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Eritrean Government: Nabro eruption killed seven 21 June 2011

Posted by admin in Africa, Eritrea, eruptions, Nabro.
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Seven people were killed by the eruption of Nabro volcano and three were injured, according to a new statement issued today by the Eritrean Government: Volcanic eruption in Southern Red Sea Region creates new landmass. Full text as follows.

Asmara, June 21, 2011- The powerful volcano that erupted in the Southern Red Sea region has created a new landmass, according to the director general of Mines at the Ministry of Energy and Mines, Mr. Alem Kibreab.  Mr. Alem said that the volcano spewing ash and lava has created a new land mass measuring hundreds of square metres.

Mr. Alem also pointed out that the eruption in Sireru has spewed smoke and ash that has affected our region.

The director general also disclosed that a team composed of geological and volcanic experts is conducting studies in the area.

Meanwhile, according to reports, 7 people have died while 3 people have sustained injuries due to the eruption. The inhabitants of the area have been moved to safer locations while at the same time they’re given basic provisions.

According to data, a similar volcanic eruption in Eritrea occurred in 1861, in Dubbi, Southern Denkel.

This is the third official statement the Eritrean Government has issued about the Nabro eruption. The previous statements were Volcanic eruption witnessed in the tip of Southern Red Sea Region (13 June 2011) and Inhabitants of Afambo, Nebro and Sirero moved to safer locations (16 June 2011). Both the previous statements said that there were no casualties.

Information
Global Volcanism Program: Nabro – summary information for Nabro (0201-101)

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The Daily Volcano Quote: the nun and the volcano 21 June 2011

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I was born in the Bicol region where Mayon volcano is … I identify with it, it looks [like a] woman to me … Always in the morning when I would make my morning prayer, I had a little statue of Mary the Madonna on my table, but when I pray I always turn to the volcano. Also in the moonlight it is so beautiful, you know, when you see its silhouette very sharply, and yet the luminous moonlight gives it such a mysterious character.

Sister Placid, OSB, quoted in Heather L. Claussen, Unconventional Sisterhood: Feminist Catholic Nuns in the Philippines (Ann Arbor, MI: University of Michigan Press, 2001), p. 26.

The Daily Volcano Quote: from Monday to Friday, a new eruption of volcanic verbiage each day.

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Puyehue-Cordón Caulle: flight disruption in Australia and New Zealand as the ash returns 21 June 2011

Posted by admin in activity reports, Chile, eruptions, Puyehue.
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Puyehue-Cordon Caulle ash cloud animation - stills (Australian Bureau of Meteorology)

From the Australian Bureau of Meteorology comes a remarkable animated sequence of satellite images showing the ash cloud from Chile’s Puyehue-Cordón Caulle volcano circumnavigating the globe between 6 and 11 June. Four stills from the animation are reproduced above: for the full sequence click on the image or follow this link to the story at Australian Business Traveller.

Most of the current news coverage of the ongoing Puyehue-Cordón Caulle eruption is indeed concerned with the return of the volcano’s ash to plague flights in Australia and New Zealand. ‘This is going to unfortunately have a knock-on effect for many travelers’ says a Qantas spokeswoman, producing as ugly and gratuitous a spit infinitive as I have seen in a long while. Australian airlines seem to be readier to cancel flights than their New Zealand counterparts: Qantas and its low-cost subsidiary Jetstar have cancelled their services in and out of New Zealand, reports the New Zealand Herald, while Air New Zealand has ‘continued near normal operations by flying at a lower altitude’ (although when the earlier cloud came in at just 3,000 metres Air New Zealand were also forced to cancel flights). Virgin and Tiger Airways began cancelling flights yesterday, and there are more disruptions today: Adelaide, Melbourne, Sydney and Brisbane have all been affected. The ash cloud has also had some effect on Cape Town International Airport in South Africa, where a small number of flights were delayed on 19 June as the ash cloud, on its second circumnavigation of the globe, passed directly across the flight paths. Among those whose travel plans were affected was South Africa’s President Jacob Zuma – erupting volcanoes are no respecters of persons.

