Eritrea Nabro volcano eruption – From the earthquake swarm until the eruption (day 1 and 2)

Last update: September 29, 2011 at 11:28 pm by By

Read also : Air traffic disruption and the aid of NASA HD satellite images (day 3, 4 and 5) (June 23)
Read also : Impressive new NASA pictures (June 30)
Read also : 31 people killed at the Ethiopian side – thousands more need aid (July eight)
Read also : Seismic activity continues below Nabro (September 14)
Read also : Evidence of ongoing activity (satellite pictures) (September 29)

Earthquake / Eruption summary : During the late afternoon and evening of June 12 2011, a series of moderate earthquakes struck the Afambo, Eritrea area. The moderate earthquakes were followed by 2 strong 5.7 earthquakes. Based on the earthquake pattern and the locations of the epicenter, volcano activity seemed imminent. Our very extensive report is also the work of many of our readers who gave a lot of input. This proves that together, we can beat a lot of information services, especially in developing countries.
This is part 1 of our Nabro volcano eruption reporting. Nabro is an Eritrean volcano with NO historic eruption record. Day 1 and 2 of our reporting describes the swarm of moderate to strong earthquakes who did initiate the explosion of a crater which at that time was still called Dubbi, as this was the only volcano in the area with proven eruption (1861) record. With the help of our readers, we were able to gradually find evidence that it could be Nabro that was erupted. Unbelievable for most, but 100% certain for the satellite analyzers among us.
Our video reporter / assembler Robert Speta has made a video based on the content of this article for those who do not like to read. Click here to watch it in our "Quake-TV.org" subsite.
Links to : Part 1 (Day 1 and 2), Part 2 (Day 3, 4 and 5), Part 3 (Day 6 – end)
To read the full story as it happened, we advise our readers to start at the bottom of the page (earthquake data) and to continue going up.

UPDATE 13/06 – 20:07 UTC : Another report from the conditions in Asmara, the capital of Eritrea : Spoke to my uncle in Asmara right now. He says that the capital is fine and that there are people in Asmara who dont even know that there was an eruption. The eruption is in Assab and due to the wind, the ash is impacting Ethiopia moreso, apparently, which would explain why Clinton is cutting her trip to Addis short. It is almost 8p so i will call again tomorrow and update everyone once people are awake and more information has been gathered.

UPDATE 13/06 – 19:20 UTC : We got the following report out of Logia, Afar, Ethiopia : I'm an exploration geologist currently based in a camp near Logia, in the Afar desert in Ethiopia. We are approximately 200 km south-southwest of the volcano. We've been sat in the ash cloud since yesterday evening. See also his picture of the ash graying the sky and the horizon

UPDATE 13/06 – 18:47 UTC : Finally we got some news from the Eritrean government. We are printing their press release in full (Ministry of Information) :

Volcanic Eruption Witnessed In The Tip Of Southern Red Sea Region
Assab, 13 June 2011 -A volcanic eruption was witnessed in the tip of the Southern Red Sea region at 9 p.m. yesterday.
Reports indicated that the eruption that took place in 4 different areas around Afambo, Nebro and Sireru causing a 5.7 rector scale earth tremor.
The ensuing dust is covering hundreds of kilometers in the area, and that the quake has been heard in the greater portion of the region as a whole, according to reports.
The Southern regional Administration disclosed that the Government has moved the inhabitants in the area to a safe place, in addition to providing them with the necessary care. No damage has so far been inflicted to human life , the Administration added.
Although similar earthquake incidents were witnessed from time to time in previous years, yesterday’s tremor was of higher scale that led to volcanic eruption.

UPDATE 13/06 – 18:44 UTC : Eruption pattern became totally different. The eruption is still going on, but seems to decrease forcefully. The ash plume has a decreased considerably in length. Quite strange is also the current patchwork (ash clouds are not continuous anymore). Click here to see the live animated infrared video.

UPDATE 13/06 – 18:20 UTC : Eskinder Nega reports from the Ethiopian capital Addis Ababa : No ash in the air in Addis,though it was cloudy today.But this is also the beginning of the rainy season,clouds are not unusual. Hillary Clinton was forced to cut short a two days visit because of concerns of spreading ash.
She arrived early afternoon and was gone by early evening, according to the media reports.

