Masaya Volcano: the mouth of hell

As most of us are aware, a lava lake appeared on the crater floor inside Santiago Crater on Nicaragua’s Volcan Masaya back in December 2015. This however wasn’t the first time Volcan Masaya hosted an active lava lake, Masaya has had a history of having a lava lake appear and disappear over the centuries and it goes back to the time of when the Spanish Conquistadors first conquered the land what is now today’s Nicaragua. The Spaniards having observed the lava lake activity had nicknamed it “La Boca del Infierno” or “The Mouth of Hell”. To give a brief geological background, Masaya Volcano is located within the El Ventarron or Masaya caldera built upon the Pleistocene pyroclastic shield volcano Las Sierras. There are four main craters, Nindiri, San Pedro, Santiago, and Masaya. Parasitic cones dot the flanks and a lava field is prominent towards Laguna de Masaya on the east flank of the volcano. Volcan Masaya is one of Nicaragua’s most active and unusual volcano which lies within the chain of volcanoes along the Central America subduction zone. This dominantly basaltic volcano has produced the odd explosive eruption as well as hosting lava lakes.

View of the 2016 lava lake at the bottom of Santiago crater. IMAGE: Richard Roscoe (

View of the 2016 lava lake at the bottom of Santiago crater. IMAGE: Richard Roscoe (

The early years of discovery

We go back to the year 1524 during the time the Spanish conquistadors had invaded The New World and at that time the Spaniards had witnessed volcanic activity from Masaya and Momotombo volcanoes. But it wasn’t until 1529 when the first known expedition to Volcan Masaya was conducted led by Gonzalo Fernandez de Oviedo y Valdez along with a local chieftain and three servants. They left Managua on horseback on 25th July 1529 and arrived at Laguna de Masaya before starting to climb at night where Gonzalo describes forcing his way through rough terrain, a reference to the lava fields on the east side of the Masaya caldera. Eventually, they reach the top and this is where Gonzalo Fernandez de Oviedo y Valdez describes a huge abyss which had a “plaza” so huge and round that “a hundred horses could play cañas in it” and a hole was present towards the south border of the plaza. Inside that hole was a lava lake, he just discovered where the source of the “glow on the mountain” came from. Gonzalo describes the lava lake at the bottom of the hole as “fire that was liquid and burning more fiercely than red hot coal” and further describes the behaviour as matter which was boiling in some parts and changing from one place to another and bubbles which reappeared here and there. From stories collected from the indigenous people it was suggested that the source of activity was previously located in the Masaya crater (now inactive), but when the Spaniards discovered Masaya Volcano it was in the Nindiri crater which was then the centre of volcanic activity.

Fray Blas del Castillo was the next person who conducted a significant expedition 9 years later, he described the crater containing the lava lake as being like “a bell turned upside down and getting narrower towards the bottom”. He then described the lava lake as having two main lava fountains with a lava spring towards the east-northeast wall with a dense cloud of smoke coming out from the cave towards the lava lake. He descended into the “plaza” on several occasions believing that the lava lake was molten gold or silver and wanted to extract samples of it. His first descent of the crater came on 13th April 1538 when he walked onto the crater floor full of ashes and basaltic rocks without technical support and holding only a wooden cross in one hand and a hammer in the other. Believing that the lava lake was molten gold and not wanting the rich to know about it, the expedition was carried out in secrecy among Fray Blas del Castillo and his companions. They spent months studying the site and the crater, and eventually brought along some equipment including chains, ropes, and containers in the hope of extracting what they thought was gold or silver. Blas del Castillo descended into the crater again in a basket and wore an iron helmet, he took with him a hammer, a flask of wine, and not forgetting his trusty wooden cross. On the ground and among some cracks emitting sulphurous fumes, he hammered away at the rocks collecting samples for over 3 hours and even hammered away at the bright crusts believing it to contain molten silver. The hole with the “molten gold” in it was in the middle of the “plaza” and it was bigger and deeper than what the party thought it was, so they were going to need more manpower and more equipment if they were going to extract the “gold”. Soon afterwards, men worked hard day and night to install pulleys and devices and they used a chain to lower the iron container into the crater to collect samples. At one point, the container got stuck and was difficult to get off but eventually they freed it with a semi melted sample. Tired, the expedition party decided to call it a day and returned to their respected places of residence and realised more chains would be needed. Word had eventually got around of the presence of the “molten gold” inside the crater and upon hearing the news, the Governor Rodrigo Contreras orders Fray Blas del Castillo to make another descent into the crater and he wanted to be present this time. On the 30th April 1538, the friar Blas del Castillo along with 7 other men descended into the crater and final managed to submerge the iron container into the melted matter after unsuccessful attempts and hauled it up full of scoria and so they managed to get their samples. Eventually, the iron container became glued to the melted matter on another attempt and the chains broke. Soon, the samples were studied and they were found not to be gold nor silver, much to the disappointment of the Governor Rodrigo Contreras who then banned Blas del Castillo from carrying out new prospectings. Fray Blas del Castillo later died upon his return to (what is now) Nicaragua from Spain after receiving authorisation from the king to find more potential gold. He was the first volcanologist of the New World.