The ash is forecast to remain to the south and south-east of Australia for the next day or so, according to the latest volcanic ash advisory from Darwin VAAC (issued 08:57 UTC 21 June 2011). The map accompanying the advisory is shown below: click on it to view the full-size original at Darwin VAAC.

Graphic accompanying Darwin VAAC volcanic ash advisory for Cordon Caulle issued 0857Z 21 June 2011

The latest news on the flight disruption is that Virgin is planning to resume flying earlier than expected, following forecasts that the ash is due to move ‘into the Tasman [Sea] tomorrow and no longer affect flights from the major cities’.

News
Drop in degrees the only danger from ashNew Zealand Herald, 19 June 2011
Operations on schedule at Cape Town International Airport – Cape Gateway, 20 June 2011
Ash cloud returns: Virgin, Tiger suspend flightsSydney Morning Herald, 20 June 2011
Chilean volcanic ash cloud affects flights in South Africa – MercoPress, 21 June 2011
Australian airlines cut flights as ash cloud returnsWall Street Journal, 21 June 2011
Major airports face ash cloud shutdown – ABC News, 21 June 2011
Jetstar, Qantas cancel NZ flightsNew Zealand Herald, 21 June 2011
Amazing animation of the Chilean volcano’s ash cloud spanning the globeAustralian Business Traveller, 21 June 2011
Virgin back in the air sooner as ash goes – News.com.au, 21 June 2011

Information
Global Volcanism Program: Puyehue-Cordón Caulle volcanic complex – summary information for the PCCVC (1507-15=)

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Nabro eruption subdued but ongoing 21 June 2011

Posted by admin in activity reports, Africa, Eritrea, eruptions, Ethiopia, Nabro.
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Nabro eruption SO2 emissions 19 June 2011 (NASA/Aura/OMI)

Above. Nabro eruption SO2 emissions 19 June 2011 (NASA/Aura/OMI).

Overall the eruption of Nabro volcano in Eritrea seems to have been going through a quieter phase over the past two days, with rather small plumes (or none at all) visible in satellite images and little evidence of further explosive activity. Toulouse VAAC issued two advisories yesterday, the first at 1200 UTC reported ‘eruption mainly producing SO2’ with a small ash cloud at FL180 (18,000 feet/5,500 metres altitude) extending to the WSW/SW of the volcano, and the second at 1800 UTC reporting ‘eruption ongoing’ with no identifable ash emission: ‘only SO2 detected since 1230Z’. The sulphur dioxide emissions from Nabro have been on a very large scale: with reference to data from last week NASA reported that ‘On June 13, OMI captured high SO2 concentrations – exceeding thousands of Dobson units – from the eruption of Nabro (Eritrea) on June 12th. Total tonnage is estimated to exceed 1Tg’. There have of course been significant further SO2 emissions from Nabro since that report was written on 16 June. A gallery of Aura/OMI SO2 data for Afar showing the size and movement of the SO2 plume from Nabro can be viewed at NASA’s Goddard Space Flight Center global SO2 monitoring site. The image at the top of the post shows the SO2 plume detected by Aura’s OMI on 19 June 2011.

NASA satellite images from yesterday show the presence of a small plume over the seat of the eruption with no significant downwind emissions cloud visible. Below are images from Aqua (top) and Terra (bottom): in each case click on the image to go to the original at the NASA Rapidfire site.

Nabro volcano, Eritrea, 20 June 2011, 1050Z, 1px = 500m (NASA/Aqua)

Above. Nabro volcano, Eritrea, captured by NASA’s Aqua satellite on 20 June 2011, 1050Z. Scale: 1px = 500m.

Nabro volcano, Eritrea, 20 June 2011, 1050Z, 1px = 500m (NASA/Terra)

Above. Nabro volcano, Eritrea, captured by NASA’s Terra satellite on 20 June 2011, 0750Z. Scale: 1px = 500m.

