Redoubt

View of Redoubt steaming on December 31, 2009, as seen from Homer Alaska. (Dennis Anderson, Night Trax Photography)

Thank you Redoubt Volcano – my story

Redoubt Volcano is a stratovolcano located in the Aleutian volcano arc of Alaska where the Pacific Plate dives beneath the North American Plate. It is 3108 m (10,197 ‘) and rated as a VEI-3 volcano. Its 1.8 km ice-filled crater is breached on the north side by the Drift Glacier. During periods of eruption, lahars flow down to the Cook Inlet. This is particularly dangerous to the Drift River Oil Terminal positioned there.

Redoubt location map. (Janet Schaefer, AVO/ADGGS)

Redoubt will always hold a special place in my heart because it was the first volcano that I followed from its first rumblings in November 2008 through its eruptions in 2009. Between March 22 and April 4 there were 19 explosive events that sent plumes as high as 60,000 ‘
(18,288 ) m . It then started building its lava dome. By September, the dome had reached a volume of approximately 70 million cubic meters. There was fear of collapse during this building process, but, thankfully, that didn’t happen.

Before and after views in the upper Drift River Valley where a large ice block had been deposited by the April 4, 2009 flood. Volcanologist Sarah Henton is looking down into the 1.5 meter deep pit left behind after the ice block melted. (Game McGimsey, AVO/USGS)

I was not into volcanoes before that time and it was quite by accident that I heard about Redoubt through another website. Out of curiosity, I went to the Alaska Volcano Observatory website to see what I could discover. www.avo.alaska.edu/activity/Redoubt.php

It was my great fortune that I could follow my first volcano on this magnificent website. Anything I could possibly want to know was right there at my fingertips: webcams, webicorders, daily and sometimes hourly updates, beautiful photos from current flyovers, Redoubt history and maps. I was so impressed that I sent the Observatory an e-mail thanking them for sharing all this wonderful information with “flat landers” like me. (Those of us who live in the Midwest have no mountains, just flat land) To my amazement, I shortly received an e-mail back thanking ME!

View of lava dome at Redoubt from the north on August 20, 2009. (Kate Bull, AVO/USGS)

Well, I was hooked. Volcanoes are awesome. I had no idea when I started this journey just how many volcanoes there are around the world. I had heard about Krakatoa through documentaries and Mt. St. Helens certainly made the news in the U.S., but that was a busy time in my life and I gave it no further thought. My interest was in earthquakes and I hadn’t yet made the correlation between earthquakes and volcanoes.

Photograph of lightning from Redoubt’s 1:20 am March 28, 2009 eruption. (Bretwood Higma

And then came El Hierro and the volcano we call Bob. For the first time I learned about undersea volcanoes and Surtsey eruptions. Watching daily on the webcam was so exciting and I just couldn’t wait to see what would happen next. And that’s when I discovered Volcanocafe and my life forever changed. I never thought I would be following a blog, let alone posting comments. And I certainly never thought that a blog would teach me so much and leave me yearning for more, entertain me and introduce me to so many new friends around the world. And now here I am nervously submitting a post. Yikes!

Bobbi

Information about Redoubt was obtained from the AVO website listed above.

Redoubt had a bad habit of erupting at night in 2009 and I couldn’t find a picture that I really thought was a WOW like this one.

Ascending eruption cloud from Redoubt Volcano as viewed to the west from the Kenai Peninsula April 21, 1990 (R. Clucas)

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113 thoughts on “Redoubt

  1. Redoubt was my first “in the numbers” volcano. That was where I cut my teeth on trying to weasel info out of the data.

    Along those same lines,

    Jack @ Finland says:
    October 15, 2012 at 18:52 (Edit)

    GeoLurking,

    What would Mr. Mogi say about this? I.e. how deep is the Uturuncu magma chamber located & how big is it?

    The problem… is that I’m trying to find two separate pieces of data… depth and size. A quake cluster could help localize the depth, but I haven’t been paying attention, and was just happy to find my old spreadsheet.

    This is a first pass at ruminating upon it.

    From the graphic, the central region is rising at about 7 mm/yr. The furrow of the sombrero is declining at about 3 mm/yr… a difference of 10 mm/yr from trough to peak. Blurring the image (in order to smooth out the terrain stuff and get just the colors) that I had extracted from a known lat-lon box, and then taking the hue channel and adjusting so that it met the 10 mm range, I get this:

    It’s a horizontal cut through the uplift area and is… about as accurate as I can make it without the actual data.

