Posted on by Jón Frímann

Special report: Update 6 on the eruption in El Hierro, Canary Islands, Spain

Special note: Please notice that my (personal) watching system is also going to include the mainland of Spain (mainland Spain has two volcanoes that I am aware of, along with some earthquake activity) when I change it next month, along with Canary Islands. Everything else is also going to be a subject to a special reports if the event is important enough. That is not always going to be case however. But I am going to post more details on this in the beginning of next month.
****
Little seems to have changed in the eruption of El Hierro since my last update on it. That was on 19 October, 2011. Harmonic tremor is constant, but appears to have dropped a little in the past few days. But with the fluctuation that is often increases again before it drops down again. This means that the eruption is ongoing, but is loosing power to continue at current eruption vent. This was not unexpected. This has however not slowed down inflation in El Hierro from what I can gather on GPS data on El Hierro.

As the current eruption vents close down it seems that earthquakes have started again under El Hierro. But the earthquakes have the depth from 28 km and up to around 5 km. This strongly suggests that new magma is entering under El Hierro and is again increasing the pressure inside the El Hierro magma sill (or chamber, but note that El Hierro does not have a stable magma chamber it seems). This increases earthquakes while the magma does not have any good path up to the surface. When a new path for the magma starts to form again, a large earthquake swarm is going to take place in El Hierro. It is not going to be anything bigger then already has taken place in El Hierro already. With the largest earthquakes going up to Mb5.0 in size. That is at least my opinion.


All the earthquakes that have happened in El Hierro since magma intrusions started in July 2011. This pictures clearly shows in my view the amount of magma (in terms of size, not volume) that is under El Hierro at the moment. As it is marked on the outer layers by the earthquakes. Copyright of this picture belongs to Instituto Geográfico Nacional.


The harmonic tremor in El Hierro at midnight on 21 October, 2011. As can be seen, it fluctuates a little bit. Copyright of this picture belongs to Instituto Geográfico Nacional.

The major risk in the current eruption cycle of El Hierro is the risk that new eruption vent is going to open up nearby a human population without warning. But El Hierro has a lot of cinder cones from earlier eruption cycles. That creates the risk that a new eruption vent is going to open up on dry land without warning. But it is impossible to know when and where that might happen.

Claims that this eruption in El Hierro is going to create tsunami due to landslides are false and have no basic in fact or reality. As landslides are unlikely to happen in this eruption episode or if a eruption happens on dry land.

920 Replies to “Special report: Update 6 on the eruption in El Hierro, Canary Islands, Spain”

      1. No, not really, the largest eruption of Krafla during the Kraflafires was up to 1.2 x 10^8 m3 and the combined lava volume was aboutish 1.8 x 10^8 m3, while Laki was a stumping 1.5 ± 0.2 x 10^10 m3, so it would be more precise to say that Laki was 100 times larger than Kraflafires.
        One should also keap in mind that Kraflafires lasted on and off for nine years. While Laki did her work in 2.

        After having run around Eldja/Laki/Veidivötn and Krafla I can say that I could not in my wildest fantasy imagine how bad Laki was compared to what we see in this video. Let us hope that we will not live to see something happening in the dead zone, and do our small part to make the powers that be to actually prepare for it.
        Another way to see it, currently a Laki eruption is beyond the US economy to handle, and it would take the combined economic effort of the EU to handle. It could very well be the single event that forced the planet to actually pull the (2,5) thumbs out of their arses and start co-operating.

      2. Me, has a idea. Carl you get drills and i will get a pump and some water, lots of water. Lurking, I need some plots. Meet you guys there in 2 hours. 😀

      3. “is beyond the US economy to handle”

        And what isn’t? We were done years ago. Sheer inertia and stupidity is all that we have left.

      4. According to those that lived through the event it started on june 8, 1783 and ended begining of february 1784. Grimsvötn erupted 1785 causing some (Karl Grönvold) to doubt that Laki is related to Grimsvötn, suggesting insted perhaps Skaftárkatlar (source of the jökulhlaup’s in Skaftá) is a more likely candidate.

  2. Thanks, Jón.
    I think you look at this ongoing eruption in a lucid perspective, since there is still danger of the opening of another eruptive vent.
    Not yet time to celebrate, I guess.

  3. Nice video Jon thank you for that. Clicking on this blog never fails to amaze. Fissure events a frightening scenario.
    …Diane and Shaun the Sheep
    HAHAHA funny

  6. Jon ! As ever your Blog is the first activity of my day (along with coffee# 1) I watched that Video all the way through and although old news I was riveted.
    As in all countries there are disputes but the level of violence was minimal.
    Storms that throw huge bolders or rock and sink ships.
    Acts of heroism and bravery…swimming 5 Km in Icelandic seas..sheesh!
    Even the animals are brave flying horses and mother cat taking on a flock of ducks! Were they Eiders or domestic?
    There is a huge sense of National Pride in ceremony and achievements
    Tucked in as part of life is a huge Volcanic eruption , horrendous snowfall, Iceburgs and storms.
    What a country! Made by strong, adventurous people.

    This clip of Krafla certainly brings home exactly what a fissure eruption entails.
    I now have a better concept and will never lightly consider a fissure eruption as “Just an eruption” again!
    Thank you Jon! You are a great ambassador for your country.

    2. And as Lurking pointed out. That was “just” 10% of the Skaftar fires eruption in the 1780´s. Laki really let loose and that was “just” a fissure eruption if Im not mistaken. 😉

      1. 1 % actually… And spread out over 9 years, not 2 as Laki was.

        A fissure eruption as in El Hierro and a Rifting Fissure eruption like Krafla and Laki are two entirely different beasts 🙂
        One should never confuse them with each other. One is the “unexplosive supervolcano” of the world, and the other is the unexplosive counterpart to Eyjafjallajökull.
        Caveat, there is nothing such as a supervolcano, there are just very big eruptions.

  7. Interesting alignment of quakes from Reykjanes to Hengill.
    More pumping taking place?

    1. Good Morning Renato.
      I think more MAR movement, but they do tend to pump at weekends don’t they?

  8. Thx so much for this Blog, I am going to Lanzerote in november for 7 days hopefully nothing is going to happen.

  9. @ Carl
    Sorry some confusion last night about BUR strain chart, what I meant was why does the strain scale keep changing – -10to+20/-5to+15 now -8to+8; me poor ‘ole brain can’t keep up!!
    Couldn’t reply yesterday, Carol nicked the laptop ’til bed looking at clothie sites – yuk!!!
    See Kverkfjoll’ s got hiccups with a 2.8

    1. If you are lucky she doesnt send for man sized pumps for you just for fun… 🙂

      It changes according to the current level of activity. If you all of a sudden see it change to 400+/- then you should be very worried.

