A Tale of Three Cities

Photograph by Kevin Sebold. Fuego on a moonlit night.

Photograph by Kevin Sebold. Fuego on a moonlit night.

It was the best of times, it was the worst of times. It certainly was volcanic times. This is the story of three great cities, one lost in the mist of time, one almost gone into the mist of time, and one that is a buzzing metropolis, doomed to disappear into the tephric mist of a time to come.

Welcome to the Capitals of Guatemala.

Ciudad Vieja

Award-winning photograph taken by Jean-Marie Hullot from Ciudad Vieja with the Volcan de Agua in the center.

Award-winning photograph taken by Dave Wilson from Ciudad Vieja with the Volcan de Agua in the center. This is a digitally enhanced photograph.

Even though Técpan was the first military center for the Spanish invaders it is Ciudad Vieja that was the first real place of government in the colonial era Guatemala. Even more correct would be to say that the first capital of what is now known as Guatemala was the Cakquikel city of Iximché, but let us leave that behind us for now. It was Ciudad Vieja that is interesting for this Tale of Three Cities.

The city was founded in 1527, and had a rather short lifespan. In 1541 Agua suffered a dramatic collapse causing a lahar that totally ruined the city forcing the inhabitants to permanently evacuate the city. For two years Guatemala was without a capital.

Because of the flooding water and the lahar devastating Ciudad Vieja the volcano was renamed into Volcan de Agua. At the same time they renamed the nearby volcano into Volcan de Fuego. Nobody knows what devastated the sides of Volcan de Agua. Most likely it was earthquake activity during a magmatic emplacement at depth, but that is just a theory. What is though known is that the side of the crater gave way, and the crater lake came crashing down picking up any loose items on the way.

Photograph taken by Dr Carmen Morataya for Volcano Café. There are definitly worse places for a morning cup of coffee. Photograph taken from the Hotell Garden towards Agua.

Photograph taken by Dr Carmen Morataya for Volcano Café. There are definitly worse places for a morning cup of coffee. Photograph taken from the Hotell Garden towards Agua.

Volcan de Agua is a youthful young stratovolcano with no known historical eruptions. It is though showing low level signs of activity. It is today judged to be dormant, but in a state that can change at any time.


Photograph from Wikimedia Commons.

Photograph from Wikimedia Commons.

In 1543 the new capital was formed in the next valley. It was named Santiago de los Caballeros. It was probably one of the least fortuitous places to have a capital in. Not only is Volcan de Agua less then 5km from the city, there is also the highly active Volcan de Fuego close to the city. To top it off the city also had to contend with Acatenango. During its history (1543 – 1776) it was inundated under tephras from Volcan de Fuego no less than 23 times, and two of those eruptions were VEI-4 category.

To really make things interesting it is placed on top of an active fault line.

Photograph from the Wikimedia Commons. Church ruins from the Santa Marta Earthquake.

Photograph from the Wikimedia Commons. Church ruins from the Santa Marta Earthquake.

On the 29th of September 1717 much of Santiago de los Caballeros was destroyed in a large earthquake. More than 3000 building were ruined and the Spanish Crown started to contemplate moving the city. Sadly they contemplated to long.

On the 29th of July 1773 the Santa Marta Earthquake struck the city with a force estimated to be 7.5 on the magnitude scale. Most of the city was left in burning ruins after the earthquake. Equally devastating was the intensive swarm of unusually powerful aftershocks that hammered the city into December the same year. In 1776 the Spanish Crown finally had it and decided to move the capital to a new safer spot. The new city was named after both the region and the country for good luck. Now we know that the move was from the ashes into the fire, quite literally. But we will get back to Guatemala City in the next installment.

Left were the ruins of the old capital, now renamed into Antigua Guatemala, basking in the shade of its large volcanoes.

Acatenango & Volcan de Fuego Massif

Acatenango and Fuego are joined to the hip quite literally. It seems like they do not share the same magmatic system, even though some researchers have extemporized that the magmatic system of Fuego runs through the magmatic system of Acatenango. The reason for this theory is to explain that some of the eruptions of Fuego carry magmatic signatures from Acatenango, but Acatenango never have the magmatic signature of the bulk of Fuegos eruptions. Be that as it may, the two volcanoes have rather different patterns regarding their eruptions.

Photograph by courtesy of Dr Carmen Morataya showing the phreatic crater of Acatenango.

Photograph by courtesy of Dr Carmen Morataya showing the phreatic crater of Acatenango.

Acatenango has had very few historical eruptions. The last real eruption cycle began on the 18th of December 1924 with a set of large phreatic detonations; this was later followed by a central vent eruption and a radial fissure eruption from the Pico Central crater. During this eruption the volcano ejected the telltale amphibole bearing dacite that is the most common lava emanating from Acatenango. The eruption ended on the 7th of June 1925 and was rated a VEI-3. In August 1926 the volcano sprang back into life with a new set of phreatic detonations followed by renewed lava ejection from the north flank of Pico Central. The eruption ended on the 19th of May 1927 and was rated a VEI-2.

On the 12th of November 1972 a set of phreatic detonations started that lasted for about a month. No lava was ejected so it is seen as an aborted eruption. The phreatic detonations was powerful enough to gut the Yepocapa saddle of the Pico Central cone.

Historically Acatenango has not suffered from frequent eruptions. Instead the eruptions have tended towards being larger than the eruptions of its twin Fuego. The greatest risks are the well documented deep layers left from large scale pyroclastic flows. The flow fields from the 370 BC eruption would have eradicated any of the adjacent towns and villages in an instant. Therefore the authorities would be well advised to prepare proper evacuation maps of all the possible routes pyroclastic flows can take from Acatenango and put in place large scale evacuations in case Acatenango rumbles back in to life.

Volcan de Fuego erupting with Acatenango in the forefront.

Volcan de Fuego erupting with Acatenango in the forefront.

Volcan de Fuego was born out of the scrap heap left by the massive Meseta volcano when it went lumbering towards the ocean in the Asquintla debris avalanche. Fuego is one of the two most prolific volcanoes in Guatemala. One could almost say that it is erupting more often than it is resting.

Normally it has small to moderate sized eruptions with an average of VEI-2. But it quite often has short-spanned VEI-3 eruptions that are more of a bother for the locals. Two VEI-4 eruptions are documented, the last in 1974 when it had numerous pyroclastic flows killing residents in nearby villages.

Fuego shows a varied pattern of behavior ranging from lahars and pyroclastic flows (the killers), via lava bombs and lava flows from central vents and fissures to spine growths and exploding extruded domes. These varied behaviors make Fuego into a fairly unpredictable volcano. What is lacking is good mitigation with pre-prepared evacuation maps from the valleys most affected by pyroclastic flows and lahars. Also the will to evacuate and being evacuated is slightly low locally, something that can be understood if one think about that the people in the villages are really poor without the means to support themselves if they evacuate.

If you think this was bad choice for cities, just wait until the next installment of A Tale of Three Cities.


P.S. Do not miss the expert comments at the end of the comments section. D.S.


238 thoughts on “A Tale of Three Cities

  1. Did you know that Kaffitár, the Icelandic gourmet coffee company gets some of their coffee from here.

  2. A tale of Three Cities explains why it is much easier to find hazard assessments for Acatenango than it is to find what the lava is 😉 Was the post from you, Carl?

    Last go at the food: fiambre. 🙂

  3. Sorry, I do not know why it got published every time I tried to save the post.
    Well, now the full post is here!

    And, for your edification. The dish saught after is called Mixta. It is a simple and common local street food.
    Image and video hosting by TinyPic

    • It was the oddest feeling ever to post the longest post ever in short tidbits. You who got to see it early should refresh and go back and check what was added.

      Ah, KarenDingZ got two DingZ for Acatenango and Amphibole bearing Dacite.