Despite the samples being discovered not to be of gold nor silver, this did not stop other people from believing the lava lake to be full of riches and having plans to exploit it. Juan Sanchez Portero who accompanied Blas del Castillo on the second descent into the crater obtained authorisation from the king in Spain but despite that, the governor wouldn’t allow him to carry out his plans. In 1551, the Dean of Leon Cathedral had big plans to use 200 slaves to dig a tunnel through the crater wall to drain it of the “gold” but was refused. In 1573, the friar Alonso de Molina got authorisation on condition that 1/5 of the riches will go to the king and in 1586, Benito Morales had authorisation but by then the lava lake had disappeared.

Not only was Volcan Masaya thought to contain riches, it was also associated with superstition from both the indigenous people and the Spaniards. Back then, the Spaniards were more religious than they are today because science in those days wasn’t understood well as it is during present day. It was thought to be “the mouth of hell” and it even prompted Fray Francisco de Bobadilla to climb the volcano in 1529 to erect a cross overlooking the crater in order to exorcise the demons and hell, a cross which still stands today. The indigenous people thought of the volcano as a god, they made offerings and also human sacrifices by throwing children and virgins into the lava lake, how charming! It is also said that a sorceress made an appearance inside the volcano when the local chiefs seeked advice.

So based on early accounts and information of Masaya Volcano, this indicates that only two craters existed back then which were the Masaya and Nindiri craters, the latter hosting a lava lake. The lava lake however wasn’t the only activity which was observed during the early years, Fray Bartolome de las Casas recalled that explosions occurred especially during rainy season when “the fire explodes with great fury”.

The lava flows and the emergence of Santiago crater

Fast forward to the year 1670, and the lava lake had progressively filled the Nindiri crater, it is said that it grew as wide as 1000m. Eventually, the lava overflowed the crater rim onto the north flank flowing for 2km and evidence of that can still be seen today. The location of the lava lake overflow of 1670 is just at the northeast point of today’s San Pedro crater.

In 1772, a fissure eruption occurred to the north of Masaya crater during the early hours of 16th March 1772 after being preceded by 2 hours of strong earthquakes. Lava flowed continuously for 8 days to the north eventually overflowing the caldera rim and parts of it branched out across the caldera walls, one branch flowed into Laguna de Masaya.

In 1852, further activity was observed in the Nindiri crater when lava was erupted onto the crater floor. Then in 1853-1859 saw the formation of two new pit craters, Santiago and San Pedro respectively. Santiago formed in 1853 with an initial diameter of 80 x 65m, later expanding to 600m wide during 1858-59. A column of “flames” and ashes was reported on 27th January 1859 and again on 27th March 1859. The Santiago crater later became the location of most recent activity on Volcan Masaya and it still goes on today.


The summit area of Masaya Volcano. IMAGE: Google Earth. Annotated by René Goad.


Activity of modern times

The formation of the Santiago and San Pedro collapse pit craters exposed the alternating lava and tephra layers in the crater walls especially that of the formerly active Nindiri crater. Santiago crater often displays degassing activity and episodes of collapse events have occurred inside the crater whether it originated from the crater walls or on the crater floor. Sometimes collapses on the crater floor have revealed some incandescence or even a lava pool. These vents would sometimes display weak strombolian activity and sometimes these vents would eventually get blocked up again following a collapse inside the crater. In some cases, a collapse on the crater floor had progressed into an emergence of a lava lake and Volcan Masaya does have a history of lava lakes appearing and disappearing over the centuries. Ok, I won’t get into too much detail now so I will focus on the significant activity which occurred up to present day beginning with 1965.

