El Hierro Volcano eruption (Canary Islands) : Part 10 – November 7 until November 8, 2011

Last update: November 30, 2011 at 1:52 pm by By

This is Part 10 of the El Hierro Volcano eruption report

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Some of this info is also posted into our Facebook Volcano PageGoogle+ VolcanoesGoogle+ Volcanoes and earthquakes
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)


Update 08/11 – 23:50 UTC :
At 22:58 UTC (also local time) a 3.7 earthquake with epicenter in the El Golfo Bay was felt by the people as a weak shaking

Update 08/11 – 21:20 UTC - The La Restinga Webcam story (continued) :
Joke Volta has called this evening Mr. Atilano, the webcam owner and got a totally different story than the person who “tweeted” that the President of El Hierro prohibited the use of the webcam.
Mr. Atilano said (unfortunately too late) that the president story was total nonsense. A typical rumor who starts to live his own live and was probably a setup by political opponents of Alpidio Armas.
He said the real reason is simply TOO MUCH VISITORS. In only 1 hour the webcam had more than 35,000  visitors!  (we are sorry, we had written 350000, a 0 too much, but even 35000 is huge !)
Mr. Atilano said that they are working on a solution. A stronger server and more traffic capacity may solve the problem tomorrow or the day after tomorrow.

Update 08/11 – 20:55 UTC :
- the 53 people evacuated from the El Golfo / Frontera area are still not allowed to go home
- police is checking all luggage on the airport very carefully from people leaving the island. The action has been decided to avoid smuggling of volcano stones. Some islanders have started an online business in selling the magmatic stones for more than 300 € /piece !
- the touristic sector on the island is complaining that scientists and media personnel are not making up for the loss in cancelled tourist accommodations

Update 08/11 – 16:41 UTC :
La Provincia writes : The volcano had its biggest explosion so far – this corresponds with the comments of Joke. The newspaper reports that the column of gas-ash-water climbed 25 meters out of the sea.
- Television Canarias has just aired video footage from this powerful eruption

Update 08/11 – 16:32 UTC :
How does an erupting underwater volcano looks like ? This beautiful picture taken out of an helicopter from the Guardia Civil and Involcan yesterday shows is giving the answer.

Update 08/11 – 16:04 UTC :
In reference to the comment of Patrick Allard, we can report that the wind is blowing from the North or from the North West,  this maybe partly the reason why smelling the gases anymore like he did last night. So, an eventual ash-steam-gas column will presently blow towards the south and will be falling in the Las Calmas sea, making standing at the edge of the island less dangerous than claimed before.

Opinion of Patrick Allard on the present situation
We have asked the opinion of Patrick Allard on the the video and other information available online.
Patrick Allard is Directeur de recherche CNRS, Paris, France. He has been working on munerous erupting volcanoes worldwide over the past 40 years and has carefully followed the evolution of El Hierro events at a distance. Mr. Allard is not a member of one of the local scientist teams. He can only give his ideas on what is happening based on the open source information available on the internet.

The new video you put on the site are  actually preoccupying. Yes, the situation might rapidly threaten La Restinga and then possibly people watching on hills at 150 m height, if  the gas-water-ash jets start to become powerful (i.e. high) enough and if wind is blowing in the wrong direction (see above for the wind direction in the 16:04 update)).
In any case, it sounds me highly reasonable that evacuation of La Restinga be maintained and that outside observers be advised of potential risks from volcanic gases and ash fallout. Strange to me the lack of sulfur odor! One must also be careful because H2S can be no more detected by nose (saturation of the detector) above a threshold of several hundreds of ppmv…Otherwise, carbon dioxide should not be a risk for people staying at 150 m elevation, given its atmospheric dilution during volcanic cloud expansion and transport.
In contrast, due to its higher density than air (molar weight 44, compared to 29) volcanic CO2 might locally form concentrated gas sheets over the sea and become a danger if these move towards the coast.