  10. Content of El Hierro lava-floaters:

    This is as good as it gets since we have 400 other samples to test before christmas.

    Here is the content of Bobs floaters.
    Solids in the white stuff:
    76 percent alumina Al2O3
    24 percent various impurities containing basically aluminasilicate oxides of various typer.
    Black stuff:
    Ferro-silicate minerals with almost no phosphorous content.

    Gases:
    So2 12%
    H2S 2%
    H2 1%
    CO2 34%
    H2O 50% (original form is steam of course, so in gaseous version it inflated the poor stone about ten times…)
    Unknown gaseous content 1%

    Weight 0,81kg dm^3 on average.

    How did it come to be? No clue. But something interesting chemically happened.
    We have though packed up a sample and prepared it for sending it to a museum for further testing if they wish to do so. But we have come to the end of our resources.

    1. Now that IS b…..y peculiar! Sounds as if the Floaterite is getting towards an aluminous vermiculite.
      Well done!

      1. We do not have a research laboratory, we have these semi-automatic machines that are really not made for any finer analyzis of samples. Basically they count the metallic content in an ore. Your basic mining lab…

      2. Aluminous vermiculite appears to be produced by weathering of volcanic ash from what I can make out from an albeit quick internet search.

        Very interested to hear what any further analysis produces.

    2. Carl, I am very curious about how this came to be.
      Sorry, but, who are “we”? (Did I miss something here?)

      1. Without going into details, I own a part of a junior exploration mining company. As such I used the lab equipment illicitly to test the floaters since I guessed we would never get any data from Bobs floaters otherwise. But, I cannot use it longer in all fairness since we have a container of ore samples to test.

      3. No, I am just an idiot regarding money… Seriously, I lack self-preservation skills in that department. I wish I was interested in shoes or something instead of companies.
        Then at least I would have nice shoes to show off…

      5. I shall spend some of my time in London in November in the Natural History museum looking at samples there. I have tended to concentrate on Biological side but I need to branch out!!!

    4. Hi guys @Carl Le Strange I have shared in my blogs and in my face too your analysis of the ‘coconuts’ expelled by EldfjallþessierþekktursemBobPancho. I hope that it should not bother you. Thank you very much. Also I want to give thanks Jón Frimann for this so amazing blog ( @ Jón I promise you that next month I will do to you a small donation ) and to all those who write in, I am learning very much on volcanoes and also English. I forgot captcha thank you. 🙂

  11. Good reading as ever. I’m off to tenerife for 5 nights from nov 24, maybe all this ElHierro business is just a precursor for Pico Del Teide to burst back into an eruption cycle!? 😉
    I’ve always been fascinated with Canary Islands volcanics, if the present day hot-spot is under El Hierro, then what keeps the the other islands active, especially Lanzarote (being farthest away geographically)? Or is there more than just hotspot activity going on in the Canaries?? I hope someone can shed some light here.. thanks!

    1. Nah, even volcanos closer than that do not influence each other to erupting.
      Even Katla and Hekla does not influence each other into erupting, it even seems like the oposite.
      If one goes it seems to relieve pressure of the other. So it might be that the high activity of Hekla the last 50 years or so have made Katla snooze a bit longer.
      A hotspot seems to affect the already existing volcanos quite a bit away, see Iceland. Also you have to take into account the various rifts and other geological thingies.
      So, nope, no eruption at Teide this week 🙂

    2. James:
      As long as you’re back before 2012 breaks, you will be OK. 🙂
      No kidding, this “hotspot” thing is more complicated than what I could grasp in the past two years when I started with this “volcanophilic” addiction.
      But it seems that there is more to the Canaries “mantle plume” explanation than what we commonly think for Hawaii.
      Here is Vince’s page (in Portuguese) with nice graphs and depiction of the whole geological setting of the area.
      http://www.meteopt.com/forum/sismologia-vulcanismo/crise-sismovulcanica-em-el-hierro-canarias-6052.html
      Just trying to give you some feedback, but I’m sure our regular experts will give you much better answers, which I would be glad to hear as well.

    3. James,

      There are various theories on the formation of the Canary Islands. So no definitive answer I’m afraid. However, it does not appear that activity in El Heirro and Tenerife are closely linked.

      This might help: http://www.mantleplumes.org/Canary.html

      Enjoy your visit to Tenerife.

  13. Yes indeed, thanks for that. It does make you wonder what’s going on in the region, especially considering how active Teide, Lanzarote, and La Palma have been in (geologically) very recent times and the large amounts of magma produced. Also, Teide is considered a Decade Volcano and considered very likely to wake up again properly, and potentially very devastatingly at any time. suggesting a healthy supply of magma around the whole area.
    The african plate (intraplate) does seem to be quite fractious.. see all the rifting going on in east Africa, other hotspots.. cape verde, madeira(?)…. etc

    1. And that is all quite normal really. Actually life is fairly calm right now.
      What you should though remember are the vast distances we are talking about here. Secondly you should really remember that volcanos do not influence each other.
      They are all individualists that like to group up around hotspots, large rifting zones, and subduction zones.
      If you wish to snow in on another hotspot that is much much more interesting than the gran canaria one I would sugest the Azores hotspot rifting zone tripple junction yummy of a place. It is together with Iceland the only place on earth that has the entire works of interesting thingies (not counting a subduction zone of course) including a caldera of gargantuan size.

      1. We must also remember the huge increase and abilities of rapid communication now. No more seeing volcanoes and earthquakes in the Pathe news at the Cinema weeks after the event. Now as we have seen with El Hierro, information is almost instant.
        So it seems that there are many more volcanic and seismic events than there used to be, in fact as Carl rightly says it’s all comparatively quiet.
        As for the 2012 thing. I remember being in the library at school counting down the seconds before the end of the world in 196.. ….erhem! a long time ago 🙂 Some crazy cult bloke climbed a Swiss mountain…. but nothing happened…. (I don’t think it was Geoloco he is MUCH to young to have been there )
        Anyway I digress….. 2012? The world should have ended a few times during my short stay on this planet and I am still here kicking A……Hem! Cough!…..
        And Well!…. If it DOES happen at least I will pass to the other side in style!