A dark patch is visible on the surface to the SW of the volcano. The atmosphere is murky and it is difficult to see precisely what this is: it looks too fuzzy at the edges and too brown in colour to be a lava flow. Burnt vegetation? An ash deposit? Below is a close-up from the Terra image:

Nabro volcano, Eritrea, 20 June 2011, 0750Z, 1px = 250m (NASA/Terra)

Above. Nabro volcano, Eritrea, captured by NASA’s Terra satellite on 20 June 2011, 0750Z. Scale: 1px = 250m.

The human impact of the eruption is starting to become clearer, althouth reports from the area affected by the Nabro eruption have been hard to come by: even in this modern age communications can be difficult in this part of the world, the political character of the region tends not to encourage the free spread of information, and enduring tension between Ethiopia and Eritrea does not help. However, an article in the Ethiopian business newspaper Addis Fortune published yesterday (although the date ’12 June 2011′ confusingly appears at the top), ‘Eritrean volcano erupts economic mayhem for Ethiopia’, gives some idea of the problems the eruption has been causing across the area: flight delays and cancellations, potential health problems, and the poisoning by SO2 of local salt deposits formally exploited for consumption. The report also refers to ‘small eruptions in Afambo and Sireru areas’ as well as ‘the major eruption at Nabro’, although it is not clear precisely what’s being described here: earthquake activity, perhaps, rather than ‘eruptions’. The BBC, meanwhile, reports on appeals from aid organizations for help for the local people in Ethiopia: the inhabitants of villages in the Biddu region near the border ‘have been left without food and traditional springs and streams have been polluted’. Teshome Assefa of Save the Children tells the BBC, ‘Many community members and especially children are reported sick and in desperate need of medical attention’. It’s good to see the BBC reporting this, not so good that more than a week into the eruption they still haven’t got the name of the volcano right (‘Dubbi’ again). [Update: the BBC has corrected its report: Nabro. Thank you.]

In Eritrea itself official news on the eruption has been sparse. A brief bulletin was issued by the Eritrean Government Ministry of Information at the beginning of the eruption stating that there had been no loss of life or any other ill-effects. It seems, however, that there have been evacuations from the affected area within Eritrea, according to a further brief announcement made on 16 June:

Assab, June 16, 2011- The inhabitants of Afambo, Nebro and Sireru have disclosed that they have been moved to a safer location. Pointing out that there were occasional quakes in their areas, the inhabitants thanked the government for the fast relocation after the eruption, as a result of which there were no causalities [sic]. It is to be recalled that the eruption of June 12th around the areas of Afambo, Nebro and Sireru released large quantities of dust and smoke and the quake of 5.7 Richter it caused was felt in our region.

On the subject of earthquakes, the staff at the Observatoire Géophysique d’Arta (OGA) in Djibouti are clearly working very hard to keep track of the seismic activity in their northern neighbour and are providing the best coverage they can via their website. Today a strapline on their front page reports a decrease in tremors, with ‘few earthquakes on the Nabro volcano site’, but there are no details as yet.

News
Eritrean volcano erupts economic mayhem for EthiopiaAddis Fortune, 20 June 2011
Eritrea volcano ash hits Ethiopia villagers – BBC News, 20 June 2011

Information
Global Volcanism Program: Nabro – summary information for Nabro (0201-101)

The Volcanism Blog

Nabro volcano before the eruption, at the NASA Earth Observatory 20 June 2011

Posted by admin in Africa, Eritrea, Nabro, NASA Earth Observatory.
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Image of the Day at the NASA Earth Observatory for 20 June 2011 is this photograph of Nabro caldera before the current eruption. The image was captured by an astronaut on the International Space Station on 30 January 2011 (we had a preview of the image here last week, thanks to our friends at NASA).

Astronaut photograph of Nabro caldera, 30 January 2011 (ISS/NASA)

The horseshoe shape of the caldera, opening to the south-west, is clearly visible, with cinder cones to the west (lying between Nabro caldera and its neighbour, Mallahle) and their dark lava flows. There is also evidence of human habitation in the western part of the caldera, with fields, houses and paths discernible in the high definition image. The area is perhaps not so desolate and barren as some reports have suggested. One can only hope that those living nearby received enough warning from the precursory earthquakes to get themselves clear before the eruption began.