In 1965, a lava lake formed inside Santiago crater which somehow was reduced to a small central spatter cone by 1969. However, effusive lava flow activity continued on the crater floor. In 1972, the spatter cone collapsed and a lava lake was visible until 1979.

During the 1980s, the activity predominately consisted of gas emissions. Collapse events had also occurred inside the crater and incandescence was observed. The odd small explosive eruptions had also occurred, one of the largest came in 7th October 1982 when ejecta and tephra covered an area of 150,000 square metres which killed a few trees and animals that were near the summit and also melted parts of asphalt on a road. During February 1989, a lava lake had emerged in a new collapse pit but then apparently disappeared in March 1989.

A lava lake once again appeared inside Santiago crater in 1993 but had gradually cooled by 1994 and was reduced to an incandescent vent on the crater floor. Strombolian explosions had occurred in 1993-94 and again in 1997-98.

On the 23rd April 2001, an unexpected larger than normal explosion had occurred catching a group of tourists by surprise. Fortunately, there were no fatalities and only minor injuries were sustained but vehicles were damaged by ejecta. In one incident, a volcanic bomb penetrated the roof of a bus landing in an unoccupied seat and in another incident, a bomb embedded itself in the bonnet of a car. The grass close to the car park caught fire. Ashfall was reported near the village of Ticuantepe.

During 2003-05, incandescence was observed in the crater again while intermittent ash explosions and collapse events were also observed. A landslide event during the night of 2nd March 2005 may have blocked the active vent which caused the gas plume to diminish. Explosions occurred in 2006 and again in 2008, and a new vent on the crater floor of Santiago was reported in 2006. Degassing continued.

Moving on to more recent years now and incandescence was observed inside the crater in 2010, and during 2011 crater wall collapses occurred causing the active vent to be blocked by the debris which in turn prompted the brief closure of the national park. In 2012, around 68 explosions occurred between 30th April and 17th May of that year. The initial explosion on 30th April 2012 ejected blocks and a column of ash up to 1000m above the summit and smaller explosions which followed ejected material up to 500m. Hot blocks which fell on bushes started fires which prompted staff at the national park to close the park following hazardous conditions. Incandescence inside the crater briefly appeared during April 2013.

During December 2015, INETER reported that magma had risen to the crater floor resulting in the formation of two incandescent vents which marked the beginning of the current volcanic activity on Volcan Masaya. By January 2016 the vents expanded revealing two lava lakes at the bottom of the crater floor before a third lava lake emerged during early February 2016. The lava lakes grew in size into February 2016 and the odd small explosions had also occurred during January and February. By March 2016 the lava lakes had merged into one and had risen in level by then, and the lava lake activity is still going on now during the time of this writing. During the activity of March 2016 a torrent of lava was observed pouring into the lava lake and was caught on camera.


After reading about the early accounts of the early expeditions to Masaya Volcano I’ve gained admiration for the Spanish friar Blas del Castillo, a brave man who knew he was taking risks by daring to venture inside the crater and extracting what he thought must’ve been molten gold or silver which turns out it wasn’t. As far as volcanic activity on Masaya goes, the activity predominately consists of gas emissions and also lava lake activity (when there is one). Small strombolian explosions occasionally occurs but as history tells us, Masaya is also capable of producing larger explosions ejecting blocks outside of the crater. Fissure eruptions are possible but very rarely does that happen. The 2016 lava lake may eventually disappear in the long run but I’m sure lava lakes will keep re-appearing during our lifetime. According to data by GVP, a population of about 989,888 lives within 10km of the volcano as there are quite a few settlements scattered around the Volcan Masaya area. The local population are prone to health hazards if a sulphur dioxide plume is blown in their direction and crop damage also occurs.


Video 1 – Drone footage of the landscape around the summit craters (prior to the current lava lake). Video credit: Chris Mayorga.