      2. Have you planned to parachute into Laki when it goes? That would be stylish. Especially with dressed in a tuxedo, martini (shaken, not stirred) and a James Bond Union Jack parachute. Of course with Jaws holding on with a stern bite to the left buttock. 🙂

      3. Everyones world will end one day, it’s the day they die. not sooner or later, so no worries, the end will come… 😉

  14. A bit slow here, on my HTC. Just to say my initial thanks was directed at Carl, but also many thanks too Renato, I’ll look forward to running that through google translate later!
    Ciao for the noo..

  15. Question for Carl to pull on your knowledge and trying to hazard a guess as to why we are seeing these strange lava bombs.

    If a you had a load of ore to extract metals from and heated it gently and placed it under considerable pressure so that its boiling point was elevated but so that it was hot enough to melt the ore but not sufficiently to induce substatial turbulence in the molten ore, would the aluminium content (as a lighter metal) rise to the surface – i.e would you get seperation?

    If the answer is yes then perhaps this is what we are seeing under el-hierro i.e prior to the large gas escape, the mantle at the hotspot could have become heated under higher than usual pressure without creating lots of turbulence in the magma, allowing it to seperate/ fractionate. When the vent opened to allow the gasesous build up to escape, the next layer to come up was then the next lightest i.e the aluminium content. But now the magma isnt under so much pressure it is able to start bubbling?

    2. Problem is that the lighter ores generally require a lot of heat to melt (Alumina melts at 1900 degrees C).
      But, if you had very high temperatures, acces to chemical reaction agents (carbons, silicates and calcium), then in theory you could get stratification of the various metalic components in the melt.
      For a mixed melt like your average basalt this is beyond human know-how and technology.
      But, who knows what the interior of the earth can do.
      What we do know is that the mantle is stratigraphied in part. The deeper the magma has come from, the higher the heavy element component is. So a high up magma is high in aluminium and magnesium.

      In this case though the temperature would probably have been to low for a simple heat stratification. A wild guess is that this is some kind of unknown chemical reaction in process.

      But, let me remind everyone. I am not in any way a geologist. I know a couple of things about mines and mining, but I am not even a mining geologist nor a mining engineer. Basically my forté is to calculate profitability and feasability of mines…

      1. How about this for a moment… the way to melt stuff and lower boiling point is the converse of the scenario I outlined above. If you place stuff in a vacuum its boiling point is lowered.. so I wonder if it could be possible that (by some mechanism) the internal pressure of the mantle at the point below el-hierro was lower than it should be, lowering the heat required for it to melt etc, combined with some mechanism that means that turbulence of the molten magma at that location is low, giving it time to seperate. I cant think of any chemical process that would be so selective to produce this result via simple chemistry

      2. I wonder what the geo satellite (cant remember its name) shows vis a vis gravitational forces at this location. Unlikely but worth looking.

      3. Scrap that idea – though it through and it would not explain a lowering of internal pressure under the crust.

      5. In theory you could vacum separate materials.
        You just cook it at exactly the various temperatures when it turns into “steam”. First you heat to the temperature of the lowest “gasing” point, and vacum that away, and then you just keap on going. Or you “just” produce plasma under vacum, and then eject the plasma stream out into the air and it should fall down according to specific weight. Then you would have pure oxides banded according to the specific weight. Beyond-tech all of it.

      6. Perhaps all you need is a pressure differential..not neccesarily a “vacuum” per se? As magma squeezes through the myriad of underground nooks and cranny’s (kind of like underground “nozzles”) localized adiabatic cooling could occur since pressure and temperature is preferrentially higher (and hotter) towards the direction of the flow source. Stratification can then occur as the various compounds within the magma and surrounding crust congeal or solidify at different distances away from the “nozzle” (i.e. different temperatures).

      7. Cap Bondo:
        Well, it is quite possible I think, but pretty much impossible to prove I guess.
        I would even go as far as to say that at current technological level even building a test-rig would be beyond-tech.

      8. I use the word “beyond-tech” a lot.
        It means that we currently do not have that technology, and that we do not even know how to go about it.
        “Future-tech” is technology which we do not have, but know in theory how to build.

      9. @JulesP

        “How about this for a moment… the way to melt stuff and lower boiling point is the converse of the scenario I outlined above. If you place stuff in a vacuum…”

        There is one variable that I think your missing.

        Water.

        Water lowers the melt point of magma quite a bit. It also goes into chemical reaction in the serpentinization of rock.

        With Carls reveleation/confirmation of the Aluminum content, that logically fits given the location. Those samples apparently are on one of the side streets of the formation process of various aluminosilicate compounds.

        http://en.wikipedia.org/wiki/Aluminosilicate

        http://en.wikipedia.org/wiki/Kyanite

        etc…

      10. But do you need to lower the temperature?

        The black stuff is Ferro – silicate minerals according to Carl. This could come from basaltic magma which is hot (1000C to 1200C) or andesitic magma (800C to 1000c). This is hot enough to convert any alumunium silicate in the sedimentary rock to aluminium oxide and silica.

        Interesting that the aluminium oxide is contained inside the black stuff. Maybe this reflects the way magma came into contact with fractured sedimentary rock?

  17. Wasn’t the supposed eruption at Hierro tackled by the lack of erupted material beneath the sea?

    1. I do not know.
      I haven’t seen anything on how it looks down on the bottom.
      I just know that we had the floaters, and aquired a couple of samples of those.
      Paying for a submersible just out of idle curiosity is a bit too much for simple curiosity.

      1. Well what still strikes me is the complete lack of earthquakes, and afterwards: deflation. There is some massive pressure from below, that’s for sure. And it’s plain logics to say that as soon as there is an opening, this pressure will be relieved. That’s why I’m still not convinced that it was a real eruption.
        The only thing that still bothers me are the floating pumice pieces.

      2. Deflation in El Hierro is minimal from the GPS data that is online.

        It is also uneven. But that is not surprising as magma collects in pockets before it erupts (most of the time).

      3. There is no deflation, at most locations there is inflation, locally very persistent and strong. That is not common for a volcano which is erupting or has just erupted.

      4. The pattern of EQs that preceded Bob and the emergence of Bob by La Restinga raises the question in my mind that we might have more than one event here.

        Bob looked more like a fumerole to me than an eruption. However, could de-gassing push small light rocks to the surface?

        Do we know when they are going to look at the sea bed?

      6. Horizontal displacement has slowed for HI03, is showing a slight increase for HI01 and has increased for both HI02 and HI04.

      7. I may be wrong, but this is not horizontal displacement, but vertical.

        If the distance between two points increases, then this can be due to either a) one moving away from the other (or both moving away from each other) but keeping the same height, or b) one being lifted (or being sunk) in relation to each other while the baseline doesn’t move, or c) a combination of the two.

