Chain of Dead Poets!

Amsterdam Island with visible craters.

The Amsterdam St Paul hotspot is one of the weaker hotspots around. It has created the St Paul and Amsterdam Islands, the now active Boomerang Seamount (last known eruption 1995), and an elongated chain of seamounts called the Chain of Dead Poets. These are remnants of the eruptive wake of the Amsterdam St Paul hotspot as the plates move on over it. The hotspot has had 2 episodes of increased activity after it became active. The first period lasted from 10 million years ago to six million years ago. The second period started 3 million years ago and lasts up until today. Amsterdam, St Paul and the Boomerang Seamount have all been produced during this second period of activity.

The hotspot is associated with the South East Indian Ridge and its rift system, and the chains volcanoes show evidence of changing in its chemical composition as the hotspot moved into the SEIR.

Amsterdam Island

The Island is the northernmost of the Antarctic sub-aerial volcanoes. It has had two eruptive centers down the line. Both with visible craters, the younger of the craters are far more visible on the image. Both of the craters are from periods of heightened activity, but later volcanism on the Island has primarily been of the flanking fissure type. Even though no eruption has been witnessed lava samples taken from the flanks of the younger crater shows that the volcano has indeed erupted during the last 100 years.

St Paul Island

The channel into St Paul natural harbour. One should keep slightly to the portside of the centerline of the channel when sailing in. The starboard side is much more shallow. By keeping slightly to portside of the middle you can get a 3 meter deep sailing ship into the natural harbour, well inside of it depth is not a problem, and you are quite safe regardless of weather. Stay away from the mammals on the beach, they are big and mean and are in no way to be compared to people in bikinis.

The island had a large eruption a few years before 1780 in which the predominant caldera formed. Even though the caldera is small for being a caldera it was probably formed by a Krakatoa style eruption starting with a for the volcanic system unusually large eruption with a subsequent magma chamber roof failure that let the ocean water down into the chamber. The ensuing steam explosion gutted the chamber.  In 1780 the vestigial remnants of the caldera wall facing the ocean crumbled and the ocean has during the following years carved out a fairly broad, but shallow canal that is open for smaller sailing ships due to its limited depth of around 3 to 5 meters.

Map of St Paul Island from Wikipedia. Note that the island is very small. The actual caldera is only slightly larger than 1 km across.

The Island is together with Isle du Kerguelen the best harbor in the southern ocean, and many trans-globe sailors make a port of call for repairs, or just general relaxation and landfall.

Boomerang Seamount

Not much is known about Boomerang that lies 18 kilometers north of Amsterdam Island. It rises 1 100 meters above the sea floor, but is still 650 meters below the ocean surface. During an expedition in 1996 they dredged up a lava sample and tested its Uranium/Thorium content. It showed that the lava had been erupted only 5 months prior to the visit.

The Seamount has a 2km caldera showing that the volcano has had at least one substantial eruption and probably have been a bit closer to the surface before.

CARL

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198 thoughts on “Chain of Dead Poets!

  1. And since it is saturday…
    This song has a special meaning to me, I used to play it back in the day when I worked as a professional writer/critic for newspapers. I used to play it when I had impossible deadlines like having to write a centerspread review of an entire opera-production in 15 minutes (2000 words).
    I write fast. You do start to write fast if you have to write for your living, if you do not you will starve.

    • Awwwwwwwww! …..Love makes the world go round… Stuff the mathematics and formulae and laws of Physics………… :D

      • A very interesting post Carl . Thank you. Another volcano I have added to my brain library of Volcanic facts.

    • Carl, I think that is a truely beautiful thing to say about your wife, it´s a beautiful song with even more beautiful lyrics…if my husabnd were to say that abut me I would be blown away…you are such a romantic….hope things for you and Haily get sorted soon..and you can both get on with your lives..

  2. Surprising how much beauty there is in this world while many of us not even know it exists – until some clever person makes a riddle and another clever person writes a post about it!

    • Ohhhhh! Sissel……..It’s THAT Photo again……… We really MUST think about Next year’s VC Calender :D
      <<<<<<<<<< :oops Has come over all unneccessary again and potters off to make a strong cup of something calming. :D

      • Yes Diana, this is a great calendar photo.. you are right, we ought to prepare something, just in case there will actually be a 2013!

      • Haha. It is good fun making a calendar. A few years back I had a Chippendale (Male Strippers) Calendar at my desk at work. The boss did not approve as since the men were’nt allowed to have ‘girly’ calendars then the same should apply to the women. Well, I thought it was a shame just to bin it, so decided that in order not to offend anyone each month the man would be ‘dressed’ in a different outfit, to preserve his modesty. Firemen, Fishermen, Rigworkers, Doctors, Cavemen…I cant remember all. Each outfit was carefully cut to fit using ribbon, fabric, fur, whaterver came to hand really. So the Boss had nothing to complain about, and it became a monthly project for the girls to get involved in, in fact some guys even contributed too. I so wish I had kept that calendar, as the company was sold the following year and we all split up.