    Making an assumption that the “chamber” is 5 km deep (SWAG), and walking through different chamber sizes to get the observed uplift at 0, 10, 20 and 30 km distance, then averaging that out I get a rough first guess at about 3.06 x 10^7 m³/yr of material coming into the system.

    The reason I question that (heavily) is that using different chamber depths I get numbers that didn’t seem to track correctly (compared to what I expected). It’s possible I’m just tired, or that I hosed it up.

    Now… a non usual caveat. I haven’t messed with this work sheet in several months. Not only am I not a professional in this field, I may have actually horked up at my guess. I really need to re-visit this and go back over the reference info… so for now, it’s a first stab.

    Whenever you see an “assumption” being made, always question what is being claimed based on it. When you assume, it is possible that you are making an ass out of u and me.

    SWAG – “Some Wild Arsed Guess”

    The reason I tossed the plot here is that there are a couple of other blog participants who have gnawed or at least nibbled on the Mogi equations. They might find the plot useful if they want to try munching on the issue.

    • Bobbi your story is so similar to mine. I think probably like so many others It was Eyjafjallajökull in Iceland that really hooked me , at least watching and looking at data.
      What a beautiful Volcano Redoubt is . So majestic. That lump of ice was pretty impressive too! Beautiful pictures.
      Bobbi I am sure you wil get similar comments to this, as you have written from experience and not as a professional.
      It was a brilliant idea to write a post that I am sure so many readers will enjoy and think back to how their addiction started.
      Thank you and very well written. Be proud!

      • Oh.. PS your first link to AVO doesn’t work for me, I come right back to VC for some reason!
        PPS …..and you sent Lurking right on down memory lane too, Bobbi! 😀

        • Hello, Bobbi, many thanks for her(their) article(item) which I have read very much with interest,
          the eruption cloud is very impressive,
          also I have come rather by chance to the volcanoes – and have become addicted,
          Popocatepetl was my first volcano
          but only by VC I learn to understand the volcanoes better,
          miraculous idea of them to write the article(item)
          Congratulations!

          • We had just come back from a trip to Tenerife/ La Gomera; it was about this time last year. I had no idea that anything was occuring in El Hierro until (back at home) we started researching our next trip… you know the rest 🙂
            Nice article Bobbi thanks x

          • You’re most welcome Lucas,
            it’s a very useful reference, thanks for your hard work, I notice Volcanodiscovery have referenced you… 🙂

          • Thanks. Tom Pfeiffer asked me if I wanted to become one of Volcano Discovery’s partners. So I advertise him (on my site: volcanismbulletin.org) and he advertises me on his. I can also edit his news section on his site 🙂

    • Mine was St. Helens and it was simply due to being close to it once closer than i wanted
      in April before the May 18th eruption flying some PacNW Labs and USGS folks around the newly erupting crater… Then over the next 10 years watching the evolution of the blast area and the crater. From the window of various Cessnas that I flew…

    • Good Idea ukviggen. It would have to be something young, not oldies like Etna 😀

      So mine would be Michael volcano (described as young) in the South Sandwich Islands, Cerro Negro (only 200 years old!) in Nicaragua or Kliuchevskoi in Kamchatka (only 6000 years old).

  2. A very OT comment…….
    I went over to my allotment yesterday. On the window of my shed I saw a cabbage white Caterpillar that should have been becoming a chrysalis. It looked odd and I noticed beneath and to the side of it, there were small white cocoons.
    I thought nothing more until I had put on my boots and went out to collect some veggies and do a bit of weeding…….
    Horror! Some of my caulifower plants resembled scenery for some Halloween movie!. Bare stalks reached to the sky, and on the remains were numbers of very, very fat cabbage white butterfly caterpillars! Being a Biologist, I suddenly got interested and looked more carefully at one of these tubby, Nay! Obese! larvae. Something wasn’t right.
    Then I put two and two together. I had heard about parasitic wasps but never actually encountered their activities.
    Here in action was nature’s way of controlling destructive populations.
    I must explain. I very rarely use chemical pest controls. I tend to share my produce with other creatures and leave pest control to teeth, beaks and other natural ways of predation. (I predate slugs with a kitchen knife I am not sure if that is technically “natural”!)
    In my garden behind the house I grow some vegetables and have never encountered as many cabbage White caterpillars as on my allotment. At home I have few avid gardeners as neighbours and the back gardens tend to be as nature intended. At my allotment (A small plot of land rented for the sole use as a vegetable plot) I am surrounded by very active gardeners. Their one aim in life seems to be to grow bigger and better than those on other plots. I suspect most use chemical pesticides to kill caterpillars amongst other pests.
    Now if you poison the caterpillars you will also poison the larvae of the parasitic wasp. So in following years there will be fewer wasps that will naturally kill your caterpillars and so you will get more butterflies and so more caterpillars and so your cabbage crops will become very holey!
    Of course being curious, I Googled the wasp to find out more. I came across this amazing video clip that showed me what my Varifocal spectacles could not show me in “the field”.
    WARNING>>>>>> If you are of a squeamish disposition do not watch this… it is truely horrifying yet absolutely amazing! The photography is magnificent.

