El Hierro

[jand]

Restingolitas floating on surface 15/10/2011, the first occasion in which were observed. Its diameter is 15-20 cm. Some of them still emit water vapor. Photo: IGN-CSIC-gob. in the Canary Islands.



According to the chemical analysis conducted by the universities of La Laguna and Barcelona, and also by the Centro Superior de Investigaciones Científicas (CSIC), published partially in the press - the author doesn't have the full results-, these globular fragments more or less thin crust is formed by a transparent volcanic glass, dark brown in color, which is named sideromelana. The sideromelana is produced by the rapid cooling of a basaltic magma. It tends to be transparent because it lacks of tiny crystals of oxide of iron (magnetite) in its interior. There may be reflections by microfracturación, and is of massive to poorly vacuolar observed samples.


The interior of the floating fragments is formed by two types of glass:


* a volcanic glass opaque black, appearing forming very thin and deformed bands (folded). This glass is named taquilita. As the sideromelana, it is the product of cooling fast of basaltic magmas, but in this case cooling is somewhat slower, by which the taquilita presents tiny magnetite crystals inside - hence its color and opacity. It is very vacuolar observed samples.


* a volcanic glass of white snow to whitish grey, which forms the bulk of the total volume of the floating fragments. Its composition is a trachyte or a rhyolite, with 65% or more - in volume - silica (SiO2). It has a spongy texture, with numerous microvacuolas, and its overall density is less than the water.


As for its genesis, there is a certain consensus in considering the dark glasses of basaltic composition as juvenile volcanic products, i.e. formed by the cooling surface of magmas emitted during the eruption in progress. Not so with glass of white color and composition richer in silica, whose origin is disputed.



III. the nature and possible origin of the silica-rich white glass


It follows from the examination of visu, and the result of the chemical analysis published so far, white glass microvesiculado could be an expanded perlite (Figure 2).



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[jand]

-Perlite expanded artificially agricultural use (improvement of soil and hydroponic substrates). Photo: USGS.



The beads are natural volcanic glass, rich in silica. They present a shiny luster and a conchoidal fracture (circular), attributes which give them the Pearly aspect which comes from his name. They are typically of rhyolitic composition and they contain more than 70% of silica in volume, but there are also small pearls traquíticas, with silica content somewhat lower (65-70%). Its main feature, however, is its relatively high content of constituent water, i.e. water molecules which are within the glass and part of its composition. Thus, the typical content of molecular water of the beads is a 2 to 6% in volume.


The beads are from the natural moisturizing, recorded at room temperature of volcanic of similar composition, but anhydrous glass (without water): pumitas, obsidian and hialoclastitas traquíticas or rhyolitic, whose molecular water content does not exceed 0.2% in volume.


The beads are crushed until desired grain size and then subjected to sudden warming in industrial furnaces, unless they reach a temperature of 760 ° and 890 ° C (temperature of glass transition or Tg), moment in which the siliceous glass softens and becomes deformable and molecular water is liberated in the form of steam, which leads to the formation of many small bubbles and the swelling of the material up to a volume of 4 to 20 times the original. The result of this expansion pearlitic is a foam glass microvesiculado, colour pure white to whitish grey, with a very low density - the gross density varies from 0.03 to 0.15 g/cm3. Expansion occurs without glass founded in no time.


The beads are industrially exploited throughout the world. Once expanded artificially, have many applications: processes of filtration, heat insulation, improves substrate cultivation, stuffed inertes...


In this case it would be a process of natural, not artificial, expansion of a perlite, happened to a molten pressure of about 20 to 30 atm (200 to 300 m in depth), unlike the industrial process, carried out at much lower pressure (1 atm). However, keep in mind that the content of molecular water of Perlite suffered natural expansion into the seabed of La Restinga could be considerably larger than the typical of which are artificially expanded. We have analyzed some hydrated volcanic glass whose content in molecular water was up to 20% in volume.


By place and geological environment where the rash develops, more plausible is that perlite comes in this case of hydration in situ of a layer of hialoclastitas composition traquítica. The hialoclastitas are splinters of glass that are formed by the sudden thermal fragmentation, i.e., rupture by sharp of magmas of any quimismo cooling to come into contact with water. Like the rest of volcanic glass, are thermodynamically unstable in the environmental conditions which have prevailed in the surface of our planet and tend to be altered, transformed into other materials. The first stage of this alteration is the hydration of glass.


These hialoclastitas in particular would have originated in a previous underwater eruption of character traquítico, whose broadcast centres could be close to current volcano. They faced on the seafloor, forming a volcano-sedimentary deposit little or nothing consolidated and saturated in water, i.e., with water filling the pores between the fragments of volcanic glass.


