El Hierro

[jand]

http://212.170.244.196/

There are four webcams now to look at on this site.

On the main page is a map of El Hierro showing where the webcams are and you can click into each one.

[jand]

Avcan

Translated

I think it is important to know that the Richter scale represents the seismic energy released in each earthquake and based on the seismographic registration.
 It is a scale that grows in the form semilogarítmica, or potential so that each point increase can mean an increase of ten or more times more energy. A magnitude 4 isn't 2 twice, but 100 times more.

The Doctor in physics from the University of Barcelona, Mr. Joseph Vila, gives us that you between magnitude 2 and magnitude 4, which increases 100 times would be the amplitude of the waves and no energy. (The energy increase a factor 33 each grade of magnitude, which would be 1000 times every two units). (Translated by Bing)

[jand]

Avcan

Translated

New official part of the Government of the Canary Islands, where stands out its last paragraph: "From the PEVOLCA address you want to convey to the people that while we are in a period of stability, the eruptive phenomenon has not completed on the island of El Hierro."(Henry):

7 REGISTERED EARTHQUAKES YESTERDAY NO IGN WERE WAYS BY THE POPULATION.


02-12-2011... 14: 21 - Ministry of economy, finance and security

The rate of emission of sulphur dioxide analyzed by scientists from INVOLCAN is less than 5 tonnes per day

The Instituto Geográfico Nacional (IGN) has confirmed the Civil protection plan by risk volcanic (PEVOLCA) that were located 7 earthquakes, none felt by the population during the December 1, 2011. Almost all took place in the sea of the Gulf and with depths between 21 and 23 kilometres. In total, since 17 July 2011, have been localized 11.907 events.

In yesterday's tremor signal remained constant, with a slight decline in the early hours. IGN added that the sign filed few pulses and these were of little breadth.

In studies of the deformation of the ground, the monitoring stations maintained the same pattern of stability in deflation in the vertical component of the stations in the South of the island and East and West of the Gulf, as well as stability in the central area and the horizontal components

With respect to the English channel, in the morning was observed emission of gases, fragments of lava and fine material, with the formation of a stain Tan which grew in size and intensity. The report of the Mission for the flight 103 SASEMAR, carried out at the first time yesterday, review activities in the area with the presence of emissions in an initial area of 0.121 km2 and has a temperature difference with swells of 2.3 ° C.

INVOLCAN

On the other hand, scientists of the Institute Volcanológico de Canarias (INVOLCAN) have been recorded since last November 10, emission rates of sulfur dioxide (SO2) lower than the 5 tons per day generated by underwater volcanic activity in the South of La Restinga.

The highest rates of emission of sulphur dioxide (SO2 into the atmosphere) were registered last November 6 reaching the 109 ± 19 tons per day. This observed maximum registration provides also a rate of emission of sulphur dioxide (SO2) relatively lower than that normally occur in subaerial volcanic systems found in eruptive phase. "This is an important part of the sulphur dioxide (SO2) emission by underwater volcanic activity in the South of La Restinga not arriving at the atmosphere because it is consumed at sea as a result of a reaction of neutralization between acidic volcanic gases and seawater of alkaline nature contributing to the decrease in the pH of sea water as well as has been reflected through measures carried out by the oceanographic vessel""Professor Ignacio Lozano" and "Ramon Margalef" of the Canarian Institute of Ciencias Marinas (ICCM) and Spanish Institute of Oceanography (IEO), respectively.

Highlight that the building volcanic island of El Hierro, which corresponds to the part of the building that lies above sea level, are not registered emissions of sulphur dioxide (SO2 given) that there are no visible emission of volcanic gases from relatively high temperatures (fumaroles, Tufts,...) within the Earth.

Measures of emission of sulphur dioxide (SO2) have been through the use of optical remote sensing type miniDOAS and COSPEC air mobile position thanks to the support and collaboration of the Civil Guard helicopter service in the Canary Islands, with the aim of strengthening the geochemical program that the INVOLCAN available for volcanic monitoring in the Canary Islands.

From the direction of the PEVOLCA you want to convey to the people that while we are in a period of stability, the eruptive phenomenon has not completed in the island of El Hierro. In this regard remains the operational deployment of Civil protection and recommended people to follow the information from the authorities, and consult the web page created for that purpose by the General Directorate of security and emergencies of the Government of the Canary Islands, www.gobiernodecanarias.org/dgse/sismo_hierro.html; and information channels established by the Cabildo of iron.

[waggy]

Any chance of getting this interesting thread split down into shorter length pages?

[woe10]

These bubbles coming out of the sea are 267 miles away from Caleta De fuste. So chill out.

[jand]

http://www.iris.edu/hq/files/programs/education_and_outreach/aotm/17/SeismicSignatures_SeismogramMSH%20addition.pdf

How to read a seismograph very very interesting and very easy to understand lots of graphs with explanations.