When ashed about the probably similar style Capelinhos, Azores eruption, Patrick Allard writes the following :
This type of eruption usually starts with a phase of gradual increase in intensity,  determined by the depth of the vent, the magma-gas flow rate, and the building rate of the cone until its emergence at the open air.
Afterwards, the height of eruptive columns becomes controlled by the extent of magma-sea water interactions (phreato-magmatic fragmentation, generating steam column from vaporized seawater, ash columns and ballistic blocks (cypressoid jets). The danger is conditioned by the height of those columns, their gas and ash density, and obviously the wind direction.
Once the vent becomes isolated from seawater, then pure magmatic eruption began. This can be more or less explosive, depending on the magma composition (viscosity) and volatile content (overpressure).

Webcam closed by the President of El Hierro ?
We have to be cautious in reporting but we want to publish this tweet captured by someone in the Jonfr.com discussion platform. It may explain why not only the image is not reached, but all the webcam configuration has been lost !

From El Hierro twitter
Nos informan que Presidencia no quiere instalar webcam porque perjudicaría el turismo, da imagen de inseguridad y peligro
Translated
We report that the president does not want a webcam because it would hurt tourism as it would give the feeling of insecurity and danger

 

 

The La Restinga Jacuzzi in action

[youtube Yg4UZmJE7BQ]

Update 08/11 – 13:17 UTC :
- We have lost the signal of the La Restinga webcam. May we ask Telefonica, the Spanish telecommunications giant, to help Mr. Atilano with unlimited capacity as hundreds or even thousands of people are trying to watch the webcam. We trust that the image will be back soon.

Update 08/11 – 12:45 UTC :
- Joke Volta reports that the jacuzzi flares are occurring approx. every 10 minutes
- The Guardia Civil helicopter has just been spotted in overflying the jacuzzi area. Pictures will probably be published this afternoon
- Joke is currently looking to the activity on top of the cliff above Puerto Naos, approx. 150 meter above sea level. She is not alone over there as more and more journalists and photographers have joined her and they all were offered an ice cream by the TVE (Spanish National Television) crew. TVE is on the spot with a satellite carrier, so eventual spectacular action will probably be shown in HD on the TV later on.
- The local Canarias TV will interrupt all programs and will go live to El Hierro in case the next phase should start.
- Pevolca will meet tonight at 18:00 (local time)
- The press people are making preparations to stay at the viewing point on Thursday night as it will be full moon.

Snapshot of the greater webcam picture as collected by Mr. Atilano

Why Thank You Mr. Atilano ?
Mr. Atilano, an El Hierro board member living at Frontera and geologist, the owner of the El Golfo webcam at meteolaspuntas.com, was asked by Earthquake-report.com to cooperate and to direct a webcam to the Las Calmas sea. Mr. Atilano told us that he will do his utmost best to get it done within a couple of days.
Well, we are so happy that he kept his word.
The action at the moment is limited BUT WE HAVE A LIVE IMAGE FROM THE JACUZZI closest to La Restinga now. The image is of superb quality.
We will still need the information from Joke of course to tell us in detail what is happening, but we can see what is going on with our own eyes.
If you do not see the jacuzzi, it may be down for a while, but the image will refresh approx. every minute and when  a new burst is sending the geyser-like column to the sea level, the jacuzzi can be well seen.
How to see the webcam image ? Click here  Good luck.
A big thank You to Max Wiltenburg who attracted our attention to the new webcam.
Important for those people looking at the webcam 1 : Joke just told us, that at the moment the Jacuzzi gets stronger about every 10 minutes. The webcam image refreshes at least every minute and we have seen the jacuzzi many times already. So try to be patient for at least 10 minutes !
Important for those people looking at the webcam 2 : If being in the laspuntas website with the meteo info, you should click on the La Restinga picture to get a better isolated picture in one browser tab.

Very Important Update 08/11 – 09:20 UTC :
- Joke reports that big stones are ejected out of the water. This is currently visible from here garden in El Pinar, even without binoculars! This is the first time that such activity occurred.
- Our so long awaited webcam shows a black screen. We know however that it is daylight at El Hierro at the moment.

