Schunday Schummary: El Hierro.

Eventos_HIERRO_15D 7 9 13

http://www.ign.es/ign/resources/volcanologia/jpg/Eventos_HIERRO_15D.jpg

El Hierro and BoB are a theme that runs right through Volcanocafe and there is still unrest there more than 2 years after the onset of the seismic crisis. It’s been a bit busy this week and the comments from the crowd (thanks loyal commentators) provide a useful lesson in reading/ navigating the seismometers…

With a big thanks to IGN for putting their data out there.

2/9/13

Bobbi:

Well, this is interesting.  4 El Hierro quakes in 15 minutes.

chie 2 9 13 16 17

http://www.ign.es/ign/head/volcaSenalesDiasAnterioresHora.do?nombreFichero=CHIE_2013-09-02_16-17&estacion=CHIE&Anio=2013&Mes=09&Dia=02&tipo=1&hora=16-17

5/9/13

Steve:

Looks like our old friend Bob is picking up again, and a strange signal from La Palma at 4.40am which also shows on other islands, but nothing listed apart from a mag 6 mid altantic ridge at 4am which would be far too early.

chie 5 9 13

http://www.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CHIE_2013-09-05&ver=s&estacion=CHIE&Anio=2013&Mes=09&Dia=05&tipo=1

Dfm:

Yup, some action from Bob, nearly all located under the El Golfo/ Tanganasoga area. Low magnitude. I think there will be more during the day.

Karenz:

It probably is the North Mid Atlantic Ridge EQ.  Note that CHIE is set to block out most external events so you would not see the complete wave form.  You can see the full wave form here:

egom 5 9 13

http://www.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=EGOM_2013-09-05&ver=s&estacion=EGOM&Anio=2013&Mes=09&Dia=05&tipo=1

Later

Dfm:

Apparently some people are stealing equipment (solar panels and batteries) from the IGN deployement in El Hierro. This causes some loss of data (and money also).

http://ciencia.diariodeavisos.com/2013/09/05/los-robos-merman-la-vigilancia-volcanica-del-hierro/

Islander:

A ha, somebody be building a SIL of his/her own powers, to have unrestricted data for him to see how far the authorities have “sunk” in scaling it down 🙂

Seems the “Pirates of The Carabeean” have struck them Spaniards a blow

Dfm:

I’m afraid it is more prosaic than that, the thieves are stealing the solar panels and batteries to get some free electricity I suppose; they do not seem interested in the scientific equipment per se. By doing this they make IGN lose data from their equipment arrays. Maybe this can explain some of the outages on the seismometers.

6/9/13

Alison:

Largest earthquake on El Hierro for a while @ about 13.25. No details up yet

Renato Rio:

Do you mean this one?

13:25:28           27.7223           -18.0185          11       Sentido            2.5       4          NW EL PINAR.IHI

Karenz:

Seismos from CMCL and CCUM which are nearby:

ccum 6 9 13 13 14

cmcl 6 9 13 13 14

A nice plot from Dfm:

This is the El Hierro earthquakes update for September.

The black circles are events for June and July and August 2013. Size for these quakes is divided by 2.

On the first part there is an event by event animation, showing the date (look up the left scale of the colorbar).

The terrain color refers to elevation (see right scale on the colorbar).

In the title you can see the current rank of the event vs Total, the day and time of the day, and finally the magnitude.

I have kept the view angle constant to avoid unnecessary confusion due to plot rotation.

Circle size is proportional to event magnitude (4 times for the current event relative to older events).

The view is from the south. The major quakes so far for September are shown including today’s 2.5@13h25.

The second and third parts are day by day earthquakes animation. Date is shown on the title bar, views are from the East then from the South.

The third part is a rotation of all the earthquakes.

The fourth and fifth parts are a rotation to a top view showing all quakes and back.

The blue mesh is the bathymetry around the island.

The last part is a zoom centred on the last event. I have changed the limits to get a wider view compared to the other sequences.

There are still 2 clusters, one located under El Pozo/ Sabinosa and the other more to the east of that under El Golfo. For the second cluster the activity is now more prevalent and is deeper, but the activity is returning also to the west cluster. The cluster under El Golfo keeps being the most active since the last update (Aug 31st) but activity is more balanced.

The “dead zone” is still there with maybe a few quakes getting nearer.

Data from IGN and NOAA, made with Gnu Octave (Linux version) and avconv.