    • cabbage White caterpillars don’t like the smell of mint (mentha) at all. So an efficient and natural way to avoid caterpillars is to plant mint between or next to your cabbages and/or cauliflowers. As extra advantage you can use the mint for tea’s, cocktails or to spice your food.

      • actually, herbs with a strong, particular smell (mint, basil, parsley, thyme …) are in general good to chase insects and spiders away. So the best way to avoid greedy insects is to plant herbs in garden and you don’t need pesticide at all. Mint is specially good against cabbage white caterpillars and mouses. Basil helps to avoid flies and mildew. And nettles are useful against aphids.

        • yes, only sprouts are real (belgian) winter-vegetables, they grow from October till march and the classical sprouts (not hybrids,..) need frost (between 0 and -5°C, lower temps damage the plant) to get a sweet flavour. Caterpillars and most insects don’t like winter/frost, so that helps a lot.
          But you have to look out for the birds, last time they ate our sprouts.

          • I have a bad case of aleurodes (white fly) on tomatoes, but they like also some mint nearby. Apparently, the only one not to suffer too much is basilicum. Black soap works a little, and as it is the end of season, I’ll wait for frost to do ths job….

    • Very impressive video, Diana. The most fascinating fact I think is the wasp larvae being able to completely change the caterpillars behaviour in order to protect themselves after they left its body. Reminds me of the gall wasps, which are able to stimulate plants to grow galls which form a protected home (with food) for the larvae from egg to adult:

      “Male gall wasps are rare, and reproduction usually occurs by parthenogenesis (i.e., larvae develop from unfertilized eggs). The egg passes through the long ovipositor of the female and into the plant tissue. After the egg hatches into a larva, it begins to secrete materials that cause the plant tissues around it to begin to grow faster than normal. The gall increases in size as the larva grows. The larva feeds on the plant tissue within the gall and pupates and transforms into an adult within the gall.”
      from: http://www.britannica.com/EBchecked/topic/224197/gall-wasp

    • Wife and I are strictly organic ourselves,believe in it won first place at fairs and rose shows with our entirely organic Austins, Kordes, and Gallicas…

        • It does, here in NE Oregon our season May through the middle of July for the once blooming roses Gallicas,etc. surprisingly Most Austins do well here we have a massive
          Gertrude Jeykll, Graham Thomas and William Shakespeare, oh and a white sport of
          Mary Rose, Winchester Cathedral. Had those on the Oregon coast and they did not do
          near as well William Shakespeare almost died a horrible death by blackspot.. this was on the south coast which has a climate very much like Cornwall…Here we spray only insecticidal soap if we get a certain type of pest that bores holes in the petals.
          It only comes out in the mid spring, and if you walk around with can of soap and just shake the plant . Also we have earwigs, white fly and aphids . But a good hosing seems to help. don’t like messing with the bees and humming bird moths…
          In the winter we mulch like mad and keep the roots insulated as we can get cold
          -25C not real unusual..

  3. Great post, Bobbi! Written in a way it is impossible to stop reading before the last dot. A lot of good information and your own “volcano experience” which is so recognizable.
    Thank you very much for sharing!

