El Hierro Volcano eruption (Canary Islands) : Part 7 – October 27 until October 31, 2011

This is Part 7 of the El Hierro Volcano eruption report


Our tweets are also posted into our Facebook Volcano Page
With the collaboration of Joke Volta, an El Hierro resident

Read also : Scientific paper reveals massive historic Tenerife volcano flank collapse
Read also
: Economic impact on El Hierro and the Canary Islands if an aerial eruption would occur

Read also: Part 1 (from July 28 until early September)
Read also: Part 2 (from September 25 until October 10 )
Read also: Part 3 (from October 11 until October 13 )
Read also: Part 4 (from October 14 until October 17 )
Read also: Part 5 (from October 18 until October 21 )
Read also: Part 6 (from October 22 until October 26 )
Read also: Part 7 (from October 27 until October 31 )
Read also
Part 8 (from November 1 until November 3
Read also
Part 9 (from November 4 until November 6
Read also: Part 10 (from November 7 until November 8)
Read also: Part 11 (from November 9 until November 11)
Read also: Part 12 (from November 12 until November 15)
Read also: Part 13 (from November 16 until November 19)
Read also: Part 14 (from November 20 until November 23)
Read also: Part 15 (from November 24 until November 27)

Data update 31/10 - 23:04 UTC
A 3.9 earthquake occurred at 22:06 UTC. It was the strongest earthquake today. The 3.9 earthquake was felt as a MMI IV, light shaking, earthquake.

Data update 31/10 - 20:20 UTC
The muddy stain looks to be more active than ever before. A satellite image would reveal a far greater stain than last week. The fact that the eruption at La Restinga increased again might be linked to the stronger earthquakes in the El Golfo area. One of the scenarios earlier discussed at jonfr.com, a dedicated amateur volcano follower discussion group, was that the La Restinga - Las Calmas - Puerto Naos eruption was feeded by deep magma movement at El Golfo. This scenario seems to become more realistic with the current events. The picture belongs to diarioelhierro.es and was taken by Gelmert Finol at 18:00 today!
The oceanographic ship, the Roman Margalef has detected magmatic material with another composition than last week. Apparently the material was red colored and totally different than the initial black stones with a white inner layer.

Picture of the increase muddy grey stain at 18:00 on October 31 2011 - image courtesy and copyright DiarioElHierro.es and Gelmert Finol

Data update 31/10 - 19:00 UTC
A very active earthquake day at El Hierro. IGN listed already 93 earthquakes today! (as much as yesterday during 24 hours). 5 of them had a magnitude of 3 or higher. The strongest one today was a 3.6 magnitude quake.
I guess we will have to a part from this article as it is growing far too long. This will be done tomorrow. The picture below was taken by Gelmert Final for

Important Update 31/10 - 11:18 UTC
Pevolca has decided that Nothing special should be done. El Golfo has NOT to evacuate but people living there have to be ready to pack belongings fastly if needed + remain calm.
People are getting more nervous by the hour with all these Pevolca meetings. Their calls to stay calm are contradictory with what people are feeling and with the number of Pevolca meetings. We trust however on the expertise of the combined committee of Emergency services, Scientists and Authorities.

Museu da Horta, Faial evocation of the Capelinho eruption from 1957-1958 - image courtesy galenfrysinger.com

Update 31/10 - 10:19 UTC - a very similar situation as at Faial (so far)
Diario de Avisos has written an article that, for those who know Spanish is very interesting to read and for those who do not read Spanish interesting to look at. The birth of an Azores Island. The similarities with the present situation @ El Hierro is astonishing. The stain, the jacuzzi and a surtseyan eruption with the creation of a new island were all present at Faial, one of the Azores islands. Click here to read this outstanding article.
The explosive eruption took place in front of the village of Capelinho, Faial. @ Capelinho everything started with 10 days of seismic activity. Afterwards a green stain followed by a jacuzzi and a grey spot appeared in the ocean (identical phenomena have been seen so far at La Restinga (see below)).
On September 27 1957, a enormous column of combined steam, gases and ash did burst up to 1000 meter high out of the ocean. The diameter of the explosive area was approx. 300 meter! The following days 3 small islands were formed. The continuous activity added more material to the islands which grew together in 1 bigger island approx. 400 meter out of the coast. The eruption phase finally stopped at October 24 1958, more than 1 year later. After the eruption a big part of the island was covered with ash and the earlier formed island did grow gradually to become a part of the main island. A portion of 2.4 square km were added at Faial.

