El Hierro

[fifi]

Yes , found it , it is an old one allright. http://www.volcanodiscovery.com/view_news/2430/El-Hierro-volcano-Canary-Islands-Spain-eruption-update---new-submarine-crater-and-lava-flows-mapped.html

[fifi]

quote:Originally posted by jand

Fifi/SurfJames/Glen/TripleH or anyone else can you please explain whats happening on the graphs for La Palma this is the second day now these movements have been there. I have checked them and there have been no earthquakes on El Hierro I can match them to.

I have got the gist of some things about reading graphs but not a lot. When I am trying to find out where a line on another Island is coming from I first look to see if there is a long fine line....if there is a very long one it means that it is very distant. The shorter ones are local to the area so I start not in El Hierro but on the La Palma graph and click on the line to show the approximate time and then go over to the El Hierro graph , the special one on the right and see if there are any peaks or explosions at that time. I still dont fully understand them but have noticed that a lot of the time that they seem to happen around the same time. The ships are effecting the graphs at the moment according to some websites because of the techniques they are using although some say that it is not true so who knows. Night. Catch you in the morning.[]

[jand]

Morning Everyone

Fifi what a memory you have !!

Wonder why they are using an old map the stain must be different surely now but they must have their own reasons.

[jand]

Data Update 01/12 – 23:50 UTC – Roundup of the day
 - 3 ships at regular times on the stain today, the Salvamar, the Ramón Margalef and the Sarmiento da Gamboa.
 - 7 earthquakes greater or equal to M 1.5
 - depth in between 21 and 23 km
 - Medium harmonic tremor with some serious bursts in between 19:00 and 20:00

[jand]

Update 01/12 – 23:55 UTC
 The catch of the day following Involcan and the Guardia Civil. Again a series of 20 beautiful colorful eruption pictures. The El Hierro eruption would not be the same without the great footage we receive from this combined team. The pictures are showing for the first time the (diluted) stain in the El Golfo bay (last set of pictures).

[jand]

[jand]

[jand]

worldpress.com

Peloche says:

 December 2, 2011 at 07:00

Hi all,

El Herrio CHIE station – Harmonic tremors compilation update

2011-11-29 00 h UTC to 2011-12-02 06 h UTC

Each complete row is 12 h

http://peloche.smugmug.com/Nature/El-Hierro/i-rScX9k2/3/O/El-Herrio-harmonic-tremors-O.jpg

[jand]

http://www.youtube.com/watch?v=DONRU_8i2fs&feature=youtu.be

3D plots of S waves for Nov to 29/11/2011

[jand]

Data Update 02/12 – 10:04 UTC
 -  The Telefonica eruption webcam clearly shows an active stain, grey for us, but beautifully colored for the helicopter crew.  It indicates that the eruption is still going on.

Data Update 02/12 – 09:34 UTC
 - 5 earthquakes since midnight UTC
 - Depths from 16 to 23 km
 - Strongest earthquake : magnitude 2.8
 - all epicenters in the El Golfo area
 - harmonic tremor very variable but mainly medium with a tendency of decreasing. In between 07:00 en 08:00  powerful bursts (probably hydromagmatic explosions)

[SurfJames]

Morning jand,

Wow - amazing pics  - it's such a beautiful island.

My understanding of these waves is very basic and I am not qualified to interpret them other than thy are low frequency waves. Also, waves of difference frequency travel at different velocities, and by interpreting the time it takes for the different waves to reach the detector sites, it is possible to work out exactly where the epicentre is.

One thing that puzzles me is that these quakes are being recorded at depths of 15 - 20km deep. Doesn't the Earth's mantle start at 14km? This puts the epicentre well inside the mantle.

Hope you have a good day.

[falkirkdan]

Some wonderful pics and video from the helicopter.    If anyone was doubting the eruptions of the volcano seeing the steaming lumps of rock being thrown up must surely change there view.

There is expressed concern that Iceland's Kalta volcano erupting very soon was the headline piece on the BBC web site.

Maybe the world is about to end.    We are all DOOOOMMMMMED!!!

[jand]

On website jonfr.com/volcano there is a blog about the pending erruption of Katla if anyone is interested again its very interesting and educational to read.

[jand]

This is just part of the story copied below on the BBC website its interesting that things seem to have started at Katla in July the same month as the earthquakes in El Hierro started?

Hundreds of metres under one of Iceland's largest glaciers there are signs of an imminent volcanic eruption that could be one of the most powerful the country has seen in almost a century.

Mighty Katla, with its 10km (6.2 mile) crater, has the potential to cause catastrophic flooding as it melts the frozen surface of its caldera and sends billions of gallons of water surging through Iceland's east coast and into the Atlantic Ocean.

"There has been a great deal of seismic activity," says Ford Cochran, the National Geographic's expert on Iceland.