    • Oh Carl are you having a melancholy day missing your babe? Thats 3 wistful songs you’ve posted today, all of them are excellent choices too. It’s not nice to be apart from your loved ones, but as they say ‘absence makes the heart grow fonder’ and hopefully that will make it even more special when you get reunited. :-)

  3. Nice post Carl

    Around 1930 some fishermen from Brittany were installed on the island of SaintPaul to fish for lobsters. (20000 a day on the good days)
    Unfortunately for them, the company they were working left them and some people from Madagascar on the island during the bad season. Many died of beriberi and scorbut. This led to the Story of the “Forgotten of Saint Paul”

  4. Words don’t come easy, indeed!
    Sometimes silence is the easiest way to express your feelings… (and music, of course!)
    Cool post!
    And the rest is silence… :)


  5. The crater at a quarter to 12. ( Wind around 90km/h)

    A stone rose on the way up to las Canadas Caldera.

    And “my” Roques de Garcia and Teide in the background.
    All images were taken today by me.

      • @ Spica – Do you know, I have been on the Teide trip a few times (before I became even remotely interested in Volcanos- when I was more interested in the hot chocolate and waffles they serve in the bar just before you get on the cable car and of course the fabulous view from the summit), but have never seen that rose (or maybe I did see it but it didn´t register) – I wonder if the stong wind was something to do with the Nadine tropical storm,yesterday it was reported that it won´t affect the Canary Islands too much, will just give us very strong winds but only at 2,500 – 3,000m above sea level – oops maybe Spica, you picked an unfortunate day to go up there. Did they still let cable cars go up if it was that windy? or did you walk it?

        • There was only one cable car going up after ours then none was allowed to go up anymore and we were in the last one down. The few meters up to the very top would not have been that much of a problem because of the height but because of the wind it was hellish. And yes it was Nadine which hit us. But thats Ok now that i am down, i had more of an adventure then many other tourists who went up there. Just one tiny regret.. we could not do the hike over to the viewpoint to Pico de Viecho. Because the sirens were howling and the employees shouting “rapido, mas rapido”

    • Great photees – stone rose looks amazing. Went to top of Teide many years ago – remember scalding my hand sticking it into a steaming vent ! Amazing lunar / volcanic landscape on the way up. Has anyone done a post on Teide ? Might be interesting to analyse a little. Last erupted in 1909 and has active fumaroles at the top. Third highest volcano in the world after Hawaii (from Wikipedia). Must go back one day.

      • Gosh I have to say KarenZ you have a very sharp eye…I didn´t even notice that, and I don´t think Spica did either..

      • I have more pics of the crater, i ll check for the object some other time. I had a very strong sulfur smell up there, the yellowish thing is sulfur and the crater is filled with fumaroles. I did not notice this piece, though i did notice other gear. I think the volcano is monitored, but up at the very top, i was very busy not being blown over some edge.
        And answering Sissels comment, sure, i did think about a post on this or maybe even 2 because we were upon the caldera on Wednesday too. And i ll most likely post many images on my Flickr. ( I did 232 today)

      • Here is another image which also shows that gear.

        The rim of the caldera is in the background.
        This caldera was not formed through a mayor eruption but with a landslide when the destabilized material slid down the north side of the volcano and so formed the valley now called La Orotava. ( The old Canadas volcano was probably 1k meters higher so around 5000 meters. ( thats what i got told)

  6. Thanks for the post Carl. I don’t know where to sort the post in ( by topic) Does anyone happen to know to which country the Chain of dead poet belongs to?

        • If it is outside of the sea-coast border set by the naval court and agreements it would be nobody that owns it.

          And this little thing creates huge problems. Take for instance the waters in the north, they are rich in gasses and oil (and fish). Today they are not legaly owned by anyone. But various states have laid claims to all that water. Those states are a short list. In amount of waterarea claimed we have this list.
          Russia, Canada, Norway, Denmark, US, Iceland.
          2 of these countries can easily defend their territory, namely Russia and the US. Then we have 2 small powers, Norway and Denmark, and a non-power (Iceland). And here it get’s tricky in a handbasket. The solutions have been different between them. Iceland gave up and more or less signed a usage contract with the Norwegians (under duress). This increased Norways problem. Denmark is just being stubborn hoping that someone will in the end help them defend that large area. Norway was sneakier, they went and signed a defence treaty with Sweden and Finland, secretly cutting both of those countries into the very sweet deal. Of course those two countries was slobbering with greed and promised to do anything to help defend Norway (incidentally paving the way for a future Scandinavia if EU goes to hork).
          That leaves Denmark, either they will sign on with the US, or with the other Scandinavian countries. Anyway we will have a triparting with 3 large powers gunning for control.

          • Thanks / merci Shérine !

            The seafloor and the fish (and the oil and gas if any) belongs to France up to 200 Nautical miles from the continental plateau, I think around the islands. If I remember well France has the second largest Oceanic domain after the US. We very cleverly kept some remote islands in some remote places in our domain. Must have included a lot of champaign bottles given out, but as we are producing it also….

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

          • I would though like to point out two small things.
            First of all St Paul and Amsterdam is contested territory. How that ends we will see.
            Second of all, the 200 nautical mile barrier is not internationally acclaimed, and never claimed by France.
            No country on the planet has more then 12 nautical mile from the actual state (continental shelf rule). That is a signed UN treaty ratified in 1982 by France.
            The Exclusive Economic Zone can be anything up to 200 NM out from the coastline of the country (continental shelf rule).
            So far so good. Here comes the Dingbat: Only continental shelf countries are counted. As such outlying parts are not covered under article 76 unless it is to be counted as an integrated part of the country. To be that it need to meet a large set of requirements, for instance not have separate governance, but most important of all, be permanently inhabited.