[jand]

volcanocafe

Copied

I found this paper that gives a good picture of the geology of the Canaries. It's quite interesting. I need to read it again though to follow more closely. I thought it was accepted that the Canaries were formed by a mantle plume but it seems it is not as simple as that and the Canaries are unique, which explains why everyone is so confused as to the activities of Bob.
http://www.mantleplumes.org/Canary.html

Reply

[jand]

http://www.mantleplumes.org/Canary.html

This link is very interesting has lots of photos and maps and explanations.

[jand]

Photo of all the Canary Islands taken by NASA.

[jand]

Avcan FB

Copied

Today, the news is that there is little seismic news unless the tremor.
A single event located by IGN of magnitude 2.0, at greater depth than the average and further away from the coast of the Gulf than usual.
The image of the transit of daily seismicity, indicated the point where the hypocenter of the earthquake under the iron was produced, and which coincides with the daily average weighted because... There have only been a quake until the time that we wrote this note!
On the other hand is still moderate tremor, indicating continued flowing gases and magma. Likewise, the eruptive stain in the calm sea (JR) is visible

[fifi]

Thanks for the updates jand.[]

[jand]

Fifi

 Did you read through the link on how to read the seismograph or have you seen this before.

It was interesting to see the same wriggles and to relate some of them to El Hierro.

Just seem to learn more each day not just about El Hierro but about volcanoes all over the world and the earths crust and mantles.

[fifi]

Yes the link is great thanks jand. It  gives much better explanations than the website I  found and put on here a few weeks back. I now know what  helicopter vibrations  looks like on a graph. []

[TripleH]

Morning everyone. Any good news?

[jand]

Morning everyone

Sorry Fifi did not mean to duplicate something you had posted a few weeks back about reading the seismic charts.

TripleH no news to report yet.

[waggy]

Thanks for the mantle plume link, jand. Blooming interesting.

[jand]

The BBC magazine has done an article on El Hierro.

http://www.bbc.co.uk/news/magazine-15917740

[jand]

Waggy

Your welcome posting things of interest for everyone to read as I find them .

I agree the mantle plume link was really interesting and in my old age never even knew about this.

[jand]

http://www.iagc.org/attachments/contentmanagers/4352/Marine%20Seismic%20Operations%20Overview.pdf

Marine Seismic Operations

[SurfJames]

jand.....You are finding more and more complex literature about volcanoes and it is fascinating.

I think we need to promote you to the post of 'Professor of Volcanic Studies' at the 'University of Fuerteventura' !!

[jand]

SurfJames

POVS it is !!!

I have a question that maybe someone can answer.

The earthquakes have stopped for now and everyone seems to be in a sense that thats it all over.

But what I cant understand is that the harmonic tremor on El Hierro is still going strong with bursts of explosions.

Where is this magma going? and is this now a more worrying sign that pressure is again building up somewhere?

I think I have read before that the magma has probably found a pathway through without obstructions therefore no earthquakes but this magma is still there and moving  but on a pathway to where could it be under the Volcano Tanganosa.

[jand]

Update 04/12 – 12:19 UTC
 Jouni Elo of Finland just wrote : I've seen quite a few times on the webcam smoking lava at the left side of the stain during the recent hour just like Joke Volta and Paul Abuelo had mentioned. Of course it would be nice if the webcam (Movistar, vista la Restinga Zona erupcion)would be zoomed in a little bit more. Maybe the controllers are still asleep.
 Earthquake-Report.com comment : NO comment

Update 04/12 – 12:00 UTC
 A number of people told us this morning that the BBC had written an article on El Hierro. The same article is also with a link in many Spanish websites (they are proud to be mentioned by the BBC).  We have been trying to attract attention to the El Hierro eruption by writing to many mainstream newspapers and websites with the result : NOT important enough.  Unless the fire is getting out of the water they will come (like NZZ earlier this week) and vanish again (we are sorry to be a bit sarcastic here, people following this website from the very beginning know what we are talking about). But, we are fair people and out of respect for the readers who send us this message, here is the link to the BBC article.

Update 04/12 – 10:27 UTC
 - Reader Paul Abuelo and Joke Volta just mentioned smoking lava at the left side of the stain. Unfortunately the many webcams we have now haven't seen it yet and are still zoomed out.

[jand]

December 4, 2011 by José Luis Barrera Morate

Translated

The new issue of large pyroclastic which saw the last November 27th in the calm sea, was very spectacular but not strange. The lavas that emerged smoky floating on the sea surface are what are called "lava ballon"; some reached up to 2 metres in size. In all the time that lasts the volcanic crisis of El Hierro, it was the first time that were so considerable fragments. They are characterized by being hollow inside and present a high vesicularidad. For now its petrológica composition is unknown but everything suggests that it will be just like the first cast: basanitas.

An underwater eruption similar to that which occurred in 1999, to the West of the island of Terceira, Azores, which lasted 10 months and was associated with an intense seismic activity. In this case arose, through an undersea fissure of 5 km, the same types of fragments (there were basaltic composition) that reached sizes of up to 3 meters. The blocks had almost no crust and its interior was highly folded; Occasionally, with hollow cores. They remained smoky floating on the water a few minutes and the scientists collected some examples rather than they hundieran. The bathymetry that had (no data were updated) indicated that the eruptive mouths were between 500 and 800 m in depth. A similar episode occurred in the same place, in 1867, with a seismic crisis lasted 5 months.