    • Hot Dog on a Tortilla. I’ve seen less imaginative uses of a hot dog. The ‘sausage pizza’ that I ordered in Italy featured sliced hot dogs instead of pepperoni.

      Then I was treated to people staring at me for not using a knife and fork.

      It was still better than the four varieties of pizza in Hurgada. Only one of which did not have calamari on it.

      • I love calamares, and I love pizza. But I prefer the two concepts to be separated as far from each other as possible.

      • somebody complained about my kennels, an inspector came around and had a look at them, couldn’t find anything, on his way out he said there is a new regulation you should know about, need fire extinguishers, so got those in the following week. I told me I haven’t got any hot dogs on the way out, he gave me a funny look and went on his way

    • The swedish version of the Mixta is called Tunnbrödsrulle (every native speaker now has to try to say that out loud, preferily take a picture and post it showing the utter befuddlement on the face of anyone close by when you say it).
      It contains two sausages, mashed potatoes, something called Boston-cucumber (which has nothing to do with the city of Boston), mustard, ketchup and shrimps in mayo. It is all roled up in a soft traditional north swedish bread.

      Image and video hosting by TinyPic

  4. *grabbing the ear of Diana*
    Now you come back here as soon as you start stealing your Husbands Sparkly new Internet, you hear that!
    *stomping fot*

  5. I’m off to north Northumberland for a few days of family stuff so Hekla can go off from any time now until Wednesday evening when I will return.

    I leave you with this thought: if 4 May is Star Wars day (May the Fourth be with you) and today is Cinqo de Mayo, then is tomorrow ‘The Revenge of the Sixth’ ? 😀

    • Have a nice trip!
      No, Hekla will not go off untill wednesday when I am leaving for a train trip up north.

      We will see tomorrow what George Takei has come up with. He is the Father of May the Fourth be with you and the Sinko de Mayo images.

      • Ok. so Hekla can go off, if Carl, leaves early that day and you, Talla, arrive late (in evening as you say). Only let me know, so I can cover that hours (i.e. have car gas-ed to go and arranged like in F1, and hope them are looking the other way on the way 😉 ). Else I need about 90 min tip-off time, for be in prearranged-picked spot before it goes off (but only need 30 min to be in visual range, wether permitting). So whould have to start off on first quake – to get first action – but probably will not be that lucky … Else the plan is to be there on very first night, when it is most powerful.
        *Hekla! You hear! Give Ample Warning Time!*

        • She has been giving warning signs for 5 weeks now… or more 🙂

          If you see something please sms me so I can get going!

          • humm… yes … you are right. Only I can not wait “in range” but for 24 /36 hrs max, else I run out of …. credit xxx plus some patience! *actually waited 2 years now, so I guess I have not run out of that*

        • Don’t know what time I’ll be back – I come from a disorganized family. If we decide on a 10 o’clock start to a trip then in reality it can start anywhere between 9:45 and 1:30, also we may stop on the way for 10 minutes or 3 hours. It’s all very haphazard. But definitely by Wednesday evening because I have to go to work on Thursday and then off again to Pembrokeshire on Friday! Then Hekla can go off again because I’ll be at a holiday cottage with friends who aren’t interested in volcanoes! (Yes! People this weird do exist!) 🙂

            • Yes! Muggles! But I’ve just pressed the +Follow button here so I’ll be able to get my fix of VC even though I may not be able to comment.

        • I’ve asked her a number of times to wait. Lets just see if she’s listening.

  6. Great Post!

    I’ve always been very interested in the central american volcanoes. I think they’re incredibly overlooked (at least on here) despite the fact that there are a whole lot of them, theyre are many very dangerous volcanoes really close to large cities, and they have everything from effusive shield volcanoes to massive caldera systems.

    It actually could be argued that some of the major central american volcanoes pose a greater risk to life-loss than what could occcur if Vesuvius were to form a large eruption, and that’s saying a ton.

    Unfortunately, they do not have similar funding that Italy does, so if one of these volcanoes were to go bonkers, it could be a huge disaster (Depending on location, size, etc).

  7. I have a bit more to add to this post as well.

    There may be 3 relatively well known volcanoes right next to Guatemala city, but what most people are unaware of is that there is another volcano that has had a more violent past that’s even closer to Guatemala city. That volcano may be a part of one of the other volcanoes (pacaya?), and is not all that active, but it is relatively comparable to Campi Flegrei in size.

    That being the Amatitlan Caldera, which sits directly south of Guatemala City.

    I made an outline of the general caldera boundary in google earth to show where it lies in regards to Guatemala City, Fuego, Acatenango, and Volcano de Agua.

    For those who enjoy reading scientific texts – there is a decent writeup on the Amatitlan Caldera here – http://www.geo.mtu.edu/~raman/papers/WundermanJGR.pdf (not paywalled).

    • Yay… another potential caldera. {groan}

      At 15.5 x 16.5 km, it would equate to about 209 km³ DRE of material.

      That’s from comparing it’s dimensions to other caldera forming eruptions published in various papers.

      • Central america is riddled with calderas similar in size to this, and it seems people love to build large cities in central america either inside, or right next to massive volcanoes. When I completed the caldera outline map in google earth, I believe there were over 10 similar sized calderas in Central America alone.

        You can go right down the road to San Salvador to find it sandwiched between the shores of the Llopango Caldera and on the slopes of the massive San Salvador Volcano, which is known for flank eruptions, and has had a large caldera collapse event in it’s past as well. Both of these municipal areas would have easily over 750,000 people affected if a large eruption were to occur.

        Of course, there are calderas that aren’t right next to major metropolitan areas as well. You can find Coatepeque and Atitlan calderas which are of comparable or possibly even larger size than the previous two caldera systems, but they’re at least not situated next to a capital.

      • I’ve been farting around locating and measuring caldera dimensions in a non-dedicated fashion for a few months now. Of the 108 that I have tallied up, the long dimension is between 16.5 km to 23.3 km with 90% conf (19.9 km ave) and the short dimension is 11.66 km to 15.86 km (same confidence) (13.76 km ave).

        Using those dimensions, the approximate material from them is 171 km³ to 273 km³ DRE (ea)

        They do seem to be much more common than the popular public option seems to be aware of.

        • So them grow like youth pimples, evolve and get squeesed.. rinse, repeat, grow, get squeesed, rinse, repeat … sounds familiar 😉
          *stomach seems cured*

        • One thing that has me really scratching my shaggy chin (I really should shave) is that these calderas have a tendency to have erupted several times.
          Since I am not as meticulous at writing things down and plot them as you are I have no real figure for it. But let us say that these calderas are 300K years or younger (most older are gone by now), and that the have had an on average 3 large tephra eruptions on the scale of a VEI-6 or larger we gett 300 Large Tephra Events. Let us now assume that you have tallied up one caldera out of 10, then we have a rather bothersome fact scratching our noses.
          There are probably on average 1 large VEI-6 caldera event every 100 years. If we then assume that there are 9 VEI-6s to every VEI-7 we would get a VEI-7 every 1000 years. And one VEI-8 every 10 000 years.
          Then we back up and say “Hm…”, as we ponder the fact that there is an almost 1 chance of us seeing a VEI-6 caldera event during our lifetime, and a 1 in 12 of a VEI-7.

          Actually I think that we would find more then 1000 calderas if we putter on.

          And then we have not even started to scratch the surface of the ocean floor. For instance, it is quite likely that the big arse pumice-raft found a while ago was a bona fidé VEI-6 eruption that could have been a caldera event. The amount of Pumice was stupendous enough. My point being that there probable another 1000 or so calderas that are close enough to the surface to make life rather uncomfortable if they go off.