            For non continental shelf claims the old 3 NM limit is still in effect unless petitioned for. France have only one petition for enlargement of an Exclusive Economic Zone outstanding and that is for Kerguelen Island. That petition was filed in 2009. Kerguelen has a 12 NM territorial waters zone, and the claim is to extend the EEZ to 200 nautical miles. Amsterdan and St Paul is thusly only claimed by France for the original Hague 1899 and 1907 claims of 3NM.

            Regarding legal claims, a petition would not be granted since Mauritius has claimed St Paul, Amsterdam and Tromelin Islands in 2007. And under the 1899 accord that dispute has to be settled in full before any petition can be made under the treaties of 1907 and 1982.

            Hope this clarifies things regarding the Territorial Waters in the area.

          • After some read here and on Wikipedia I conclude that Boomerang Seamount is probably located outside the territorial waters of Amsterdam Island (if the island actually has territorial waters) but probably inside its exclusive economic zone (if the island has such a zone)……. not quite as easy as I thought!

          • Hello Sissel!

            Both EEZ and Territorial Waters are 3NM for Amsterdam and St Paul.
            Sea Law was a mandatory course for attaining your Unlimited Master’s license.

            @DFM:
            Will probably be that France keep them. There is a sort of Juris Prudence about naval power projection that comes into play. The ability to take and to hold an Island is not a small part of Naval Law. That is why Thatcher got a fire under her ass during the Falklands. Since the Falklands was disputed territory the Islands would after a set amount of time automatically have gone over to Argentina. And since France have ample resources to hold the Islands against Mauritius it is more a question if France will relinquish the hold of the Islands to Mauritius.
            Basically, if a claim is laid down a year before hostility starts, the island goes to the victor of the ruccus after I think 12 months. Or you do it the US way… “Biggest fleet can do what the heck they wan’t”

          • So it looks like the Boomerang Seamount is not French but stateless, being located outside the territorial waters and even outside the EEZ of Amsterdam Island.
            At least as long as it stays underwater. The day it goes Surtseyan everything will be different.

          • After it comes up above the surface there is a precedent from when a volcano came up above the surface in the mediterranean.
            The first country to place a flag ontop of it, and posting a guard wins the land.
            If a private person claims it, or a group of private citizens claim it they will have to mark it clearly and leave a guard and then file for nation status. Nation status is either granted by UN, or if 5 recognized states recognize it as a new country.
            Naval Power Projection proviso is of course a factor here too. You must be able to hold it.

  7. Great pictures, Spica!
    Wouldn’t it be an idea if everyone who visits a volcano together with a camera makes a small (or big) report (=post) about it? A new tradition for volcanoholics?


  8. Here’s a gentle discussion related to the comments on a previous post about lack of adventurous spirit in the younger generation. After watching this video and noticing the genuine fear in the young girl. (Notice her hands tightening into fists when the volcano fires up strongly and makes her jump),take a moment to think about this father’s role.
    Now is this father wrong in putting his child into this sort of danger? Is it right to make or encourage a child do what you love doing even though it is scary?
    My take on this is…… This parent is giving his child a very unique experience with all the loving and physical protection he can give. Whether she ever becomes a geologist is anyone’s guess , but at least she has experienced danger and fear in a “safe” situation.
    This father is more caring than the one who lets his child roam the street s. Who has no idea where they are. Who allows his child unlimited access to the internet. These are the children in real danger and when a scary situation happens, a road accident, a drug dealer, a child abuser, the children have no idea of the danger or how to deal with it.
    Now over to you all. I am sure there are many young people out there reading this blog. It would be lovely to hear from you too. (Don’t be scared! we don’t bite……. Even the Dragons don’t bite anyone less than 18 years old……after that you are on your own!)

    • I agree, Diana. This little girl is learning about danger in a safe way – but I remember someone posted a video a while ago of a group of teenagers at the edge of a small crater when it exploded – clearly they had little or no idea of the danger they were in. I had a very adventurous childhood but there were always responsible adults around who could say “That’s it – time to get out of here” when things got dangerous. So I learned, figuratively, to judge the edge of the waterfall. I was always horrified by the “gap year” children who came through Malawi (this was in the days before mobile phones) and got themselves into some horrible scrapes. Usually a local person helped them out but, even then, they seemed to have no idea of the trouble they were in, or the trouble they had caused to others.

      • But, thinking about it, I was also horrified at the kids who just spent their “holiday of a lifetime” slumped in front of a TV watching videos when there was the whole of Africa outside ready to explore. :-)

    • I agree on your point of view wholeheartedly Diana. You do not grow strong and free children by pampering the spine out of them. And, the kids roaming the streets are just neglected and I would say abused by their parents through lack of interest in what they are doing.

    • I agree with you as well. Although having said that, my Dad was a very keen bird watcher and used to drag us along to the various cliffs in the area. However he didnt realise that when you drive up close to a cliff edge in a car, to the kid in the back it looks like you are about to go over the edge. That left me with a phobia of cliffs and even harbours, to this day I fear having to drive along a harbour in a car, which has caused problems when I’ve had to go and pick up hubby from his ship!
      When I had kids of my own I was probably so overprotective of my son, not letting him near high or dangerous places, that he went totally the opposite way and started Sky Diving at 16 years old and one of his many skill is Rope Access work, he loves to dangle over a void…So all my fears as a young mum just fed his enthusiasm for danger I guess.