And a still frame:

dfm still

Aaaannd one more for luck:

Alison:

A 2.8 on El Hierro, at 22km this time. Maybe starting to wake again?
1231126 07/09/2013 12:18:03 27.7745 -18.2027 22  2.8 mbLg  W FRONTERA.IHI – El Hierro

Dfm:

Last one was in July, 22 is pretty deep, sure looks interesting. It is west NW of Orchilla that a zone which was quite quiet for the last weeks.

corc 7 9 13 12 13

Schteve x

 

All screenshots courtesy of:

http://www.ign.es/ign/resources/volcanologia/HIERRO.html

For a bit more on monitoring the Canary Islands:

https://volcanocafe.wordpress.com/2012/08/22/plotting-for-beginners-part-one-aaaaand-another-look-at-malcolm/

Great selection of links for El Hierro (thanks Spica,) and in the comments; instructions (courtesy of Sissel) for accessing the other seismometers:

https://volcanocafe.wordpress.com/volcano-monitoring/

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54 thoughts on “Schunday Schummary: El Hierro.

    • Hi Spica, you are most welcome, I’m very jealous of yr trip to Lanzarote; it’s absolutely gorgeous. Don’t miss Cueva de los Verdes 😀

      • This is odd, Schteves answer to Spica is not visible in the recent answer list…
        And what on earth is that thing in the spam-box?

        Edit: And now it has appeared. Seems like the update was slow… But still no clue what the in the spam-box is.

        • I put the reply in via the notifications thingy, I don’t usually do that…
          The thing in the dungeon looks as though it was done automatically to provide a link from “wonder what’s up with bob2 to a new article tagged with those catagories, but then why did it end up int schpam?

          • Good question, and should we release it from the spambox?
            If it is meant to be available as an internal pingback it should be released… Hm… I think I will release it.

  1. Rudiger Escobar Wolf has pointed out that there is an earthquake swarm taking place south of Guatemala City and that it might have been triggered by yesterdays large earthquake. There seems to a risk that this smaller quake swarm might migrate into Pacaya volcano.

    • My Wife who has spent some time in Guatemala-knew a Mestizo lady who was a bookstore
      owner. She asked her;’Why is everyone here so sad?” The owner said”It is the Volcanoes.
      One day we will all be gone…”
      She loved Guatemala, but always held this in the back of her mind ….
      Fuego erupted when she was there ( a small one)..

  2. Glad to see something interesting happening there again.

    Something that has been on my mind a little lately is that it is around 50 years since Surtsey.

    I wonder if anything will happen there again in my lifetime.

    Also, Anak has had a pretty long period of quiescence by its standards, so I’m hoping to see more happening there, too, but within months rather than years,

    David

    • I do not think that there will be renewed activity in the Vestmannaeyar area in the next decades.
      Anak will probably put in an appearance again very soon 🙂

      I think that for Iceland the next item on the agenda will be somewhere under the Vatnajökull.

  3. Etna

    The strombolian activity at the Southest crater is ongoing for the third day in a row. The strombolian ejections are still fairly small reaching up to 40 meters above the crater. Loud explotions are still heard by local residents.
    The activity at Bocca Nuova seems to have stopped after the crater floor collapse yesterday.

    Seems like Etna has changed its behavioural pattern from the paroxysm-mode seen the last year into a new pattern. What that pattern will end up as will unfold in the days and weeks that follow. For the time being we can enjoy the show of Etna playing at being Stromboli.

    One thing of note is that the strombolian activity at Etna continues even though harmonic tremor is very low. Except for a few events that might be LP earthquakes there has not been any measurable activity.
    http://www.ct.ingv.it/en/tremore-vulcanico.html

    • This is a combination of Carl having been there a few days ago and Lady Etna wanting to be Schunday Schummarised… 😀

    • I think Etna might go back to sleep or just continue this activity. This activity is weak. It doesn’t seem like it will ramp up. After those paroxysms earlier this year, it was drained. It just ran out. So I think it will either return to dormancy or continue this current weak activity.

      • Also, another factor that I would add to its sudden quiescence is that it most likely lacked the gas pressure to create another paroxysm. Essentially, it spent most of its pressure and erupt-able magma from February to the beginning of June. While it has multi-month period of repose, it still lacks the gas-rich magma which causes its paroxysms.

          • I doubt we will see any paroxysms at all. That phase is most likely a thing of the past now. We will have to wait and see what the new pattern will be like.
            Most interesting is that we have two cold vents opening up, and that takes energy, so there is defintly magma somewhere in this highly intricate volcanic system.
            I would not be surprised if activity suddenly picked up the pace.

