Activity update around the world

Etna has had its ‘paroxysm’ #many. Every eruption is spectacular, but when they are so frequent it gets easier to focus on what is different with every eruption. Bruce Stout and Newby noted that the activity lasted much longer than previously in this series of paroxysms. Why this is, is off course a mystery, but maybe as time progresses we will find out if this is again some kind of new behaviour for Etna. For now, I don’t think many people mind that Etna keeps doing these things, since the eruptions are not much of a nuisance to the people living around it (at least, not more than usual with Etna’s eruptions), but are nice to watch for everyone.

Mr. Behncke of the INGV in Catania has written a nice summary / eyewitness report of the activity, which can be read on his Flickr-photostream. The question is indeed if this longer-lived activity can still be called a paroxysm.

Webcam image of today’s paroxysm. Image by INGV

Inge B. pointed to some images released by the INGV showing the Italian island of Vulcano, which seems to show a bit of unusually strong fumarolic activity.

Eolian island of Vulcano. Image by INGV.

The island is known to be volcanically active in recent history. The last eruption has been recorded in 1888 at the Fossa cone. The cone can be seen in the webcam image above. The Fossa cone has been the main center of activity in the last centuries, and fumarolic activity and gas emissions are ever-present to some degree at the Fossa cone. Sometimes, the activity peaks, like for example in 1985 and 1990, which shows that the town at the bottom of the Fossa cone is still under constant threat.

The Vulcanian town of Volcano Porto at the base of the Fossa cone. Image by INGV.

The island of Vulcano is off course most famous for being the place that gave volcanoes their name. In Greek and Roman mythology, the god Hephaestus, or Vulcan, was the god of fire and was thought to have its workshop below the Eolian island, leading to the frequent release of fire from the mountains on it. It is also the type locality for one of the 5 main types of magmatic eruptions; Vulcanian activity. This type of activity is characterized by viscous magma, andesitic to dacitic, that frequently erupts explosively and generates volcanic blocks and bombs that rain down on the surroundings. For comparison, Sakurajima is the best example of Vulcanian activity in recent years. The area where the volcanic blocks and bombs rained down during the 1888 eruption on Vulcano is where the town of Volcano Porto is now built, leading to the constant threat mentioned before if Vulcano decides to really wake up and go back to the behaviour the ancient Romans knew it for.

Meanwhile, Tolbachik seems to be re-thinking it’s decision that the eruption has now lasted long enough. Strong seismic activity has been recorded, together with strong gas-steam activity and a big thermal anomaly was seen on satellite images. Estimates of the erupted volume are well above 1 km3, so this number continues to rise for now.

Also, Granyia noted that the Chilean volcano Lascar had seen its alert level raised to Yellow, after reports of small explosions and some ash in steamclouds. Looking at the webcam, it looks like some glowing can be seen. Sernageomin reports (.pdf, in Spanish) that during a helicopter flyover, temperatures above 600 degrees celcius were measured in the crater using a thermal camera, which confirms the reports of glowing at night.

Lascar webcam image. Image by sernageomin.cl

El Nathan

———————————————————

Post update by Spica:

The Sheepy Dalek bar is open and Alan sent in another Evil Riddle:

I shan’t beat about the bush – a real spiny subject this, but at least you wouldn’t need a tv aerial!

What am I?
What are my special properties?

Good luck and have fun!

Alan C.

356 thoughts on “Activity update around the world

  1. I’m having a hard time correlating Etna visible activity with the tremor.

    It *looks* paroxysmic *now*, as I post – but tremor doesn’t show the usual peak; in fact on one station (ETFI) it appeared to peak a few hours ago, and has been going down as activity intensifies.

    This is a strange one; the post-mortem (and words of wisdom from Boris) will be interesting.

    • Yes, I am sure there has been a new vent opening lower down on the NSE crater cone. I thought I have seen two distictively different plumes on the webcams half an hor ago. Dr. Behncke described the ash from a newly opened vent as being reddish brown, and this is the case here too.