      • In this case, I disagree. The father can’t protect his daughter from a stronger eruption at all. He does never know what the volcano which is erupting will do next and he puts her life in danger just to get the attention of people who watch this video – or get into the Guiness book of records or whatever.

        This is no safe distance to an erupting volcano at all. :shock:
        (Have myself been near to erupting volcanoes, so I know what I am talking about.

  9. …and another gentle, quiet Sunday morning question for when nothing much is happening Volcano wise…….
    What do Dolphins, Beluga whales, Mount Etna and an atomic Explosion have in common?
    I bet the Mathmaticians and Physics Boffins have a good explanation to how this works. :D

    Answer is here!

    • For those who wonder what volcano this is the answer is Lokon-Empung. It is a double volcano, and the current set of eruptions (ongoing since 2011) is at a double crater situated in the saddle between the two volcanoes. The double crater is named Tompaluan and has been the center of the eruptions for more then 200 years.
      Empung last erupted 1775+/-25 years.

      This is a minor and ongoing eruption.

  10. Word of advise…

    Don’t whack yourself on the side of the head with a 10 inch long 3/4 inch socket extender. Not fun. When you are laying on your back, peering up into the dark recesses of your truck and a shiney thing slips out of your hand… about all you can do is wince and turn your head. You know its gonna hurt.

    • It is one of those moments when you just have to take it like a man, and say words only a man says under a truck when he is very alone and have dropped something on his head.

    • Poor Lurking! Was it one of those moments when your life kicks into slow motion? You know what is going to happen but you can only lie back and watch. The few times in your life when you really have the power of prophecy!!

      • There is no slow motion with a tool rocketing towards your head under a truck. About the best you can do it to try and whip your head to one side.

        Oh, and a little known semi-factoid. Many injuries from electric shock do not come from the electricity itself. They come from you trying to get away from it. It is amazing at all the stuff you can run into or hit while trying to get away.

        That last one is a life experience that I have picked up over the years. No more than one hand in the gear if you have to measure a live voltage, keep the other behind your back and don’t touch anything else… and look around first so your brain has a mental image of whats around you. Even if you don’t have time to think about it, you have an instinct to flee towards open space.

        • When I was a teenager I got an electric shock from my then boyfriend electric guitar. It was a weird thing, we were sitting on the floor and he was playing, I had my hand resting on the fire surround, which had a metal coating on it. One of the strings that stick out from the knobs that tune the guitar brushed against my earring, and a jolt of electicity went through my ear and down my arm into the fire surround. I cant remember if we ever figured out why that happened, if it was wiring fault in the guitar or in the socket, he was playing the thing and felt nothing. Although it wasnt actually that sore, just a ‘shock’ to the system I dumped him shortly afterwards for trying to kill me!

        • About electric shock, my pop would time an engine by holding a spark plug wire.
          He could wire 110v electrical systems without turning the power off..
          Never could quite do that..

          • As long as you don’t touch the wrong thing… not a prob. It’s when you complete the circuit that you get into trouble… fast.

            I was de-installing some equipment several years ago. The military is rabid when it comes to “tag-outs.” Thats where you go through the system diagrams and place Red Warning tags on all breakers and switches that provide power to a system. Every tag is logged in a central repository, after permission to take the system down is granted. Switches thrown, tags hung.

            I secured the 60hz 120VAC, 400 Hz 120VAC, 400 Hz 440 VAC, 400 Hz Gyro input. Voltage readings were taken on the power panels to make sure they were dead. After the gear was removed the lines were to be terminated and wrapped so that no one would have an accident after the system was removed until the ship finally went cold and dark. (it was being decommissioned) Despite all of that, when cutting through a cable, I felt a searing heat from the flash and the end of my pliers were blown off, into the insulation in the bulkhead. (wall). Fortunately, due to my paranoia, I was using a face shield, 10Kv gloves in leather over gloves. No ill effect other than scaring the shit out of me.

            Extreme Caution is not a personality defect, it’s what keeps you alive.

            I rechecked all the switches and tags and none of them were out of place. (they get checked by an independent person after they are hung before work is allowed to proceed) My guess is that somewhere along the ships 30 year history, someone had interconnected to the power feeds of the system and it had backfed into my circuit.

  11. Sometimes a man walks out into the garden with his guitar…

    The movie theme “Paris Texas” is actually named “Dark Was the Night, Cold Was the Ground” and was originally written by the Reverand Blind Willie Johnson. In ’45 his house burned down, and Johnson contracted malarial fever from the wetlands, he died after his wife had tried to take him to hospital where he was denied admittance due to being black and blind.

    His song was on The Golden Record sent out into space in 1977 on the Voyager craft. It has also been sent out as a Radio-message to the stars. So in a way this is the official sound of Earth.

    Regarding this version, sometimes a man just has to go out into the garden alone with his guitar.