          Musings from a midnight mind…

          • since you are burning the midnight oil, I often thought the missing eruption in 1150 or there about was an underwater one, most likely in the Azores, it would fit in many ways

            • said it wrong, it was an island and went caboom and disappeared under the sea waiting to be ‘discovered’ again by VC

            • I would not be surprised.
              But I do not think the Azores are involved, then they would have found the Tephra layer a long time ago on the nearby islands.

            • ”said it wrong, it was an island and went caboom and disappeared under the sea” = that was featured in soap ”LoST”, and was in SouthPacific. Azores is Atlantic but film company can be fooling. 1150 possibly too early to have Poroguese or Dutch seararer stories or are we again thinking Atlantis.. question

            • I didn’t know those things Islander, it was something in my mind when I read about about the Lisbon EQ when I was in school in the mid fifties, yah, when getting older one remembers a lot of things from the old days and forgets car keys, panic and then finds them where they should have been in the first place

          • The known record of eruptions at Amatitlan shows at least three large (between 34 and 75 km3) eruptions since 191 ka. and maybe another 10 or 15 smaller ones… and obviously if you count Pacaya’s eruption as part of the caldera-volcano system, then you have thousands of smaller eruptions.

            • Hello Rudiger and welcome to VolcanoCafe,
              Thankyou for your comments, you seem to know your stuff 🙂
              You are of course welcome to comment where ever you wish, but the “live” discussion is on the current post which you will find at the home page. You are much more likely to be read and responded to there, even if your comments are refering to a previous post…
              The current post is about Nevado del Ruiz, but there you will find comments on Hekla, El Hierro, Popocatepetl and whatever else is going on…
              Please do hang around and chat with us.

              Note: Rudiger’s extensive and fascinating main reply to the post was caught up in Pending. It has been released and is at the bottom of the comment string on this post.

        • They’re definitely much more common than public opinion knows about.

          To me, calderas are part of the life-cycle of many volcanic systems. Some volcanoes will never go caldera since they don’t have enough energy input, or don’t have the right type of magma being emplaced into the system.

          Other volcanoes undergo caldera collapse events at seemingly regular intervals (see Krakatoa). I think for a lot of stratovolcanoes, the cycle is just much longer since there isn’t quite the prolific volume of magma being emplaced in the system as you would see at a volcano like Krakatoa. Others may have a similar magmatic input, but are much better at releasing the energy due to less sticky magma or other circumstances.

          You can find this pattern in a lot of volcanoes worldwide, especially the older ones.

          I’m also of the belief that VEI -6 events occur on average more than once every 100 years, but that’s more just my own speculation than any statistical fact. I think that history just hasn’t accounted for the size of some of these events as well as some of us think.

          One thing that always bugs me is that Tambora was supposedly of the same size as other VEI-7 eruptions in the Holocene. I’m not saying Tambora was a small event, but Tambora’s caldera is actually relatively small compared to other Holocene-created calderas. Aniachack (aleutions) and Okmok are both larger, and the Aira Caldera (which was supposedly around the same size as Tambora) is over 2x the size of Tambora’s Caldera.

          I don’t think large eruptions are very common, but I do believe they’re more common than what a lot of common research would state. Note – this is just my opinion, and is far from a fact.

          • It probably has to do with the effective depth of the magma chamber when the system goes hot. Deeper chambers tend to support a larger overall collapse structure (In My Opinion… spelled out the eliminate confusion with IMO, who have nothing to do with what I just said.)

          • Totally agree. One other thing to remember is that many of the calderas are comparatively gentle collapse structures like the Monowai seamount. Not all of them are giant kaboom types like Tambora, which I imagine was like Pinatubo ramped up ten times. The PFs went a huge distance over the ocean.

            One eruption I would really like to have witnessed was Novarupta/Katmai in terms of its dynamics. I imagine it started as a fairly vigorous flank euption but nothing particularly spectacular until the chamber roof (i.e. Katmai, several kilometers away) lost it’s structural integrity and turned into a giant piston. Alternatively, the eruption was purely gas-driven and emptied the chamber all of its own accord and Katmai just fell into the hole without much ado. …Or both 😉

            Also to remember in terms of frequency (this came up in the TVZ series) there are a number of buried calderas out there which we just haven’t recognized as such but these are also (geologically) quite recent structures.

            And then again there is the chaotic nature of the statistical fluctuation. These things are not spread nice and evenly over the course of history but occur with much greater frequency during certain phases (like the ignimbrite flare-up that led to La Garita and its sisters). I have the feeling we might actually be in the middle of one such phase now.. if time weren’t quite so long / our lives so short..

  8. And as we where looking away an old favourite has suffered what could be a magmatic emplacement episode.
    Something looking a lot like harmonic tremor episode happened at Grimsvötn 1,5 days ago.
    http://hraun.vedur.is/ja/oroi/grf.gif (the part before was a storm)

    I just had the feeling he is to quiet nowadays. And lo and behold. And no, an eruption is still years away. Far to little acumulated seismic release recorded yet:

    Thank you for a volcano that is predictable for once 🙂

    • I wouldn’t be surprised if Grimstvötn kept up its fireworks for a while yet, kind of like it’s telling us, “You thought that was big? You guys don’t know the meaning of big. Watch this!”

        • Yes, but the really really bad shit is a word normaly heard in a quiet room by a guy very silently saying the most horrible word known to mankind. It is the kind of word that you just know will be uttered one second after someone accidentaly push “The Button” and start the third world war.


  9. First, be aware of this definition:

    anthropomorphic – suggesting human characteristics for animals or inanimate things

    So, be aware that part of this is in jest.

    With the talk of calderas and the large number of them out there, Yellowstone decided that it wanted to remind us that it is still around. Sort of like Grimsvotn sneaking a few changes in while we were fawning over Hekla.

    Mag 4.2 Monday, May 06, 2013 at 03:13:42 UTC
    42.608°N, 111.947°W Depth 11.3 km (7.0 miles)

    Yes, that is down in the depth vicinity of the believed chamber area. And, to top it off, is right along the line that the last set I tracked that went from under the lava dome in Yellowstone Lake to under the north shore of that lake. they never went as far as this location, but it is along that line of bearing.

    I imagine that quite a few loons were shaken loose and will be wandering around now from site to site.

    Be warned.

  10. So I looking at Hekla right now. 0542, and at its peak I see a puff of steam. Does any one else see that. I have a screen shot but cant upload it until after I get home from work. Its just right of her highest point. Looks like a fumurole.


    • According to them who have actually been up there, the ground is still warm enough to make condensation vapor from the cracks at the top. Not really a fumarole per se, there is not enough continuous water supply for that. But cold dry air will make any water evaporated in a crack show up as condensed vapor… effectively “steam” for the temperature and pressure of the atmosphere.

      Someone who has actually been up there can elaborate. If they wish.

      • I thought the “warm spot” was east of the peak, and dead. The last photo I saw of it was from 2005 I think. And now its visable on the Mila webcam. The sun is catching it now.

        • When I hiked Hekla the warm spot was just at the top and slighly to the south. I did not went east of the peak, because there was a slope downwards from there.

          In that warm spot, there are several ground cracks which release a lot of steam, just like a normal hot spring, but only steams comes, and the ground is hot to touch, around some 50ºC. In contact with the cold air above, all steams condensates pretty much into a lot of mist,

          Anyways there is almost always a lot of mist in Hekla, but when the weather is clear and cool you can see the steam at the top, but that only from a few kms from Hekla and with binoculars. Go 20km away and not even with binoculars you can’t see it. So its only a small thing and most likely you will almost never see it on Burfell webcam, which is about 15km away.

      • Warm spots I don’t know about. I do know that much of the uplift seems to be in that area. But then, last year, around Feb, the uplift seemed to indicate that a sizable quantity had taken off to the south and was lurking in a field… pretty much in another volcanoes fissure swarm.