  2. A small bit on the tremor graphs of Etna. INGV has a fine map showing the position of all the outdoor devices they have installed. You can zoom, set checkmarks at the top which ones to be displayed and you can also grab and drag the map, f. i. north to the Eolian Islands.

    Here the position of the three stations producing the tremor graphs: http://oi46.tinypic.com/311tbav.jpg

    EBEL (EtnaBELvedere) is no more, since it has been taken out by the March 1 paroxysm
    ETFI (EtnaTorredelFIlosofo) is high up on the southern slope, at the foot of the SE craters. This is the most relevant to look at at the moment. When the New SE crater is erupting, it will most probably show much higher values in tremor levels then the other two.
    EBCN (EtnaBoCcaNuova) is high up on the western slope of the summit craters. It will show the highest tremors when Bocca Nuova/Voragine are erupting. – Not working at the moment!
    ESLN (EtnaSerraLaNave) is way out, some 5km SSW of Etna. It will certainly show the same patterns as the other two, albeit on a very much lower level. – Not working at the Moment!

    With a cursory glance over the three graphs (when all are working) sometimes it is hard to see a difference between them. As the online graphs automatically adapt the hight of the highest spike to the hight of the display, all fill the graphs from bottom to top, so all graphs look alike. One has really to read the numbers on the left to realise that there is a huge difference between the three. – No expert on nothing – Granyia

    ETFI is going rapidly down right now.

    • Whenever you feel like it, please send it in and someone will see if they can make a nice post about it. There is not much written about the Galapagos Islands on VC, so it’d sure be interesting.

  3. Riddle attempt: → The creature from White Island. The odd looking dome growth. I’m gonna hazard that the composition is rhyolite. Properties? Ultra thick cool material.

  4. Thanks for the update Nathan, nice one.
    I’m hoping to witness some action while me n’ Lizzie are in Sicily at the end of the month…
    We’re staying 5 nights in Catania and 5 in Palermo, which gives us the option of a visit to Schtromboli and/ or Vulcano…
    So fingers crossed for an eyewitness report on Etna’s 25th of April paroxysm 😀

    • Nice! I shot my gravatar there near Gioiosa Marea, I love Sicily! Are you staying over a night at Stromboli as well to hike to the summit and see the action up close, which I did not to my great regret 😉

      • Just had a close look at yr Gravatar, great photo!
        We were thinking to maybe do the summit hike as a day trip from Palermo, but it may require a stay. I haven’t properly researched the logistics yet…
        I do enjoy “bagging” volcanoes, I know they are “only” “tourist” volcanoes, but I ve climbed Vesuvius,Teide and Teneguia which could be considered active; as well as Solfatura, which is dormant but busy.. When I start thinking of the dormant, extinct and long extinct ones I’ve visited, the list gets pretty long. Holidays in the Canaries and Italy certainly help 🙂

        • You should also consider going to Iceland: Great country for “collecting” active volcanoes.
          This eg. is Hveradalir in the Kerlingarfjöll mountain range, not far from Langjökull. 🙂

          • We’ve researched it… Of course…
            Irpsit gave a few very useful pieces of advice…
            Lizzie would be game; only problem is, Lizzie really wants to see the northern lights ( as would I, but if I had to choose it would be volcano bagging forr me…) and whilst it is possible to combine the two possibilities, it is “iffy” for both or either… Irpsit suggested September.
            Schtill, it seems a lot less expensive than it used to be, so we can always make two trips 😀

          • It just depends. It is possible to see Northern Lights as well as some active volcanoes also just now (around Easter or even in February). There are some hot temperature areas in the vicinity of bigger roads, so that they are also accessible in winter, eg. Hengill, Hrómundartindur, Hveragerdi, even Krýsuvík near Reykjavík, but also of course the Mývatn area up north near Akureyri.

            Just if you intend to go to the “wilder parts”, i.e. the highlands, then you would have to chose the summer, highland roads normally open end of June, beginning of July.