IMPORTANT SCIENTIFIC UPDATE ON NABRO VOLCANO (source : The Volcanism Blog)
Nabro is a stratovolcano reaching to 2,218 metres a.s.l., truncated by nested calderas of 5 km and 8 km diameter, the latter caldera having a wide breach to the SW.
Although Nabro has no recorded Holocene eruptive activity, the GVP (from which this description comes) notes that ‘ Some very recent lava flows were erupted from NNW-trending fissures transverse to the trend of the Nabro volcanic range’, so if the current activity is from the Nabro complex it does not necessarily represent the surprise re-awakening of the volcano after millennia of dormancy.
Wiart and Oppenheimer (2005) identify these ‘recent basaltic flows’ as originating from ‘Vents … located between Nabro and Mallahle calderas, and fed in part from fissures aligned perpendicularly to the NVR [Nabro Volcanic Complex] axis’ (p. 104), although, working with strictly limited data, they do not venture a date for these flows. Satellite imagery shows these flows as weathered, but fresher and distinctly darker than surrounding material.

UPDATE 13/06 – 16:34 UTC : The ash cloud would probably travel to Saudi Arabia, Jordan and Israel

UPDATE 13/06 – 16:30 UTC : The Lufthansa flights to Ethiopia have been canceled because of the ash concentration in the atmosphere.

UPDATE 13/06 – 16:16 UTC : Ash from ongoing eruption at Nabra volcano in Eritrea is likely to reach southern border only; may cause more problems to Egypt, Jordan. (source : Jerusalem Post).

UPDATE 13/06 – 15:52 UTC : Reader Avo reports from Mekele (Northern Ethiopia and approx. 200 km from the volcano) : I am a Frenchman living in Mekele, Northern Ethiopia, East from the volcano. I found this site while trying to know where the ashes where coming from.
Waking up this morning, everything was covered by a 1mm, sometimes 2mm layer of black ashes. The sky was cloudy today, but abnormally greyish. Ashes where still in the air till noon, as I got some in my eyes a few times.

UPDATE 13/06 – 14:08 UTC : New " 12:00 UTC Ash advisory bulletin" for Air Traffic. Click here or on the picture below. The plume is gradually extending but for the real risk also ash concentration should be looked at.

UPDATE 13/06 – 13:28 UTC : Tim reports from Asmara, Eritrea:
Confirmed that there is indeed some volcanic ash in the air in Asmara, Eritrea.
Tonights Lufthansa flight has been canceled
The Department of mines is monitoring the event closely.

UPDATE 13/06 – 12:05 UTC : NASA satellite images in combination with Google Earth have given the final clue in the discussion which volcano was erupting. It is NABRO volcano, a volcano that has NO sign of being erupted in recent history. This will be a major scientific research eruption. We are still awaiting further news from Eritrea, but this news is making us happy, as Afambo will be far enough away from the volcano to not have received a direct impact.

UPDATE 13/06 – 12:1705 UTC : Intermediate overview of the current situation (by Pieter De Leeuw):
The estimated height of the ash cloud is ~13.5km, according to the VAAC. This is an essential piece of information in predicting the current size of the eruption, as the height of the ash cloud often reflects the force behind the eruption. In this case, it would so far be an average-to-large eruption. For comparison; the ashcloud from the Eyjafjallajokull only came up to 9km in April 2010, the more recent Grimsvotn eruption in Iceland forced ash up to 20km in the air, and the 1981 Mt. St Helens eruption's ashcloud reached 25km into the atmosphere.
There however is some uncertainty with this way of estimating the size of an eruption. The height of the ash-cloud is influenced by many factors, such as prevailing wind, eruption style and eruption angle. In this case strong winds seem to prevail (the plume traveled over 250km in 2 hours after the onset of the eruption). The eruption style seems to be a 'gray' eruption (with much ash, little lava) instead of a red eruption (much lava, little ash). The eruption angle is however not possible to determine. Most eruptions occur horizontally, but exceptions do occur, as happened with Mt. St. Helens. A landslide triggered a so called 'lateral' eruption. This is a possible scenario, as the earthquakes (up to M5.7) were strong enough to possibly have created landslide.
Also, when estimating an eruption size based on the magnitude of the preceding earthquakes, one should take into account that this volcano (Nabro volcano ER) possibly has been dormant for hundreds to thousands of years.
This could mean that the overlaying ground was not ductile for magma movements, and therefor a massive force was needed to force it's way up to the surface.
These are all plain speculations based on the information we currently have, and by no means an official report.

UPDATE 13/06 – 12:05 UTC : The eruption is continuing at full strength based on the infrared weather satellite images from Sat24 at 12:00 UTC. Click here to watch the latest animated version.

UPDATE 13/06 – 11:13 UTC : Ethiopian media has warned citizens to protect themselves from the ash and smoke coming from the volcanic eruption.