"There have been more than 500 tremors in and around the caldera of Katla just in the last month, which suggests the motion of magma. And that certainly suggests an eruption may be imminent."

Scientists in Iceland have been closely monitoring the area since 9 July, when there appears to have been some sort of disturbance that may have been a small eruption.

[SurfJames]

quote:Originally posted by falkirkdan



Maybe the world is about to end.    We are all DOOOOMMMMMED!!!

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

I reckon the little microbes will get us all in the end Dan. A sudden viral plague could wipe us out.

Mother nature will shake us off the planet when our numbers get too big!!  []

[falkirkdan]

Well SurfJ you should read Last Light by Alex Scarrow, I read/listened (talking book) as Lybia etc was kicking off.   Then read the sequel After Light, I am in the middle of that.

[jand]

Update 02/12 – 14:17 UTC – a research expedition to an Icelandic magma chamber
 A lot of people do not know how a magma chamber looks like. It is shown almost never as it mostly is buried deep under the ground and as the eruption channels have been closed by magma or by collapsed walls. The video below shows a team visiting a magma chamber below an Icelandic volcano (dangerous as rockfall can kill them instantly). Magma chambers are not always like the one showed on this video, but are often big crevasses filled by magma when active. (thanks to the discussion platform VolcanoCafe)

http://www.veoh.com/watch/v24165320mjYmzFeW

IMO Brilliant !!

[jand]

Volcanocafe Copied.

GeoLurking says:

 December 2, 2011 at 15:08


Well... I can't give you a "risk assessment" in the proper sense, partly because I am not as well knowledged in the variables that drive this as the actual geologists.

I can tell you about a few possibilities, but you absolutely have to realize that because they could happen, it doesn't mean they will

Early in the swarm, I noted a circular "dead zone" of quakes underneath and slightly north of the dominant cone up on the ridge line. (Tungurahua complex) My initial interpretation was that this was a region of "tough" and hard to fracture material. I wouldn't (at the time) go so far as to call it a "plug", but given the more info I know have about El Golfo, that may very well be what it essentially is. If that is the case, it probably is in the dominant path for the pre-slide original El Golfo volcano.

The line of quakes, the original line, seemed to outline a cylindrical area along the present axis. I was originally perplexed about there being no "path" that indicated where the magma came from. This can occasionally be seen as the quakes track back to the source area. These seemed to me to indicate that magma was forming in place. Later poking around the net lead to a paper that discussed that melt could form from the pressure changed following the El Golfo slide. Yeah, it's been a few thousand years, but to me, it seems plausible since the crust is slow to respond to stress changes (if it changes too fast or too much, you get quakes.) Melt forming and percolating out would change the loading could cause that.

Once the quakes started forming lower, im what can only be the Mantle (aligned with the original set), my thoughts are that it could be a recharge of the magma expended at Bob as the upper region emptied out. How the magma/gas got to Bob from the north shallow quake area still eludes me... but a diffuse line of quakes arc out in a circuitous route that eventually head to Bob's location. This could be the path. If so, that means that the underlying structure of the Island is tougher that you would expect.

As a rule, magma and gas will take the path of least resistance.

(Apparent "plug", and circuitous path to Bob)

This doesn't rule out a rifting event. If enough stress builds that can crack open the tough basement of the island core.. you could see that. I am still of the opinion that if there is going to be an onshore vent, the material is going to probably follow the back side of the slide debris and come out near one of the scarp faces. This would be consistent with the location of a lot of the cones.

Another scenario is that magma and gas could use one of the per-existing pathways. In these, you already have a crack or seam that can be easily opened up alongside of the disparity in the residual ancient magma, and the material that it originally flowed through. It is very likely that the pathways wall will behave differently than the material inside when heated... instant seam/micro crevice that can then be expanded.

This is probably what allowed Bob to spring into existence with virtually no quakes. Well, that and the Jurassic era sediment layer which is not as difficult to get through as hardened volcanic rock.

Things to watch... gas emissions. If they start ramping up.. I mean really start ramping up, then something is on the move. Though we have seen gas levels rise at El Hierro... they are still quite small compared to other volcanoes. Almost.. diminutive. This is likely because most of it went into the water. If land based measurements start climbing fast... then I would worry.

Another item to watch... uplift. Unfortunately, IGN seems to enjoy playing hide the data. With the REALLY STUPID policy of only showing distance changes from a few stations to a few outliers stations on another island, they are making their data almost totally un-usable to the public. The same public they claim is too stupid to understand things volcanic and that should just accept what the IGN geologist tell them.

@IGN

Well.. if the public is too "stupid" to understand... try talking to the public on their level. People think in terms of up-down, north-south, east-west. INTENTIONALLY mangling your data output into a "distance to" on a diagonal line to site on another island is... well, begging people to not know what they hell you are talking about.