However, although it seems unlikely, cannot it be ruled out at all that this glass of traquítica or rhyolite and character Pearlite composition might be a product sooner of the current eruption.



IV. mechanism of formation of the restingolitas


A possible mechanism for the formation of the restingolitas is then schematised in five steps. This mechanism is consistent with existing data on the eruption in progress, explains the observed facts, as far as possible and compatible with what has been published to date on products and volcanic processes that occur in relatively shallow submarine eruptions. Now, needless to say that its nature is purely tentative and should be considered only a first working hypothesis that he may or may not be confirmed by subsequent studies. The scale of the figures is approximate.



1 Hydration in situ (represented in the illustration by more intense yellow color) of a hialoclastita traquítica formed in a previous eruption produces a layer of glass Pearlite that lies on the seabed as a volcano-sedimentary material, not consolidated and saturated in water.
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[jand]

2 Fragments of fluidal basaltic lava at very high temperature (red material in the illustration), from a submarine lava, very vigorous, source of the current eruption, fall on the layer of hialoclastitas perlitic and accumulate quickly on them. In the fall the fluidales fragments of basaltic lava is crushed and coalesce among themselves. The elevation of temperature makes the layer of water vapor marina located directly on the basalt grinding. It produces a degree of mixing between the fluidales basaltic pyroclastic and the sediment formed by fragments of glass Pearlite.

[jand]

3. Due to the sudden rise in temperature, the fragments of glass from the hydrated traquítica hialoclastita pearlitic expansion occurs. This process occurs when the layer higher bonded basalt is kept still warm and fluidal (deformable). In the expansion, the bonded layer is bulging and stretched. The water vapor produced in the process is trapped within the expanded perlite (grey material with thick dotted in figure), under the bonded layer.

[jand]

4. By its low density, expanded perlite tends to ascend by flotation. Globular masses of expanded perlite are separated from the layer of hialoclastitas hydrated, breaking the layer bonded fluidales and plastics that lines and forming keels.

[jand]

5. During the ascent through water Navy up to the surface, grinding basaltic drawing that forms the crust of the Globular mass cools very quickly to give rise to sideromelana (s in the figure), while that portions of agglutinated basaltic found inside they cool more slowly and give rise to taquilita (t). The expanded perlite (EP) also cools and water vapor trapped inside is released to the fracturing of the bark of sideromelana. The degassing is facilitated by the drop in molten pressure to which the clastic amounts is subject.

[jand]

V. other possible origins of the silicatado of white glass


Other materials more or less similar composition that could be present in the background and release large amount of water vapor to suffer a sudden warming are gels Aluminum-silicon and the zeolites, both very frequent and abundant products of alteration of hialoclastitas and other volcanic glass. In the first case is gels, i.e. character colloidal solids consisting of two components, in which the continuous phase is a glass aluminum-silicatado, and the discontinuous phase water liquid.


In the second case is crystalline solid matter: the zeolites are minerals that form a large group of aluminous silicates hydrated alkali and alkaline-earth metals (sodium, calcium, potassium...) Its name, from Greek "zeo", boiling, and "lithos" stone, from exactly that many components of the Group releasing water vapor and swell under the flame of a torch, property called intumescencia. If the zeolites, and not the beads were the material suffered the abrupt warming and expansion by release of water in the form of steam, to be covered by high temperature lava clasts in the seabed, said global warming had to produce the complete fusion of material zeolítico, which then cooled rapidly to accommodate the white glass.



VI. conclusion


The restingolita, in particular the silica-rich volcanic glass, microvesiculado and of white colour which forms the interior of the floating clasts, could have come from the natural expansion produced by the release, in the form of steam, of molecular water in hydrated materials, product of the alteration of volcanic glass originated in past and present on the seafloor eruptionsnear the current point of emission. This expansion would have been caused by suffered sudden warming to accumulate on fluidales fragments of youthful basaltic lava. These expanded alteration materials could have a vitreous initial character (beads) or lens (zeolite), and having experienced during the expansion process thermal softening or a total merger.




Download report (PDF)



Since AVCAN we thank Juan j. Coello Bravo its deference for publishing this report here.

[jand]

There are photos and graphs on the link under each numbered section.

http://www.avcan.org/?m=Noticias&a=noticia&N=911

[jand]

http://www.01.ign.es/ign/resources/volcanologia/jpg/histograma_HIERRO_2011_10.jpg

[jand]

canarias7.es

5 Million cubic meters of volcanic material in 4 days

The volcano located in the calm sea has issued 5.5 million cubic metres of material in just four days, as they have revealed the data collected during the expeditions of the Spanish Institute of Oceanography (IEO).