Video 2 – Lavafall cascading into the lava lake during March 2016. Video credit: Richard Guevara.

Video 3 – The current lava lake activity on Masaya Volcano. Video credit: Marc Szeglat.


Masaya, the “Mouth of Hell”, Nicaragua: Volcanological interpretation of the myths, legends and anecdotes – Jose G. Viramonte and Jaime Incer-Barquero.

Pit crater structure and processes governing persistent activity at Masaya Volcano, Nicaragua – H. Rymer, B. Van Wyk de Vries, J. Stix, and G. Williams-Jones.

Global Volcanism Program

90 thoughts on “Masaya Volcano: the mouth of hell

  1. A 1 km wide lava lake?

    Well, uh, that’s a thing. I can’t even begin to imagine the apocalyptic sight that must have resembled for the people who got a chance to witness it. Anyone foolhardy enough to get close to make estimates or observations back in those days deserves to be remembered, because that takes serious guts.

  2. A fascinating story! It must have been unbelievably hot, to get a sample from the lava lake without any protective shield. Thanks Rene for this post!

    • Good old friar Blas del Castillo for having the guts to get inside the Nindiri crater.

    • I left a sarcastic comment on that article accusing the DM of turning an innocent study of the earth’s CO2 cycle into a doom-laden explosive we-are-all-going-to-die story. Ramping up the sarcasm, I noted they’d missed out on a secret UFO base being discovered in the “potentially exploding” CO2 reservoir. I think that was too much. They squashed my comment.

      This story was an absolute pile of excreta, even for the DM!

      • Well, when I clicked on the article-thought:”How are they going to work Yellowstone into this…?”

    • Without being cynical, but with the experience of BSE and lung research, some georesearcher(s) somewhere is worried about maintaining funding.

      Same thing is currently a UK anti-diesel panic, probably generated by car manufacturers and air purity/lung research both keen on more funding. The logical thing, to ban diesel cars built before 2001, as done by Paris, would sadly remove pretty well all London busses….

      Whatdayamean of-topic????

  3. I do find the following comment somewhat offensive: “Back then, the Spaniards were more religious than they are today because science in those days wasn’t understood well as it is during present day”. Why are scientific knowledge and religion mutually exclusive? Both statements may, in fact, be true, but assigning causality may make the entire statement untrue.

    Recovered from the dungeon of Akismet – Admin

    • Editorial remark:

      You would need to put in historical context. Back then the catholic Church was rather “ambivalent” in their opinion of science. Nowadays the same Church is the one most in favour of science among the Worlds christian sects.

    • I agree with your comment: science and religion can co-exist well. It is also true that in those days, people would have looked at these volcanic phenomena quite differently – and we still talk about Pele. But the goal of the investigators was clearly financial gain, not religious benefit, even if carried out by a priest with a cross. Many people will do for money what they wouldn’t do for love.

    • Because religion is archaic, backwards, superstitious nonsense which should be entirely irrelevant by now. That’s why.

      • mjf, please be nice. Just because you don’t hold religion close to your heart, other people do. Let’s not start a comment war on this.

          • I appreciate the replies to my thoughts. Very thoughtful and respectful.

            This is a great forum and I’ve been lurking for years and enjoy reading these very well-researched posts.

            Back to lurkerdom!

      • I think the point I was trying to say in the article was that nearly all of the Spaniards (and also the natives) didn’t know what a volcano was back in the 1500s so it was either thought of as a god, or thought of as a portal to hell. So science wasn’t understood well back in those times.

        By the way, I believe there’s a God but that’s my own personal business. Not that it’s got anything to do with this so let’s not sidetrack.

        • You’re article is very clear. I’m sorry if I may have been a bit too strong with my original comment. Moving past this, will you be detailing the massive explosive Masaya eruptions at some point in the future?

          • Another post might be on all the weird-and-wonderful schemes the good folk of Nicaragua have employed to alleviate the SO2 pollution they get from Masaya when the lava lake isn’t performing. Using the Air Force to drop bombs into the crater was one, I seem to recall.

  4. Estimated “11.62 inches of rain over the next 10 days…”


    • Lucky them. A 7week deluge to provide the water needed for the next 7-year drought. I am sure there are plenty of places to store it for future use. Talking about which, how is that dam doing?

