Limits...
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

Model deduced from elastic inversion of the SAR-derived surface displacement field. The left panel shows the surface projection of the three elementary sources used in the model in map view. The centre and right panels show the same sources in a 3D perspective view, looking from the SE and SW, respectively
© Copyright Policy - OpenAccess
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4562108&req=5

Fig12: Model deduced from elastic inversion of the SAR-derived surface displacement field. The left panel shows the surface projection of the three elementary sources used in the model in map view. The centre and right panels show the same sources in a 3D perspective view, looking from the SE and SW, respectively

Mentions: Comparison of observed (Data), predicted (Model) and residual (Residual) deformation for the various components of ground motion deduced from ascending (left panel) and descending (right panel) SAR data. The top row corresponds to InSAR, the middle row to range offsets and the lower row to azimuth offsets. The thick-coloured arrows show the direction of sensed ground displacement: red for line-of-sight (LOS) and blue for along-track (AZ). InSAR and range offsets are sensitive to motion only in the LOS direction. The LOS vector makes an angle of 29° with the vertical for the ascending pass (34° for the descending pass). For clarity, only the horizontal component of the LOS vector is shown by the red arrow. In contrast, azimuth offsets only provide information on the horizontal component of ground motion in the direction of the satellite track (AZ). In each panel, motion in the direction indicated by the thick-coloured arrow has negative sign (cool hues), whereas motion in the opposite direction has positive sign (warm hues). Note the colour scale is common to all components. Thin arrows represent the modelled horizontal component of ground motion derived from the elastic inversion. The shaded area SW of Nabro received substantial tephra fallout and was excluded in the inversion. The blue rectangle represents the surface projection of the normal fault deduced from the model (Fig. 14). The red rectangle shows the surface projection of the dike, and the orange circle the surface projection of the pressure source. See Fig. 12 for a perspective view


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)

Model deduced from elastic inversion of the SAR-derived surface displacement field. The left panel shows the surface projection of the three elementary sources used in the model in map view. The centre and right panels show the same sources in a 3D perspective view, looking from the SE and SW, respectively
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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

Fig12: Model deduced from elastic inversion of the SAR-derived surface displacement field. The left panel shows the surface projection of the three elementary sources used in the model in map view. The centre and right panels show the same sources in a 3D perspective view, looking from the SE and SW, respectively
Mentions: Comparison of observed (Data), predicted (Model) and residual (Residual) deformation for the various components of ground motion deduced from ascending (left panel) and descending (right panel) SAR data. The top row corresponds to InSAR, the middle row to range offsets and the lower row to azimuth offsets. The thick-coloured arrows show the direction of sensed ground displacement: red for line-of-sight (LOS) and blue for along-track (AZ). InSAR and range offsets are sensitive to motion only in the LOS direction. The LOS vector makes an angle of 29° with the vertical for the ascending pass (34° for the descending pass). For clarity, only the horizontal component of the LOS vector is shown by the red arrow. In contrast, azimuth offsets only provide information on the horizontal component of ground motion in the direction of the satellite track (AZ). In each panel, motion in the direction indicated by the thick-coloured arrow has negative sign (cool hues), whereas motion in the opposite direction has positive sign (warm hues). Note the colour scale is common to all components. Thin arrows represent the modelled horizontal component of ground motion derived from the elastic inversion. The shaded area SW of Nabro received substantial tephra fallout and was excluded in the inversion. The blue rectangle represents the surface projection of the normal fault deduced from the model (Fig. 14). The red rectangle shows the surface projection of the dike, and the orange circle the surface projection of the pressure source. See Fig. 12 for a perspective view

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