Monday, 13 June 2011

Strong earthquakes are setting off a powerful volcanic eruption in Eritrea (based on satellite images)

UPDATE 13/06 – 13:28 UTC : Tim reports from Asmara, Ethiopia : Confirmed that there is indeed some volcanic ash in the air in Asmara, Eritrea and tonights Lufthansa flight has been cancelled.The department of mines is due to send a team to investigate as I believe this eruption had been underestimated.

Asmara currently hosts around 50 geologist due to the countries mining boom, most of which do not know this is occurring. Sadly Eritrea is a bit of media black spot.

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, butthis news is making us happy, as Afambo will be far enough away from the volcano to not have received a direct impact.

Nabro volcano eruption June 12 2011 - the other green sign free of clouds is Dubbi volcano.

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.

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.

Important request to Eritrean and Ethiopian readers : If anybody of our readers has friends or relatives close to the area of the volcanoes would you be so kind to ask them for more information. Please let us know by the form below.

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 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 reaches Sudan.

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.

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)

Last update: June 12, 2011 at 10:51 pm by By Armand Vervaeck and James Daniell 1 Comment

May we ask our Eritrean and/or Ethiopian readers to tell us what exactly is going on here by filling in the form below.

UPDATE 22:35 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 following satellite picture clearly indicates that an eruption is going on in the area. Look at the upper right quarter. A point will gradually grow to a major cloud, which means that based on the scale the eruption is very huge.

Click here for the animated cloud cover in Ethiopia / Eritrea

We do appreciate the person from the Netherlands and a few other people immediately afterwards who traced this satellite picture. Satellite pictures courtesy

UPDATE 22:02 UTC : @ 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 earthquake 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

The red point is the location of the first tremor - the landscape has a volcanic origin

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 thevolcano. 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 : These magnitudes can lead to serious damage if the epicenter is below or very near to Afambo (which is very 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 Mw5.7 has been also recorded at depth 9km in around the same area. No record of damage has yet been recorded.

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 is’nt 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 this shallow depth 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).

UPDATE 20:56 UTC : The earthquakes are continuing with the last one as the strongest so far with a 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 status as the distance to the ridge fault is to big to create this 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 kmModerate 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.

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 REGIONM 5.7 2011/06/12 21:03 Depth 9.9 km ERITREA – ETHIOPIA REGIONM 5.7 2011/06/12 20:32 Depth 10.1 km ERITREA – ETHIOPIA REGIONM 4.8 2011/06/12 19:44 Depth 9.9 km ERITREA – ETHIOPIA REGIONM 4.7 2011/06/12 19:37 Depth 10.1 km ERITREA – ETHIOPIA REGIONM 4.5 2011/06/12 18:01 Depth 10.1 km ETHIOPIAM 5.0 2011/06/12 19:21 Depth 10.0 km ETHIOPIAM 4.7 2011/06/12 17:47:21 13.538 41.588 Depth 10.0 km ERITREA - ETHIOPIA REGIONM 4.8 2011/06/12 17:18:10 13.381 41.764 Depth 9.9 km ERITREA - ETHIOPIA REGIONM 4.3 2011/06/12 16:33:12 13.507 41.722 Depth 10.0 km ERITREA - ETHIOPIA REGIONM 4.8 2011/06/12 16:24:44 13.436 41.682 Depth 10.0 km ERITREA - ETHIOPIA REGIONM 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 : 5.1UTC Time : Sunday, June 12, 2011 at 15:37:05 UTCLocal time at epicenter : Sunday, June 12, 2011 at 06:37:05 PM at epicenterDepth (Hypocenter) : 10 kmGeo-location(s) :Almost below Afambo, Eritrea

128 km (79 miles) WNW of Assab, Eritrea

Links to important mapsUSGS Did You Feel It MapGoogle satellite map of the area showing the kind of terrain the earthquake took placeUSGS historic earthquakes map

USGS Seismic hazard map