  12. Michio Kaku might be a numbnuts regarding volcanoes (refering to his Yellowstone Foopah), but now and then he actually get it right.
    I liked this one. Kaku doing an anti-doom and gloom piece. Generaly I agree on this one, but he did a better job of saying it than I did. This article should be set in perspective of the Alcubierre-White Warp-engine.

    http://bigthink.com/ideas/26650

    • Isn’t Kaku an Astrophysicist ? liked that article. BTW I feel that there is a distinct possibility that we may indeed travel to the stars within 100-150 years.

      • Yes, he is an astrophysicist, so here he knows what he is talking about, something that was not true when he talked about Yellowstone.
        Now that they have a theoretical model for a warp drive that seems to pan out I think we will see experimental engines within 10 to 20 years. And ships within 100 years. It all depends on the funding really.
        And… One little thing for the physicists to do. We do not know how to navigate in folded space. But, that is a theoretical problem that we should be able to pinpoint given a few years more. The problem needed two of the millenium mathematical problems to be solved. Poincarés conjecture is now solved, but the Riemann hypothesis still remains, and we need that to be able to navigate safely any space that is derived solely from prime-number distribution (bang your head on that one Kaku).

  13. While we have been busy looking at El Hierro, Tjörnes, and Fuego little unassuming Soputan has had a bit of indigestion on the 18th. It lofted up a 9100 meter high ash column, making this the largest subaerial eruption for a while. Fuego did for instance have 900 meter high columns. It is always the small unassuming ones that surprises you.

      • I particularly like the rooster. He seems to make it in to a lot of these early morning “Hey look, that mountain is erupting” videos.

        There is something clarifying in the roosters call. Something that says “Alright, get your ass out of bed and go do something.”

      • This was a huge vulcanian type of eruption
        If the last one has been even stronger than this one, I wonder how it would have looked like. Although this one was not strong enough to reach the stratosphere. Had it been in Iceland or Southern Chile, maybe it would.
        Weird behaviour of the birds and rooster, isn’t it? Although I would have expected a noisier event.
        And who is “buracho 69″? The cameraman? In Portuguese the guy’s name would translate “hole 69″. :)
        Anyway, never underestimate an Indonesian volcano, or a rooster or a cameraman!

    • Soputan I believe is very similar to sakura jima being a frequently active volcano that formed on the boundary of a large caldera as a resurgent somma. Regarding soputan, its part of the 20 x 30 km Tondano caldera in Sulawesi

      • Trust GVP to miss those tidbits. That explains how such a small volcano can have so much Oompf.
        Okay, sounds like another Somma “Supervolcano” rebuilding edifice for another caldera event. Explains the vigorousity of the eruption quite nicely.

        • One interesting aspect regarding Tondano, is that it’s not just Soputan that’s linked to it. Lokon-Empung, which also just experienced a minor eruption is also part of the same Tondano Caldera system, except it’s situated on the northwest corner of the ancient caldera. That being said, they’re both active quite frequently, so I highly doubt the fact that they’re both erupting at the same time means annything.

          This is just guesswork, but if these volcanoes are anything similar to Aira (sakurajima), I would imagine that they probably have shallow magma chambers that are fed by the much larger and deeper Tondano caldera magma chamber.

        • That was another lovely tidbit!
          I guess (after checking eruption records) that both of them are systemically pressurized from a deep chamber exactly as you say. Both volcanoes seem to be far more synched up than just the current eruption.
          Tondano is much larger than I thought, it is really one of those that should be in Lurkings list of very large caldera events.
          You also have the Mahawu volcano that also has shared eruptions with the others.
          My guess is that Tondano is semi stable as a caldera event volcano. When pressure builds up in the central magma chamber lava flows up and out into the sub-chambers under Mahawu, Lokon-Empung and Soputan. Then they in turn erupt relieving pressure. They mind shudders at what will happen when those features grow silent as they become to large for frequent eruptions.
          On the other hand, while waiting for it to go “super” both Lokon-Empung and Soputan are slowly going closer and closer for a Vesuvian eruption, at least Lokon-Empung seems to be developed enough for that. Nothing beats a Somma-caldera for potential of being nasty.

  14. Sbout 1.25 in you can see a small pyroclastic flow. Another one at 2.35, or if it is vigorous activity from a flank vent…
    It almost looks like the width of the ash column is as wide as the top of the little volcano. Stonker of an ash plume during that eruption too.

    • Hello Lucas!
      If you do not count Heklas very short and almost impossible to percieve seismic run up, then no. I have never heard of a totally silent run up to eruption. Normally it is various degrees of noisy.

      • Its just because I was looking at the past eruptions at Wrangell (Alaska) and a report in 2002 in which several people reported steam and ash clouds on August 1 and 2, even the AVO admitted that the report was unusual because a video taken clearly shows ash plume-like clouds (even tinged!) without any seismicity.

        • What you detect also depends on how well instrumented the area is. When Hekla went up, the quakes never got above Mag 2.4.

          According to GVP, the Hekla eruption was a solid VEI-3, and using Hayakawa’s method of sizing the eruption, had a magnitude of 4.73.

          Eyjafjallajökull from a couple of years ago was a 4.25.

          (Hayakawa’s method uses the mass of the erupted material in kg. M = log(mass) – 7. If you assume 2700 kg/m³ for magma and 1000 kg/m³ for tephra)

          Seismic intensity falls off pretty rapidly with distance, so unless they had the gear up on the mountain, it’s quite easy for the noise to go undetected. Hekla’s small quakes prove that. (Hekla is instrumented quite well)


          And a note about GVP data, by GVP.