Video of the Capelinho Faial surtseyan eruption

Important Update 31/10 - 09:05 UTC
PEVOLCA meets again this morning at 11:00 AM local time (10 UTC) to discuss the present situation. The present meeting is a surprise as the last meeting was only yesterday evening. The apparent reason is the continuously changing data from the earthquakes and other seismological instruments. Yesterday evening Pevolca had decided to do nothing at all and to wait for further events + of course to monitor further. The meeting from this morning may be bad news for the people at El Hierro, although the outcome is very unsure.
- The reason might be the number of volcanic earthquakes and the strength which have been increasing gradually.
Yesterday we counted a total of 93 earthquakes, today in 9 hours already 41.
Yesterday 6 earthquakes were greater than magnitude 3, today already 2.
Harmonic tremor does not show a lot of difference and the depth is not really alarming, but the seismic activity (number and strength) is another story. @ earthquake-report.com we do not like the situation of the people living in the El Golfo bay. As we have already seen in many other eruptions, a very strong earthquake (M 4 to M 6) may start a number of events. Especially a very strong earthquake might change the possibility to escape to Valverde drastically. We @ earthquake-report.com do not know what the Los Roquillos tunnel can resist and how many people can fast be evacuated from the El Golfo Bay to Valverde by other roads, pats etc.
Nobody knows what will be the next move of the volcano will be, but the best outcome, an immediate subsiding activity, is not high listed in the calender of the volcano.

Update 30/10 - 21:18 UTC
@ earthquake-report.com we are surprised to see ONLY Spanish seismologists and scientists in the area. Spain had only one eruption in almost 40 years. The Icelandic seismologists and volcanologists have experienced multiple eruptions and are experts in Surtseyan eruptions (eruptions who form a new island). Of course these contacts can exist behind the scene but we are unaware of them.

Data Update 30/10 - 20:53 UTC
Pevolca decides to stay alert and not to take any additional action at the moment. They told the press that " an eruption is not imminent at the moment", as the hypocenters (depths) are still around 20 km. Once again Pevolca called onto the population to stay calm. Mr. Santana, in charge of safety, declared this afternoon that the earthquakes focal depths should rise to 8 to 10 km before a real danger for an eruption should exist.
- Pevolca has also decided that the Los Roquillos tunnel will remain open
- Joke Volta told us a few moments ago that an eventual evacuation of Frontera and the neighboring localities like Sabinosa, Tigaday, Belgara, Las Puntas and Los Llanillos would be a little more difficult than La Restinga because they are with several thousands and a lot of the people living in the El Golfo area are foreigners (with limited skills in Spanish).
@ Earthquake-report.com, we think that indeed there is no immediate danger, but this can change at any moment. We trust on the expertise of the Spanish scientists

Data Update 30/10 - 14:12 UTC
Seismic activity remains strong. Another magnitude 3.9 earthquake occurred at 13:05 UTC (14:05 local time). This earthquake was well felt on different parts of El Hierro. Another concern is the accumulated energy? Click here to see the graphic? The continuing strong earthquakes is pushing the graph higher. Deformation graphics on the other hand are relatively stable.

Data Update 30/10 - 11:55 UTC
- As expected in our update of 07:53, a meeting will be held at 19:00 to evaluate the situation after the strong 3.9 magnitude earthquake. Will be present : scientists, authorities and the person in charge of safety and emergencies.
- The 3.9 earthquake from this morning 07:46 was followed by 1 M 3.0 and 8 M+2 earthquakes.