The Institute has seen the rapid growth of the submarine volcano of El Hierro with the images collected by the team embarked on Ramón Margalef between 24 and 28 October.


The researcher and Marine Geologist of the IEO Juan Acosta, said that the comparison of the two maps shows a change in the form of the heat of the volcano and seen "substantial growth" of the cone and the volcanic heat.


To superimpose both maps, researchers have been able to estimate that only in those four days the volcano issued almost 5.5 million cubic metres of materials and even though they are estimated data "are much closer to reality", has tempered Acosta.


The volcano is still active and "much stronger", said the investigator, not only emit gases and material fine, "visible from the surface" but still emitting lava.


When the situation is more stable in the area it will have to make another recognition and repeat the operation because it is the only way to scientifically prove the increase of activity under the sea, explained Acosta.


At the moment the ship Ramón Margalef is in the port of Los Cristianos (Tenerife), as civil protection has banned the navigation in the area of the calm sea.


The boat continues waiting for the official authorization to initiate studies on the part of the Gulf, which according to Acosta, could start tomorrow.


"The IEO would be delighted to be able to be useful there" and the boat will be available when it is "necessary", Acosta has insisted.


The Spanish Institute of Oceanography (IEO) is a public research body, dedicated to the knowledge of the sea through nine coastal oceanographic centres, twelve stations mareográficas and a fleet of seven research vessels, which included Cornide Saavedra and Ramón Margalef.

[kevin2003]

[kevin2003]

[Florence]

To give everybody a break from the relentless cut and paste jobs, which may or may not enlighten you to the current situation, here is the Daily Mails tongue in cheek take:

http://www.dailymail.co.uk/sciencetech/article-2059576/El-Hierro-Volcano-eruption-New-Canary-Island-emerges-underwater-volcano-rises.html

[jand]

Mail online article about the creation of a new Canary Island. http://www.dailymail.co.uk/sciencetech/article-2059576/El-Hierro-Volcano-eruption-New-Canary-Island-emerges-underwater-volcano-rises.html?ITO=socialnet-twitter-mailonline

--------------------------------------------------------------------------------

Duplicate Posting link already posted by Fifi at 1430.

[jand]

Frequency spike of the 3.5 this evening.

http://www.01.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CHIE_2011-11-10&ver=s&estacion=CHIE&Anio=2011&Mes=11&Dia=10&tipo=2

[jand]

http://www.canarias360.com/panoramicas-de-El-Hierro/volcanes-de-malpaso-El-Hierro.html

[jand]

Interesting Video although in Spanish.

http://www.rtve.es/alacarta/videos/teleplaneta/teleplaneta-05-11-11/1241424/

[fifi]

I found the article about the volcano needing to grow a bit more before becoming totally explosive. Here is a synopsis.http://www.lavanguardia.com/vida/20111109/54237712216/los-cientificos-esperan-que-con-los-dias-la-erupcion-se-vuelva-explosiva-en-el-hierro.html



As far as I am aware the Torrents or GLUGs that are mentioned in the article below are similar to the above photo which looks like an erupting volcano but is in fact caused by underwater gasses This may be the reason why Raymond Matabosch thought he saw five erupting vents the other day(Fi)

The spokesman of the Scientific Committee, María José Blanco, Director of IGN in the Canary Islands, explained today that the GLUGs of gases and magmatic materials which can be seen for days are more frequent than expected (initially thought that they would be sporadic episodes) and that, since Saturday, are formed by a new material: ashes, whose composition is being analyzed.

White has insisted that these GLUGs (torrents) are formed by accumulation of gas in the focus of the eruption, not because the volcanic edifice has grown and is closer to the surface.

According to the latest available measurement, which held the 28th the vessel of the Instituto Spanish of Oceanography (IEO) Ramon Margalef, the volcano has issued 0,031 cubic kilometers of magma, 0.015 deposited in the volcanic edifice that has grown from the bottom of the sea and other 0,016 scattered in a tongue of lava.

Scientists are still driving the stage that the eruption will become explosive (by the reaction of the lava with water) if the volcanic cone continues to grow reaching to within 150 meters of depth, but qualifying that is still far from occur.

"A volcanic edifice was founded in 18 days with a height of 100 metres, but in order to grow more and not be unstable, it has to much broaden its base." And that requires a contribution of cubic meters more. "I.e., as the building is high, its growth is slower," explained María José Blanco.

 Ramón Margalef ship will be starting  a new bathymetry of the zone tomorrow to update the data on the depth of the crater of the volcano.  The phenomenon is behaving as they expected, except for the fact that the tremors are still happening in the North of the island, a circumstance which does not allow them to rule out the start of another underwater eruption in the Gulf.