        • For as far as I know it will require a stay, but you will be glad you did indeed stay since the best crater visits are at dark, which is ehhh kinda late in May 😉 Also, for as far as I know the boat goes to Milazzo and takes at least an hour if you have the quick one, and a drive from Milazzo to either Palermo or Catania is at least 1.5 to 2 hours as well.

          Also, look into visiting Etna to avoid surprises. The funivia (cable lift) to the top is not the cheapest, especially if you include the tour, but they are worth the memory later on I heard 😉 If you know in advance, it’s not that bad anymore if you plan for it. And if you like hiking, there are dozens and dozens of awesome cones to visit in the flank forests, and caves not to forget.

          And not to forget, you can buy SD-cards for your camera at the Rifugio Sapienza shops, for those dumb bastards who left their card in their laptop in their hotel/house 😀

    • You could be onto something:

      “High quality quartz crystals are single-crystal silica with optical or electronic properties that make them useful for specialty purposes. USGS estimates that about ten billion quartz crystals are used every year.

      Electronics grade crystals can be used in filters, frequency controls, timers, electronic circuits that become important components in cell phones, watches, clocks, games, television receivers, computers, navigational instruments and other products. Optical-grade crystals can be used as lenses and windows in lasers and other specialized devices. Although some natural quartz crystals are used in these applications, most of these special crystals are now manufactured.”

      From: http://geology.com/minerals/quartz.shtml

  5. Dr. Boris Behncke from INGV Catania has also described the recent developments on Etna over at Erik’s in a comment (citing):
    “If anything, Etna’s magmas have become more primitive (or mafic) in recent years and decades, and at the same time the activity has become more voluminous, more frequent, and more explosive. The trick is the gas – mostly water vapor, which seems to be the main factor that makes Etna’s eruptions explosive, actually much more explosive than one would expect from a basaltic volcano. Think that Etna emits about one million tons of water vapor EVERY DAY, and that’s water vapor from the Earth’s mantle, not anything picked up on the way. We have a lot of evidence that magma transport at Etna from the upper mantle to the surface has become more efficient lately, with more rapid magma ascent, and thus less loss of gas (mostly water vapor) on the way, so there’s more water vapor in the magma when it comes to the surface, and therefore it’s more explosive. At the same time, the more rapid magma ascent reduces the amount of differentiation in the magma and therefore it retains more of its original mafic characteristics. Some of the most explosive eruptions in Etna’s recent (past few millennia) eruptive history have also been the most “primitive”, magmatically speaking.” http://www.wired.com/wiredscience/2013/04/brief-explosive-eruption-from-etna/#disqus_thread (date: 3 days ago)

    • Etna is in a phase of heavy posteruptional degassing at the moment, as it may seem from watching the webcams: http://www.malinpebbles.com/Images/FOTOS/Meine-Webcam-Seiten/pubweb/Etna.htm

      Boris Behncke emphasized on the role of Etna’s gases re. eruption intensity also in another interesting comment over at Erik’s (citing again):
      “(…) we now definitely know that gas is THE driving force of explosive volcanism, much more so than the chemical composition of the magma, and Etna’s magmas contain unusually high amounts of gas like sulfur dioxide, carbon dioxide, and most of all, water vapor. Etna’s paroxysms are MADE by water vapor – which is initially built as H2O molecules into the structure of crystals like amphibole, then liberated at decreasing pressure and eventually forms bubbles in the ascending magma. Once a certain threshold is passed, the vapor decompresses and increases much more than a thousandfold in volume, making the magma foam – and that’s the lava fountain.

      By the way, today’s lava fountain was still quite energetic, and lasted longer than the lava fountaining phases of all earlier paroxysms of this year. There were also pyroclastic flows, and significant tephra falls in the east-southeast sector of Etna.” http://www.wired.com/wiredscience/2013/04/past-volcanic-eruptions-in-the-auckland-field-more-common/#disqus_thread (date: 3 hours ago)

      This is something which could also apply to Grímsvötn volcano in Iceland, i.e. that the explosivity eg. of the 2011 eruption was not only driven by the water resolved by melting the glacier, but also because of very gas/water rich magma arriving directly from the mantle, at least in some phases of the eruption. Anyone here, who knows more about that?