Important Update 30/10 - 07:53 UTC
- Based on all what follows Earthquake-Report.com predicts that PEVOLCA will meet very soon. Main reason : The increasing strength of the earthquakes.
- The strongest earthquake since October 8 (a M 4.4 quake at the time), now a Magnitude 3.9 quake, occurred at 07:46 this morning in the El Golfo bay. Its epicenter was close to the Frontera coast line. The 4.4 earthquake on October 8 was the start of a number of events like the beginning of harmonic tremor and the start of the green stain (eruption) soon after. The depth is still a secure 22 km. Some scientists are linking however the magma area below the El Golfo to the still continuing eruption to the south of La Restinga. These are however speculations who cannot be proofed.
- At earthquake-report.com we do not consider quakes up to Magnitude 5 as dangerous for houses, although indirect damage can be triggered by rockfall and landslides in mountainous areas like El Hierro. Authorities will certainly follow up the El Hierro landscape scars when the quakes get again to Magnitudes 4 to 5. This will be a major concern for the El Hierro authorities from now on.
- Harmonic tremor remains the same as during recent days. This may change fundamentally if the quakes continue and are getting more powerful.
- Since midnight UTC IGN listed 11 earthquakes and only 2 of them were lower then 2! The last 3 quakes had values of 3.2, 3.9 and 3.0.
- Authorities have closed the Los Roquillos tunnel out of fear of Rockfall for the 3 to 4 magnitude quakes in the beginning of the month and have reopened him last week due to the pressure of the population. Will authorities close the tunnel again ? We do not think that they will take such a decision very soon as technicians have improved some parts of the tunnel. The concern among scientists and PEVOLCA must grow though.
- Joke reported yesterday that the Frontera population reacted completely different to the earthquakes than the El Pinar and La Restinga people. More indifferently and certainly not as alerted as them.
- Those people wanting to follow the discussions among specialized volcano amateur followers can click on this link. We can warmly advise it. A lot of scenarios are being discussed.

El Golfo Bay, area of the current many earthquakes who are getting more and more powerful - image Joke Volta taken on October 29

Data Update 29/10 - 16:15 UTC
One of the strongest jolts of the last couple of days occurred at 15: 04 UTC and had a magnitude of 3.6 (depth 23 km). It was felt on the island as a III MMI shaking (weak shaking). Click here for the epicenter location.

Data Update 29/10 - 13:42 UTC
Joke Volta reports from Tigaday (Frontera) - (she sits with her laptop in a restaurant with wifi connection) - that the green stain has encircled the coast of Tigaday (Frontera). The stain could be better viewed when exiting the Los Roquillos tunnel (yes, the tunnel who was closed far a while because of the rockfall danger). Together with Joke in the restaurant : 2 observers with laptop/binoculars - one from press agency EFE. So, Joke our local earthquake-report.com volunteer reporter, is amid the trained professionals :). Thanks Joke on behalf of our readers. (ER: Joke was refused admission yesterday in a press meeting at Valverde - As a resident of El Hierro she really felt pushed away from the news. We can understand her...)

Data Update 29/10 - 13:22 UTC
- Harmonic tremor goes slightly up and down.
- Yesterday IGN listed 63 earthquakes, 4 above or equal to 3, 27 in between 2 and 3 and 32 lower than 2. The strongest tremor was a M 3.3 quake at 14:16 UTC.
- Today, Saturday IGN has listed already 32 earthquake, the vast majority with epicenter in the El Golfo area. The tremor of 10:46 UTC this morning (1 hour later at El Hierro) was the strongest at M 3.3.

Update 29/10 - 13:18 UTC
Cienciagob channel on YouTube (sciencia gobierno España) is showing a 48 seconds 3-D simulation of the volcano island and the new crater. We think the picture below (probably the 3-D is extracted from the data on the picture) is far better than the video. Click here for the video.