    • Interesting indeed! This clearly demonstrates how consistent the inflow of magma is under Grímsvötn.

      Ian, did you see my ruminations in the end of the comments section of the previous article? It’s about moment tensor analysis and interpretation of earthquake mechanisms in Bárðarbunga before and during the eruption. I would have liked someone else to comment on it, but this new (and truly awesome) article got in the way.

      • Changing nick apparently puts you in the dungeon to rest for a while.

        Apparently it does. Akismet never ceases to amaze. Did you like the dungeon?

        So that’s who ate all the cookies!

        • Cookies? I didn’t find any cookies. All I could find was an old hat stashed away in the darkest corner. I left it there for later if anyone else gets hungry 😀

          • Beats what I ran across yesterday. All the clerks in the office were yammering back and forth at each other about the hyper sweet cupcakes in the break area. But were shy about the one made with bacon.

      • I did see the moment tensor analysis and took a really quick look and will get back to look at them closer. Not that I know a whole lot but I have learned enough to maybe give a few thoughts. It looks really interesting

      • I wrote a piece about finite element analysis of Grimsvötn as a predictive tool a while ago.

      • Sorry, just been so busy and had a few moments to put these up. They are from an IMO Powerpoint posted on their public pages along with the plot above

        Did not notice there is not IMO logo on the pictures

  5. Two images, cross-section, in the light of the earthquakes on the eastern side of Katla. That region does look interesting, since it does have direct linkage to the mid systems and is above the main intrusion areas.
    So we have a cross section of that eastern cluster, and the cross section across the two main areas, or vents in the caldera itself, which also shows nice vertical stacking, which is typical for a vent, similar to what we saw at Eyjafjallajokull.
    The cross section line has EQ data 1km wide. So its not a clear cut cross section, but the line takes an area 1km wide along the transect line.

    The view is from west to east.

      • Probably has a minimum of 2 years tactical training 😀 Special assault program… True story…

    • It is a bit small: we could call it a dwarf-continent (and rather wet: in-continent?) But it might be better to just re-instate Gondwana. That was a real continent. They don’t make them like that anymore.

    • When I was little, some 50+ years ago We would go to Yosemite to watch the fire falls.

      They would build a bonfire at the top of the cliff then push it over where it would fall 1000 feet or more. (I think the rim is around 2000 feet.)

      What I really remember was the sea of late 1950s and early 1960s cars filling the meadows in the valley. That was the real reason they stopped. The cars were tearing up the place parking on any flat space off the road. Y is about a 2 or 3 hour drive from the N. Cal population centers and 4 or 5 from the LA region.

      Not as fun to go there anymore with the millions of people that now visit (even with the auto limits and restrictions.) It really has an urban feel. I think the last time I went about 18 or so years back, they even had a video rental store. People had TV antenna on their RVs. This is part of the greater SF Bay area TV market, it is weird to see the local new on the hotel TVs.

      Used to also go hiking in the back country, when in high school, with a church social group. When we got to college age, one of the members went hiking alone, fell 2000 feet to his death. Another time I was there when someone (not in our group) was swept over Nevada falls. They were playing in the pool at the top. One can not see the current, the water is so clear. When our group came back down the search and rescue was looking for them said that the body might never be found or found months or years later.

      Pretty to look at, but it is not Disneyland.

  6. I have a question if someone might know the answer. Its not a hard question, but it is a confusing subject and I am not sure what is correct.

    Lets say we know that an X volcano has a magma chamber the size of 100km3.
    We also know that only around 10% of the chamber volume actually erupts to the surface.

    So in our case, that would mean theoretically that our X volcano will in a theory case erupt 10km3 of material.
    But is that material DRE or the tephra/ejecta volume?

    That is my question. Does the magma chamber volume count as DRE? Since it is under great pressure, I cant really imagine it as equally to tephra/fallout volume.

    So if our volcano erupts 10% of the magma chamber (100km3) does that mean 10km3 DRE, and actually around 30-40 km3 ejecta volume? Or does it interpret to 10km3 total ejecta and around 2km3 DRE?