Click on the image to go to the original at the NASA Earth Observatory.

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Daily Volcano Quote: the ubiquity of volcanic forces 20 June 2011

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If now, however, we take a broader view of volcanic phenomena, and, in addition to the … still existing proofs of the general distribution of volcanic centres, as they have been termed, we also take into consideration the occurrence of eruptive rocks of similar origin which are everywhere found disturbing and breaking through the strata of even the oldest rock formations, it will be seen, as least as far as the geology of the earth’s surface is at present known to us, that there is scarcely a single area of any magnitude, of either the land or sea, which, at some period or other, has not been broken through or disturbed by what may be termed volcanic forces acting from within the mass of the earth itself; and it is impossible to come to other than the conclusion that these agencies must have played a most important part in determining the main features of the earth’s external configuration as well in our times as throughout all periods of its history.

David Forbes, ‘On Volcanoes’, Nature, 4 August 1870, p. 283. [‘An outline of a lecture delivered at St. George’s Hall, Langham Place, 9th June 1870, by David Forbes, F.R.S.’]

The Daily Volcano Quote: from Monday to Friday, a new eruption of volcanic verbiage each day.

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A look at Nabro’s history 19 June 2011

Posted by admin in Africa, Dubbi, Eritrea, Erta Ale, eruptions, Ethiopia, Nabro, volcanoes.
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Nabro is a little-known volcano. Its remote and inhospitable location has meant that very limited fieldwork has been carried out, and much of what we do know comes from remote sensing. Pierre Wiart and Clive Oppenheimer have analysed much of what is known about Nabro in a very useful paper published in the Bulletin of Volcanology in 2005: ‘Large magnitude silicic volcanism in north Afar: the Nabro Volcanic Range and Ma’alalta volcano’. The article is based upon remote sensing data and very limited fieldwork: thus eruptive sequences are established with reasonable clarity, but there is little dating information.

The authors note that much research on north Afar has focused on Quaternary basaltic volcanism, but that silicic volcanism in the region has been little considered, although ‘comparable volumes of silicic magma [compared with basaltic] have been erupted in the region’ (99). The Nabro Volcanic Range (NVR), which the authors identify as a single volcanic massif covering approximately 110 km and trending SSW-NNE from the Afar Depression to the Red Sea, is one significant but little-studied focus of silicic activity. The NVR encompasses the Edd Islands off the Red Sea coast, Dubbi volcano and the Edd lava field, Mabda volcano and the Bidu volcanic complex (Nabro and Mallahle calderas, and Bara Ale and Sork Ale volcanoes). The paired calderas of Nabro/Mallahle are described as follows:

Nabro has an 8 km diameter horseshoe-shaped caldera breached to the SW, and facing the 6 km diameter caldera of Mallahle. Nabro’s caldera contains a young volcanic centre, topped by two additional collapse craters. The flanks of the volcano are strongly dissected by gullies, whereas the inner walls of the caldera form 400-m high cliffs. The older of the two craters inside Nabro’s main caldera is also horseshoe-shaped and similarly open towards the SW. The walls of the innermost crater are 200 m high. (102)

Nabro and Mallahle are described as very similar in geomorphology and lithology, both being predominantly composed of trachytic lava flows. ‘On Nabro, geochemical and spectral evidence highlight at least two main periods of eruption of these flows’ (103). Both basaltic and silicic products are evident: ‘Whereas the main periods of edifice growth, collapse, and post-collapse volcanism have been characterized by silicic products, later volcanics of the Bidu Volcanic Complex include NNW-SSE basaltic lava flows, which streamed from vents or fissures located between the two calderas’. The authors suggest that these flows probably tapped separate source regions to those that fed the silicic volcanism, and note that ‘their superimposition on the boundary between the two calderas and orientation (i.e., perpendicular to the NVR axis), are enigmatic, but clearly not coincidental’ (103).