            • I think paroxysms will occur once enough gas-rich magma is generated. But as of now, it is not fully recharged. It does not have significant quantities of gas rich magma yet. The paroxysms from February to May(forgot the dates) spent almost all of said magma, which was built up in quieter times.

              So I think there are 2 probable ways this could end:

              1:Gradual buildup. If this weak strombolian activity continues, it will keep building pressure. This will lead to more paroxysms in due time.

              2:Return to dormancy. I see this most likely. This current activity shuts off at a later date, and it returns to quiescence.

          • Something to think about…
            Yesterday, a pic was noted about a hole that had opened up… a collapse structure near one of the touring trails. At the time, the issue of why it was round was kicked about.

            Heres an idea for you. Collapse structures form when there is nothing to hold the roof up… and the ground/rock can’t hold itself up. That implies a cavity or chamber. Is it possible, that magma is draining back into a lower chamber, or has found a series of dikes/sills to travel down? Could we be seeing the potential onset of a flank-wise draining of the summit chambers? Maybe a Puʻu ʻŌʻō style draining out a side rift?

            Could that be why Boris is eerily quiet? Too busy to mention anything because he and INGV are trying to determine what it’s up to?

            Historically, Etna has been known to pull a stunt like that. Maybe all the energy pushing those paroxysms popped open an old tube somewhere.

            • I believe that you may be right. Perhaps a flank eruption is in order. Maybe it could mean that activity may be coming to a halt for now and magma is withdrawing.

            • I fear that you have a good point here.
              I am trying to get hold of Boris to get some info, but so far squat.
              Not a single word for two days…

              It is easy to underestimate the change of Etna, this is a new phase, and what will happen is far beyond my knowledge to even speculate upon. And, if one does not know a lot about Etna one can easily be lulled into believing that she can’t pull a big stunt out of a hat, but she can and has done so many a good time.

              During the last 100 years she has had 20 flanking eruptions, and that is half of all known in recorded history. So, a surprise one is not out of the question as Lurking points out. One should remember that in under half a year 4 of the 5 craters have been active, and that is a lot. Even I had missed that Voragine put in an appearance in April.

            • Flank would be bad. Of all of Etna’s eruptions, the ones that are most likely to be a threat to the average Mk-1 mod-0 hominid would be flank events.

            • MDATC, you should remember that Etna is very complex, she can easily deflate in one spot and erupt at another at the same time. The craters are not interconnected, or interconnected in such a bizarre way that you can’t interpret what one is doing and assume it has anything to do with the next one over.
              So, Bocca Nuova emptying does not stop Southest crater from erupting, but might mean that lava is going somewhere for a flank eruption, or going to Voragine, or even into a new crater that forms somewhere…

              Etna is to complex for my befuddled mind. But, it is up to something somehow and somewhere.

            • You are right. Withdrawal of magma likely caused this collapse. It might be a flank eruption, the Voragine might erupt etc. We will have to wait and see.

            • Something similar happened on St Helens a few weeks before May 18th 1980. Old crater collapse into itself is what I remember-trying to find the literature,
              Also the picture.
              As it is-I do not think it is good. Boris and his comrades are probably very, very busy…

            • Boris is not answering questions… that is a first.

              They are of course doing their job and quite busy at it, and their job is to save lives of the locals, not keeping us volcanoholics happy. Boris will give us the news when he get the time. 🙂

  4. Back on the hole forming on Etna thing.

    First: This is wild speculation by a non Geologist.

    Reportedly the hole formed at the north end of Bocca Nuevo, as reported by KarenZ.

    The link that was provided:

    http://www.etnawalk.it/News/Read/229/collasso-del-fondo-settentrionale-della-bocca-nuova

    Bocca Nuevo should be “BN” on this graphic.

    IF the magma has found it’s way down a lateral rift system, I would expect to see if manifest in the West Rift or the NorthEast Rift system. As you can see, there have been incidences of cone formations along those regions… historically speaking.

    This doesn’t mean that it hasn’t retreated to a lower chamber, as Carl mentioned, it’s a bit of a complex system. And, it was one of the items in the last riddle set. “Wow! It certainly is one mutant, mean, lethal strato.” Paraphrasing that… it has gone through quite a few stages of eruptive processes over it’s history and has had time to develop unexpected interconnecting feed systems.