    Confusing stuff

    • For effusive eruptions, it is the lava that goes, and so 10% of the lava volume would be 10km3 DRE. There is a small correction because magma is 10-20% less dense than the rock it comes from (and the DRE is in rock volume) but I am not sure anyone makes that correction. Some parts of volcanology seem a bit handwaving. But explosions are different, as there is actually rather little lava involved. Most of it is pulverised rock. Same as with real explosions: most of the flying debris is not TNT but bricks and mortars. The lava comes up later, through the hole made by the explosion.

      • “Some parts of volcanology seem a bit handwaving”
        You made my saturday afternoon with that comment 🙂

        10 Points!

    • For explosive eruptions, the general rule is that the DRE volume will be 40% of the bulk volume. So, if a 100km3 chamber is 10% emptied, this will result in a 25km3 bulk ejecta eruption. Of course, this isn’t what always happens, but works as general guide. Another example is the Fish Canyon Tuff eruption which emptied a 2000km3 chamber and resulted in a 5000km3 bulk deposit. Basically 0.4km3 DRE = 1km3 bulk.

    • This is not so easy at all Andrej!
      If we separate regular eruptions from caldera events it becomes easier.
      I am here going to use the 500km3 magma reservoir (total system) of Grimsvötn and compare it to Yellowstone.
      Yellowstone has a total volume of roughly 2000km3, but the amount of eruptible magma there is 5 percent, so it only has 100km3 of eruptible magma suspended in non eruptible magma as chrystal mush. Whereas all of Grimsvötns magma is eruptible.
      So, first we would have to look at the quality of the magma.
      So, currently the largest possible eruption at Yellowstone would be around 10km3 and at Grimsvötn it would be 50km3 without additional magma entering the two systems.
      In reallity the magma of Yellowstone is too stale to erupt without a fresh intrusion, whereas Grimsvötn is good to go at any time (geological time).

      Now we are ready for your question(s) Andrej.
      During regular intra-caldera eruptions (explosive) the total DRE volumes go between 1/5000 (1998) and 1/250 (2011) of the total magma volume (DRE) at Grimsvötn. The 1998 eruption is to be seen as smallest known and 2011 as the largest known intra-caldera normal eruption from Grimsvötn.
      Rift eruptions from Grimsvötn range between 1km3 DRE (Gjálp 1996) with minimal ash and tephra to 15km3 lava with 10km3 tephra (Laki) (total 14km3 DRE). This gives eruption sizes between 1/500 and 1/36.
      Now we have come to the caldera events of the Saksunarvatn tephras, the largest holocene Icelandic eruption sequence. Those 5 caldera events are not only the largest known sequence of caldera events at any volcano on the planet, they also happened in a very tight timeline (less than 500 years). The total amount ejected is 150km3 (DRE). The sequence spanned from 5km3 (DRE) to 50km3 (DRE).

      There are many things that are odd about these eruptions, first of all the tight proven sequence of them. There was almost no recharge between them. They where also so powerful that they left less ash-thickness in Iceland than they did at the Faroe Islands and in Norway.
      If you Count them as separate events you get eruption volumes of 1/100 to 1/10 of the total magma reservoir volume, but if you see it as a serial-event then you get a grand total of 1/3.3 (DRE).

      My Point was that it is very seldom that 1/10 of a volcanoes magma reservoir is erupted regardless if you Count it as DRE or not. At the most powerful volcano on Earth we only get 1 single eruption that comes up to the 1/10 size among thousands of eruptions from that volcano.

        • It is probably one of these subjects I should do a post about, I Think any comment on it would be to dense to make a good Reading… 🙂

          • I disagree, it’d still make good reading regardless of the density/heaviness of the subject matter. I’d be very interested in hearing your views on it and trying to understand the secretive ice kettle…

          • I agree with Beardy Gaz. It would make a highly educational post, and for many also perhaps eliminate a misconception or two along the way about this subject, like this comment did for me 😉

  7. OT and FYI…

    It is now six months since the last Sakurajima eruption and nine months since it last erupted at all regularly in its usual style. I can’t recall the last time it took a complete pause of anything like this length.

    What’s it up to? Magma supply interrupted – or is the magma going elsewhere…? I’ll let you know if I find out!