A very large eruption or eruptions in the past is evidenced by the presence of extensive ignimbrites, which the authors believe are ‘associated with collapses of both Nabro and Mallahle that formed the present day calderas’ (103). The age of these ignimbrites is unknown, but their spectral characteristics and state of preservation suggest their creation in a single eruptive sequence. The present-day ignimbrites cover an area of ~600 square kilometres, with a bulk volume tentatively estimated at 20 cubic kilometres. Prior to erosion of course a much greater bulk must have been present: the combined ignimbrite outcrop today lies within a 30 km radius of Mallahle, and the authors propose that if there was originally a single ignimbrite sheet extending this distance with a mean thickness of 40 m, the eruption magnitude may have exceeded 100 cubic kilometres (bulk volume):

These speculative upper and lower bounds on the ignimbrite volume [20-100 cubic kilometres] suggest an eruption (or eruptions) comparable in magnitude to the largest known historic eruption, that of Tambora in Indonesia in 1815, which expelled around 50 km3 of (dense rock equivalent) magma. This inference is compatible with the comparable caldera dimensions of Tambora (6 km), Nabro (8 km) and Mallahle (6 km). (107)

The total volume of the NVR is estimated by Wiart and Oppenheimer to be ~550 cubic kilometres, broadly comparable to that of Erta Ale. Overall they conclude that ‘the Erta’Ale range and NVR are, therefore, of broadly comparable area, volume, and age (Quaternary)’ but differ markedly in their composition and eruptive nature, with the Erta Ale range being composed of 91.4% basalt, 8.1% dark trachyte and 0.5% rhyolite, while the NVR is estimated as being 50% composed of trachyte and rhyolite (109). The authors suggest that the nature of the basement is responsible for this difference in composition, with the presence of continental crust on the margin of the Danakil region promoting the evolution of volatile-rich and ultimately explosive magmas.

The overall picture of Nabro is of a complicated and fascinating volcanic complex with a violent but varied history involving both explosive and effusive activity, some of the latter being possibly relatively recent in date, and set apart from the more northerly Afar volcanoes by its greater involvement of silicic and explosive magmas. The current eruption involved some initial explosive activity, but appears to have subsequently settled down to an intermittent and relatively low-level effusive event. It is to be hoped that clear images from the satellites will soon show the extent of the lava flows, and their sources. Given the evidence of Nabro/Mallahle’s history, it could be that their sources lie between the two calderas, replicating the behaviour which seems to have characterized the most recent activity at this obscure and intriguing volcano.

N.B. Several people have been in touch or left comments here to say that the Wiart & Oppenheimer paper is freely available via ‘a well-known file hosting site’. However, the paper in question is copyright Springer-Verlag 2004, and this blog respects copyright. Accordingly I won’t be providing the link here, and I respectfully ask that no-one else does so via the comments.

Reference
Pierre Wiart and Clive Oppenheimer, ‘Large magnitude silicic volcanism in north Afar: the Nabro Volcanic Range and Ma’alalta volcano’, Bulletin of Volcanology, vol. 67, no. 2 (2005), pp. 99-115 [DOI: 10.1007/s00445-004-0362-x]

Information
Global Volcanism Program: Nabro – summary information for Nabro (0201-101)

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Nabro eruption quieter, but continuing 18 June 2011

Posted by admin in activity reports, Africa, Eritrea, eruptions, Nabro.
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The eruption at Nabro is continuing. The announcement by Toulouse VAAC yesterday that the eruption had ‘stopped’ was, as we said at the time, not definitive. The latest from Toulouse (18:00 UTC 18 June 2011) is that the ‘eruption currently gets weaker’ and that the plume is ‘mainly composed of SO2 and water vapor’. The VAAC’s prediction for the next 24 hours (graphic here) is that no ash from this eruption will be detectable from 00:00 UTC on 19 June. Ethiopian Airlines has announced that it will be resuming flights to Khartoum after they were disrupted by the ash cloud from Nabro last week.

At 08:00 UTC this morning NASA’s Terra satellite captured a MODIS image of Nabro showing a small lightish plume with a diffuse ash cloud drifting south from the volcano. Click on the image to go to the original at the NASA Rapidfire site.