          It is important to note that tephra and lava volumes are listed without correction for vesicularity (the void space occupied by air bubbles, or vesicles), the extraneous fragments of older rock included accidentally in the deposit, or compaction of ash layers with time. The tephra volumes displayed, therefore, are bulk tephra volumes, and not Dense Rock Equivalents (DRE), or volumes of new magma erupted.

        • I guess as Carl say it depends on the monitoring systems, how sensitive or how far away they are.
          This eruption took everyone by surprise. The tour Guides had assured everyone it was safe!. This is the Masaya shield volcano in Nicaragua. and although dangerous and frightening this is not a full eruption more of a discreet explosive event…. but seems no warning . This is probably due to degassing rather than the movement of magma which would cause earthquakes.
          Non the less it must have been scary.

          • Masaya is not even nearly as well equiped as Hekla, same goes for Wrangell.
            We forget that Hekla is (not counting Etna) the most well monitored and studied volcano on the planet. Just as Lurking said.
            The reason for that is that people live around it, and it is hard to predict, and ontop of it Hekla has the capacity to cause some real life concern for millions of people. If you think Eyja was ashy, take a look at Hekla going at it full Swing. To put it short, Hekla has erupted half of the known European ash. And the weird part is that it is a very young volcano. It kind of gives pause to what it will be able to do as it grows mature and even more grumpy.

    • Grimsvotn in 2011 had only earthquakes an hour earlier. Well, actually it was having earthquakes, floods and ocasional tremor months before, but it was silent in the 2 weeks before the eruption. Everyone knew it was going to erupt in soon, as its a very active volcano but I guess it came as a surprise when it erupted so strongly that Saturday in May 2011, after weeks of silence.

      The Westman Islands eruption in 1973 had only a few earthquakes hours before its eruption and it kind of caught everyone by surprise when it erupted in the middle of a January night (and just at the edge of the city), after nearly 5000 years of sleep.

      Hekla always has a history of being very quiet before it starts its eruptions. Other volcanoes seem more noisy: history records show that Oraefajokull, Laki and Katla had strong earthquakes before their eruptions.

      • Nope, the run up started half a year before that. I remember us having a lot of fun around christmas allready about when it would go “boom”. Loads of pre-cursor quakes, large tremor spikes and so on. We knew that it was going to erupt at least 6 months prior to the fact, only thing we did not know was the exact when. So the 1 hour thing was just the last final rush before “boom”.

  15. Carl, when I read your post above I get the feeling that you actually sailed into the natural harbour of St. Paul yourself. Is that right?

    • No, I have a friend who did though.
      It is on my list of things of “want to do in life”, so I had him write down how to enter that harbour since there is no official chart for entering. It is definitly a place where you don’t want to end up hanging on some shoals, it is far to any kind of rescue.

      And yes, I am planning to one day circumnavigate the world to look at a lot of Islands before they disappear under the water for a long time.

        • My big “thing” in life is that I want to sail to nearby Kerguelen. It has like no other place on earth gotten into my brain. Others dream about warm islands, and I who hate being cold and rained on dream about going to one of the most dreary and rainy places on the planet. :)

          Edit: And of course I am going to go looking for a copy!

  16. Interesting phone call. A guy in Michigan just called me and ordered Teriyaki Steak for take out. (I’m in Florida) Turns out it was a friend of mine who had messed up the entry on his phone.

  17. Been away for a couple of days. Just caught up on blog. Enjoyed the Chain of Dead Poets post, songs and videos. Learned about a new volcano (Soputan). And of course I always love to read the comments from everyone. Have to go do laundry now – ughhh. Sheepy dreams to all.

  18. SOme really deep quakes near Habunga. New surge of magma?

    Sunday
    23.09.2012 22:03:41 63.649 -19.018 21.2 km 1.0 99.0 8.7 km NNE of Hábunga
    Sunday
    23.09.2012 22:02:50 63.652 -19.021 19.6 km 0.5 99.0 8.9 km NNE of Hábunga
    Sunday
    23.09.2012 22:01:12 63.630 -19.066 25.3 km 1.1 99.0 5.8 km NNE of Hábunga

    • To small to count as anything really. This is just normal small micro-quakes at Katla.
      Anything worth noticing there would be a swarm with a couple of hundred quakes ranging around 2M on average.
      To put it in perspective, if you see something looking like what Tjörnes looked like last few days, then you have cause for concern.

          • It is the same picture but if you look at websites tracking its progress it seems to be following a satellite trajectory, so I wonder if it is now on its second trip round the world.

          • Alyson, that is impossible. When a satelite or any other orbiting object hits the atmosphere it will burn up quickly.
            Discovery shuttle hit the earths atmosphere at a perfect angle for giving a long fire trail. It still did not cover more than continental USA.
            There is just no way that a meteor can circumnavigate the globe and still be burning. The friction of the atmoshpere would be to great.

          • Nope!

            If you read the BBC link above you will see other people in my location also describing seeing something that proportion-wise was closest to a train.

            I confess I shouted O- M- G–!!! It’s a flying f——–g saucer! Look!!! at my nearest and dearest, as I then jumped up to turn the light off…………………..