        With the odd motions of El Hierro’s uplift, I think the idea of Graboids may have much more merit that we usually give it. (jesting)

        • Right before the 2000 eruption the closest GPS station was SOHO near Katla. It had a movement of 15mm east and 10mm south. As of friday there has been no movement in these directions yet. How much Uplift at Hekla would we need to read those kind of measurments 53km away?

          • That motion was due to the emplacement at Eyjafjallajökull. 1998 to 2000 was busy years in the Myrdalsjökull area with 3 different emplacements taking place. The largest was of course the second known emplacement at Godabunga.

        • I don’t have a ready Mogi model for Hekla… too many different chambers. But at that range, the quantity would have to be phenomenally large to produce that amount of uplift.

          For example, at a 10 km depth, and a “chamber” inflation of about 1.44 x 10^12 m³, I get something on the order of 1.27 x 10^-13 mm uplift at 53 km… and an offset along a radial from that spot of 6.73 x 10^-13 mm. (less than the width of a sheet of paper)

          Keep in mind that this is a quick and dirty calculation and may be error prone. I haven’t had a chance to double check it.

          • You should only see minimal inflation just around Hekla.

            Before Eyja, and that was a large eruption, one saw a spot inflating some 20cm upwards and a few kms away only a few cms. Some more kms away the inflation was less than 1cm and lost within the noise.

            Same for Hekla, Katla, Grimsvotn…. unless its a hell lot of magma

            • Current inflation at Hekla is about 15cm since last eruption.
              The hypocenter of uplift is 1km north of Hekla with 30mm in the last 5 weeks.

              I do not agree that Hekla does not uplift.

              One should also remember that Hekla has a lot of magma even right after an eruption. Eyja needed quite a lot to erupt since she was clogged up in her opening.

            • Sorry, average uplift 2 cm annualy and now 3 cm in a few weeks. You guys do the math.

            • nearly or just past 29 cm – I checked GPS data yesterday – One Eyjo GPS did 8 cm abowe the annual uplift in years 2008/2009/2010. So possibly Hekla has another 5 cm to go (6 weeks), but we do not know if that is Hekla style, if she needs more or less. Faster expansion can mean less resistance left, that or more stuff coming out. But where is the feeder? I think it may feed from Dead Zone, west side of it, or it colud be “runoff” from Central Iceland, areas North- and North-East of Hekla (from under the Hreppar Microplate ~ the Microplate Melt.)

            • I have a new theory for from where Heklas weird lava comes from.
              There is a cave under Hekla where the Graboids crawl when an eruption has finnished. And with time the cave will be filled with Assblaster that melt the rock. When enough rock has been melted the volcano erupts ejecting molten rock and Graboid-eggs (previously believed to be lava-bombs).
              After the eruption the process starts again.

              Edit: For Lurkings evening BBQ.

              Image and video hosting by TinyPic

  11. Good morning VC, and thank you, Carl, for your very interesting article! I am looking forward to the next part!

    Took me a good while to read it and all the comments from last post and this one, so te picture I saved of Tungurahua is from over an hour ago. Tungu is in full swing again flinging lava in all directions; it has been lively for a couple of days now. I only wish they would un-tilt the webcam so that some of the lava wouldn’t have to flow uphill!

  12. Morning Caffers! Smashing day here, and i’m tearing my eyes off Hekla for a while to geocache the beautiful ancient coral reefs of Derbyshire.

    Thank you for the excellent post, Carl. More ideas for my honeymoon to ponder!

    And Gullfoss webbycam is back, the day can only get better 🙂 http://www.livefromiceland.is/webcams/gullfoss/

    • @ Karen Z, I just thought I better be ready for a screen grab, but can’t find the instructions anymore, could you let me know, thanks

      • For a simple screen grab you can use the PrintScreen button on your keyboard and paste the buffered image into a viewer of your choice (e.g. xnview, photopaint,…). In Windows 7 the built-in Snipping tool is an easy option because you can choose the area you want to grab.
        For webcams that are not streaming you can just right click and safe the current image.
        For recording streaming webcams I use CamStudio, a free screencasting program

  13. when you sit in the front of the webcam the side where it says Pingvellier there is a zit, been watching it for a while now, it is getting longer and seems to ‘slide’ down’ the mountain and is more pronounced ?

  14. And while we’re on the topic of Volcanoes that are close to Central America, Nevado Del Ruiz has continued it’s earthquake swarm, but the swarm has become shallower and shallower.

    When it started during early april, the swarm was centered at around 6-7 KM in depth. As of the last major quake (3.1m about an hour prior to this post), the depth is at 3.59km. That’s a rise of about 2-3km in approximately 2-3 weeks.

    I’m pretty surprised that Nevado Del Ruiz hasn’t been elevated to Orange alert at this point. Deformation + increasingly shallow earthquake swarm + increased emissions seems to be as obvious sign of an eminent eruption as there is possible. This swarm also is not subtle, it’s had over ten events that have registered larger than 2.5m so far..

  15. Just to let you know I am back and Thank you Hekla for not erupting whilst I was off Line :D. My goodness this is so fast now 🙂

    • Ah, back in your husbands sparkling new Internet?
      Good to see you again. I first thought you really was going to disappear…

    • Hmm, for me it is the second link on the expanded sidebar. Otherwise, the alpha dragons (=admins) have to deal with it.

      • what expanded sidebar ?! I’m using mozilla v20.0.1 on a winxp and also on win7 machines and I don’t see it.
        right hand top of page is blank

        left hand top has
        “posted on”
        and “comments”

        base of page has (apologies for copy paste)

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        but no link to hoard anywhere 🙂

    • As i mentioned earlier, you have that gray bar with + on left side of screen, click the +
      and it opens Link menu ;D

  16. Morning!
    Just back from an epic rugby tour – not much rugby but loads of drinking and getting a sunburned nose while the boys surfed, played softball and generally chased girls around what is apparently ‘Britain’s Best Beach’ (Woolacombe). Sheer Heaven.
    And now I have creatures living in my head that weren’t there before, and they are very noisy!
    So it was nice to catch up on VC and get all dewy-eyed about Guatemala where I spent my honeymoon. Will have to go and dig out my pics from Antigua etc … and no, not THOSE pics …:) 🙂

    @Carl – didn’t get the e-mail either!

    • I have wondered since yesterday. Rather quiet. Small ish transitient at HEK again, this shows how touchy the situation is, in my mind, two or three small quakes and it might go off. Steaming can happen in early morning, but rather can be moist cloud, carried up the side *It can be rizing sun, solar heated, not from Hekla itself*

      • No you are correct. Its actually rizing and falling *dancing* = Its a recent discovery that some Icelandic volcanoes do, possibly before erupting, but nobody knows exactly why.
        = I think it shows how fluid the *earth* under is. It might also be them waves visible in InSar Radar images. It may also be temporary pressure rises that then transit to other chambers. Lots of speculation … still highly suspect. Transitients, quakes, inflation, and possibly more we do not know *yet* about.
        Anyways I do not go near Hekla except having hard hat!

        • And ontop of that one should never look for daily GPS motions. GPSes are suffering from all sorts of disturbances so one should instead look for longer trends. I never look at anything shorter then 1 week trends.

          Islanders work cloathes when near Hekla:

          Image and video hosting by TinyPic

        • Magma ascent vs gravity; the magma ascent is not smooth continuous motion. But I thought that Hekla was “full”.

  17. Regarding the Post!
    I got poked by Dr Morataya for my use of the Ciudad Vieja image. I was kindly asked to tell everyone that it is a digitally worked on photograph (partially a digital painting) and that it does not look like that today.
    All in the name of scientific accuracy.