        It’s possible but unlikely that the GPS points on the island move horizontally away from each other (and then back towards each other). They do move vertically.
        However, by trigonometry, you still have a resulting change in distance, but the reason is not horizontal but vertical displacement.

      8. As far as I know it is horizontal displacement on the IGN GPS:es. I do not know why they only show 1 axis of displacement. They do not even say if it is NS displacement, or if it is EW displacement. Behorkingly annoying, and gives useless data really.

      9. Well, not totally useless. I cobbled together some spreadsheet formula that allow me to extract lat-lon (y, x) changes among the various stations.

        I gave up since I would need to derive some thickness of the crust try and kludge my way into the Mogi model and get some sort of estimated vertical component out of it. If anyone has a masochistic tendency, that would eventually yield a vertical component.

        But yeah, the changes you see in the IGN data are variations in horizontal displacement. They seem realllllllllly focused on geoid measurements and if it doesn’t support that, they don’t seem to care. So, no vertical data.

        A dark voice in my head says that it has to do with taxable property… then I snap myself out of it with “nah, can’t be.”

      10. Well, to be honest, I could not have devised your wait of gleening the data out of their data to make those plots.
        Well, I would not be surprised of it had to do with the property part 🙂
        Or perhaps it has to do with them placing them on the other side of various weak points to see if something starts to slide. I do not think the placemant was selected in regard to volcanic eruptions, I think they did it to be able to detect mountain movements before they became a problem.
        IGN are not idiots really, and when smart people do something odd, there is normaly something obvious behind it. 🙂

      11. If compared to the chunks of floating lava bombs found at Surtsey, these things aren’t a bit too different to be called magma?

      12. I did not really get this one.
        Did you mean that the floaters of EldfjallþessierþekktursemBob are not magma due to not be alike the bombs of Surtsey?

  18. Carl le Strange,
    I don’t get it. You must be some kind of X-Men-Superhero-Bastard.
    I’m running like an idiot for years from early till late for job family andandand, but wherever I may stand, you make me feel like I would need 3-4 more lifetimes to reach your level of whatever. If I look at what I read from you since I peered in this blog, I have to say you leave me speechless. And now the “coup” with the analyze of Bob’s ejecta. I am humble and impressed. Don’t know any institution that would have done that with this efficiency. Respect. Just had to say it. Big up for you.
    Sheeeeeeeeeeeet from what planet are you… Do you have a secret for changing the speed of time? How much do you sell it?
    Well, I humbly stop here and continue reading with pleasure.

    1. GeoLoco:
      I am just spending my severance check right now. And since I am forbidden to work with energy for a long time, I have to come up with something else to do in life.
      Basically, I was a bastard and got fired. Nothing more to it.
      The speed, well it is easy to do things in high speed if you misuse company resources on your hobby. Any company lab could have done it.

      Regarding planet, well… Uranus would fit. My motto is “The brown ring of quality”. 🙂

      1. @ Carl
        Nice to know I’m not alone being a ‘toe-rag’ , there’s a lot I’d like to tell about a certain research lab but can’t – not openly for all to see at any-rate and yes I do ‘stuff-the-system’ where I can!! You’re a brave chap!

      2. Love it… Uncontrollable freethinker. I shall call you hat bbqing megaballed uranian bastard master of the pigbearsheep.
        Writing this while preparing kid’s evening milk. Do I have a problem with priorities? …

      3. GeoLoco, you should always prioritize your family. Otherwise you end up like me sitting alone in your apartment without a family or children.
        Backside of being a career driven bastard is that you loose sight of those things that really matter in life, like I did.

      4. Best advice a man could get. Well aware of that, I always did even “hard” choices priorizing my wife and kids. Just sometimes anyone feels like a volcano and needs a vent… 🙂 When time is missing for “serious” things, Jon’s blog and exploding minds are just too good entertainment.
        Might the holy sheep lay it’s warmest wool over you when you end this day to fall asleep.

  20. Indeed – well said Geo-Loco.

    Jon draws some great talents to this page, and a few bystanders, like me.

    Jon, if you are going to set up in Spain, I would love to know a bit more about Mallorca. It is said to be non-volcanic yet is riddled with inter-linked caverns, and Journey to the Centre of the Earth was inspired by them. It has a geyser at its centre, which has also had hot bathing nearby, since the Romans were there, and when I commented on a sulphurous smell in one town on the coast at about 6.00am the bus driver said that it was often in the air in that location. It seems to be a seismically stable island, and the geyser is a steady 17 feet high. Just curious, that’s all.

    1. Texas Jacks (if it’s still there) and The Cowboy Bar (watch out for the cockroaches in the sawdust).

      1. Lurking, I do not think I have ever been as perplexed as by this sentence.
        It is like a sentence opening a novell by Hemingway, or perhaps more like Elmore Leonard. I am kind of caught, what will happen next, do the cockroaches have baseball bats, where is the lady in high-heeled wellies (Diana). And, did the Butler do it. I want to read that dang novel now… 🙂

      2. No, it wasn’t the butler. It was this lonesome cowboy, coming down from the smoking volcano and riding – eh – an (Icelandic?) sheep ….

      4. The last mentioned species has ben taken into consideration being exposed (partially) in a sophisticated Icelandic museum.

      5. Sissel, how do you “partially” expose a (hm) banana in the beforementioned highly sophisticated museum?

        Or did you mean that “part” of the species being exposed?

        *smilling innocently*

      1. Could well be post- volcanism at Mallorca because there are seamounts nearby: http://www.google.com/#pq=geology+of+mallorca&hl=en&sugexp=kjrmc&cp=11&gs_id=2e&xhr=t&q=volcanism+%2B+mallorca&pf=p&sclient=psy-ab&biw=1200&bih=490&source=hp&pbx=1&oq=volcanism+%2B+mallorca&aq=f&aqi=&aql=&gs_sm=&gs_upl=&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=a4183349b9a276ea or here in open library: http://eprints.ucm.es/9958/ . See also this text: http://eu.oceana.org/sites/default/files/reports/OCEANA_Seamounts_Balearic_Islands_ENG.pdf . And this one could say exactly what you found out (if I’m right – no geologist neither) http://www.sciencedirect.com/science/article/pii/004019519290220Z as it is talking about a “termal anomaly” in Mallorca.

  21. In the year 2005:

    SEBASTIAN MUNN, THOMAS r. WALTER & ANDREAS KLUGEL of the Institute of marine sciences of Leibniz, IFM-GEOMAR, Kiel, Germany and the University of Bremen, Germany

    They published an article on the GRAVITATIONAL instability on the island of El Hierro and four experimental models of development.

