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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

Photograph of part of the fissure system taken in 2012. View approximately to the W—a small cone, formed in the 2011 eruption, is apparent on the left and the front of lava effused from vent (e) (Fig. 10) apparent on the right. Behind is the modified cone of the SW pit crater
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Fig11: Photograph of part of the fissure system taken in 2012. View approximately to the W—a small cone, formed in the 2011 eruption, is apparent on the left and the front of lava effused from vent (e) (Fig. 10) apparent on the right. Behind is the modified cone of the SW pit crater

Mentions: It is not until 29 June, when there remains only a weak ashy plume drifting to the south, that the ground surface south and southeast of the tephra cone becomes unobscured. A smaller lava flow has advanced east from the SW pit rim and then diverged with one branch heading north where it ponded in the adjacent crater and another moving south down the flank of intracaldera edifice. High temperatures are evident along levées of the main lava flow, where incandescent lava was likely more exposed. By 2 July, the eastern lava flow had advanced further into the adjacent crater. Particularly striking in the 29 June ALI SWIR bands is the revelation that the aligned cinder cones seen in the SAR images from 18 June onwards coincide with intense thermal anomalies. The location and orientation of these vents suggest the possibility of their source being a NW–SE-striking dike (Fig. 11). These vents do not appear to have contributed significantly to lava eruption after 20 June.Fig. 11


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)

Photograph of part of the fissure system taken in 2012. View approximately to the W—a small cone, formed in the 2011 eruption, is apparent on the left and the front of lava effused from vent (e) (Fig. 10) apparent on the right. Behind is the modified cone of the SW pit crater
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4562108&req=5

Fig11: Photograph of part of the fissure system taken in 2012. View approximately to the W—a small cone, formed in the 2011 eruption, is apparent on the left and the front of lava effused from vent (e) (Fig. 10) apparent on the right. Behind is the modified cone of the SW pit crater
Mentions: It is not until 29 June, when there remains only a weak ashy plume drifting to the south, that the ground surface south and southeast of the tephra cone becomes unobscured. A smaller lava flow has advanced east from the SW pit rim and then diverged with one branch heading north where it ponded in the adjacent crater and another moving south down the flank of intracaldera edifice. High temperatures are evident along levées of the main lava flow, where incandescent lava was likely more exposed. By 2 July, the eastern lava flow had advanced further into the adjacent crater. Particularly striking in the 29 June ALI SWIR bands is the revelation that the aligned cinder cones seen in the SAR images from 18 June onwards coincide with intense thermal anomalies. The location and orientation of these vents suggest the possibility of their source being a NW–SE-striking dike (Fig. 11). These vents do not appear to have contributed significantly to lava eruption after 20 June.Fig. 11

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