Eruption in Eritrea: 1,000 km plume

Infrared image of Eritrea eruption plume, 13 June 2011 07:30UTC (Sat24.com/Eumetsat/Met Office)

A significant eruption is evidently under way at Dubbi volcano (although there is still some doubt about the precise identity of the volcano involved [UPDATE – it’s Nabro, not Dubbi: see update here]) in Eritrea, north-east Africa. An earthquake swarm occurred during during the evening of 12 June, with moderate quakes followed by two strong quakes of magnitude 5.7, all around 10 km depth:

12 June 2011 15:37UTC: mag 5.1 Eritrea-Ethiopia region (USGS info)
12 June 2011 19:21UTC: mag 5.0 Ethiopia (USGS info)
12 June 2011 20:32UTC: mag 5.7 Eritrea-Ethiopia region (USGS info)
12 June 2011 21:03UTC: mag 5.7 Eritrea-Ethiopia region (USGS info)

A volcanic eruption appears to have begun around the time of the last 5.7M earthquake, at about 21:00 UTC. Toulouse VAAC identified the volcano as Dubbi and issued two Volcanic Ash Advisories so far for this eruption today: at 04:00 UTC the eruption was reported to have started at 23:00 UTC on 12 June 2011, and to have produced a plume between FL150/300 (15,000-30,000 feet/4,500-9,000 metres altitude), while at 06:00 UTC the volcano was described as being in ‘continuous emission’ with ash at FL300/450 (30,000-45,000 feet/9,000-13,500 metres altitude) and trending W/WNW.

Eumetsat image, 08:00UTC. Thanks to Eruptions commenter Shérine France for providing the link. Click on the image for the original.

Dubbi was responsible for the largest known volcanic eruption in Africa in historical time, in 1861: more than 100 people were killed, ash fell more than 300 km from the volcano and the lava flows travelled 22 km and reached the Red Sea. Other possible candidates for the current eruption include Nabro and Mallahle.

UPDATE. Via Oxford volcanologist David M. Pyle’s Twitter,here are MODIS images of the Eritrea volcanic ash plume. Thanks to Clive Oppenheimer of Cambridge University (via Earthquake-Reports) we have a useful news report from the Cambridge Geography Department site related to Clive’s Eruptions that Shook the World book: Eruption in Eritrea, 12 June 2011. ‘Loud explosions were heard in Afdera, across the border in Ethiopia, and ashfall is reported as far as Mekele in Tigray province’ … the identity of the volcano is still to be confirmed – Nabro or Dubbi? And more coverage can be found at the Simplement Géologie blog (in French), Séisme et éruption volcanique en Éritrea, Afrique, and at Volcano Blog, Eruption of Dubbi in Eritrea. The Irish Weather Online site has identified the volcano as Nabro rather than Dubbi, on the grounds that satellite images show plume is originating at a point too far south to be the latter. Nabro has no recorded Holocene eruptive activity, so its awakening would be an interesting development. Confirmation one way or the other is still awaited.

ACKNOWLEDGEMENTS. A major source of information on this eruption has been the comment thread at this post over at Dr Erik Klemetti’s Eruptions blog. And excellent ongoing coverage is available at Earthquake-Report.

News
Eritrea volcano eruption: ash plume length exceeds 1,000 km (630 miles) – Earthquake-Report, 13 June 2011 (title changes as the post is updated)
Quake storm hits Ethiopia-Eritrea – Stuff.co.nz, 13 June 2011

Information
Global Volcanism Program: Dubbi – summary information from the GVP for Dubbi (0201-10=)