UPDATE 13/06 – 11:09 UTC : As more and more journals are picking up the story, the guessing in between both Nabro and Dubbi goes on merely because everybody has still to rely on the satellite images. Those sources who have HD satellite images are putting their money on the Nabro, which would be a MAJOR EVENT for science, as this volcano has NO record of any historic eruptions so far. We @ earthquake-report.com do not guess anymore. We are simply awaiting news from the Asmara authorities.

UPDATE 13/06 – 10:47 UTC : A reader report out of Asmara, Eritrea (Ip number reflects Kenya intersat, probably the connecting carrier for Eritrea):
I live in the capital of Eritrea, Asmara, and I did not feel the earthquake, but the plume from the volcano is covering the whole of Asmara since the morning, but now it is clearing somewhat. I just heard that the flight Asmara-Jeddah-Frankfurt which was supposed to depart tonight, has been canceled. (We can not confirm the flight cancellation news but it looks normal to us).

UPDATE 13/06 – 10:37 UTC : The report below is bad news for the people living in the immediate surrounding of the volcano. Normal eruption behavior in the rift volcanoes is a lot of flowing lava, even lava lakes. The big cloud which can be seen at the bottom of this page leads to the prediction that a huge explosion did set off the eruption. It is embarrassing that 12 hours after it happened still NOBODY can give detailed information of this eruption. Additionally if the volcano is Dubbi volcano, then we do fear for the wellbeing of Afambo as this village (town ?) is very near the crater.

UPDATE 13/06 – 10:30 UTC : Loud explosions were heard in Afdera (Afdera is approx. 30 km from the volcanoes), across the border in Ethiopia, and ashfall is reported as far as Mekele in Tigray province (Mekele is approx. 200 km from the volcanoes). $$$

 

UPDATE 13/06 – 10:24 UTC : The international press is waking up as the ash cloud threatens airline traffic. No additional info however out of Eritrea and this will be the only source that counts. Apart from Eritrea the satellite companies (NASA, etc) have certainly HD images enabling them to locate the exact crater. For now, we still use the term "undecided".

UPDATE 13/06 – 09:54 UTC : What a crazy situation! In trying to find more information in Eritrea on the ongoing eruption but even more on the extend of damage in and around Afambo, we could find only ….. yes, our own article! I hope that Eritrean news sources will try to get information out of Afambo soon. Why ? Is international help needed if damaged ? It takes many hours, even days before aid is organized and every hour lost is important in such cases.

UPDATE 13/06 – 09:29 UTC : Reader John Tucker did send us the following report (based on an Israeli source) :a Hebrew journal is reporting it as Nabro – I rab it through google translate: A cloud of volcanic ash from the volcano Anabro (Nabro), on the border of Ethiopia – Eritrea, makes his way to the north – west. Satellite photographs show that the last few hours the cloud is now over Sudan, in the Red Sea. According to certain forecasts, in a few days volcanic ash could reach Israel, located about 1,700 km from the volcano. In this case, there may be cancellation of flights from Israel Strip. [ http://www.masa.co.il/ ] click on the volcano photo

UPDATE 13/06 – 09:10 UTC : Thanks to our readers we have received the url of the Ash cloud advisory above Africa. Click this link or the picture. It links to the latest report of 06:00 AM UTC. A new report will be released in approx. 3 hours.

UPDATE 13/06 – 08:50 UTC : Why is almost NOBODY in the world reporting on this extraordinary event ??

UPDATE 13/06 – 08:46 UTC : We expect that some airlines will have to divert from their normal routes as the ash plume is extending further and further. Especially flights from Europe to East Africa are flying that route (at least i did last year).
Is the ash concentration in the clouds monitored above Africa ?

UPDATE 13/06 – 07:23 UTC : We are still guessing on which volcano erupted. Opinions change from Dubbi to Nabro. The satellite images are not convincing. The local press has not even mentioned this volcano eruption (at least not the ones we are following)

UPDATE 13/06 – 06:55 UTC : The initial explosion (see pictures below) creating a vast ash cloud has now gone into a normal eruption plume.

UPDATE 13/06 – 06:27 UTC : We truly thank our thousands of readers who have also contributed a lot to this report by giving tips of satellite images, etc. while we were resting for a couple of hours.

UPDATE 13/06 – 06:27 UTC : Volcano ash cloud is stretching now over more than 1,000 km (westerly direction) and has reached Sudan.