    • “Orbicular Jasper is a name given to a highly silicified rhyolite or tuff that has quartz and feldspar crystallized into radial aggregates of needle-like crystals forming orbicular (spherical) structures.

      It is often used as a decorative stone.” From a.m. website.

  6. Alan’s Riddle: My spine is of the bigger variety but special properties? I don’t know… Needle of Mount Pelee?
    Beginning in October 1902, a dramatic volcanic spine grew from the crater floor in the Étang Sec crater, reaching a maximum width of about 100 to 150 m (300 to 500 ft) and a height of about 300 m (1,000 ft). Called the “Needle of Pelée” or “Pelée’s Tower”, this extraordinary volcanic feature rose up to 15 m (50 ft) a day, and became twice the height of the Washington Monument and more or less the same volume as the Great Pyramid of Egypt. It became unstable and collapsed into a pile of rubble in March 1903,[22] after 5 months of growth.

  7. And something else dug up from the depths of the millions of useless information ever read and heard: The Mineral Ulexite
    Gigantic hunks of Ulexite are found in the form of fibrous, compact veins. When polished, these specimens become the well-known “Television Stone” or “TV Stone” sold to amateur collectors. The optical effect exhibited by Television Stone is caused by each of its individual fibers acting as fiber-optic cables, transmitting light from one surface to the other. Since all the fibers are parallel and compacted together, any image at below is transmitted through each crystal fiber to the top surface. For this effect to be seen, the specimen must be polished with smooth surfaces. Fibrous Ulexite bundles can also be carved into cabochons that display strong chatoyancy. However, due to its low hardness, it is unsuitable for gem use.

  8. Foudn another promising candidate for Alan’s 😈 riddle:

    Ulexite: aka telveision stone.

    & Granyia got there first 😉

  9. Silica? & Fiber-optic cables?

    Alternatives to silica could be fluorozirconate, fluoroaluminate, and chalcogenide glasses, & sapphire

  10. Cactus Quartz, or Spirit Quartz, was first discovered in 1986 in the Magaliesberg Mountain Range near Pretoria, South Africa. It was called “Spirit Quartz” by the South African tribal medicine men who used them for healing rituals. Cactus quartz is formed by a quartz or amethyst crystal being encrusted by a second generation of smaller crystals grown on its faces. It occurs as quartz, citrine and amethyst, and comes in a wide range of colors, including purple amethyst, violet amethyst, smoky, milky clear and golden citrine.
    used in many cultures for healing.
    It has the same properties as quartz.
    Quartz crystals are piezoelectric meaning when an electrical current passes through them they vibrate a small amount. Quartz is widely used for making fibre optic cables for cable TV (No ariels needed.)

  11. Oh i do like this site !!lots of info and funny chat. I have visited a few places volcano related, just for holidaying but now i realise i was drawn by the volcanos. The canary islands up in the restaurant on lanzarote where the floor is hot and the food cooked over a pit. Clumbing up Etna walking around a steaming vent in the freezing cold with very thin air.
    Sailingaround the crater that is santiorini
    wowing at the

  12. Oh i do like this site !!lots of info and funny chat. I have visited a few places volcano related, just for holidaying but now i realise i was drawn by the volcanos. The canary islands up in the restaurant on lanzarote where the floor is hot and the food cooked over a pit. Clumbing up Etna walking around a steaming vent in the freezing cold with very thin air.
    Sailingaround the crater that is santiorini
    wowing at the layers of pumice and black ash thinking of how it must of been before the eruption and confusing at the new volcano growing out of the sea

    • Hi Geekileece! I think the bar is open. Have one on me. 🙂 Welcome to VC and the Sheepy Dalek bar. You sound like the vast majority of us feel. 😀 You should feel very at home here 😀

      • Yes welcome from me too. I do feel very left out on the holiday front though. 😦
        Never been anywhere near a volcano as I never had enough money to travel far. Still I have Been up Arthur’s Seat and Castle rock on Edinburgh and also visited Fingals cave on the Isle of Staffa and seen the superb structure of the basalt columns. I have climbed Snowden (which I think is an old volcano?) and climbed Ben Nevis twice, not sure if that is volcanic either? So now I have talked myself into feeling good again as they were once volcanoes. LOL I have even picked up floating pumice on the shoreline in Spain but I have no idea where that came from.