It takes me several minutes to try and UNF@@K your data just so I can get a clue about what the stations are doing. This process is so laboriously slow that I just use the Nagoya data instead... complete with it's sequence drop outs. I don't have to extract the n/s and e/w vectors, and I don't have to fight through a nascent understanding of the Mogi model to come up with some vertical axis. That's so dodgy that I don't even trust it.

—

Back to Tungurahua.

What's gonna happen? I don't know. I do know that uplift and gases are the two things that you can watch. With El Hierro's recent past to guide you... the only thing you can say for certain is that it could make a showing anywhere along that line of quakes... even off to one side a bit. And it's not going to give you much warning when it does.

El Golfo or El Julan, or La Playas sized landslip? Not likely. Near impossible. Landslides yes, monster slides no. (the only large block that is left is San Andreas, and that is not in the danger area) Every thing else has already fallen off.

Dunno if it helps... that that's my take on it.

Reply

[jand]

Update 02/12 – 10:47 UTC – Is this the beginning of the end of the current El Hierro eruption ?
 -  While inspecting the deformation in the different stations of the Canary Islands, we might have found a fundamental change in deformation. Still too early to call it a certainty and based on data until November 30, we see a slight deformation increase in almost all GPS stations outside El Hierro. The contrary happened with a decrease of the  HI03 GPS station. This might (not sure yet as a longer period is needed) indicate that the magma pressure below the island is decreasing all together. Another indication is the fall back in number and energy of the earthquakes.
 http://www.01.ign.es/ign/resources/volcanologia/html/deformacion.html

[TripleH]

At last

[SurfJames]

Good Evening jand.

Thanks once again for these posts. I have found them fascinating.

Interesting that deformation might be occurring around the island. Perhaps the olcanic situation is waining....or is it the lull before the storm?

[falkirkdan]

quote:Originally posted by SurfJames

Good Evening jand.

Thanks once again for these posts. I have found them fascinating.

Interesting that deformation might be occurring around the island. Perhaps the olcanic situation is waining....or is it the lull before the storm?

I think we have already got the storm tonight on the Clyde[V][V]

[jand]

http://www.01.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CHIE_2011-12-02&estacion=CHIE&Anio=2011&Mes=12&Dia=02

Looking at the graph for the harmonics today cant see how they say it is slowing down?

[TripleH]

quote:Originally posted by jand

http://www.01.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CHIE_2011-12-02&estacion=CHIE&Anio=2011&Mes=12&Dia=02

Looking at the graph for the harmonics today cant see how they say it is slowing down?

Doh

[SurfJames]

quote:Originally posted by falkirkdan

Well SurfJ you should read Last Light by Alex Scarrow, I read/listened (talking book) as Lybia etc was kicking off.   Then read the sequel After Light, I am in the middle of that.

Sounds interesting Dan - never heard of it, but I'll get a copy.

Thanks matey. [8D]

[pennylane]

Hya people..had some catching up to do on this thread lol.....fam tasks took over this week...nuther grandchild overdue..r jen not too well....and r steph had me MI5 driving backwards and forwards to Manchester in search of her 'beloved' heart throb..Dappy..ha ha.......so Jand, you weren't far wrong with this :
FiJanSurfPenny Detective Agency!!!!
ha ha....
some developments eh, very interesting and thanks for your updates and pics guys......
Glen x

[jand]

http://www.01.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CHIE_2011-12-02&estacion=CHIE&Anio=2011&Mes=12&Dia=02




TripleH this graph of El Hierro from yesterday shows that magma is still moving   and the slight gaps inbetween the spikes means there have been explosions and the spikes peaking means that something strong is still happening under the earth with the magma.

This is the reason IMO nothing is slowing down and IMO the people on El Hierro need to stay alert.

[jand]

earthquake-report.com

Update 02/12 – 23:59 UTC
 - the volcano did nothing spectacular today. No smoking lava at the surface and not even a Felt earthquake. After a lot of excitement the last few weeks it looks like it is all over, but a volcano has a changing character. In other words nothing is sure. - We have just loaded some beautiful (non) spectacular images from the southern landscapes. Click here to see Jokes images of the day.
 - Harmonic tremor gradually got stronger since 10 AM this morning
 - 5 earthquakes today, the latest one at 06:00 !
 - GPS deformation at HI03 climbed again 3 mm after November 30 (see message below). If these data are correct, they are an additional sign that the eruption is not over yet.

[jand]

laopinion.es

Translated

Ultrasound detects whether eruptive mouth to the North of the iron

CARMEN SANTANA
SANTA CRUZ DE TENERIFE scientists from the research vessel Sarmiento de Gamboa analyze images taken in various profiles seismic made yesterday on the seafloor of the Gulf, North of El Hierro, to know whether there was a second eruptive mouth in these waters of the island.
In particular, researchers at the Sarmiento de Gamboa made four seismic reflection profiles getting information about the more superficial layers of the ocean floor where the swarm of earthquakes (the area with more seismicity detected so far in this side of the iron) is located.