Update 08/11 – 08:35 UTC :
Just in from Joke Volta : much stronger jacuzzi action this morning

Update 07/11 – 23:59 UTC :
We have noticed a strong decrease in harmonic tremor. As it is dark at the moment, we do not know whether this subsiding harmonic tremor has influenced the activity of the erupting vents,  but normally this should have been the case.

Strong harmonic tremor decrease at 21:00 on November 7 2011

Update 07/11 – 22:28 UTC :

Joke Volta : It looks like i see a ship  navigating at the edge of the stain (or rather what i suppose to be the edge of the stain). It is shining his floodlight over the water.  Joke thinks that it will be probably the Roman Margaleff oceanographic ship. If it is indeed the Roman Margaleff, we will expect him to analyze the gases and to make a new topographic map of the erupting vents.

NASA Earth Observatory image taken on November 2
With all the current events, everything goes so quickly that an image 5 days old maybe beautiful to look at, but has no added value anymore to find out what is happening today. The resolution is, contrary to the RapidEye pictures, not defined enough to see the erupting vents.
The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite acquired this natural-color image of El Hierro and a plume of volcanic material in the surrounding waters on November 2, 2011.

NASA Earth Observatory Image acquired on November 2, 2011

Update 07/11 – 18:09 UTC :
- Joke Volta sends a message that the size of the jacuzzi is constantly changing at the moment (she can see the jacuzzi now from her garden at El Pinar)
- The webcam they have installed at El Pinar is of NO use as only big eruptions may be seen with it.

Update 07/11 – 17:57 UTC :
The whirlpool activity is still very strong and so is the harmonic tremor graph who is still saturated.  The graph shows almost continuous submarine explosions.  The current activity is needed to feed at least 3 active vents who are spewing magmatic material into the sea.  Sometime later today or later this week,  on condition that the current activity continues, the explosive phase or Capelinho’s / Surtseyan phase will start.

Saturated harmonic tremor graph from midnight November 7 until 18:00 - the corresponding action can be seen in the Las Calmas sea jacuzzi

Update 07/11 – 16:04 UTC :
We have finally a webcam from the El Pinar area towards the Las Calmas sea. We couldn’t realize it, but some other people did. We thank them to give us finally eyes on the sea. Only ….. we will have to buy some glasses. We guess the webcam will get eye surgery soon, so that the world will be clear again :)). We will try to embed the webcam in this page, but for those among you who cannot wait to see it, here is the link  (when we were implementing the link, the wamera went to surgery we think because the image went black – but we have seen the Las Calmas sea live !)

New jacuzzi closer to La Restinga (07/11/2011) - image courtesy Guardia Civil and Involcan

Update 07/11 – 15:30 UTC :
Jacuzzi activity information
To picture to the right is a new jacuzzi who started his activity today.
The 2 other ones are still active and are located approx. 1 mile out of the La Restinga coast.
The previous was about a mile from the Restinga, it is still active …
For more pictures of the new jacuzzi, click on this link

Update 07/11 – 15:04 UTC :
PEVOLCA (meeting noon today) does allow La Restinga people to enter the village during daylight hours.
Remark earthquake-report.com : hopefully people have been posted on the distinction on different emitted gases.  The Pevolca decision, which will have been based on all important data is contradictory with recent activity.

Important Update 07/11 – 11:55 UTC :
- Joke reports that people coming back from La Restinga told her that the venting activity is gradually getting nearer to La Restinga.  The rotten egg odor disappeared. Please check below for the exact explanation about the odors in an explaining note from Patrick Allard .

Very strong harmonic tremor with regular bursts - image 07/11 from 12:00 to 13:40 - Image courtesy IGN - click on the image to enlarge

Update 07/11 – 11:55 UTC :
- Low tide today will be at 17:19. The difference between low and high tide is approx. 1.5 meter

Very Important Update 07/11 – 11:12 UTC :
Involcan Canary Islands has released a very important picture showing the water temperature at the Jacuzzi spot.  It only confirms our expectations, but we are really happy that this picture was released to the public (we had been talking internally about the lack of this heat picture since a couple of days). The difference in temperature in between the normal sea water and the jacuzzi spot is 11 degrees C

Water temperature at the Jacuzzi point - Image courtesy Involcan and Guardia Civil

Update 07/11 – 10:55 UTC :
PEVOLCA will meet to discuss the present situation at 12:00 noon.