In the underwater eruption of La Restinga has happened something similar; We have spent almost 3 months and a half of seismic activity and a rash of almost 60 days. A very rich in gases and low viscosity magma is ejected outward shaped pillow lavas. The outside of the pillow it is separated and is very rich in gases vesicular internal area is amounting by low density that has. A new very fine vitreous crust which also reaches the surface, is generated in many of them, during the ascent. Part of the interior has been destroyed by the effect of the degassing and the fragment floats for few minutes. We have the so-called "lava ballon" (in the attached picture you can see a large fragment taken from November 27th in the mar de Las Calmas).

It is not even new data of bathymetry of the eruptive zone of La Restinga, but everything suggests that there should be more than one mouth lined according to an undersea fissure and projection towards Earth?. It would be interesting to determine the direction of this fissure, and link it with which mark the two clouds of epicenters which occurred pre and post eruption from October 10. The structural model of the crisis is still to be defined.

[jand]

volcanocafe

Copied


Una Canaria says:

 December 4, 2011 at 15:03

What about this article? LP waves were precursors to an enminent eruption at Dececption Island Volcano?
 http://europa.agu.org/?view=article&uri=/journals/gl/gl1122/2011GL049671/2011GL049671.xml

Reply

Una Canaria says:

 December 4, 2011 at 15:08

I say this because this kind of signals have detected in one of the seismographs on the islands for several days. And that's not a good sign, but everything seems calm.These waves are known as events "screw", couse they appear in that form on the seismographs.

[jand]

http://www.earth-prints.org/bitstream/2122/1338/1/01%20seidl.pdf

The link above is very interesting re the screw like signals on the seismographs.

Copied below interesting discussion on volcanocafe and the graph they are discussing is the one I posted the other day re the movements on the graph for La Palma.

 http://www.01.ign.es/ign/resources/volcanologia/EHIG/imagenes_sismica/DIA/EHIG_2011-12-01.jpg

Sissel says:

 December 4, 2011 at 16:48

It is not possible to recognize any tornillos in the El Hierro signal, because of the strenght of the signal.

Una Canaria says:

 December 4, 2011 at 16:53

That´s right, Sissel.

Una Canaria says:

 December 4, 2011 at 16:35

It is only a theory. I think it could the possibility that the magmatic bag is so large that reaches to La Palma. The consequences? I do not know. Bets are accepted!

Reply

Carl le Strange says:

 December 4, 2011 at 17:32

I would be surprised if the blob of magma was that large, but there seems to be some sort of very deep connection on the hotspot plume level since it seems to be driving both places alternatively.

Reply

Una Canaria says:

 December 4, 2011 at 16:41

A note: in the south of La Palma is the volcano Teneguía. Its last eruption was in 1971, 40 years ago (I was not born yet )

Reply

Una Canaria says:

 December 4, 2011 at 16:44

As I said, it´s only a theory. But it is interesting.

Reply

Una Canaria says:

 December 4, 2011 at 16:49

Now, you imagine that these LP waves will increase. It could ensure an imminent eruption within other manifestations or minor, as happened with the Galeras volcano, or the volcano of Deception Island? (Mother, but what I'm saying? I must have drunk too much coffee...)

Reply

Una Canaria says:

 December 4, 2011 at 16:51

I think I'm possessed. I have to have a drink of something. :-V

Sissel says:

 December 4, 2011 at 17:11

Wish I was sure there is no danger. It must be terrible to live on El Hierro without knowing the whole truth (of course, nobody does at this moment). So it is for the inhabitants of the neighbour islands.
 Instead of posessed I think you are very concerned. Because you care.

[jand]

geology.com

Copied.

Did You Know?

. Seismic activity at Galeras has displayed characteristic signals known as "tornillos". "Tornillo" is Spanish for 'screw', and these seismic signals are so named because their shape on a seismograph resembles a screw with a wide head and tapered tail. At Galeras, these signals are generally regarded as short-term precursors to explosive eruptions.

. In 1993, Galeras erupted with no warning (seismic precursors) while a group of volcanologists and visitors were visiting the crater of the active cone. Nine people were killed and six were injured in the explosion; because of the lack of seismic activity, many of the victims were not wearing adequate safety equipment. The disaster served as a cautionary example to other volcanologists, and now many are much more wary of venturing into an active volcanic crater.

[fifi]

quote:Originally posted by SurfJames

jand.....You are finding more and more complex literature about volcanoes and it is fascinating.

I think we need to promote you to the post of 'Professor of Volcanic Studies' at the 'University of Fuerteventura' !!

Hear hear. Thanks jand. Still up to my eyes painting the house but loving learning more and more each day.[]

[Paddster]

quote:

Photo of all the Canary Islands taken by NASA.


Brilliant picture,must admit.........[]

[jand]

Fifi

Hope your painting goes well.

Your second in command is holding the fort for you!!!

[jand]

Paddster

Glad you liked the picture I thought it was brilliant too.