        • Half of Northern Ireland is a 50-million-year-old basalt plain, have you been there? Surely you have seen Giant’s Causeway?

          • Hi Granyia, no never been to Ireland. Too many troubles when I was younger. Hubby wanted to go at one time for the good fishing but now he has too many disabilities so can’t fish any more poor man.
            I have been to Cornwall and on Dartmoor which was also formed by volcanoes when the earth was young. 😉 Actually all the west coast of the UK is a good place for looking for minerals, especially Cornwall as you can still find some in the spoil heaps from the disused tin mines.

  13. Just been outside – it is a bit wet. May have to dust of the wellies (sadly not red 😦 ) if this rain continues.

    But have a mug of coffee so off to do more research for the riddle. Cactus quartz sounds very good but Alan 😈 aka Fred said the answer wasn’t quartz.

  14. Hi

    Here is the update on the density plotting for El Hierro. Up to today.

    In this plot the first part shows daily earthquake density with a mesh of 90 x 90 m.

    For the last days the plot shows the limitation of the system. Too few earthquakes and too much dispersion (see the scale on the right blocked at 0.9)

    The second part shows a cumulated earthquake density, with a day by day cumulation.
    Data is from IGN & NOAA, made on Gnu Octave.
    The second part shows very well the most active areas and the evolution of the quakes focus.

    • Hi, Alison, I don’t think the riddle is solved yet, many suggestions have been made, but none was ding-ed if I haven’t overlooked it. So, have your dinner, make yourself a cup of good tea, snuggle into your favorite armchair and start delving into research of bushy spiny things that can be used as tv aerials… 😉

    • It is rated as a “High – 5” event, that should be pretty good! Visible over almost all of Scandinavia and even in Scotland!

  15. OK so this is complicated for me at this hour of the morning my friend Arther Itis and Husband’s alarm clock woke me. So here goes for another stab at Alan’s riddle.
    How about Gadolinite-(Y). Found in a small Swedish town of Ytterby. This name means remote/far out could it mean in the bush? I try not to cut and paste but it’s far too early to create this in my own words…..
    “The mineral gadolinite ((Ce, La, Nd, Y)2FeBe2Si2O10), discovered in a quarry near the town of Ytterby, Sweden, has been the source of a great number of rare earth elements. In 1843, Carl Gustaf Mosander, a Swedish chemist, was able to separate gadolinite into three materials, which he named yttria, erbia and terbia. As might be expected considering the similarities between their names and properties, scientists soon confused erbia and terbia and, by 1877, had reversed their names. What Mosander called erbia is now called terbia and visa versa. From these two substances, Mosander discovered two new elements, terbium and erbium. Today, erbium is primarily obtained through an ion exchange process from the minerals xenotime (YPO4) and euxenite ((Y, Ca, Er, La, Ce, U, Th)(Nb, Ta, Ti)2O6). ”
    (Thanks to Jefferson Lab for this information All properties of erbium can be found here http://education.jlab.org/itselemental/ele068.html )
    not sure where the spiny bit fits in though unless it comes from the fracture of Gadolinite.Fracture: Splintery – Thin, elongated fractures
    Erbium is alloyed with vanadium to make it softer and easier to shape. Erbium is added to fiber optic cables as a doping agent where it is used as a signal amplifier. You don’t need aerials for cable TV!
    Ye Gods! my mind is getting as warped at Alan’s!!

    • I have stopped digging any deeper into the unknown as I think the solution is somewhere not too far awy from quartz. Or why had Fred a “(Sharp intake of breath)” yesterday at 18:05 and said “Quartz it isn’t!” ? Could it be that the riddle is solved already and fred has just not been on for a time?
      Hope your Arther is better!