    I quote only the conclusions:
    ”
    The structural evolution of El Hierro has been strongly
    controlled by the formation of volcanic Rift zones. the
    distribution of pyroclastic cones, the orientation of
    dams on the island, and the morphology of the flank at sea
    they reflect a system’s break with a triangular geometry in its
    central part and divergence in the area of the Rift, a continuation in the
    the West and Northeast submarine flanks. This study
    He suggested that the configuration of the Rift is controlled by the dissemination of gravity
    the overlap of volcanic edifices consecutively.
    Similar experiments with sand
    We have reproduced both the formation of subaerial area and the area
    underwater in their geometry. In addition, the
    experiments showed that during the diffusion process
    they have the flanks without stress of El Hierro
    stabilized by the radial spread, while the flanks
    surrounded by areas of rift maintains its potential for
    collapse in the form of giant landslides.
    http://foro.tiempo.com/seguimiento-especial-crisis-sismicavolcanica-en-el-hierro-t135081.1488.html

  22. Latest from Earth Quake Report. Note the very optimistic view of the mayor of El Pinar:

    http://earthquake-report.com/2011/09/25/el-hierro-canary-islands-spain-volcanic-risk-alert-increased-to-yellow/

    “Update 21/10 – 10:03 UTC: The acid rich green seawater has reached the western part of the island (Frontera side). This is really bad news for the people living there as the experience of La Restinga learned us that a lot of fish did not survive these waters. Hopefully the acidity will have been diluted a bit since the last 24 to 48 hours.”

    “Update 21/10 – 09:42 UTC – overview of the last 10 hours:
    – harmonic tremors activity similar than yesterday.
    – after the updates of the IGN data we noticed 22 volcanic earthquakes yesterday. The focal depth was in between 11 to 26 km.
    – since midnight UTC today, 6 volcanic earthquakes have been recorded by IGN. Focal depth in between 11.8 and 22.3 km.
    – we are mentioning these earthquake parameters because they are of high importance to predict eventual activity. If earthquakes are getting more powerful the risk on landslides increases (like people of Frontera experienced) and if they are getting shallower (in between 0 and 5 km) magma may have found a way up the seabed / island (higher degree of alert can be expected soon).”

    “Update 20/10 – 23:46 UTC – afternoon and evening overview:
    – The La Restinga people will finally be allowed to return to their village indefinitely from tomorrow on as the volcanic activity has been decreased a lot
    – The Red alert level 1 will be maintained for La Restinga for the time being
    – Biologists are fearing the the marine system may need more than 1 year to recover
    – The submarine GPS controlled robot has start his work today. The robot will sample and analyze water quality and has an autonomy of 4 to 6 months.
    – The mayor of El Pinar said that the volcano is almost dead!
    – At Earthquake-Report.com we do not share the “almost dormant again” stories told by the mayor and the president of El Hierro. We agree that the activity has subsided but the harmonic tremors have not yet ended and we notice even more volcanic earthquakes than the last 10 days (19 earthquakes during the last 24 hours)”

    1. Eruptions in area like El Hierro happens in rift episodes. This is just one of many eruptions that is going to happen in El Hierro. It is not until the magma flow has stopped in El Hierro that this eruption is over.

      So far that has not happened. So the eruption is going continue while that is. But breaks can happen between eruptions, those breaks can last up to few hours and up to several months.

  24. Thanks for the wiki link, Jon.

    Surprising to see that there are 3 kinds of granite in Galicia. The houses there are built from granite, with extremely thick walls.

  25. Looking at Lurks plots, the quakes off of Restinga to the E and SE, I think that this is far from done and magma is indeed looking for a way out.

    As the vent is forming off centered, it looks also to me that its following an old fracture or vent to the surface. Remember this is the N ring of what was formerly a much larger island. That said this vent could continue to extrude stuff out and slowly start to emerge but its going to be build on deposits. That island rose from the sea floor and made it to 5500 ft asl. That didnt happen in a vacuum. In addition there have been CLEAR landslides running out for as far as 135 kms and that too didnt happen in a vacuum.

    So for now, Jon is likely right. No island formation but maybe not right on the quake that sets those hills to moving. A 5.0 quake properly placed on the island on that rift with a slope of 14 up to 8 degrees would set it off very nicely I think.

    I am truly wondering from that paper that I posted up over at Eruptions what it would take to start that action to happen. I know its on everyones mind especially with at least 8 miles of vertical overbear on those hills and inland to another 3. Its already beyond the angle of repose in a lot of places -The clock is ticking

    1. Even if “the clock is ticking”, I’d refer you to the article that (I think) Carl posted a few days ago, outlining why a landslide on a mid-oceanic island is extremely unlikely to lead to the sort of tsunami that a major upslip earthquake could cause, due to the point nature of the event, and the widespread dispersion.

      That said, I do think there’s much more to come from el Hierro. What we’ve seen so far seems to me most like a large magma pool that has degassed in the last few weeks (with the gas pulling along a relatively small amount of areated, lighter, molten materials), but in which the ‘heavy’ magma continues to build; in this reading of what’s going on, an explosive eruption is somewhat less likely so long as ‘degassing’ continues, but remains possible, with a large magma discharge over a longer period of time the more likely probability. This could be a multi-year event. In fact, in terms of safety, I hope it is.

      For what it’s worth….

      1. I agree with you on all points.

        A landslide is actually simple mechanics. You need fracturing rock, enough degree of the slope, and a triggering mechanism.
        Yes, the hills are in part steep enough for a landslide. So, in theory a part could fall down into the ocean. What is not possible is a large scale slide. Why? Because the combined degree of the slope from top of the mountain down to the bottom of the sea-floor is just not there. Why? Because the sea-floor is allready corevered with previous slides.
        There are a couple of parts that are unslid, but they are so relatively small that it will not really matter, unless you are physically at the slide point. End of story 🙂
        I do think it could be a Krafla style of time-scale to this one. This since an eruption-phase only temporarily halts the inflation as clearly shown by Lurkings plots.
        But, a larger eruption could curtail the activities of course.

      2. Josh, I would agree with you save one thing. Its happened before and apparently in geologic contemporary times. The paper I posted on Eruptions outlined almost exactly what I suggested. They were very in depth with their information and especially on the angle of repose and the amount of overbear (on El Hierro).

        There is a Spanish IGN paper on the same thing that I am trying to get access to that states their opinions on the same thing.