This is considered feasible, but unlikely at this time.  The Scientific Committee also need to evaluate the risk of the eruption   progressing further by the eruption of subsurface crack that has emerged and come to occur on land.

[fifi]

quote:Originally posted by Florence

To give everybody a break from the relentless cut and paste jobs, which may or may not enlighten you to the current situation, here is the Daily Mails tongue in cheek take:

http://www.dailymail.co.uk/sciencetech/article-2059576/El-Hierro-Volcano-eruption-New-Canary-Island-emerges-underwater-volcano-rises.html

Ah no....not enough Scientific detail and slightly out of date. Definitely not good enough for me.[][] Minute by minute detail is far more exciting.[]

....and we need to get to page 4 to please Woe 10....and FAST.[][][]

[jand]

Quote From Florence

To give everybody a break from the relentless cut and paste jobs, which may or may not enlighten you to the current situation,

Well looks like 19068 (read posts) are still enlightend by them.

[Florence]

quote:Originally posted by fifi

quote:Originally posted by Florence

To give everybody a break from the relentless cut and paste jobs, which may or may not enlighten you to the current situation, here is the Daily Mails tongue in cheek take:

http://www.dailymail.co.uk/sciencetech/article-2059576/El-Hierro-Volcano-eruption-New-Canary-Island-emerges-underwater-volcano-rises.html

Ah no....not enough Scientific detail and slightly out of date. Definitely not good enough for me.[][] Minute by minute detail is far more exciting.[]

....and we need to get to page 4 to please Woe 10....and FAST.[][][]

Ah - heres me trying to bring some levity to the proceedings.  In anycase I am a mere mortal and most of what has been cut and pasted is errr.. incomprehensible?  Your photos are great - perhaps lots of them will be good with a brief description and update (in good English) will be much much appreciated (certainly by me).

[jand]

Florence Quote To Fifi

In anycase I am a mere mortal and most of what has been cut and pasted is errr.. incomprehensible? Your photos are great - perhaps lots of them will be good with a brief description and update (in good English) will be much much appreciated (certainly by me).

You really are an ungrateful person.

The posts haved been translated from Spanish into English and not hand written by Fifi .

You want good English then translate them yourself!!!!!

[n/a]

Ha! 900th post! This thing will still be going when Gold Acre start selling property on the latest complex to go broke on the new land mass just south of what used to be El Hierro.

And page four too. RESULT!

[][][][8D][)][)]

Damn! Jand pipped me with another rant. Congrats on getting the 900. XX

[fifi]

I missed a few posts there too. Thanks jand.


(Ah - heres me trying to bring some levity to the proceedings. In anycase I am a mere mortal and most of what has been cut and pasted is errr.. incomprehensible? Your photos are great - perhaps lots of them will be good with a brief description and update (in good English) will be much much appreciated (certainly by me).)Quote by Florence

I do my best to translate the articles Florence. Sometimes I use three different translation services, Bing, Spanish Dict which gives two different translations and also Google. A lot can be lost in translation and it is often necessary to check and read all three to get the true gist of a story.

If you are a fluent speaker the option is there to read the full articles in the links from the Spanish papers. []

[Florence]

quote:Originally posted by jand

Florence Quote To Fifi

In anycase I am a mere mortal and most of what has been cut and pasted is errr.. incomprehensible? Your photos are great - perhaps lots of them will be good with a brief description and update (in good English) will be much much appreciated (certainly by me).

You really are an ungrateful person.

The posts haved been translated from Spanish into English and not hand written by Fifi .

You want good English then translate them yourself!!!!!

You promised never to reply to any more of my posts.  You promised!  What happened?

[kevin2003]

[fifi]

Oh no. HES BACK.[][][]

[jand]

Avcan

Translated from Spanish

Note 314 AVCAN - earthquake activity - VOLCANIC - island of HIERRO - 10 November 2011-21: 30 h peninsular - seismic activity continues moderada-alta, seismicity moderate marine zone of the Gulf and with a very important sign of volcanic tremor in the area of la Restinga, which has increased amplitude and has become more unstable, presenting some explosions. The magnitude of earthquakes between 3.5 and 1.2. New earthquakes 34. Depths between 17 and 22 km (four to 12, 13, 15 and 16 km and other two to 23 and 26 km). 99 The day before yesterday. 54 Yesterday. Today will be 41. In total van 11424 earthquakes located in El Hierro by IGN from 9: 00 pm of the day 19 July 2011 (Henry)

[kevin2003]

quote:Originally posted by fifi

Oh no. HES BACK.[][][]

I never went away.[]

[fifi]

I told you it was a fascinating subject.[]