      • Thanks Granyia. Arther’s doing well. 😀 I am spending the day listing yet more stuff on ebay (Sigh) The key bashing and fiddling with small coins and small specimen bags isn’t doing my temper any good 😀
        @ Newby…….. Re Holidays……What are those? 😀 😀 I am in similar position (Another deep sigh) However One day I might win the lottery so I plan so as I am prepared 😀

        • Haha, all those years of paying in for my state pension Plus paying income tax at 30% (or was it 33%?) and people complain today that the standard rate is 25% and have the nerve to blame us baby boomers because things are in a state, all that paid in and peanuts paid back to us. Such is life! And I am perishing with the cold here at the moment in what is supposed to be the warmest area of the UK. Max 10C today and can’t afford to put the heating on any more.
          Sorry folks, rant over. A hot coffee and feeling better. 😀

  16. Well, ’tis obvious that our Granyia is well read-up on AA Milne!
    Winnie the Pooh fell into a gorse bush honey hunting
    gorse is genus Ulex – the prckly subject – so we have Ulexite!! DING!!!
    Ulexite (NaCa hydroxyborate) – nickname TV Mineral from optics c/f fibre optic cables

  17. Graniya said this earlier, but to mention it again. Incoming CME is expected April 13. If you look at solarham. com or spaceweather it is not yet here. I d like to remind people that we also have some aurora cams in the crows nest. Our Icelanders may get to see the real thing, for the rest of us ( and maybe Schteves Lizzy) we could at least watch it via cams.

  18. Dunno if this has been posted:

    Dr Boris Behncke’s video of Etna on 11/04/2013. The sound is impressive: Vulcan’s forge.

  19. Yesterday I have added to my Chile cam page the Chaitén webcam, as it hadn’t been working for a long time. It was pitchblack during the night, but at daybreak I was amazed to see that glow: http://www.aipchile.gob.cl/camara/show/id/14 Can somebody please tell me if that is a normal occurence at Chaitén?

    Btw., I got a message from my web host telling me that the server has been hacked into, that they are working at it, but that it may be necessary to change the hard drive on it. So I apologize to all here if the webcam pages are not accessible, I hope it goes over soon!

  20. OT:

    Just came across the phenomenon of Streetview Hyperlapsing. Creating a timelapse from Google Streetview images. Some piece of software exists which can create stunning images from that! Now, there is a simple version of that software, as a webpage, so anyone can just play away a bit.

    For example, this was the latest one I did, of some volcano off course.

    After you generated it, the link in your browser window will be ‘your’ timelapse.

    • A bit confused about this (A lot actually) I seem to have half a grey “screen” to the right and a time lapse they prepared earlier on the left. I cannot get the grey screen to fit…..
      Am I being very blonde here?

      • Hmm, works fine here, perhaps something with the browser or so. They recommend Chrome and a decent computer. Just clicking and waiting a couple of seconds should do the trick.

        Visiting the base link, http://hyperlapse.tllabs.io/ should get you to the place where you can mess with it yourself.

        btw, this is what it can look like if you have too much spare time:

        • Hi el Nathan, i have trouble with it too. I press create and it says loading. But i gave up ater 20 min in mozilla and gave up in chrome as well after 20 min.
          My compu is decent so is my internet connection. No clue what’s wrong…

    • It loaded with me, albeit very slow, and then there was a fully transparant movie. I saw the background of the Port of City X and the progress bar below that showed where the film is at and that it was moving – but no volcano trip.

      • Hmm, misbehaving websites today. Ah well, it wasn’t brilliant or anything, just a nice view of Shasta you can see on Google maps with street view, but then moving.

  21. There has been a magn. 4,9 quake near Peloponnes in Greece this morning:
    4.9 21km SSW of Gefyra, Greece 2013-04-09 03:36:28 36.515°N 22.917°E 24.0

  22. Hekla strain is taking a fairly steep drop since the 3.6 quake in the north of Iceland showed up at 16:14. Mind you it was already falling anyway so probably not a lot to do with the quake.