        With the fact that the seismo gear was attenuated to be able to pick up other stuff its now into the realm of no mans land. I couldnt square what was happening with what we were seeing. I think this volcano is far from done and even the slightest pull back into the vent and into the chamber that allows that normally 50 ish water to cool it creates the pressure cooker at depth in the crust. A resurgence back into it might create the quake I am speaking of. In fact Jons GPS monitors by station indicate a huge amount of torque is being applied from two sides of the moutains. The inverted “C” of the old cinder cone is a rift, and a huge one at that. Rifts tear as I understand it dont start their tear at the centers, but at the corners and in this case its sitting from 0 to 5500 feet on about a 15 mile stretch. If half of that fell in the consequences for the US, the EU and the NE coast of S. America would be unbelievable. I always assume the worst…Then I am prepared for it.

        There are no plans, for either evacuation or sheltering for something like this. I would have agreed with you even two days ago… Now I am not so sure because of the distance the last few have gone and the size of the blocks that were moved. If there were 1 km blocks 35 kms away that were torn away before, it can certainly do it again. Its also in a chute arrangement there on the SW side where the eruption is happening. And, well they detuned the seismos which means its far stronger than indicated.

        I hope for the sake of all of us that something like this doesnt happen but as long as this little noisy guy is active we have to do just as I said… Assume the worst.

        Grand Banks Tidal Wave of 1929

        While unusual, Atlantic Ocean tidal waves are not unknown. On November 18, 1929 a magnitude 7.2 earthquake hit about 250 km south of Newfoundland, along the southern edge of the Grand Banks. It was felt as far away as Montreal and New York City. Some chimneys fell off houses on Cape Breton Island and a few landslides blocked highways. The real damage was done by the tidal wave that followed.

        About two-and-a-half hours after the quake a tsunami struck the southern tip of the Burin Peninsula. There were three main waves causing local sea levels to rise between two and seven metres.

        Natural Resources Canada reports, “At the heads of several of the long narrow bays on the Burin Peninsula the momentum of the tsunami carried water as high as 13 metres. This giant sea wave claimed a total of 28 lives – 27 drowned on the Burin peninsula and a young girl never recovered from her injuries and died in 1933…

        “More than 40 local villages in southern Newfoundland were affected, where numerous homes, ships, businesses, livestock, and fishing gear were destroyed…Total property losses were estimated at more than $1 million 1929 dollars (estimated as nearly $20 million 2004 dollars).”

        So, the research of Dr. Steven L. Goodbred, Jr. and his colleagues and experience says that what happened before could happen again.

        Ancient Tsunami Devastated Eastern Seaboard: Long Island and New Jersey Inundated Long Ago | Suite101.com

        http://rupert-taylor.suite101.com/ancient-tsunami-devastated-eastern-seaboard-a114840#ixzz1bTJvfYE1

  27. And as a friday evening treat combined with a Swedish culture lesson.
    There was once an authour called Astrid Lindgren who wrote childrens books, a lot of them, and sold horkingly well.
    One of the series was about Pippi Longstocking (Pippi Långstrump). If a book sells well, you will have a movie made from it. Pippi turned into a frenchise with many movies made. Here we see the very happy cast relaxing in the grass. Quite literally in the grass… Kids of yesterday was not better than todays.

    http://louisesa.blogg.se/images/2008/pippi_1203094130_551342.jpg

    1. Well, no. It is on the other side of the planet and I am in the shadow zone. So I am not getting any signal clearly. If I get any signal, it is too small to see on my helicorder images.

      1. Sorry, Jón. Probably those human noise spikes got me confused.
        But now I hear at AVCAN that people from La Restinga are seeing another whirlpool in the waters!

  29. Pity there’s no “like” button. Pippi was my favourite book when I was a kid. 😀

    3. Inwas always convinced that the monkey and the horse were smoking grass too… 🙂

  30. Magnitude Mw 7.5
    Region KERMADEC ISLANDS REGION
    Date time 2011-10-21 17:57:17.0 UTC
    Location 29.15 S ; 176.07 W
    Depth 40 km
    Distances 1193 km NE Tauranga (pop 110,338 ; local time 06:57:17.5 2011-10-22)
    895 km S Nuku’alofa (pop 23,611 ; local time 06:57:17.5 2011-10-22)
    876 km S Ohonua (pop 1,241 ; local time 06:57:17.5 2011-10-22)

  32. NZStuff Stuff.co.nz News
    por BreakingNews
    Breaking: A tsunami potential threat advisory is in effect for New Zealand. More details soon
    há 6 minutos

  33. The Hellishideatowreckyourtown gang seem sheepish so far, or has the Lady mayoress of Hveragerdi had engineers nut roast for tea this week?

      1. They would more like serve coffee with a L O T of cakes with a lot of cream … – as fas as I know Icelanders …

  34. AVCAN Latest Information: The research vessel that was near La Restinga has had to leave the area (now approaching the port) as it has returned to the eddy detected in surface bubbling and popping material that has not been collected for security reasons. Try to extend the information but for now, to comment that there is no evidence that this poses a risk to the population. Stay alert for possible communications from the authorities (Fernando)

  35. Really OT
    If anyone can get UK tv Channel 5 -now Iceroad Truckers in India
    Hells bells Indian driving!!!!!!!!!!!!!

      2. This is long period trace of the Mw7.6 earthquake. At least that is what I see.

        They have a mix of long period and short period seismometers it seems.

      4. AVCAN says at facebook that it is Kermandec and that La Palma and El Hierro don’t register it, becuase La Palma picks up only high frequencies and El Hierro only low ones.

  38. The teleseismic signal from the Kermadec earthquake is now being captured by all seismographs, from USA to Europe (Etna’s included).
    Interestingly, only the CHIE station at the Canarias is not reading anything. All the others in the Islands are showing a sharp signal.
    Could that be explained because the crust is getting too ductile for capturing shallower waves and that’s the reason why we don’t detect earthquakes at shallower depths st El Hierro?

    1. I think you just had a stroke of genius here Renato. It has been glaring me in the face for a week and I did not catch it.
      Of course the ductility would eat everything pretty much, it would be sucking any wave-front like a sponge(Bob).

  39. The AVCAN personal suggest that the seismic waves at El Hierro have been scaled down so that people don’t get worried about the magnitude of the ongoing tremor.
    That explains why the seismographs at El Hierro station could not capture the Kermadec EQ waves.
    Plausible, yet, worrisome explanation.