    Again, this is just random musing by a non Geologist. My selection of those two rift systems as being likely candidates, is only from their proximity to the new hole in the ground… and that sort of massive flow field from the Western Rift. (see Gurgle Earth)


    Mike Ross seems to have the same questions/observations about the new hole.

    That’s interesting.

    What was holding the floor up before?

    Where did it go?

    (think Kilauea a couple of years ago…)

    • Wonderful links. Must be great doing a walk up there at the moment with a huge feeling of “just what are we walking on here?”

      I agree that Etna is far too complicated to call. You never know what is going to happen next. The main thing is that something seems to be happening all the time.
      Couple of points to bear in mind:

      Boris once stated that there is a general pattern (as much as you can say there is any reliable pattern on Etna) of flank eruptions following phases of summit activity, so maybe this is the first sign of something like that happening.

      Second, he also stated there seems to be a trend of increasing gas content in the magma ascending from depth, making the eruptions (at least at the SE crater) more explosive. If there is a flank eruption can only hope that the rest of the system is full with degassed magma. If not, we might see one or more of the summit craters giving us some fireworks as the pressure from the new gas is released.

  5. The weathergods are having fun now…

    After a stunningly beatifull day with 25 degrees celcius there was fog… Loads of fog, and through that fog appeared snow… and it is 12 degrees and snowing. Must be some very weird layer of cold air somewhere above. Sigh…

    Time for night chocolate and sleep it all away.

  6. I wish there were somewhere that you could see inflation rates of SakuraJima online. The activity it has shown in the last few weeks has seemed to be quite a step up from what it has shown for the previous few years, which were already more active than average.

    I know the inflation rate supposedly started to increase around 2010/2011, but I would be interested in seeing what the case was now.

    • I am always amazed by documentaries like this.
      It is always the “Oh God, we will die” hyperbole.
      In this case the answer is simple and fairly well known. About 400 years ago the shift of the magnetic pole started to increase. It is the magnetic deviation that you can see on maritime navigational charts. As the shift progresses and pick up spead the magnetic field temporarilly grows weaker, before a new magnetic “north” pole asserts itself. Curiously enough the “north” pole could well end up in the south.
      As the new pole asserts itself the magnetic field comes back into strength, evidence seems to give at hand that it is much faster at reasserting itself then its dimming. We know this from magnetic traces in iron ores.
      As a magnetic lava cools down the magnetism gets locked in the trajectory of the magnetic field at the time of cooling. There are ores quite literally pointing in every possible direction (hm, almost at least).

      I would be surprised if this even kills a single human being, and if it does it will be someone out sailing caught very unawares. It could of course do a bit of damage to electronic systems, but even that is not that likely since the magnetic effect is very small on electronic circuitry.

      Now I am just waiting for a documentary about the dangers of putting on socks. On average 8 000 people die every year while putting on socks in the morning. So, during the estimated time the pole shift takes, 64 million people will have died from sock related accidents. Kind of puts things into perspective doesn’t it?

      • Since you already put the “north” in parentheses, here is the naming convention: “The north pole of a magnet is the pole that, when the magnet is freely suspended, points towards the Earth’s North Magnetic Pole in the Arctic. Since opposite poles (north and south) attract, the North Magnetic Pole is actually the south pole of the Earth’s magnetic field”
        http://en.wikipedia.org/wiki/Magnet#Pole_naming_conventions

    • I only get into trouble when I forget what foot already has a sock on it, then try to put another one on it. The usual result is me hopping around the bedroom stumbling over the dog.

      So, socks aside… there is a line of thought that tries to couple leaps in evolution with magnetic field reversals. I have yet to be able to track down the book on it. It’s in my list of things to keep an eye out for. I pretty much have an idea of how they are going to square the two ideas with each other. The increase in cosmic ray bombardment will enhance the natural mutation rate and spur the onset of new cellular tricks, some of which are beneficial and that lead to new critters.

      On the catastrophic side of things… I wonder if the changes in circulation of the core, could affect the core-mantle boundary, perhaps causing a ripple like feature that disturbs the until then stable features and accumulates. If it does, can it cause a higher heat flow into the mantle, driving new plumes or dampening out existing ones?

      It’s not the same, but I have been intrigued by the Laschamp geomagnetic excursion’s seemingly coinciding with large caldera structure formation in Italy.