  23. I just stumbled upon this website “Volcanofiles” (volcanophiles) made by a group of young people, they write in the “about us” section “We’re a group of graduate volcanology students who are keen to share our experiences of working on volcanoes – the science, the fieldwork, and what our ordinary life is like in some of the extraordinary locations that we go to.” – Pictures, short comments, some interesting tidbits of the volcanoes they visit and a list of publications should make an interesting read. There is a long blog archive menu on the left.
    http://volcanofiles.com/about-us/

    • It is because of the storm that the eruption column cannot rise. Could also be difficult then to calculate the production rate.

      • “It is because of the storm that the eruption column cannot rise.”
        No, no, not entirely correct, but winds can affect eruption columns (and creating downdrafts on lee side if winds are correct velocity) and do affect the fomulas used for total eruption volume.* See this image from Eyjo in year 2010, eruption column seen “stop” at certain altitude and it appears as there was “inversion” at that height (3000 – 4000 m ?) http://www.flickr.com/photos/35133216@N05/4722475070/sizes/l/in/set-72157623710680985/
        Main reason it does not rize is “the condition of the atmosphere”. It can be “Stable Air” existing at that altitude, when there is temperature increase (hotter) as we go higher, i.e. if there is relative gain abowe -1 Centgrade each 100 meters in altitude, “Unstable” is when its opposite (say -2 C cooler per each 100 m altitude). In such condition a “box” of air will increase its speed upwards (and this is one cause for thunderstorms to name one example of moist unstable air). http://weatherfaqs.org.uk/node/16
        That said a “box” of hot air, can not rise if its relatively hotter abowe, only relatively cooler. In meteorology terms a “inversion” may exist, that the eruption column can not penetrate. http://en.wikipedia.org/wiki/Inversion_%28meteorology%29
        And observing the column at Popo today (I watched the timelapse many times, slowed to 5 fps), there seems be more physics at play. The “weight” of the plume seems too much for it to rise (too heavy = typical Pyroclastic), and the hot air in it seems not be able to rize at all, not untill some of the heavier-mass (ash) has fallen out, then it seems be able to rize. A Radiosonde for Mexico City today should reveal if there was invesion abowe 5000 meters.
        *wisdom I heard in news just recently.

    • BTW in this text it says that during the last bigger eruption, in 2001, small pyroclastic flows initiated by lava dome explosion, ignited forest fires near Tlamacas.

    • Yes, it even made it into the VAAC reports with FL200 ash.

      Backing out the edifice height and calculating with Mastin et al, the emission rate is about 0.01069625 m³/s DRE. Not the most energetic of eruptions… (about the equivalent of throwing a 5 gallon bucket of rock into the air every two seconds)

      Note: This image link may break later, if so, the parent page is at
      http://www.ssd.noaa.gov/VAAC/messages.html

      • Did you take into account that the plume height of just 400 m is heavily influenced by a storm pushing the plume downwards and then more or less horizontally away from the source?

      • Vertical wind profile data is difficult to locate. If you have a link for it, I could take a stab at it.

        The explosiveness of the eruption is what is used by the Mastin equation. Since it was intended for making estimates of remote data, there will always be some slop in the results. Even if you double the result, it is still quite a small eruption rate.

        I have not seen any work done on the affect on plume height due to a prevailing upward or downward moving air mass. I’m sure it could be done, but to be accurate, whoever did the research would probably have to account for particle size, drag, etc.

        • I saw somewhere a paper re. an eruption in Iceland, but I don’t know, if it was Eyjafjalljökull, Hekla or Grímsvötn and can’t find it a t the moment. But I remember, that they said there it was the first time they had taken into account a storm pushing the plume down and sideways.

          • Sorry, didn’t read the other comments above, but later. So probably it was more the weight of the eruption cloud itself what pushed it down. Different conditions.

            I was at the time thinking about a storm a.m. because also the wind of the smaller fires (forest fires? rift zone eruptions?) was blown energetically away from the source.

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s