Joke Volta reports :
- A lot of people felt the increased earthquake shocks this morning
- yesterday we have been watching the Burbuja – Jacuzzi all day long
- the people who were not in La Resinga during the evacuation have been allowed a short visit (30 minutes) to get some belongings from their houses.
- more and El Hierro residents are leaving the island to other Canary Islands and even to the mainland
- The NO GO point guarded by the Guardia Civil has been displaced a little higher (no more the traffic square leading to Tacaron) towards El Pinar for so called “organizational reasons”
- Pevolca and all authorities are telling us to stay calm and to continue our normal daily life. Are they believing what they are asking from us …
- A lot op people are cancelling the rent in La Restinga and others are closing their houses
- some people did expect more activity at low tide
- we see more and more tourists showing up at the viewpoint
- This morning Monday, the first resident of El Pinar has received a notice that an exempt of

TVE, the Spanish state television network, has an amost permanent viewpoint spot at the NO GO point - image courtesy Joke Volta

Update 07/11 – 09:28 UTC :
- Reader Marco Schaapherder just told us that we might not have seen a shift in earthquake depth since  midnight.  He was right! Magma may have found his way up a few more km, as the focal depths are getting up to 14 km now.

Overview and Data Update 07/11 – 08:33 UTC :
- 12 M+1.5 earthquakes since midnight, the strongest being a M 3.8 earthquake at 02:34 UTC
- The M 3.8 was not felt on the island because it occurred approx. 100 km to the west of El Hierro and has, we think, nothing to do with the current activity below El Hierro.
- Interesting to know about the 02:34 3.8 earthquake, is that the earthquake (no depth given) occurred 45 km from a seamount (an underwater volcano) rising 500 meter from the seafloor, but still 4000 meter from the surface
- Harmonic tremor subsided a bit in the early hours of November 7, but gas picked up again since 05:40 UTC. The graphs are still showing bursts in between 20 to 50 minutes.
Understanding the current and next phase of the eruption (06/11/2011)
Earthquake-report.com received a note from Patrick Allard,  Directeur de recherche CNRS, Paris, on the current and expected El Hierro events, and is happy to share it with our readers.

According to today’s last observations, I agree that the eruption is in a transition phase between purely submarine and Surtseyan-type subaerial, and that the relative calm in the afternoon could have simply resulted from partial removal (collapse?) of the upper part of the new volcanic cone.
From my experience, a clear change towards subaerial activity will be associated with a change in gas composition, that will be manifested in the gas smell: instead of ‘rotten egg’ (i.e. H2S emission), Local people will start smelling SO2 emission (i.e. sulfur from striking matchstick).
Sulfur dioxide is charactersitic of high temperature magmatic gases, whereas H2S is more typical of lower temperature hydrothermal gases or residual magmatic gases that have previously reacted with liquid water.
The main gas precursor released during such a deep seismogenic phase of a basaltic eruption is carbon dioxide, the earliest exsolving magmatic volatile. Huge amounts of magma-derived CO2 shoud currently being released from the eruptive vents and through sea water, generating the jacuzzi and the billions of gas bubbles bursting at the sea surface. Therefore, measuring/monitoring both the chemical composition and the mass output of emitted volcanic gases should become an important priority during next days and weeks.

FYI – Wikipedia description of Harmonic tremor :  Harmonic tremor describes a long-duration release of seismic energy, with distinct spectral (harmonic) lines, that often precedes or accompanies a volcanic eruption. More generally, a volcanic tremor is a sustained signal that may or may not possess these harmonic spectral features.
A harmonic tremor is a sustained release of seismic and/or infrasonic energy typically associated with the underground movement of magma and/or venting of volcanic gases from magma. Being a long-duration continuous signal from a temporally extended source, a volcanic tremor contrasts distinctly with transient sources of seismic radiation, such as tremors that are typically associated with earthquake and explosion.

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

Update  – 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

[youtube Ewv_wazJhYY]

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