of the eruption through analysis of regional seismological and infrasound data and satellite remote sensing data, supplemented by petrological analysis of erupted products and brief field surveys. The event is notable for the comparative rarity of recorded historical eruptions in the region and of caldera systems in general, for the prodigious quantity of SO2emitted into the atmosphere and the significant human impacts that ensued notwithstanding the low population density of the Afar region. It is also relevant in understanding the broader magmatic and tectonic significance of the volcanic massif of which Nabro forms a part and which strikes obliquely to the principal rifting directions in the Red Sea and northern Afar. The whole-rock compositions of the erupted lavas and tephra range from trachybasaltic to trachybasaltic andesite, and crystal-hosted melt inclusions contain up to 3,000 ppm of sulphur by weight. The eruption was preceded by significant seismicity, detected by regional networks of sensors and accompanied by sustained tremor. Substantial infrasound was recorded at distances of hundreds to thousands of kilometres from the vent, beginning at the onset of the eruption and continuing for weeks. Analysis of ground deformation suggests the eruption was fed by a shallow, NW-SE-trending dike, which is consistent with field and satellite observations of vent distributions. Despite lack of prior planning and preparedness for volcanic events in the country, rapid coordination of the emergency response mitigated the human costs of the eruption.
authors.affiliation: School of Earth Sciences, University of Bristol, Queens Road, Bristol, BS8 1RJ UK ; Department of Earth Sciences, Eritrea Institute of Technology, PO Box 12676, Asmara, Eritrea.
authors.forename: Berhe
authors.initials: B
authors.lastname: Goitom
authors.affiliation: Department of Geography, Downing Place, Cambridge, CB2 3EN UK.
authors.forename: Clive
authors.initials: C
authors.lastname: Oppenheimer
authors.affiliation: Department of Earth Science and Engineering, Imperial College, London, SW7 2AZ UK.
authors.forename: James O S
authors.initials: JO
authors.lastname: Hammond
authors.affiliation: Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Univ Paris Diderot CNRS, 75005 Paris, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Grandin
authors.affiliation: Laboratoire Magmas et Volcans, Université Blaise Pascal, Clermont Ferrand, France.
authors.forename: Talfan
authors.initials: T
authors.lastname: Barnie
authors.affiliation: Department of Geography, Downing Place, Cambridge, CB2 3EN UK.
authors.forename: Amy
authors.initials: A
authors.lastname: Donovan
authors.affiliation: Department of Earth Sciences, Eritrea Institute of Technology, PO Box 12676, Asmara, Eritrea.
authors.forename: Ghebrebrhan
authors.initials: G
authors.lastname: Ogubazghi
authors.affiliation: Department of Mines, Eritrea Geological Surveys, PO Box 272, Asmara, Eritrea.
authors.forename: Ermias
authors.initials: E
authors.lastname: Yohannes
authors.affiliation: Department of Mines, Eritrea Geological Surveys, PO Box 272, Asmara, Eritrea.
authors.forename: Goitom
authors.initials: G
authors.lastname: Kibrom
authors.affiliation: School of Earth Sciences, University of Bristol, Queens Road, Bristol, BS8 1RJ UK.
authors.forename: J-Michael
authors.initials: JM
authors.lastname: Kendall
authors.affiliation: Department of Geological and Mining Engineering and Sciences, Michigan Technological University, 1400 Townsend Dr, Houghton, MI 49931 USA.
authors.forename: Simon A
authors.initials: SA
authors.lastname: Carn
authors.affiliation: Wilson Infrasound Observatories, Alaska Volcano Observatory, Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK USA.
authors.forename: David
authors.initials: D
authors.lastname: Fee
authors.affiliation: Department of Geological and Mining Engineering and Sciences, Michigan Technological University, 1400 Townsend Dr, Houghton, MI 49931 USA.
authors.forename: Christine
authors.initials: C
authors.lastname: Sealing
authors.affiliation: National Oceanography Centre Southampton, University of Southampton, Southampton, SO14 3ZH UK.
authors.forename: Derek
authors.initials: D
authors.lastname: Keir
authors.affiliation: Institute of Geophysics, Space Science and Astronomy, Addis Ababa University, Addis Ababa, Ethiopia.
authors.forename: Atalay
authors.initials: A
authors.lastname: Ayele
authors.affiliation: School of Earth Sciences, University of Bristol, Queens Road, Bristol, BS8 1RJ UK.
authors.forename: Jon
authors.initials: J
authors.lastname: Blundy
authors.affiliation: COMET, School of Earth and Environment, University of Leeds, Leeds, UK.
authors.forename: Joanna
authors.initials: J
authors.lastname: Hamlyn
authors.affiliation: COMET, School of Earth and Environment, University of Leeds, Leeds, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Wright
authors.affiliation: Global Resources Development Consultants, Asmara, Eritrea.
authors.forename: Seife
authors.initials: S
authors.lastname: Berhe
keywords: Afar; Danakil; InSAR; Nabro; Satellite remote sensing; Seismicity; Volcano monitoring