A few earthquakes whose number and magnitude slightly high, in some cases, have made in recent weeks the possibility that might appear a second mouth on the volcanic phenomenon affecting the island since last October.
This information is being processed and will offer a kind of ultrasound of marine subsoil which can confirm if the underwater eruption in La Restinga might not be the only one in El Hierro.

"We hope that Yes can confirm whether there is or not a new eruptive with these studies although first focus there is to see the data," said yesterday Juan José of Dañobeitia, director of the unit of technology marine of the Centro Superior Investigaciones Científicas (CSIC), the body attached to the Ministry of science and innovation that coordinates the issuance of the Sarmiento de Gamboa.

Campaign
The research vessel, which travels a team of 25 people, including scientific and technical, intends to complete his campaign of research today on El Hierro that has lasted 72 hours before heading to waters of the Canary Islands to carry out another mission on the continental shelf of the Islands.

The follow-up of the eruptive phenomenon campaign was requested by the Scientific Committee of the Plan of Civil protection by volcanic risk (Pevolca) that manages the episode volcanológico of El Hierro.

The campaign for El Hierro has done various tests of Geophysics with measures of gravimetry, seismic profiles (by refraction and reflection) and bathymetry.

The studies, which will be concluded today, have been conducted by a multidisciplinary scientific team composed of researchers from the own marine technology unit of the CSIC, the Spanish Institute of Oceanography, geological and Mining Institute and the hydrographic Institute of the Navy.

Seismic profiles made in the North of the island have not been able to repeat in waters of La Restinga, in which the volcanic phenomenon takes place. "These are very slow operations and virtually no time gave us," explained yesterday to Juan José Dañobeitia. "Moreover, there were certain risks by having a cable two miles and a half behind the ship to perform the analysis." "If it was anything not gave us time to react", added the researcher.

It is that Wired tended by the stern of the Sarmiento de Gamboa, to carry out a seismic profile, which is made with an acoustic emission source every twenty seconds.

"This operation is giving information of the different views on the merits and marine, duly processed data, provides an image of the surface layers, in the case of the Gulf area," according to Juan José of Dañobeitia, responsible in the CSIC of programming, support technological and logistical Oceanographic ships and Spanish Antarctic stations.
Translate webpage http://www.laopinion.es/sociedad/2011/12/01/ecografia-detectara-existe-boca-eruptiva-norte-hierro/383132.html  Clear All    Rate this translation:
Thank you for your feedback.

[jand]

volcanocafe

A few pictures for those with insomnia. These show the differences between estimated s wave speeds and the average estimated s wave speed for the November 2011. The average estimated s wave speed was 3.153 km/s.

More than 0.75km/s over the average speed: http://oi42.tinypic.com/23uc0ep.jpg
 Close to average (within -0.55km/s and +0.75km/s): http://oi39.tinypic.com/15zppna.jpg
 More than 2.5km/s below the average speed: http://oi40.tinypic.com/34pmjvt.jpg (the red ones only; the light blue ones are not as far from the average).

KarenZ says:

 December 3, 2011 at 03:08

Ignore the reds in the above pictures; the angle was zero so threw the calculations out. Using depth as basis for calculating speed on these produces velocities in the same ranges as the others.

Apologies for any confusion caused.

Reply

ATMJ says:

 December 3, 2011 at 03:22

graph is cropped along x axis

Reply

GeoLurking says:

 December 3, 2011 at 05:59

@KarenZ

From "Relationships between compressional-wave and shear-wave velocities in elastic silicate rocks" Castagna, Batzle, and Eastwood

Figure 1 notes that Limestones have a typical ratio of 1.9 for Vp/Vs, Dolomite – 1.8, Clean Sands 1.7, Very Limey sand – 1.6. All these are laboratory conditions.

http://www.ipt.ntnu.no/pyrex/stash/GPY00571.pdf

I mention this for reference... and to remind all that there is a layer of Jurassic era sediment underlying the island.

Mudrocks... the rocks that come from sediment, such as Mudstone, Siltstone, and Shale. Per Wikipedia, Slate comes about form metamorphosis when temperatures go above 200-250°C and the pressure is high enough.

From earlier posts, we know that as the process continues and the temperature and pressures are high enough, Phyllite is the next rock that can form. I don't think the pressures are high enough to form Schist. Phyllite probably exists in areas where there has been magma intrusion nearby.

So.. great plots, but remember to always take the speeds with this in mind. I'm still trying to work out how much time the ray path spends in each layer under the island... so bear with me. It's been a long week.

Reply