UPDATE 13/06 – 00:47 UTC : From now on we will have to wait for local reports, pictures, video's etc.
We are very eager to get a confirmation that nobody was hurt and that no damage was inflicted during the earthquake and/or eruption.
Many scientists will board airplanes to take a close look at the volcano, take samples, etc.

UPDATE 13/06 – 00:15 UTC : This is a very recent Google earth picture (combined with satellite cloud image). The size of the cloud is 150 km on 50 km! (91 on 35 miles).

UPDATE 23:46 UTC : We are now convinced that the erupting volcano is the Nabro volcano (an official confirmation is still missing)

UPDATE 23:16 UTC : As long as we have no confirmation of local authorities we have to guess on the name of the erupting volcano. Dubbi volcano is one scenario as his activity could be traced to 1861. Based on the coordinates of the beginning of the eruption as well as the location of a number of the more powerful earthquakes, Pieter De Leeuw (Netherlands) has traced the eruption as probably coming from the Nabro volcano, a crater with a diameter of 8 km. We agree with him. Nabro volcano has no records of recent eruptions.

UPDATE 23:10 UTC : According to Global Volcanism Program, both Nabro and Dubbi belong to the Bidu volcanic complex

UPDATE 22:59 UTC : Earthquake-report.com wants to know as fast as possible the situation in Afambo. The continuous earthquakes may have been damaging. Depending the activity of the nearby Dubbi volcano, people in very nearby Afambo are at risk. We hope to receive OK signals soon, but as said earlier on, communications with this part of Eritrea will be very basic and it can take a while before the news reaches the outside world (if not cut off by the ongoing events).

UPDATE 22:45 UTC : This will be a very special volcano eruption because we expect that the eruption comes from the Dubbi volcano who had it's latest recorded activity in 1861.

UPDATE 22:35 UTC : The satellite picture below clearly indicates that an eruption is going on in the area. Look at the upper right quarter.

Click here for the animated cloud cover in Ethiopia / Eritrea

We do appreciate the person from the Netherlands and a few other people who wrote us about the satellite pictures. Satellite pictures courtesy http://www.sat24.com.



UPDATE 22:02 UTC : @ earthquake-report.com we expect that it will take at least 12 hours before we can get a more precise picture of what happened. We will keep you updated just as we do with all other earthquakse and volcanic events that we are following up.

UPDATE 21:45 UTC : The earthquake intensity of the 5.7 magnitude earthquake (latest one) caused 451 people to feel a strong shaking and 17,000 people a moderate shaking (theoretical values)

UPDATE 21:44 UTC : As reported below, the last known eruption of one the volcanoes dates back to 1861 (Dubbi volcano) and killed 106 people

UPDATE 21:36 UTC : Some more information on the volcanic complex :
Mallahle is the central of three NE-SW-trending stratovolcanoes in the Danakil horst SW of Dubbi volcano, and lies SSW of Nabro volcano.
These two volcanoes, along with Bara Ale and Sork'Ale, form the Bidu volcanic complex. The complex Mallahle stratovolcano is truncated by a steep-walled 6-km-wide caldera. Mallahle is formed of rhyolitic lava flows and pyroclastics. Basaltic lava flows blanket the slopes of the
volcano. Recent obsidian flows are found on the NW flank of Mallahle and older obsidian flows were erupted on the northern caldera floor.
Flank spatter and scoria cones are most numerous on the western side of the volcano. Extensive ignimbrite deposits associated with the collapse of Mallahle and Nabro volcanoes blanket the countryside.

UPDATE 21:28 UTC : The 5.7 magnitudes can lead to serious damage if the epicenter is below or very near to Afambo (which seems to be nearby (based on the seismological data)) . We do not think that there will be injured people as the series started with moderate earthquakes and as people will stay on the streets after so many earthquakes. The current situation tends to become very dangerous.

UPDATE 21:23 UTC : A new Mw5.7 at a depth of 9km has been recorded in the same area. No record of damage so far.

UPDATE 21:03 UTC : Lucas Tavares reports in our Facebook page : I was studying about this volcanoes past hours. Maybe the shakes surrounds the Mallahle or Nabro Caldera, there isn't any known eruptions of these volcanoes! Shakes are becoming stronger!

UPDATE 20:58 UTC : We have still no trace (as expected) of what is really going on. This last 5.4 earthquake can be damaging at the given shallow depth and when the epicenter is located below a village or town. As we are unsure of the exact epicenter (the error margin may be 10 to 30 km different than reported by the USGS) we have no certainty as yet.