      5. I had heard that La Palma station was dead, a couple of days ago. Didn’t give it much attention, but now it makes some sense…

    2. So, basically El Hierro tremoring for the last few days have been a lie???!!!

      Idiots, so while we and everyone else thought the eruption changed on 12th, they scaled it down… This is idiotic and dangerous.
      See here, the point of re-scaling. Lurking actually caught that it was a scaling, but since no one believed it, we stoped thinking about the possibility. I hate when idiots try to “protect the innoocent”.
      http://www.01.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CHIE_2011-10-12&ver=s&estacion=CHIE&Anio=2011&Mes=10&Dia=12&tipo=2

      1. This does look like a scaled down version of the tremor chart. This means I need to re-evaluate the data that I already have.

        It is really serious to do this. As it skews the data points as the eruptions progresses over time.

        In short. It becomes impossible to know if the eruption is increasing or not.

        I missed the comment about this from Lurking (a lot of comments, I did read every comment that was made).

      2. I totally agree Jón, it is really irresponsible.
        I saw the comment, but I did not think they could be that stupid, so I stupidly enough disregarded Lurkings comment. I should not have done so.
        I should have checked it very well instead. Lurking is very seldomly wrong. Mental note in the future.

      4. To be fair, perhaps they were just trying to bring the seismographic outputs back within the chartable limits? It’s like an mp3 file vs a CD – you lose the top and bottom of the range, and thus the high fidelity of the data at the extreme ends… dialing it down makes it harder to desegregate the middle data, but allows you to see when something hits the extremes more easily.

      5. Then you post that you have done so. It takes a couple of minutes, and half the world knows. And people do not get pissed off.
        El Hierro has been a PR catastrophe from day 1.
        I still remember the Cabildo el Presidente Supremo Generalissimo calling for an international photography competition when the tremoring and erupting started, things like that kills trust in an eye-blink.

      7. If you squint a bit and look at the lowest frequencies here, you can actually notice a dip (dark red) in the lowest frequencies in the spectrogram at 18:17:
        http://www.01.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CHIE_2011-10-21&ver=s&estacion=CHIE&Anio=2011&Mes=10&Dia=21&tipo=2
        I suppose that’s the Kermandec earthquake.

        Also here in the hourly chart:
        http://www.01.ign.es/ign/head/volcaSenalesDiasAnterioresHora.do?nombreFichero=CHIE_2011-10-21_18-19&estacion=CHIE&Anio=2011&Mes=10&Dia=21&tipo=2&hora=18-19

        And do you think it’s possible that the “earthquakes” (vertical yellow lines) in this chart actually show the subsequent waves of the Kermandec earthquake rather than local shocks?

      8. Yes Ursula, it is really clear if you use control, shift, + and increase the size!! The dip is really noticable then. I feel so annoyed that they fooled us all for so many days!

      9. I do not believe it is scaling. The change can clearly be seen at the same time in the colour coded spectral plots for most of the other stations, and in the amplitude plot on CCAN and EGOM. Also if you expand the time scale about the reduction in amplitude by clickihg on the plot there, you will see that the change in amplitude tails off more or lss exponentially over a period of about 3 minutes. That would be hard to produce just by changing scale.

    3. If that is the case. It means that I am reading this eruption all wrong. As I use the start of the eruption to follow its progress as the time passes. Since the harmonic tremor is that important to monitor the progress of the eruption.

      I have made a model for El Hierro. It is forecasting now a 69% chance of new fissure opening up in the next 12 to 48 hour. I base that on the amount of earthquakes that have been taking place in El Hierro. I do not yet know where the new eruption vent might open up. But I advice. I might be wrong on this. But I will see.

    4. It would explain why a few weeks ago, before the vent opened up, there was interviews with locals that the press who said that there was a constant tremor, not just when they had an earthquake, but all the time.

    5. I went through the hierro tremor chart from beginning yesterday, hour by hour and could’nt get my head around the fact that here was huge drop in tremor and yet wery small eruption followed. Scaling the chart down did cross my mind, but i discarded that option as it wasn’t reported anywhere, only speculated here, but that explains a lot.

    6. my vote:
      the gain is turned down quite low at El Heirro due to ongoing Harmonic tremor , tremor is swamping the telesseismic signal

      1. Well I hate to be smug but that is what I suggested at the time: a recalibration of the trace to prevent full-scale maxing out.

        The lack of legends on these IGN records is disgraceful, its sloppy science.
        On the other hand the Icelandic data is presented beautifully in real time and even archives are accessible with a little thought by non-Icelandic speakers. That is achieved by a population of 350,000. The population of the Canary Islands is 7-fold greater. No excuses.

      2. Did I attribute being the father of re-scaling erroneously to Lurking?
        Mea Culpa, mea maxima culpa Peter!

        I totally agree with you. In so many ways it is a miracle what IMO does with it’s small resources. Yes, they do not have all the money in the world to do things, but they always make the best decission possible with what they have, think thoroughly scientific, meticulous of details.
        I hope the Icelanders really appreciate their volcanologists and their volcanological authority. They should have a Buy a Beer for a Volcanologist day or something because they are a pride for their country.

  40. Raoul Island is the most at risk from tsunami. The NZ authorities are trying to contact conservation workers there.

    Is it normal for a 7.4 in the Southern hemisphere to effect Northern hemisphere seismometers as much as this?
    Small spikes yes, but the Etna which Mafl posted is bigger than I thought it would be.

    1. Very long-waved earthquakes would go straight through. Like this one did.
      We are talking ultra-long wave here with a cycle that are many kilometres long.

      2. The function of the wave-length is the same as the slip fault-area x time. Loooong wave in this case. I guess the slip-fault was biiiig, but slow. Kind of a huge wet burp contra a more explosive burp.
        I think they where wise to put out a tsunami warning.

  41. Jón, do you think that it is also possible the “more ductile crust” explanation, which could respond for the lack of shallower earthquakes?

      2. You just should not give me bad ideas…
        The Other Lurker, Chris, Rick and Islander will have our hides for SvampurinnBobPkyngjabylgju. Jón is surprisingly cool with our fake Icelandic names. 🙂

    2. I think that the magma is not meeting any resistance as it goes upwards. Why that is I do not know.

      But the lack of shallow earthquakes before a new vents open is a big problem. But not completely unheard of. For Heimaey volcano there where not a lot of earthquake activity before the fissure did open up there.

      1. Hear, hear. If I were on Hierro I would be greatly reassured by an Icelandic expert on the spot.
        And they could do no better than borrow Jon and his geophones.

    2. Somebody is now suggesting at AVCAN to test this idea by taking two earthquakes of the same magnitude from before and after the suspected rescaling and check what their signature is in the seismograms. Maybe something that Lurking could easily pick up?