  4. Some video of a small lahar at Soufriere Volcano on Montserrat due to tropical storm Rafael
    A good example of what Not to do in that case if I may say

  5. Just checked in real quick before going to work and found my post is up. So glad you all seem to like it. When the dragons were asking for help in submitting posts, I just didn’t have time to put together a technical post. so I thought an easy read might work. Thank you one and all for your support. Will read your comments later today when I get home from work. 😀

    • Thank you Bobbi for a great post! I thoroughly enjoyed it – I would have said so earlier but WP wouldn’t let me post earlier today. I’m going to add Redoubt to my list of beautiful volcanoes. 🙂

    • Brilliant Bobbi, well done for a really nice post and thanks for the great photos! My interest in anything volcanic was zilch, until Bob on El Hierro…I firstly found two places to find more info, one was Jon Friman´s and the other was ER – I think it was ER that led me to here …I was blown away by the huge font of information provided here by everyone and was glad when other commenters asked questions that I was too embarrassed to ask myself. I was fascinated by the web cams, the helicopter flyover photo´s & video footage, the links that were posted to help us find out more and I just loved the way everyone was welcome to post a comment & become a part of the VC community. I am not the sort of person that would normally even read blogs, let alone make a comment on one….but the “gang” on VC from the start have been so welcoming, friendly, funny, entertaining and most of all so generous in sharing their knowledge and helping people like me to understand a little bit more..

    • So love the majesty of Redoubt–impressive is an understatement! What I would give to visit Homer and bring home a pic like that and know I had seen it with my own eyes! Have always thought it was magnificent—my fav. That last pic is an all time keeper-look how small Redoubt appears! Symmetry rocks! Thanks so much for sharing your story, Bobbi!

    • Thank you, Karen. I don’t know why the link hasn’t worked. I have it saved on my favorites and that is exactly the way it comes up on the bar. It’s getting close to Halloween – maybe the goblins are at work 😀

  6. Bobbi says:
    October 16, 2012 at 12:22
    “When the dragons were asking for help in submitting posts, I just didn’t have time to put together a technical post. so I thought an easy read might work.”
    Bobbi – this is ideal!
    Interest and passion for an item is the most important! 🙂

    @ All
    Bobbi has set the scene here – anyone else’s ‘pet’ edifice will be most welcome.
    Please send ’em to Spica at her email on the side pannel
    Also, don’t forget to credit illustrative material.

  7. A big thank you to everyone for your kind and interesting comments. I was a little afraid that this might come across as a bit “corny” but I was reassured when Carl mentioned a while back how much he enjoys some personal input. It helps us get to know each other a little better, whether posting or commenting. I know how much I enjoy reading personal comments from each of you. 🙂

    • It wasn’t corny at all. I found it interesting. 😀

      I was going to add a more personal touch to mine, then completely forgot about it. 🙄 So you’ll have to guess.

    • Something written from the heart and with genuine enthusiasm is never corney. Why?
      Because the words want to flow out, the writer doesn’t tend to over think how to write a description or especially something associated with an emotion.
      Readers therefore conciously or unconciously pick up on this.
      I Remember being made to write, “Thank you” letters after Christmas. (I hated doing it but it taught me good manners) Most went…” Dear Aunty …… Thank you for the grey, wool socks you knitted for me.. They are lovely and warm. I had a good Christmas. I hope you did too. ”
      Like most children I was selfish and didn’t realise the effort and time put into those woolly socks, lovingly knitted with wool from a ” pulled back” old woolly jumper that was beyond darning, but some of the expensive and rationed yarn could be salvaged and made into a pair of child’s socks.
      A letter written to Aunty today would be far more interesting for her to read ! Hindsight is a wonderful thing!

  8. A very enjoyable post Bobbi, thank you. And Redoubt is a beautiful volcano. Here’s something for you in return (not volcanic, but totally AWESOME): 😀

      • Thank you all for the Nice blogs i was not so very often here because the father of my husband was critical ill last saturday morning hè is now in à better world and donderdag we have the funeral it is good so no more pain! But it is Sad we can not missed him but after his Brain damage hè was sitting in à wheelchair and had à lot of pain sofar. its good so friendly greetings two weeks before we have got a little granddaughter she weight seven pound and all is good with her and her mother friendly greetings to all her i enjoy all of the blogs Deanne

        • I’m so sorry to hear about your husband’s father. But, I am very happy to hear of your new granddaughter. A new baby in the family is always a blessing, but especially so during sad times.

        • I’m sorry, Deanne. I’ve been through this myself during this year.
          Life proceeds its course. It’s painful sometimes, yet inexorable. One must conform and adapt,
          But a new life is born, to reinitialize the cycle so that you and your family may regain the lost hopes.
          Wish luck to the new born!

        • Thank you for the update. I am very sad to hear about your father-in-law. But congratulations on your granddaughter. You must have very mixed feelings at the moment. A big hug from me.