      From Wikerpedia:

      A minority opinion, held by such figures as Richard A. Muller, is that geomagnetic excursions are not a spontaneous processes but rather triggered by external events which directly disrupt the flow in the Earth’s core. Such processes may include the arrival of continental slabs carried down into the mantle by the action of plate tectonics at subduction zones, the initiation of new mantle plumes from the core-mantle boundary, and possibly mantle-core shear forces and displacements resulting from very large impact events. Supporters of this theory hold that any of these events lead to a large scale disruption of the dynamo, effectively turning off the geomagnetic field for a period of time necessary for it to recover.

      And Italy was the location for the demise of several parts of the Tethys oceanic plates. Some of which still seem to dangle from the old subduction zone where they went under. 3D plotting of all the quakes in those areas tends to show them hanging there… almost vertically.

      But… look on the bright side everybody! You will be some of the first hominids in the new Chron!

  7. OT: The Potato Gambit.

    5 April [1945], the USS O’Bannon sighted the Japanese submarine RO-34 on the surface and made to ram it. At the last moment, the officers decided that the sub may be a minelayer, and the rudder was turned hard to avoid the collision. This action brought the destroyer directly alongside the sub. As the Japanese sailors attempted to man their three-inch deck gun, the O’Bannon’s deck hands, not having side arms, grabbed potatoes from nearby storage bins and pelted the Japanese with them. Thinking the potatoes were hand grenades, the submarine’s sailors were too occupied with throwing them away from the sub to fire. This gave the O’Bannon the opportunity to distance itself to fire its guns at the sub and damage the conning tower. Although the sub still managed to submerge, O’Bannon used depth charges to finally sink it. During this period, the O’Bannon also splashed at least two enemy aircraft in various attacks.

    • Now, that is the sort of war game I could get into. I get kind of scared when they start throwing harder stuff at me.

    • The most unlucky ship in the US Navy… USS Porter, DD 579.

      USS Porter’s DD-579 “Other History”

      From November 1943, until her demise in June 1945, the American destroyer William D Porter was often hailed – whenever she entered port or joined other Naval ships – with the greetings: ‘Don’t shoot, we’re Republicans!’

      For a half a century , the US Navy kept a lid on the details of the incident that prompted this salutation. A Miami news reporter made the first public disclosure in 1958 after he stumbled upon the truth while covering a reunion of the destroyer’s crew. The Pentagon reluctantly and tersely confirmed his story, but only a smattering of newspapers took notice.

      Fifty years ago, the Willie D as the Porter was nicknamed, accidentally fired a live torpedo at the battleship Iowa during a practice exercise. As if this weren’t bad enough, the Iowa was carrying President Franklin D. Roosevelt at the time, along with Secretary of State, Cordell Hull and all of the Country’s WWII military brass.

      And it goes down hill from there.

      http://bobrosssr.tripod.com/porterstory.html


      As a sailor, one thing that my uncle loved to do was to relate sea stories from his time on board the USS Strickland DE333. My visits seemed to cheer him up since I was about the only member of the family that could relate to what he was talking about… having been stations on frigates, destroyers and cruisers myself… though not in any shooting war.

      One thing I never had to contend with was getting the ship underway with the entire crew drunk off their ass or hung over.

      The Strickland was closer in capability to my first ship, a frigate. Though we had SM-1 missiles and a single 5″-38 as opposed to her main battery of 3 x 3″-50 guns. (pretty much 76mm). We were typically assigned picket duties much like the modified DER333 was.

      At about 1590 tons full load, that thing had to ride like a freaking cork. I rode a hurricane on that Frigate, and it had about twice the displacement (3,426 tons full), and it was no fun at all… terrorizing to the point of laughter. By the time we made the outermost channel marker at Pearl Harbor, the seas were at 30 ft with 80 knot wind gusts. The storm essentially ran us out of port. We came in, gassed up and quickly left. The ship behind us (USS Goldsborough) had one fatality when a wave smacked a guy into a bulkhead fixture. The two that were washed over the side were recovered after the storm, alive. (anecdotal reporting puts one of them winding up in some felled trees, and one officer clinging to a buoy. If true, that that would have been one hell of a story.)

      After we made it out of port, we hooked up with PHIBRON 3, our assigned task group. Watching those Amphibs lift the screws out of the water was impressive… and I imagine was a bit hard on the machinery driving them.

      • Ah, “the Butler did it” just changed to “the Porter did it” 😉

        And when I do not watch for 48 hrs, Etna erupts, and I lose many of my links, then have new window appear: “Warning, you can not save, disk is full”
        Grumble..

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