    3. “Otherwise the signal in CHIE in the first day of the tremor is saturated because CHIE is an old analogic station. ”

      Quote from an email to me from Resurrección Antón
      Seismic Database Technical
      (I was after waveforms to ‘hear’ the tremor.)

      1. Hello David:

        Waveforms are cool if you rebuild a comfy reading chair with an electromechanical actuator. Then basically you can feel the quaking 🙂
        I call mine the “Volcano chair”.
        QVS – cool.

      3. Ah, someone has done a new version of it. I have an old program that does it.
        Iris data is good. I just wish I could get data for Hekla and Katla for my Eruption recliner 🙂

  44. Kermadec Islands:
    June 6 2011, 7,6M 211km east of Raoul Island
    October 20 2011, 7,3M 112km east of Raoul Island
    October 21 2011, 7,3M 230km east of Raoul Island

    Interesting place to be in. I guess the researchers on Raoul Island don’t need to stir their gin&tonics…

      1. But why does it not show on Tenerife:
        http://www.01.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CCAN_2011-10-21&ver=s&estacion=CCAN&Anio=2011&Mes=10&Dia=21&tipo=1 Compared to http://www.01.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=EOSO_2011-10-21&ver=s&estacion=EOSO&Anio=2011&Mes=10&Dia=21&tipo=1 Gran Canaria, and Fuerteventura http://www.01.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CFUE_2011-10-21&ver=s&estacion=CFUE&Anio=2011&Mes=10&Dia=21&tipo=1 ? Would that mean also “more ductile crust” under Tenerife because of Teide volcanic edifice?

  46. Kermadec Islands quake
    The NZ agency exaggerated (again) – i guess better do not take any risk.
    The quake was bout the same magnitude than the July 6 one.
    All tsunami agencies (with buoys around the pacific like NOAA) immediately reported NO ADVISORY or WARNING
    Idem for GDACS
    The July 6 was almost not noticed on the buoys , although theoretically it was a wide tsunami – but never with danger to the North Island of NZ.
    It happened early in the NZ morning and people where woken up to go for higher grounds.
    They were angry on GNS Science because NZ was the only agency calling a tsunami warning.
    Today the same history
    Armand – earthquake-report.com

  48. 1106920 21/10/2011 19:10:04 27.8032 -18.0401 22 1.7 mbLg NW FRONTERA.IHI
    1106919 21/10/2011 18:49:17 27.7843 -18.0353 22 1.6 mbLg NW FRONTERA.IHI
    1106917 21/10/2011 18:28:51 27.7898 -18.0549 23 2.1 mbLg NW FRONTERA.IHI
    1106916 21/10/2011 18:16:26 27.8117 -18.0528 20 2.0 mbLg NW FRONTERA.IHI [+]
    1106840 21/10/2011 17:38:22 27.7342 -18.0827 25 2.0 mbLg W FRONTERA.IHI
    1106836 21/10/2011 16:27:52 27.7719 -18.0304 22 1.8 mbLg NW FRONTERA.IHI

  49. El Hierro
    Just got a message from El Hierro stating that different agencies and geologists are verbally fighting with each other about magma or no magma. IGN says magma others doubt it – where have we heard that again Carl ??
    It is quite chaotic over there with all kind of scientists from different agencies with their own calendar

    1. I still think it’s weird that scientific institutes claim this eruption without the real proof.
      By the way, hi Armand! Remember me? We’ve had mail contact during the Nabro eruption. 🙂

    2. I can understand the pressures of people who want to return and get on with their businesses and living. However if there is doubt then it is better to err on the safe side.
      This scenario is so sad!
      Looking at the IGN tremor recordings all is not over yet.

    3. Well Armand, I will not comment on idiots making fools of themselves. But they should really ask someone like Pall Einarsson to come over and save their silly buttocks.
      The samples we have are definitly of eruptive origin, ie. lava. But since they seem to be hell-bent on finding basalt pillow-lavas, and totally disregard that the floaters are hellishly more interesting, they say it is no lava. It is a Muppet show over their.
      I bet it would take Páll about 15 minutes to take a look at the situation and form a statement something like this “Eldgós a El Hierro. 18.39 an 800 meter long fissure opened up. IMO is following the situation closely.” And that would be the end of discussion…
      I wish IMO was running that show. I love their bone-dry reports, an IMO report is like being hit in the head by a stone-tablett from God. You just can’t argue with it, and you instictively trust it, because it is God that has Spoketh.

      1. Isn’t there some kind of exchange platform for vulcanologist to allow each other on the scene in case of an eruption. There are not so many submarine eruption specialists in the world.

      2. I do not know really.
        I guess there is one among those who work with volcano warnings and such. But, I guess that is up to each country. And Spain has an ego issue even on the best of days, and even admitting that they need help will probably not happen. Which is sad, because IMO are really the Champions at their game. I guess that USGE are pretty good (but I do not know what economic cut-backs have done to them) and INGV are also very good.
        But except them it would be only PhiVOLCs left that have a clue about what they are doing. To be honest, IGN are second or third-rung in the volcanic business. I just wished they admitted it and asked for a hand.

  50. About rescaling, check this, I found two similar earthquakes at similar position and of similar magnitude (2.6/7), both felt on the ground (II intensity) and while the hourly spectrograms show a similar picture, the seismograms definitely don’t. So, rescaling, yes or no, what do you think?

    Before rescaling:
    1104799 12/10/2011 12:27:24 27.6665 -18.0238 13 II 2.6 4 SW EL PINAR.IHI
    http://www.01.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CHIE_2011-10-12&ver=s&estacion=CHIE&Anio=2011&Mes=10&Dia=21&tipo=2#
    http://www.01.ign.es/ign/head/volcaSenalesDiasAnterioresHora.do?nombreFichero=CHIE_2011-10-12_12-13&estacion=CHIE&Anio=2011&Mes=10&Dia=21&tipo=2&hora=12-13

    After rescaling:
    1105621 15/10/2011 03:52:21 27.6668 -18.0559 16 II 2.7 4 SW EL PINAR.IHI
    http://www.01.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CHIE_2011-10-15&ver=s&estacion=CHIE&Anio=2011&Mes=10&Dia=21&tipo=2
    http://www.01.ign.es/ign/head/volcaSenalesDiasAnterioresHora.do?nombreFichero=CHIE_2011-10-15_03-04&estacion=CHIE&Anio=2011&Mes=10&Dia=21&tipo=2&hora=03-04

Comments are closed.