    • As I commented in my general reply to your post, it looks like a high dynamic range picture taken from underneath the Santa Catalina arch in Antigua Guatemala, and I guess that other than the amazing color intensity effect, it should pretty much look like what Antigua look today…

  18. And I’m back from Mickey’s Dungeon after 5 days with zero internet. Will have to read up slowly, since today is the first free day with awesome weather around here.

  19. A bit of Hekla news.
    IMO installed gas meters in march that came online in April.
    Not so mysteious really, I am happy that they finally did that.
    What is mysterious is the very un-IMOish name of the gas-meter station. Café Hekla.
    Islander, is there an actuall Café Hekla that they have put it in, or is this some weird joke?
    Or is it a blinking eye in our direction? 🙂

  20. Lurking!
    Have you read the:
    “Recent volatile evolution in the magmatic system of Hekla volcano, Iceland” by Séverine Moune a,⁎, Olgeir Sigmarsson a,b, Thorvaldur Thordarson b,c, Pierre-J. Gauthier?
    If not I recommend it. It has pretty good data on the gasses in the 2000 eruption. I would though like to point out that one should disregard the part where they discuss the 1913 Lambafit eruption since that one was never a Hekla eruption.
    If you have a problem of opening it just holler and I will send it to you.

  21. So I found this earthquake catalogue for Hekla-Torfajökull from 1990 to 1996 in the appendix of the dissertation “Seismic activity related to the 1991 Hekla eruption, Iceland” by Heidi Soosalu from 2004. It is in pdf format. Now I wonder how to extract the data, since it cannot be selected as text. It would be really nice to have these events included in the 3D animation.

  22. Earthquakes at Hekla:
    14.00 0.7M 10.5 SW Hekla
    14.12 0.3M 9.9 SSW Hekla
    14.16 1.7M 16.8 SV Hekla

    Possible but unconfirmed Harmonic Tremor with “wet” signature at MJO.

    • As we say here “hit happens. Let it come. I can take it!
      *has new coffee, No. 3 today*

      • 14.37 1.0M 14.8SSW Hekla

        (and what looked like a nice little avalanche of snow on the slope of Hekla)

          • One thing that is critical, is the address of the stream.

            Generally, those are not readily given. Sometimes you can find it by dissecting the web page using “view page source” and looking for where the HTML document sets up the stream for it’s embedded player. You’re skill at reading HTML and whether or not there is a streaming URL listed will determine your success.

            I used VLC to capture video from the DeepWater Horizon submersibles with a lot of success. My only drawback was running out of diskspace and connection timeouts that messed up some of the recordings.

            A side benifit of using VLC, you can accelerate the video on playback and breeze through the hours of nothing happening until you find something of interest. You’ll have to get some sort of video editor to pluck out the interesting parts into another video file. I use AVS tools for that. Even went out and bought it since I had known about it for years. It’s a really good suite. I have even used it to capture video from streams where the URL is too well hidden to use VLC. I had to use a capture window… but I was able to get it. It’s not as elegant a solution as capturing it directly.

            Your mileage may vary.

        • nothing confirmed, we are pondering what happened, possible four quakes of wet signature, possibly under H, but no (further) strain drop. Personally I whould put her onYellow, but thats just me.

          • Seems like IMO have given a kick to MJO and reset it.
            Strain just died away after two minutes of being offline.
            harmonic tremor seems to have been instrumental error.
            Still checking validity of quakes.

        • “FED is offline”

          Good Lord I wish. I’m getting sick and tired of loosing value in money just because it sits in a bank account.

          Did you know that if you lock the value of the USD to it’s equivalent 1934 value in gold, the market looks just like the shit pile that it really is? “record high” my ass. (note, this is essentially pricing the DJIA in gold based dollars.)

          Not for the feint of heart.

  23. Well, ’em quacks dont quack like a duck, they quack like an albatross.

    Due to a number of reasons it seems like I will not be able to do much with the earthquakes under Hekla. I could only really confirm one of them, but the locationing is impossible to make. The reason it did not show up is from it being very low frequency.
    And low frequencies earthquakes normally show up as way to large, so I would at least say they are a quarter of the size. And they do not spike like regular quakes.
    So, we had at least one “earthtross”, possibly more.

    • Ok. Earthly´tros they were. Interseting indeed. We likely are much nearer the muck.
      Question of them be running (hearing them runnig they could be Sheep, Goats, Horses or Zebras. Even Giraffes are possible, Moose or Buffaloes are not considered valid!)

    • Ah, Yes, Langtbortistan, always interesting, one completly forgets “Gates To Hell”™ 😉

      • Langtbortistan is same place as FarFarAwayLand, for then not knowing.

          • next to “WhereDidIPutThatVolcanoThing”… and negboring country to “OftenSerios-QuakeSwarmSouthZoneFlats” heavyly monitored by IMO.
            *apartment slowly filling with food-related-fumes, and I will be feeling very fed soon after next 30 minutes, nammi-yammi*

            • Here its gaining more strength, so able carry very heavy Armour 😉

  24. OT: A Short Rat Dog Story

    I only call them rat dogs because of their size. They are quite comfortable being dogs, and act the part appropriately. However, there are instances where situational awareness just isn’t there. They love to chase squirrels. The other day was the first time that I saw a dog run past the squirrel towards the tree, only to have the panicked squirrel overtake and pass the dog as it bolted for the security of the tree. The dog never even saw the squirrel. The last time I saw such a sudden and unexpected move like that there was a large number Three on the side of the car.

    The dog didn’t notice the squirrel until it rounded the trunk and took off up the branches. Stopping to admire it’s defeated opponent. “Yeah, I blew your doors off.”

  25. Like the one happening just now?

    Otherwise was forwarded the reason for the daily unrest seen at HAU SIL. There is roadwork there nearby and asphalt decking of both roads nearby (i.e. work-in-progress on both sides of Haukadalur.) This map explains, I put some Green colour on Hekla area. Technical details at Vegagerðin.is http://i43.tinypic.com/314tb14.jpg

    • Funny thing road work. My stepson used to drive for a local paving company. One thing I learned was that many tack trucks (those nasty vehicles that lay that black crap that gets on your car) are equipped with radar guns. The on board control unit uses it in figuring out how fast to lay down the tack.

      So, if your detector goes off while passing a paving crew, it isn’t necessarily the police officer that is typically there shooting the radar, though if you get his attention I’m sure that he would be more than happy to come talk to you. :D.

      Speaking of such… over south of Crestview, near Duke Field, a pickup sped into the paving/construction zone and killed a worker. Highway Patrol didn’t have to go far to find the driver. He met the business end of one of those pavement rollers. The pavement roller won. In fact, it barely moved if at all. I think the charge was DUI manslaughter.

      • Today I was buying gas from my favorite Chevron Station in Downtown La Grande, Or.
        The owners are a Korean Couple that emigrated here when their daughter got married
        to a local rancher’s son she met in college. Good folks. Like another Korean family I know.
        He’s ex- ROK army, and one bad dude,if you make him mad. sort of “Crouching Tiger”kind of guy. Any way I was filling up my van and Linny (the owner) was talking to me as we saw this
        sharp Mercedes C-class motor by, with these rather sharp-looking young women driving.
        trailing was this cheap Kia putt-putt car, driven by this rather slovenly guy who I think was
        enamored by the driver and passenger of the Merc. They signal and slow down as the they do the Kia driver doesn’t KA-BANG! he hits the back end of the Merc. knocking a small chunk out of the Merc’s bumper and basically dismembers the front end of the Kia to the radiator.
        leaving a mess of oil and antifreeze on the street. Linny looks at me and says:”That is why I
        and momma drive a Lincoln-drove too many of those Tin Cans in Korea!” “Looks like the
        Mercedes girls are not happy.”
        I Don’t think anyone was. The Kia drooled all over the street….