            My sensible eldest daughter calmly said ‘It’s a meteor, Mum,’ and sighed…

            Well okay we were actually watching ‘Avengers’ and the sky had just opened to let the alien invasion through in the movie….. Hubby kindly paused the film for me to run outside and watch and listen for a while longer. It was silent, but huge.

          • According to the astronomers it was between the size of a fist and a small fridge. The one that crossed Britain went into the Atlantic. Once anything hits the atmosphere it only lasts a few minutes – either comes in to land (the space shuttle), lands in a severely melted form (meteorite) or breaks up totally – which is what seemed to happen in the UK event. It was probably space junk.

          • You are right Talla, if it comes in a flat trajectory like that it is normally space junk. It could though have been a small hard meteorite. Have happened that those have gone in a flat trajectory too.

      • Alyson, you are an eye witness of this event. I very much appreciated your live report on September 21 on “Name that Volcano Riddle”.

        • Thanks Sissel
          I know it doesn’t make sense, but the reports from over North America included a gas station attendant in Florida who could see 4 lights in a row, and that is above the lights of the gas station. I would guess it was about 5 miles or less away from me, above an area maybe less than 5 miles distant, judging from the angle it went out to sea, as I watched the glow remain visible. It was moving too slow, and it was too big, and I have no rational explanation for what I saw, but I think it is possible it may still be on its way.
          There were lots of UK reports on that meteor watch site, about a third of the way down if you scroll down the comments.
          It was a different site that had what may be the first report, of a very bright light exploding into the atmosphere above Finland. The BBC report, above, describes what I saw.
          I don’t know what it could be, though, and if Randolph only saw a 3 second blip that is still quite long if that was it entering the atmosphere….
          Anyway if it is still going we will hear more, and if it isn’t we won’t.

          • Simpler solution to the problem. It is an old satellite that came in a to flat trajectory, bounced when hitting the atmospheric boundary and then broke up. Different fragments then reentered on a slightly less shallow angle at different parts of the trajectory. That quite well explains the multidude of sightings.

  19. Now there’s a feather in your bonnet…

    The team then turned their attention to actual bird bones found around or near Neanderthal archeological finds and discovered that many of them were wing bones that had been manipulated with sharp stones, causing cutting marks, a clear indication that they had been used for some purpose other than as food as wings don’t have any meat on them. They noted also that the Neanderthals appeared to have a preference for birds with dark feathers. Also, they found that marked bones were found at many of the sites indicating that whatever was going on wasn’t local. These findings indicate that Neanderthals were clearly using the long wing feathers for something, and the logical conclusion is that it was for adornment, as that was what humans tended to do with them.

    Read more at: http://phys.org/news/2012-09-evidence-neanderthals-feathers-adorn.html#jCp

    • And another OT.

      When Danish Vikings sailed across the North Sea and conquered England, they left their mark on the English language and place names. That’s common knowledge, at least to historians.

      What’s perhaps less known is that the influence cut both ways. Although England was under Danish rule in the Viking Age, the English were culturally and politically more sophisticated than their neighbours to the east.

      Historian Marie Bønløkke Spejlborg … writing her PhD thesis about how the English some 1,000 years ago left a significant imprint on Danish society. It is, for instance, likely that it was the English who inspired Danes to organise themselves into cities, according to her historical sources.

      http://sciencenordic.com/english-inspired-vikings-build-cities

    • I think science has given Neanderthal a short shift. I don’t think he was as stupid and
      primitive as science has said he was.. Also there is evidence that neanderthal DNA is
      in modern humans of Central Asian and Northern European. Guess what groups are in my DNA..Grunts, puts down club, crawls into cave…
      Goodnight all-oh!We had rain! not much but enough to help the folks out on the fireline
      in E.Oregon,,

      • I find it very interesting to see how fast the worlds scientists are back-pedaling from the picture of the neanderthal as a brainless muscular moroon now that it is a proven fact that all europeans are neanderthals (at least a large percentage of the DNA is the same).
        I guess the predominantly white researchers of european decent found it rather uncomfortable to be associated with the picture of being hairy savages going around clubbing women to drag them home to the cave.

  20. Dang it Lurk,I had to read that one too. My Mom’s family were highlanders from Sutherland, Scotland. Name was Anderson. They were descended from the Vikings that found the Women good looking,but they put up too much of a fight to take back to the longboat-so they stayed..
    A good war and sea story with a a bit of history of the relationship of Norwegians in the Shetland islands, is the Book by David Howarth-“the Shetland Bus.” about the effort to help the Norwegian resistance in WW2..

    • Being someone who likes a bit of home comfort the Viking ruins on the Shetlands amazed me by their house ‘clusters’, with a shared fire at the centre, to keep several properties warm with one fire. Even today Scandinavian houses are built to much higher specifications than British ones re preparation for winter weatherability.

      • I redid my Belgravia house to modern Scandinavian building specs and installed central heating scandinavian style. My two tennants evacuated the building within 3 months since it was “to warm and un-brittish”…
        Found a couple of other tennants of definite un-brittish nature who liked not freezing their appendages of in the damp cold.

        So, I think the drafty cold english houses are just some perverse cultural thing out of likeing to suffer.