UPDATE 20:56 UTC : The earthquakes are continuing with the last one as the strongest so far ( magnitude of 5.4 at a depth of 10 km).

UPDATE 20:33 UTC : We are more and more convinced that one of the nearby volcanoes went into an active state as the distance to the ridge fault is too big to create these kind of earthquakes. Additionally almost all the earthquakes are occurring near the volcano complex on the picture (courtesy Google Earth)

UPDATE 19:37 UTC : This unusual series of moderate earthquakes have also occurred a couple of months ago in the Gulf of Aden. The earthquakes are typical for separating irregular tectonic plates. The series in the Gulf of Aden had their epicenter in the immediate area of the ridge fault.
Due to the close-by volcanoes, an eruption pattern of the Dubbi volcano is still possible. The pre-eruption pattern of both the Icelandic and Chilean volcanoes from the last few weeks is also present here. Compared to Iceland and Chile, Eritrea has other concerns than looking to beautiful eruptions. We will follow up these events and will come back to you as soon as we can get more data ?
UPDATE 16:11 UTC : Other agencies are reporting totally different and less dangerous numbers : GFZ: 4.9 @ 43 km and EMSC 4.7 @ 200 km
Moderate shallow earthquake with an epicenter almost below Afambo.
Approx. 15 km from the Dubbi volcano. The peak of the Dubbi volcano is 1625 m. There have been four known eruptions. In 1400 lava was determined to have reached the Red Sea while in 1861 ash was thrown over 250 km from the volcano. Two further events were suspected between 1861 and the 20th century.

Links to : Part 1 (Day 1 and 2), Part 2 (Day 3, 4 and 5), Part 3 (Day 6 – end)

During the late afternoon and evening of June 12 2011, a series of moderate earthquake struck at first near Afambo in Eritrea and later 100 km more to the south in Ethiopia. At the moment of writing, we do not know whether these earthquake have a tectonic or a volcanic origin.

Other moderate earthquakes which occurred after the first earthquake which is described in detail

M 4.5 2011/06/12 21:37 Depth 15.0 km ERITREA – ETHIOPIA REGION
M 5.7 2011/06/12 21:03 Depth 9.9 km ERITREA – ETHIOPIA REGION
M 5.7 2011/06/12 20:32 Depth 10.1 km ERITREA – ETHIOPIA REGION
M 4.8 2011/06/12 19:44 Depth 9.9 km ERITREA – ETHIOPIA REGION
M 4.7 2011/06/12 19:37 Depth 10.1 km ERITREA – ETHIOPIA REGION
M 4.5 2011/06/12 18:01 Depth 10.1 km ETHIOPIA
M 5.0 2011/06/12 19:21 Depth 10.0 km ETHIOPIA
M 4.7 2011/06/12 17:47:21 13.538 41.588 Depth 10.0 km ERITREA - ETHIOPIA REGION
M 4.8 2011/06/12 17:18:10 13.381 41.764 Depth 9.9 km ERITREA - ETHIOPIA REGION
M 4.3 2011/06/12 16:33:12 13.507 41.722 Depth 10.0 km ERITREA - ETHIOPIA REGION
M 4.8 2011/06/12 16:24:44 13.436 41.682 Depth 10.0 km ERITREA - ETHIOPIA REGION
M 4.7 2011/06/12 16:12:03 13.397 41.734 Depth 10.0 km ERITREA - ETHIOPIA REGION
M 4.5 2011/06/12 16:09:30 13.443 41.696 Depth 2.9 km ERITREA - ETHIOPIA REGION

Most important Earthquake Data:
Magnitude : 5.1
UTC Time : Sunday, June 12, 2011 at 15:37:05 UTC
Local time at epicenter : Sunday, June 12, 2011 at 06:37:05 PM at epicenter
Depth (Hypocenter) : 10 km
Geo-location(s) :
Almost below Afambo, Eritrea
128 km (79 miles) WNW of Assab, Eritrea

 

Links to important maps
USGS Did You Feel It Map
Google satellite map of the area showing the kind of terrain the earthquake took place
USGS historic earthquakes map
USGS Seismic hazard map

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2011-06-19 05:47:16 4.0 Eritrea
2011-06-19 05:32:37 4.0 Eritrea
2011-06-19 02:33:12 3.2 Eritrea
2011-06-18 04:37:52 4.1 Eritrea
2011-06-18 03:32:18 3.0 Eritrea
2011-06-18 02:51:40 3.1 Eritrea
2011-06-18 02:47:21 3.8 Eritrea
2011-06-18 00:03:39 3.3 Eritrea

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