  26. Just finished writing and formatting the Nevado Del Ruiz post – should I email it to spica, or the VC email?

      • Just sent the post, you should be able to copy / paste it into wordpress and have it ready to go. I used photos from wikimedia commons, so there shouldn’t be any issues regarding ownership or copywrite stuff.

  27. It is now 30 years since the first pop music concert was performed in the Soviet Union.
    Back then they had gotten the idea into their heads that they should have a large tour with a large western pop band in the Soviet Union.
    They invited the French synth group SPACE (mainly just because space was big in the Soviet Union.
    What followed was a epitomal moment from the eighties. Long haired men with glitter in their hair performed in what looks like ABBA clothes with industrial argon-lasers strapped to their heads.
    At the same time you have clips of cold war moscow, uniforms, a tv producer constantly zooming in on party leaders and famous sports men. And a surprising amount of crying young people.
    One should know that except for a limited number of “troubled demented youths” nobody had heard pop music in the Sovit Union before this moment.
    This is a pearl for those who remember their cold war. It was never more eighties then this. Some of you might even remember the music. In Russia this is still seen as an iconic moment when the young people started to strive for freedom.
    For those to young to remember, this was from a time when people actually knew how to play, notice that Didier Marouani is one of the best keyboard players of all time.

    • “nobody had heard pop music in the Sovit Union before this moment”.
      Humm.. they had heard lots of western music, over The Long Wave Radio, mostly from Germany and Sweden, I guess, but probably not many had seen it performed.
      30 years ago .. thats just 1983, and the Soviet youth probably knew a lot more about Pop and Rock and Roll than they admitted, but not seen much of it up close.
      – I belive the hottest label was “Wrangler” cotton trousers ?

      • Yepp, you see some Wranglers in the opening sequence.
        The Radio Luxemburg long wave transmissions was not that effective since the Soviet Union controlled all radio production. They just blocked out the bands used.
        And the quote you used continued with a part about “troubled demented youths”. Up untill this moment pop music listening was enough for you to risk a visit to the asylum for a bit of reprogramming.
        But the point is that this is the first state approved listening of pop music. And not only did 1 million russians view the tour, they televised the final concert in Moscow and sent it out over all of the Russias.
        Pretty much they opened a can of worms. In retrospect this little concert had two effects, The Communist Party made Space into the biggest band ever in the Russias, it still is touring there in sold out stadiums. The other thing is that they started a cultural trend that in the end created a cadre of youth who wanted freedom and consumerism more then they wanted the USSR. It might be one of the moments that in the end toppled the Soviet Union due to change from within.

        • I went to various places in the Soviet Union in 1984. By far and away the richest and most desirable place to live – as evidenced by the large number of residents who had got rich off the system and gone to live there – was Estonia. The reason? Easy to pick up Finnish TV!

        • And it was you Carl who showed a video on this site of two ladies singing in a Russian “War Concert”. https://www.youtube.com/watch?v=-bBdFcdPJiQ The lady in question, in uniform, delivering a Russian song, was Elena Vaenga. Thanks Carl! I now have two CDs and loads of clips of her work, including stashed away a YouTube full version of the War Years concert. A fantastic Russian singer! And a bit better than “Space!”.

    • Not really fitting the genre of “pop,” but the keyboardist is not bad….

      Allegedly they played for Dmitry Medvedev in 2008 by request. I wonder how it was received.

      And some sort of interview with the band. At the end they perform one their most famous songs, “Smoke on the Water” done in what appears to be lounge music style. Very weird. All we need now are Leisure Suits for the band.

      Here is the normal version done at Montreux in 2006… which is where the events detailed in the song occurred in 1971.

    • Well, that was pretty amazing. Took me back to a time and place I had never been before, if that makes sense, which I guess it doesn’t.
      I watched all 1 hour 25 minutes of it (not something I would normally have done had it not been for a bout of insomnia). It starts off pretty slowly and gently and I was getting ready for some background muzak while doing some work on my other computer. But there are some pretty startling moments in it. The first song “prison” – “how can you sing when you are locked inside your prison” and the chorus of kids with their mouths gagged.. pretty strong imagery given the circumstances. I am surprised the authorities let them perform. By the end they were really rocking out and the sight of the audience letting rip as guards struggle to keep them in their seats is priceless.

      • Yes, I read the contents, did not take much notice of it otherwise. Found it intersting and put up link to this post. Why?

      • Chiefio has some good ruminations.

        He does take an unorthodox approach towards estimating the impact of the climate on success/failure of civilizations… not that different from what we do here when guestimating the volcanic effects.

        Now… if ya want unorthodox, my idea about OCS having a larger role in the maintenance of the Junge layer is about as out there as you can get. Sure, SO2 can load it up fast, but OCS would have a longer effect, replenishing and keeping the sulphate levels high over a longer time as it sediments out.

        But… even in that paper that Carl pointed me at, they don’t even consider OCS in the range of volatiles that they explore.

        For them that don’t wish to dig for the VC posted article… my idea in a nutshell.

        SO2 reacts and forms sulphate at the drop of a hat. Eruptions into a high humidity environment tend to leach SO2 from the column and lessens the amount that is available to reach the tropopause. This is based off of a paper that I read years ago, but do not have available for reference.

        As such, high latitude volcanoes generally have less humidity to deal with, and a lower tropopause to reach for.

        SO2 in the stratosphere (above the tropopause) form sulphate, which then (overtime) glom together into larger and larger particles. Once they get heavy enough, they sediment out and drift back to the surface of the earth. While doing this, they are found in the “Junge” layer… or the stratospheric aerosol layer. This layer is where sunlight is screened out and lessens the amount of energy that can reach the surface. In the VC post about it, I reference a paper that lays out a decay rate that sulphate concentrations follow. It fits known large eruptions effects on the climate, such as Pinatubo.

        But… that leaves us with a slight problem. How can not overly explosive eruptions, like Laki or Eldga have an effect on the stratosphere if their eruptive column probably didn’t make it that high? My answer is OCS (Carbonyl Sulphide) It is the most stable sulphur compound drifting around in our atmosphere. Able to ride the major circulation patterns and reach the tropopause (edge of stratosphere) as part of normal circulation. At these really high altitudes, UV-C light can get at the molecules. OCS dissociated under 200 and 270 nm radiation (UV-C). once that happens, it easily becomes sulphate. From there, if it has happened to have drifted up into the stratosphere, can become part of the Junge layer and screen sunlight.

        Yeah, its a bit of a wild assed idea, but it does provide a plausible (to me) mechanism that flood basalt events can affect the Junge layer over a long period of time.

        Standard Caveat: Not a scientist, not a geologist, not even a Short Order Cook, though I have made home made potato chips on the stove that impressed my wife.

        Now, back to Chiefo’s musings. Based on a rough estimate of SO2 vs Tephra volume from Hekla 2000, I come up with somewhere around 232.77 to 1114.46 Mt of SO2 for Hekla-3. That’s getting up towards the realm of Pinatubo’s estimated 10,000 Mt. Toss a nice fat OCS load up along with it to maintain that layer… well, it starts getting interesting.

        • it is good to ruminate, another reason I like VC, Scientist are by profession limited to many outside interests and money for research etc. a bid like a horse with blinkers

        • I really like your OCS idea. There’s been a recent paper released from Oxford on supereruptions “not being as deadly as thought” which really pisses me off as I have a half-finished article on this very topic and then the people with real cred go and beat me to it… oh well, the sorry tale of the amateur I guess. But it all goes back to the line of reasoning started with Taupo and how particularly large ash-laden eruptions don’t always end up in the ice record or even coincide with any obvious climate change. In other words those eruptions that do have the oomph to get up into the stratosphere (by several orders of magnitude) don’t have the correlating climate impact.