        • Deanne you have had a very rough time this year. Sometimes a death is a blessing in disguise. He suffers no more.
          How is the baby? How are the Father and Mother? It is usuallyabout two weeks after the birth the realisation sets in that this little person will change parent’s lives forever after! 😀

    • Oh! Ursula! That is one to try with the grandchildren on a wet afternoon! I love doing stuff like this with them. The egg into a bottle is a good one too and Popping corn is even better…you can eat it!. “Magic”!

  9. [at] Jack@Finland

    Uturuncu is something of a scary critter. Taking the InSAR imagery released at about the same time as recent press release, doing all the gizmo stuff mentioned earlier in order to derive the uplift, I get a new set of numbers after considering the depth localization put out in this paper:

    Recent crustal deformation in west-central South America” Thesis by
    Matthew E. Pritchard towards his PhD.

    He states that the center of uplift is in the 22 to 24 km depth range. Tossing that in the model and running various sized chambers, I get a volume increase (average) of between 2.04 x 10^7 m³/yr to 2.15 x 10^07 m³/yr. (0.0204 km³ to 0.0215 km³)

    These averages are of the volumes needed to yield the observed uplift at 0, 10, 20, 30 km distances from the center of the uplift. (which is an interpretation of the InSAR graphic)

    The paper was submitted 5/12/2003, and seems to indicate that this has been going on at least that long. His InSAR data uses imagery from 1992 through 2000 for his estimated uplift rates of 1 to 2 cm/yr. If those hold closer to being the truth, then my values are out to lunch. (much too small)

    For sake of argument. (another way of hinting at an assumption), if my calculated rates are typical back to 1992, then the volume entering the system over the last 20 years is 0.408 to 0.430 km.³

    If the inflation rates that he has derived are more accurate, then I’m probably off by a factor of about 2.5 or so. That would make it in excess of 1.02 to 1.07 km³ of volume increase over the last 20 years.

    I do recommend poking around in that paper. He covers uplift in other sites such as Cerro Blanco, Lazufre, and Hualca Hualca.

    Note: If you think this looks different than when I first plotted it, you’re correct. I had hosed up the units. The image was in dd°mm’ and Google Earth was set for dd.ddd°. This has been corrected, and the previous instances of the plot on the forum have been changed.

    • The good news there is that 20 km is normally considered too deep for a caldera forming eruption… unless the chamber is 20 km wide. Is it?

      • Don’t think so… but I haven’t seen any information one way or another.

        Figure 2.5 places the depth at anywhere from 13 km to 35 km depth, with 22 to 24 km being in the center of the projection, and with the lowest error. (mis fit)

        In Figure 2.7, for the horizontal prolate at 18 km inferred depth, the ellipsoid is about 2 km wide, but that may just be a propositional positional estimate and not size. The finite crack model that fits is at about 12 km depth.

        Its like swinging at flies with a baseball bat. Your gonna hit one of them… eventually, but you don’t know which one.

      • Not that it would be “good” if this erupts, but at the very minimum, a supereruption in the altiplano would probably be the least disastrous area for any large caldera to post a large VEI 7 or VEI 8 event.

        Compared to other massive calderas, the altiplano has very little civilization nearby, and even in the case of a supereruption, I would think most of the ashfall and tuff deposits would affect uninhabited areas.

        • That is quite interesting stuff. So if it inflated 0.5 km3 per year (average), that means we reach a volume of 500 km3 (which I think its a confortable VEI7) in about 1000 years. But I think such a 25km wide caldera, would probably erupt more than that. Let’s then say about 10.000 years, for a kind of 5000 km3 of new magma. Let’s assume only 20% of it erupts, and let’s assume we were having inflation for the past 5000 years. Then we would have a 1000km3 eruption (small VEI8) in 5000 years: almost tomorrow, by geological terms.

          But volcanoes do not work like this, they are irregular.

          The most interesting thing would be to know for how long inflation has been happening there.

          But we do not know how long has this inflation been going and how constant. If it was constant the inflation would only

    • According to new info (see http://volcanoscience.blogspot.fi/2012/03/new-info-on-bolivian-volcano-uturuncu.html ) the uplift began around year 1992.

      Another reasonable ball-park estimate: Taking 1,5 cm per year inflation it should be around 30 cm in total by now. Estimating the inflated volume with a circular cone of height 30 cm and radius of 50 km (from GeoLurking’s figure above), the volume amounts to 0,8 km3, which is within the same decade with GeoLurking’s figures. Hence, I’d trust we figured out the the scale somewhat correctly.

