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First recorded eruption of Nabro volcano, Eritrea, 2011.

Goitom B, Oppenheimer C, Hammond JO, Grandin R, Barnie T, Donovan A, Ogubazghi G, Yohannes E, Kibrom G, Kendall JM, Carn SA, Fee D, Sealing C, Keir D, Ayele A, Blundy J, Hamlyn J, Wright T, Berhe S - Bull Volcanol (2015)

Bottom Line: 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.

View Article: PubMed Central - PubMed

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.

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 SO2 emitted 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.

No MeSH data available.


Related in: MedlinePlus

a Seismicity around Nabro for the period 23 February to 17 September 2011. Locations for the 31 March event are shown by the blue star (USGS location based on distant stations of the Global Seismic Network) and yellow star (our location based on stations in Ethiopia and Djibouti). Colour codes display temporal evolution, events with horizontal errors exceeding 2 km are coloured grey and symbol size represents magnitude (ML) classes (see legend). Plots (b) and (c) show double-difference relative locations for events occurring between 12 and 17 June and between 18 June and 17 September 2011, respectively
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Fig6: a Seismicity around Nabro for the period 23 February to 17 September 2011. Locations for the 31 March event are shown by the blue star (USGS location based on distant stations of the Global Seismic Network) and yellow star (our location based on stations in Ethiopia and Djibouti). Colour codes display temporal evolution, events with horizontal errors exceeding 2 km are coloured grey and symbol size represents magnitude (ML) classes (see legend). Plots (b) and (c) show double-difference relative locations for events occurring between 12 and 17 June and between 18 June and 17 September 2011, respectively

Mentions: While residents of Siroru, a village situated on the southwest floor of Nabro’s caldera, clearly felt the shaking, people in the vicinity of Maebele and Wade (close to the USGS-located epicentre) were not awoken by the event. Moreover, damaged houses were observed around Siroru but not in Wade or Maebele. A maximum intensity of VII was estimated for the Siroru area and of less than IV in Wade and Maebele (Ogubazghi et al. 2014). Based on these observations, the epicentre was relocated to 13.33° N, 41.68° E, placing it within the caldera (Ogubazghi et al. 2014). This is close to our relocation of the earthquake, using data from the stations in Ethiopia and Djibouti, to 13.35° N, 41.69° E (horizontal error of ±1.2 km), with a magnitude ML 4.8 and time of 18:33:37 UTC on 31 March 2011 (yellow star in Fig. 6a).Fig. 6


First recorded eruption of Nabro volcano, Eritrea, 2011.

Goitom B, Oppenheimer C, Hammond JO, Grandin R, Barnie T, Donovan A, Ogubazghi G, Yohannes E, Kibrom G, Kendall JM, Carn SA, Fee D, Sealing C, Keir D, Ayele A, Blundy J, Hamlyn J, Wright T, Berhe S - Bull Volcanol (2015)

a Seismicity around Nabro for the period 23 February to 17 September 2011. Locations for the 31 March event are shown by the blue star (USGS location based on distant stations of the Global Seismic Network) and yellow star (our location based on stations in Ethiopia and Djibouti). Colour codes display temporal evolution, events with horizontal errors exceeding 2 km are coloured grey and symbol size represents magnitude (ML) classes (see legend). Plots (b) and (c) show double-difference relative locations for events occurring between 12 and 17 June and between 18 June and 17 September 2011, respectively
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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Fig6: a Seismicity around Nabro for the period 23 February to 17 September 2011. Locations for the 31 March event are shown by the blue star (USGS location based on distant stations of the Global Seismic Network) and yellow star (our location based on stations in Ethiopia and Djibouti). Colour codes display temporal evolution, events with horizontal errors exceeding 2 km are coloured grey and symbol size represents magnitude (ML) classes (see legend). Plots (b) and (c) show double-difference relative locations for events occurring between 12 and 17 June and between 18 June and 17 September 2011, respectively
Mentions: While residents of Siroru, a village situated on the southwest floor of Nabro’s caldera, clearly felt the shaking, people in the vicinity of Maebele and Wade (close to the USGS-located epicentre) were not awoken by the event. Moreover, damaged houses were observed around Siroru but not in Wade or Maebele. A maximum intensity of VII was estimated for the Siroru area and of less than IV in Wade and Maebele (Ogubazghi et al. 2014). Based on these observations, the epicentre was relocated to 13.33° N, 41.68° E, placing it within the caldera (Ogubazghi et al. 2014). This is close to our relocation of the earthquake, using data from the stations in Ethiopia and Djibouti, to 13.35° N, 41.69° E (horizontal error of ±1.2 km), with a magnitude ML 4.8 and time of 18:33:37 UTC on 31 March 2011 (yellow star in Fig. 6a).Fig. 6

Bottom Line: 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.

View Article: PubMed Central - PubMed

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.

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 SO2 emitted 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.

No MeSH data available.


Related in: MedlinePlus