          People often talk of the Toba bottleneck for instance. Well, that bottleneck funnily enough only affects homo sapiens but not the other great apes, which does not tally with a volcanic winter hypothesis. Much more credible is the fact that homo sapiens had moved into the very habitat hit by ash fall whereas the other great apes were still living in the forested regions west of the rift valley and places like Borneo. Likewise Homo Florensis survived Toba but was only a few hundred kilometers away… but upwind.

          • Haven’t read it, so this is wild arsed speculation.

            Perhaps Sapiens had switched to a food source that was adversely affected by ash, that the other great apes were not using? Maybe some species of cricket was wiped out that made up 90% of the human food source. (Or some species of grazing animal.)

    • like the article something to look into, the more we know the better. We are living in interesting times, my grandmother used to say, there is nothing new it all has been here before, the older I get the more I seem to agree. Volcanic ‘winters’ and solar minimums seem to coincide with empire collapses in the past, so the future ……

      • Funny you should couple the two ideas. (Solar Minimums and Volcanic Effects).

        If you dive into it, catastrophes tend to be the result of a combination of unfortunate circumstances that each contribute their share to the “bad event.” Be it a chain of equipment/structural failures that leads to a news worthy event to the loss of a food supply and over predation that leads to an extinction.

        • I read a lot, always have, some of the old histories have a lot to tell us, one has to allow for customs at the time of an area etc. and apply the knowledge we have gathered in the meantime, plus a bid of common sense and we are in a new place and think we know it all, just for it to come crashing down, because we over looked something which is staring us right in the face, if we only had an open mind.

          • “because we over looked something which is staring us right in the face, if we only had an open mind”

            And…. that falls in with the 2nd part of Taleb’s Black Swan. It’s explained away after the fact. “If only we had known about…”

            It’s not really a matter of knowing about it… it’s about ignoring it because it lurks out in the thin nether regions of the tail in the Gaussian Distribution.

  28. Cbus20122 post about Nevado del Ruiz is in. Any dragon who wants to press the publish button, feel free to.

  29. Very interesting article! I’m Guatemalan and I’m doing a PhD studying Fuego volcano, so I was glad to see someone writing about Guatemalan volcanoes and about the risk related to their activity. I do have a several comments about the article, and I hope they won’t be taken as “malicious hair splitting”, but rather to further the discussion about these fascinating ideas.

    I’m pretty sure your first picture (which seems to be a high dynamic range picture, although I feel Agua volcano should look bigger in such a picture) was not taken in Ciudad Vieja but actually in Antigua Guatemala, from bellow the “Arco de Santa Catalina”, looking south to volcan de Agua (compare for instance with this image http://commons.wikimedia.org/wiki/File:2010.05.13.135948_Arco_Antigua_Guatemala.jpg). This picture pretty much shows what Antigua looks like today (on a day with not traffic? or maybe early in the morning?), including the no-parking signs, if you stretch your eyes a bit.

    Regarding the 1541 lahars, I guess nobody knows exactly what happened, but the early chronicles (see Remesal, 1619, and Feldman, 1993 for a compilation) agree that very intense rain happening for several days prior to the lahars, whether there was also an earthquake is not as clear, since references to the “earthquake that came from above” may just relate to the lahar and associated rumbling and shaking phenomena. The simplest hypothesis is that this resulted from an extreme rainfall event, which recur every so many years during the tropical storm season (the event happened on September 11, at the thickest of the storm season), an probably had nothing to do with volcanic activity, and maybe not even with any seismic activity. Recent examples of similar events at Agua include lahars and mudflows during tropical storm Stan in October of 2005, the rainy season of 2006, affecting the town of Palin on the E flank, tropical storm Agatha in 2010, affecting the town of San Juan Obispo on the N flank, etc. All such events only cause a few deaths compared with the 1541, but examples on other nearby volcanoes, like the lahar that destroyed Panabaj, on the flank of Toliman and Atitlan volcanoes during Stan in 2005 shows that such events have the full potential to cause a similar disaster, entirely related to extreme rainfall. But maybe an earthquake also contributed… but this we will probably never know.

    The controversy about a crater lake breach is also difficult to settle, but I don’t think there is any good evidence for the crater lake hypothesis. None of the original sources (eyewitnesses) that I know mention a crater lake, although I neither aware of any description of Agua’s summit before Remesal’s account of a climb in 1615. Two other lines of evidence suggest to me that the crater lake breach hypothesis is unlikely. First there is no evidence of lake sediments on the current crater (although the crater is partially filled with colluvial material from the inner walls), suggesting that a long term lake probably didn’t exist within the crater. Secondly, the breach in the crater drains to the wrong barranca, and therefore a crater lake breach probably wouldn’t end up in Ciudad Vieja (or what today would be San Miguel Escobar), it would instead end up either in San Pedro Las Huertas or San Juan El Obispo. As I mentioned before, a crater lake is unnecessary to explain a lahar associated to heavy rain, and for the lack of evidence of such a lake, it seems more likely to me that the lahars were just caused by the collapse and transformation of saturated flank material.

    The story of the Antigua moving, first contemplated in 1717 and finally done in 1776, after the Santa Marta earthquakes, is full of political intrigue and power struggles between the religious and civil powers of the time, and the natural events (eruptions and earthquakes) were used by both parties (those who wanted Antigua to remain as the capital, and those who wanted to move it) for or against the move, and in the end the decision was probably motivated by many other reasons than just the obvious “natural hazards threat”, as always, things are more complex than they seem at first. There have been a few very interesting analysis on this, and for an in depth analysis you can read Christophe Belaubre work (http://www.revistas.una.ac.cr/index.php/historia/article/view/1754). In any case the new Capital General, Martin Mayorga, finally prevailed over Cortes y Larraz and the capital was moved!

    The volcanological relationship between Acatenango and Fuego is a difficult one to assess, given that we know relatively little about both volcanoes. Geochemically they seem different in some aspects, with Acatenango having some more silicic rocks, but there is broad overlap in compositions (see a plot of the whole rock TAS that I made from the CENTAM database here: http://www.geo.mtu.edu/~rpescoba/downloads/Whole_rock_composition_TAS_diagram_Fuego_and_Acatenango.tif).

    (Image placed inline by GL. See link for original version. For R E Wolf, if this is not acceptable, please advise and I will remove it.)

    I suspect that this difference would decrease if we do more sampling of Fuego especially of the older rocks, as the sample dataset may be skewed towards younger products (e. g. 1974), and in general I think that so far we have only scratched a tiny bit of Fuegos eruptive history, this may be difficult because having Fuego been so active in the last few thousand years it may be difficult to find outcrops of older rocks.

    I did not understand the comment on the blog stating that “some researchers have extemporized that the magmatic system of Fuego runs through the magmatic system of Acatenango. The reason for this theory is to explain that some of the eruptions of Fuego carry magmatic signatures from Acatenango, but Acatenango never have the magmatic signature of the bulk of Fuegos eruptions”. What does that mean and where does the idea come from? I am aware of the hypothesis by some authors (e. g. Chesner and Rose, 1984) that magmas from both Fuego and Acatenango may have in common that they pond at the base of the crust, and then ascend through the crust to shallower independent reservoirs, but I think that’s different from what the blog post says. Maybe I’m not getting it right?

    Overall I don’t see any evidence that Acatenango produces bigger eruptions than Fuego, and in that sense I don’t know what to make of the blog statement that “Historically Acatenango has not suffered from frequent eruptions. Instead the eruptions have tended towards being larger than the eruptions of its twin Fuego.” To my knowledge, the only Acatenango eruption for which there is any quantitative estimate of volume (eruption P-4 in Basset, 1996) has a min volume between 6.3 x 10^7 and 1.3 x 10^8 m^3, which would put it in the VEI 3 – 4 category range, similar to the 1971 and 1974 Fuego eruptions, and probably similar to those in 1932, 1880, 1717, 1581-82. The 370 BC pyroclastic flow mentioned in the blog entry, and which I assume would correspond to the sample AC.196 from Basset (1996) with a radiocarbon age of 2330 yBP, reached a distance of ~ 10 km from the Pico Mayor (Acatenango) crater, and although it would have been a large pyroclastic flow, the distance it reached is comparable to many of Fuegos pyroclastic flows. I think overall, both volcanoes can produce similar large eruptions, which is in itself very worrisome.