      So, nothing remarkable yet. Taking the quite long repose period and the nature of the volcano (a strato-/supervolcano?) I’d expect Uturuncu to sleep still at least a few tens or hundreds of years. The next eruption will most likely be an explosive one (VEI4 to VEI5), but not anything like VEI7 or 8. If it still sleeps over thousands of years, we can start talking about VEI6 to 8 being practically possible.

      Caveat: I’m a mad physicist, not a “stone-scientist”…

  10. Great post Bobbi, you can’t go wrong with this. I think all of us here share similar memories of “our first volcano”, of catching the bug. It’s what keeps us all so passionate about it. As for Redoubt, I remember the reports of the first fumaroles appearing high on the mountain and initial suspicions that maybe the volcano was reactivating and then the endless will she, won’t she. And then finally she did.

  11. Carl and everyone:
    This is a picture of the INGV control room (and attached text), posted by Dr. Boris Behnke over his Flickr account.
    After December the Institute might have 2/3 of their personal reduced by fund cutting.
    Sad news!

    • Nice link.

      I’ve noted that the Laschamp event was coincidental with some serious activity in Italy, but like that link, I don’t have anything other than time coincidence to go on.

      One idea that I have is that fast movement of magma as the system changes/adjust/leads upto the large eruptions. It’s not the only known geomagnetic excursion, but it is the best known.

      There are several points of view about them, but here is one that I sort of like:

      (Wikipedia)

      In computer simulations, it is observed that magnetic field lines can sometimes become tangled and disorganized through the chaotic motions of liquid metal in the Earth’s core. In such cases, this spontaneous disorganization can cause decreases in the magnetic field as perceived at the Earth’s surface. In truth, under this scenario, the Earth’s magnetic field intensity does not significantly change in the core itself, but rather energy is transferred from a dipole configuration to higher order multipole moments which decay more rapidly with the distance from the Earth’s core, so that the expression of such a magnetic field at the surface of the Earth would be considerably less, even without significant changes in the strength of the deep field.

  12. Its really COLD here in Iceland. I was playing outside football as it is strong north wind and -3ºC. I arrived home really frozen! Today the temperature was basically under zero the entire day. Lots of frost. The Icelandic winter has began here. No more garden work for me…

      • This crater is one of the top beautiful spots of Iceland. It is about 1km wide, which should have been a quite large tephra explosion. It was an eruption of Krafla but outside of the main caldera, about 2500 years ago. I think it was estimated as a VEI4 intensity eruption, probably a large blast (there is a lot of water from the Myvatn lake just by it).

  13. Good morning, evening or G’day folks.
    You will be relieved to hear there is no rumination this morning. 😀 It’s colder here and I need to get moving to keep warm. Trying to save on the heating bills and also keeping weight down! I am into my layers, starting with (<<<<<<<< Looks both ways to make sure GeoLoco is not in sight and whispers…..) thermal underwear!
    Bardabunga appears restless too
    http://hraun.vedur.is/ja/oroi/dyn.gif.
    Katla also is stirring. http://hraun.vedur.is/ja/oroi/aus.gif
    From SILs Askja South westwards to Hekla, http://hraun.vedur.is/ja/oroi/hau.gif the tremor status. is interestingly active. Whether this is increase in the rifting activity or magma is sloshing about and seeping into assorted faults and cracks somewhere down that "valley" I don't know, but it's odd they all show more tremoring than last year, of that I am sure.

    • The winds are strong but not horrendously gale force and are not coming from the south at the moment more NorthEeasterly. Of course the winds on the mountains are considerably stronger than on the lower land but at the moment I am not convinced all this tremor is wind induced. Likewise even though there has been rain I don’t think rivers are causing the increase in tremoring.

  14. A while back I asked how the valves on the strain meters were opened but I can’t find where or if there was an answer! Sorry! I am having a “Losing marbles morning” . I am presuming it is by remote control. Also why do they open the valves? Is it to set a “norm” so that the strain can be accurately measured Or are there other reasons?
    http://hraun.vedur.is/ja/strain/1sec/index.html

    • I assume that there is an automatic pressure valve, which opens at certain value, if I have understood correctly, strain= pressure in measurement pipe created by ground movement, and too much pressure= something goes pop…

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