Important Update 29/10 - 08:13 UTC
We are happy to share the new October 26 RapidEye.net satellite image with you. We have to send more than a thank you message to the RapidEye people (a commercial satellite company) as their satellite images are outstanding and were revolutionary in revealing the precise eruption vents (grey muddy color). The image below has been taken on October 26, 2011 . What else to see on the picture ? The stain becomes more and more impressive but at the same time very concerning as it is spreading in the El Golfo bay (see also earlier updates). The stain is stopped at La Restinga (right just above the muddy colored eruption spot) by the sea currents. But ... the eruption is not over yet! (Thanks to Markus for alerting us that the new image was online)

Click on the image to go the greater High Definition picture - courtesy and copyright RapidEye.net

Update 28/10 - 15:50 UTC
The IGN listing shows an earthquake occurred at 14:16 UTC with a magnitude of 3.3 approx. 700 meter from the beach in the El Golfo bay. The depth was a safe 22 km. Click here for the epicenter location.

IMPORTANT Update 28/10 - 13:12 UTC
The 'Ramon Margalef' is finally showing us the type of evidence that we were looking for. His modern instruments deliver a 3-D Ocean floor image where the new crater and even the fresh lava flow can be seen!

Image New El Hierro volcano crater and Lava Flow - image courtesy ieo.es

Data Update 28/10 - 10:39 UTC
- Until the last recorded earthquake, a total of 12 tremors has been listed so far by IGN since midnight UTC today. 5 quakes were in between magnitude 2 and 3 and 7 tremors had a magnitude lower than 2.
- Yesterday was a very active seismic day with 54 earthquakes in total. 3 had a magnitude of 3, 16 were between 2 and 3 and the rest below 2. The depth of the earthquakes was still at a safe 20 km average with only 2 more shallower, one at 8.8 km and 1 at 11.9 km. The vast majority however was within the same range. When reading these values, instrumental errors can not be excluded.
- Deformation is stable at station HIO3 but is steadily increasing at the Frontera stations (the area with the most earthquakes).
- Harmonic tremor is slightly decreasing, but this does not mean the the magma activity is over yet. Similar conditions happened before.
- Alpidio Armas (translated by some people as Alpidio Weapons 🙂 ) has declared that the aid package promised by the Canary Islands and Central governments will be published soon.
- Authorities have announced that the Los Roquillos tunnel linking Valverde with Frontera will remain unconditionally open.
- The students from La Restinga who were following lessons at Valverde since the evacuation are allowed to return to La Restinga where the school will reopen.
- IGN personnel has declared that they will stay at El Hierro as long as it takes. (ER: The current situation with a lot of earthquakes and continuous harmonic tremor means that magma below El Hierro is still active and a change to the positive or the negative can occur within a narrow time frame.)

We apologize for an update which appeared here for only a couple of minutes and which was based on some older news.

Update 27/10/2011- 14:54 UTC : overview October 27
- The Ramon Margelef oceanographic ship has done certainly research in the El Golfo bay. We will have to wait until later today to find our whether the ROV made also a dive along the southern coast.
- The Spanish "Tesorería General de la Seguridad Social" Social Security authority has announced that it will grant the entreprises and trade and service companies on El Hierro to spread the social security payments over a period of 12 months.
- Scientists aboard the Ramon Margalef have reported yesterday that they are very sure that magma is circling around at a depth of 20 to 25 km below El Hierro and that the activity is still going on.
- La Frontera feared damage to the marine ecosystem after the arrival of the stain to Sabinosa. The stain has steadily moved with the see current is now been seen at 100 meter from the Sabinosa coast).
- The seismic activity remains unchanged since the last couple of days. Since 00:00 UTC today IGN recorded 25 earthquakes. 2 quakes had a magnitude of 3.0 (1 just occurred at the following location)