    • Apparantly the GPS trajectories are still moving in the same directions, so inflation is continuing at the same speed. Main inflation is in the caldera center and at the northern coastline of the caldera lake (ocean, whatever).
      As you know I share your concern for when a steady preassure valve all of a sudden Corks up.

    • I can neither confirm nor deny this rumour. The post may or may not be scheduled for tomorrow evening.

      How is Momotombo doing?

      • Momotombo is boring…
        There may or may not be a Hekla article in the making.

        • It is both written and unwritten at this juncture in the spacetime-continuum.

          After that I will leg it to Guate to climb Acatenango and Volcán de Atitlán.

        • Camera and ash samples would be nice. You got anyone who can do geochemical analysis lined up?

          • I will grab some samples and later I will see where I can have them analyzed.
            Camera is on hand, a sneaky small Leica since it is not safe to bring a huge regular camera up those Mountains.

  8. Enjoyed the article Rene. I always like the historical information of the experience of those that were there. The intense heat of anyone getting close enough to get samples without proper attire must of been unbearable, yet they went more than once. Not to mention the poisonous gases.

    • Nice! I have a feeling that’s Katla proper. I’ve always had an issue with the entire caldera as officially mapped, it’s far more complicated than just a single caldera. Godabunga could well be an entirely separate volcano (or one in the making) that just happens to form the other side of the big caldera ‘ring’ and there may be others. Just my thoughts though and they could be wrong…

    • How does it compare with this? De-iced view of Katla from the northeast

      • Or this one:

        I have a feeling the 1755 eruption was a fissure eruption from Godabunga, but without samples, that’s just a hunch…

  9. Yes, that is Katla. And it might be a ring fault, but I dont know. Given its other characteristics, this could very well be the secondary (deeper) magma reservoir under Katla.
    This feature or shape is not evident in the 1999-2010 period. It appeared, (or at least became noticeable), in the 2011-2016 period. It coincided with the deep dike intrusions, or with a little delay, which got me thinking it might be a magma body there, with earthquakes on the wall of this body as the strain increases as the new magma might enter into the system. It is around 8-10km to 18-20km deep, which is where it was estimated a magma body should be, based on petrology studies (Budd, D. A., V. R. Troll, B. Dahren, and S. Burchardt (2016)).

    This was said from the study (Quote):
    “To characterize Katla’s recent plumbing system, we established mineral-melt equilibrium crystallisation pressures from four age-constrained Katla tephras spanning from 8 kyr BP to 1918. The results point to persistent shallow- (≤8 km depth) as well as deep-crustal (ca. 10 – 25 km depth) magma storage beneath Katla throughout the last 8 kyr. The presence of multiple magma storage regions implies that mafic magma from the deeper reservoir system may become gas-rich during ascent and storage in the shallow crust and erupt explosively. Alternatively, it might intersect evolved magma pockets in the shallow-level storage region, and so increase the potential for explosive mixed-magma ash eruptions.”

    It was not determined at what location it might be, but just the depth, so this is one of the possibilities.

    Looking at the caldera, there are some main areas:

    The blue line is the fissure area of the 1755 eruption.
    The red square is the area of activity in 2011 and also in the past 2 years with the stars (M3+). Note that M3+ quakes also appeared on the 1755 fissure and also on the east caldera seismic area (white ellipse), which is where I also the potential next eruption site down the line. This east area and the red square area, are also the two areas where there are evident EQ stacks right down to this anomaly, so it might be a vent formation or an old vent with water running down and causing the H-T earthquakes. There are many possibilities.

    Yellow star is the 1918/1823 eruption site, and the pink star is the area of 1955 possible subglacial eruption.

    Pink ellipse is the outline of the ring of earthquakes, or the anomaly from the past years.
    The yellow line is another ring-like are of earthquakes, but it is around 2-4km deep, and was present also in the 1999-2010 dataset.

    Looking at the bedrock topography, there does not seem to be an initial connection of the ring anomaly with surface features.

    Its fairly easy to say that there is much more at Katla than meets the eye. Or at least what we can see on the official simple plots.

  10. Next post is up! (If you spot the double meaning in this, you get a bonus point.)

    For the sake of brevity, we tried to keep the post a short one. When that failed, we just went for a shorter title..

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