        • Oh lucky you!
          Whereabouts is it, an old girlfriend used to rent a mews house along Cadogan Lane – very convenient as we could walk to work in the Geological Museum in Exhibition Road in South Ken!!!
          Off ‘chipping’ tomorrow – too wet today !!

          • I will not give out my home adress in a comment on the Internet ;)
            It is though close to two rather famous pubs.
            One of my neighbours is the Umpteenth Earl of Stoke-on-a-Pole (complete with pink and purple robes with stars on them and a hat stolen from Harry Potter, grey bearded fellow) and the other neighbour is the unpronouncable embassy. Seeing a grown man dressed like a fairytale magician come up to you to inform you that your behaviour is not proper british is though a bit fun. That came after I tipped over a bowl of bean stew in my lape and ran out into the balcony roaring with pain. The general idea was that the rain would cool me off. I of course came out at the same moment my neighbour decided to take a walk with his basset. I guess a bean drenched roaring swede is fairly unbritish.
            I am so getting rid of the house…

  21. According to the “Encyclopedia or Earthquakes and Volcanoes, third Edition” Tondano have been active around the last turn of the century with a 300 meter long rift emitting gases, and also had mud explosions during eruption of Mahagawu, Soputan and Lokon-Empung. And that is not good since it tells us that the 3 active sub-volcanoes are not big enough as pressure relief valves for the bigger Tondano system.
    There is in the end a quite large change that one of two things will happen. The first and least likely is that Tondano goes caldera again. That would though most likely take that at least two of the volcanoes go silent, and that does not seem likely. The other and more likely is that the went at one of the 3 sub volcanoes explosively increases in diameter to be able to handle the pressure. Ie, a blow out. That is basically what happened at Vesuvius in ’79, the vent-system had grown to narrow to release the pressure from Monte Sommas large chamber and it blew out enough gunk to be able relieve the pressure. My guess is that either Soputan or Lokon-Empung will go in a bigger fashion in the not to distant geological future.

  22. Archaeology is another of my passions. For many years I, along with a group of others, excavated mesolithic sites on the high Moors of the Pennines. There, 10 – 8 thousand years ago our ancestors lived by hunting the deer, wild cattle and smaller animals that roamed Northern Britain after the last ice age. I particularly became interested in the climate and biology of those times before the introduction of farming .
    This was well after Neanderthal people survived in the same ways. However I think, although not physically alike, far from being insensitive and uncultured. there is so much evidence that they had complex ideas, were very skilled and had well organised social structures.
    To make delicate tools and miniscule barbs for arrows out of stone is a skill more or less lost today.
    To hunt, to know how animals behave, again skills that most of us have not got.
    The one find in archaeology that sums up how much like ourselves these peoples were was the remains of a new born infant close by it’s mother who must have died in childbirth. The infant was laid on the wing of a large swan.
    How touching. How sensitive. How sadly beautiful.

    • Hi Diana, Yes, archaeology can be suddenly very moving. The Romans buried neonates (very young babies) under their houses. This is seen by most as evidence of their heartlessness, as though they were treating their babies like household rubbish. But I like to think it is because by law burials had to be made a long way from urban settlements (a good idea if you look at the mess that burials caused in the late medieval/early modern period) and the families wanted to keep their little ones close by rather than out on the dark hillsides. I was cleaning the bones of one such neonate one day, who had been buried under a doorway, when I came across a tiny bronze bracelet. So sad to think of the story behind this gesture.

      • Hi Talla

        The presence of the bracelet could point in the other direction. Maybe the infants were buried under the house to be with the Lares of the house.

  23. OT: the UK’s “year with no summer” has quickly turned into full-scale Autumn. It was the equinox on Saturday and our first storm started yesterday with non-stop rain and strong wind. It’s been raining in Wiltshire for over 24 hours now. If it hasn’t reached Diana yet then it soon will. :-(
    On topic: the MJO SIL has been agitated since yesterday morning – is Iceland also having bad weather?

  24. Hello Carl and Spica (hope you enjoyed your Holiday, nice photos) and all.

    Quite happy at the moment, because one of the 2 book’s I have ordered finally came.

    Volcanoes of the Antarctic Plate and Southern Oceans. Interestingly it covers the St.Paul – Amsterdam volcanoes.

  25. A bit OT, but I came across this reference and wondered whether it might include early historical references to volcanic earthquakes:

    Guidoboni 1989 E. Guidoboni, ed., I terremoti prima del Mille in Italia e nell’area mediterranea. Storia, archeologia, sismologia, Bologna 1989 (Engl. ed. Catalogue of ancient earthquakes in the Mediterranean area up to the tenth century, Rome 1994).

    • Talk about short memory, they did 9 cm in 7 days last time around. And that was on quite a few stations.
      This time around the average uplift was 2 to 3 centimeters with La Restinga as an outlayer with 4.5 cm.

      Yes, it was an inflation period, but not the largest, not even second largest. And the speed it happened with seems to be normal for the system.

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

      I think it will take at least a minimum of one more inflation period before an eruption will occur. It the next one keeps to form and goes in a new direction that one will most likely not cause an eruption either.

  26. Another deep quake near Habunga.

    Monday
    24.09.2012 12:25:30 63.637 -19.068 26.4 km 1.4 99.0 6.5 km NNE of Hábunga

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