    As you mention in the blog, the 370 BC pyroclastic flow would have cause a lot of damage if it would have happened in recent times, mainly because it’s on the other side of San Pedro Yepocapa (you can download the google earth .kmz file with the location of the sample as given by Basset, 1996, from here: http://www.geo.mtu.edu/~rpescoba/downloads/Pyroclastic_Flow_AC196_Basset_1996.kmz ).

    Now the topic of evacuations is a very hairy one. It is very clear that a big eruption from Acatenango can easily destroy the towns around the volcano, but when such an eruption may happen, and therefore when to evacuate, is a very difficult question to answer. There have been at least two forma hazard assessments done for Fuego and Acatenango, the last one by Jim Vallance et al. (2001), which can be accessed here:
    Some larger (thousands of people) towns that could be within reach of eruptions like those happening in the past include San Pedro Yepocapa, Acatenango, San Antonio Nejapa, San Miguel Dueñas, and Alotenango, depending not only on the size and character of the eruption, but on the location of the vent (e. g. Yepocapa vs Pico Mayor). Calling for the evacuation of several tens of thousands of people, especially if the crisis extends for days or even weeks, and may not end in a catastrophic eruption, can be a very difficult decision. The people at CONRED (Guatemalan disaster reduction agency), the local authorities and most than anyone else the people at risk, would certainly face a hard choice. And one could ask hypothetical questions, like: should an evacuation be called for a crisis like the 1924 – 1927 eruption? What about the 1972 eruption? And if so, who should evacuate? Compared to what has happened at Fuego in recent years (e. g. September 13, 2012), these were really minor eruptions, but the potential for a catastrophic one is always there.

    The record of eruptions at Fuego is also a controversial matter, which I hope I will be able to clarify at least a bit with part of my dissertation. The GVP lists 7 eruptions possibly having a VEI of 4, which are basically the same as those classified as “fuerte” by Meyer-Abich (1956), plus the 1974 eruption and excluding the 1953 eruption, which is given a VEI 3 in the GVP; but some of those older eruptions, like the 1737 eruptions may not have been that big or may not even have happened at all. It seems that at least the 1581-82, 1717, 1880, 1932, and 1974 eruptions were most likely in the VEI 3 to 4 category, and probably many more were at least in the VEI 3 category (e. g. the many eruptions happening between 1702 and 1717).

    The blog entry states that “Two VEI-4 eruptions are documented, the last in 1974 when it had numerous pyroclastic flows killing residents in nearby villages.” Is this saying that the pyroclastic flows killed people? Or is it saying that the eruption overall (possibly due to other hazardous phenomena) caused those deaths? To my knowledge, there are no confirmed fatalities due to the 1974 eruption pyroclastic flows, although there were a few casualties from collapsing roofs due to airfall tephra accumulation. There have been also casualties due to the lahars.

    I also have to take issue with your comment stating “What is lacking is good mitigation with pre-prepared evacuation maps from the valleys most affected by pyroclastic flows and lahars”. I don’t exactly know what you mean with “evacuation maps”, but I don’t think how maps would really solve the problem of preparedness and crisis management in this particular case. With all their limitations, CONRED, INSIVUMEH, the local authorities, and of course the people in the villages themselves have made a big effort over the last 10 – 15 years to improve their capacity to respond to volcanic crises. Whether or not such efforts are fruitful or not is difficult to evaluate, and may only be assessed with some degree of clarity in the aftermath of a (hopefully “successfully” managed, whatever that means) real volcanic crisis. My perception is that this will depend a lot on how the potentially destructive crisis unfolds from the volcanological point of view. As the situation is currently my gut feeling tells me that, if it develops very quickly without clear and scary precursors, producing large pyroclastic flows that reach the communities, it may end in tragedy. But if it develops more gradually and there are enough (clear and scary) premonitory signals, there are better chances that a large amount of people will evacuate. Heavy tephra fall in their communities may be in the end what could save people from the pyroclastic flows! Again, the September 13, 2012 eruption is something we should look at more closely to get a better sense of people’s potential response to a future crisis. In any case I see the current efforts, including the simulation exercise done at Fuego last week, as a good thing and a step in the right direction.

    I think your comment “Also the will to evacuate and being evacuated is slightly low locally, something that can be understood if one think about that the people in the villages are really poor without the means to support themselves if they evacuate.” is a really important one, and I totally agree with this. The issue here can’t be isolated as a solely volcanic hazard driven problem, especially in the context of uncertainty.

    Finally, your closing remark “If you think this was bad choice for cities” is a very interesting one, because it shows the perspective of someone who obviously is focused on the volcanic (and seismic?) hazard issue, but is not seeing the complexity and myriad of other things that may go into choosing the “best” place to settle a city. I agree with you (I have to, I’m a volcanologist/geo-hazardologist) that it would make sense to avoid geological hazards as much as possible, but I also recognize that avoiding climate related disease, having nearby fertile soil and water (especially in the context of the XVIII century), having some protection against potential military threats, etc, etc, and many more etc’s, certainly also played an important role. Putting the capital city in the northern lowlands of Peten, far away from most volcanic and seismic hazards may in the end not play out that well, if you don’t believe me just ask the Mayans…

    I encourage you to keep writing on this fascinating topic, and I will be looking forward for the next installment of A Tale of Three Cities.

    Edit: rescued from dungeon by UKV (new commenters seem to disappear there until ‘approved’. If I knew how to move this to the ‘live’ topic I would. Anyhow – very warm welcome to VolcanoCafé!!

    • Just a quick correction, my comment on the picture of Agua volcano was not for the first picture (which is obviously of Fuego) but for the second one in you blog post (see also comment by Steph). Thanks!

      • Thank you so much for sharing your knowledge!
        Humanity has thrived on the good soil around volcanoes for ages and it is no coincidence that population density maps look like volcanic hazard maps all over the world. It is a blessing nowadays that dedicated experts like you may save people from the devastating effects of the next load of “fertilizer”.

        Carl will certainly appreciate your in-depth comment when he is back from his trip with “crappy internet connection”.

    • A most excellent follow comment! Thank you very much!

      For All, Re: Tropical Storm Rainfall Rates. Here in Pensacola, a few months ago, we had a rainfall of about 21 inches in a 24 hour period. That system was not a tropical storm at the time, it later drifted out into the Gulf and became a storm that gave South Florida a large amount of water. Personally, I have seen rainfall rates up into the tens of centimeters per hour. When tropical system run up over mountain ranges, they tend to unload water like it’s going out of style.

  30. The second photo in this post was taken in Antigua under the Santa Catalina Convent Arch and it was not taken by Jean-Marie Hullot, but a photographer named Dave Wilson. See original photo from Dave Wilson here: http://www.flickr.com/photos/dawilson/2557500872/

    I believe the confusion may have entered because Huillot created a Fotopedia page for Volcan de Agua including this photograph, without a caption specific to the photo. See Fotopedia entry here: http://www.fotopedia.com/albums/5533542b-6046-49cc-a8e0-02516b9ffedf/entries/36f7d1f3-81b8-488c-a351-a6cf2c0c3289

  31. I was about to correct your caption on the “Ciudad Vieja” photo but I see Steph has already beaten me to it! This image was shot in Antigua in summer 2007 and post-processed to make it look more like a painting than a standard photograph.

  32. Pingback: Comments to A Tale of Three Cities | VolcanoCafe

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