Nabro volcano, Eritrea, 18 June 2011 (NASA/Terra)

News
Ethiopian Airlines flights disrupted by ash cloud from Eritrean volcano – Bloomberg, 14 June 2011
Ethiopian Airlines to resume flights to Khartoum, Sudan, today – Bloomberg, 17 June 2011

Information
Global Volcanism Program: Nabro – summary information for Nabro (0201-101)

The Volcanism Blog

The Daily Volcano Quote: oceans of lava 17 June 2011

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From the record of the eruptions of Vesuvius it is evident that the volcanic energy has been increasing in intensity from the time of Pliny down to the present day. During the last two hundred and thirty-eight years more eruptions have been recorded than during the whole of the preceding eighteen centuries. The same increase of energy is also visible in Etna and the Lipari Isles. A study of the table of the frequency of eruption in these three volcanic centres points to a reciprocity in their action that proves them to be outlets to one and the same great reservoir of heated matter. … The attraction of the sun and moon … exercises the same kind of influence on the subterranean lava surface as the water of the ocean. But since the tidal influence only produces appreciable effect on large sheets of water, the observed effects on the lava imply a large molten surface beneath the earth, in which the lava tides originate. And when the superior mobility of particles of water over those of lava is taken into account, we are driven to the conclusion that the lava ocean under Vesuvius must be enormous, and comparable in size to the Atlantic or the Pacific.

‘Vesuvius’, The Pall Mall Gazette, 10 March 1869, p. 12. From a review of John Phillips, Vesuvius (Oxford: Clarendon Press, 1869).

The Daily Volcano Quote: from Monday to Friday, a new eruption of volcanic verbiage each day.

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Reports from Nigeria: dormant volcano stirring? 17 June 2011

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Some rather strange reports from Nigeria seem to suggest some kind of volcanic activity in Gombe State in the north-east of the country: emissions of some kind, possibly including toxic/environmentally harmful gases, have apparently been taking place in the Abaduguri range in Funakaye Local Government Area. North-eastern Nigeria does have a history of active volcanism (although how recently the area was active is not known) so the idea isn’t intrinsically unlikely. Descriptions of the supposed current activity, however, are rather baffling.

The Nigerian Observer quotes the National Environmental Standards and Regulations Enforcement Agency saying that ‘the rock, which has been emitting smoke in the past seven months, was a sign of “a dormant volcano which may erupt in future”‘, while a scientist from the Centre for Geodesy and Geodynamics of the National Space Research and Development Agency called the activity ‘a result of the impact of an earthquake that occurred in Pindiga formation, Gombe State, hundreds of years ago’. Elombah.com reports that ‘Local communities living around the Ndanijam Kargo Hill  in Funakaye Local Goverment Area and the surrounding villages in Gombe State of the North-Eastern part of Nigeria have been advised to relocate as a result of smoke emission at Abadaguri rocky range because the dormant volcano in the area is likely to erupt any time from now’. The gas has apparently been ‘gushing out from the rocky area’ for seven or eight months, and has ‘an odour of burning plastic’. The Daily Champion reports reassuringly that the Nigeria Meteorological Agency has described the eruption as ‘extinct or dormant’, and adds the interesting information (from a Funakaye local official) that ‘the crack where the smoke was emitting from, used to be the entrance to the house of a renowned hunter in the area, Abbaguri ,who lived in the cafe hundreds of years ago’.

Perhaps the situation will become clearer as new reports emerge. Hat tip to Eruptions commenter Shérine for spotting these mysterious reports.

UPDATE. Experts from Nigeria’s Centre for Geodesy and Geodynamics have been testing gases at the location of the emissions, reports the Abuja newspaper Daily Trust. Apparently their analysis revealed that ‘gases could result to the formation of magma capable of causing volcanic eruption in the area’.

News
Dormant volcano comes alive in north-eastern Nigeria – Elombah.com, 10 June 2011
Volcanic eruption in Gombe dormantDaily Champion, 12 June 2011
Smoke-emitting rock may erupt, says NESREANigerian Observer, 17 June 2011

Information
Global Volcanism Program: Biu Plateau – summary information from the GVP for the Biu Plateau volcanic field (0204-05-)

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