The Mayas and their lack of volcanoes

In a country that normally looks like this there should be volcanic eruptions to be had one would think.

Alberts latest article was a tour de force of the classic view of Mayan collapses, as it has been perpetuated in classic literature. The general idea is that the large downfalls in the Mayan empires would have been caused by large distant eruptions.

This is of course an unfair summing up of Alberts quite more complex reasoning. But, the gist is still there.

For a few years I have had a problem with that particular history writing. My first contention was that there is no need to go looking for large eruptions afar when Guatemala itself is amply filled with large volcanoes and calderas. My second contention is that the Mayan civilization never had the civilization-spanning downfalls portrayed in almost all literature.

Now I can hear a lot of people screaming at me, but wait a bit and I will explain further.

A little more than a year ago I armed myself with my minor in archaeology and my knowledge in volcanology and mounted an expedition on my own to track down the volcanic culprit. As I went full on Indiana Jones I had the help of temple-guards, the fabulous Mayan museum of Museo Popol Vuh, and my dear wife Doctor Carmen Morataya.

It all turned into the shortest scientific expedition of all time, and me and my wife meandered away and sat down in the grass of Kaminaljuyu to watch a combination of a Mayan religious ceremony against a backdrop of an ash cloud belching out of Pacaya.

It was all quite romantic and uplifting, especially after the scientific anti-climax. But, now it is time for your Rayban-wearing faux Indiana Jones to get down to writing about what he found that cut his sciencing down to roughly 30 minutes.

The archaeological view

Who stole my ash? The white layers are from periods of more evolved small ash producing eruptions. The darker layers are from periods of small basalt to andesite eruptions. No big suspicious layer of ash. Photograph by Carl Rehnberg.

Archaeology as a discipline can be cooked down into being the art of following water, climate, food, technology, religion and ruling douche-bags throughout a civilization. Preferably it should all be clearly stratigraphic, including the water.

First of all, the timescale of the Mayan civilization is daunting. Between 8000 BC and 1500 AD we find all of the development of the human civilization, and all of the large empires are just like twinkling lights flashing in the endless night compared to the Mayans. It is by far the longest lasting and most stable civilization that humans have constructed to date, and it is almost preposterous to think that any of todays empires will ever outlive the Mayan civilization.

Between 8000 and 2000 BC we have the archaic period where they developed farming, villages and the city concept. They learned to tame the waters to increase harvests. It is during this period that the famously protein-rich Guatemalan food came into existence with an abundance of maize, veggies, beans, meat and fish.

Same pit from a different angle. Do note that the only discontinuity is artificially inserted. In the real stratigraphic layer there is no habitation disconnect. Photograph by Carl Rehnberg.

After that we have the pre-classic period where writing was developed that lasted from 2000BC to 250 AD. The classic period lasted from 250 to 950 AD and the post-classic from 950 AD to the Spanish occupation.

Guatemala City is known as the City of Eternal Spring, and basically it has the perfect weather. Always. That being said, there is a phrase that is true about Guatemala; “If you do not like the climate, walk 500 meters”. Guatemala has roughly 300 different climate zones, ranging all the way from the type of humid heat that can only be found where a tropical rainforest intersects with the Pacific Ocean (a climate only loved by sun-soaking Swedes) to alpine coniferous forests at the snowlines of mountains, via dessert terrain.

The climatological golden zone in Guatemala is and has always been the volcanic highlands with warm days and cool nights. There is also enough rain to cause pretty much your shoes to sprout buds and leaves if left unattended.

Temple and low pyramid structure buried by the Mayans so that the Spaniards would not be able to defile it. Photograph by Carl Rehnberg.

To the west you have a drier coastal plain ripe with huge sugar-cane fields that rapidly turn into a coastal rainforest. To the east you have true rainforests and wetlands going towards the coast against the Atlantic.

This means that there will always be a nearby favourable climate zone if your own for some reason changes to be inhospitable. This was most likely what happened in the South-east and East-central parts around 900 AD. The land warmed and dried out, and the population moved into the fertile highlands.

And here comes a hint, during the large downfalls of the Mayan civilization only parts where affected, the rest continued with business as usual, or even became re-invigorated.

The same excavation from a different angle. Photograph by Carl Rehnberg.

Let me further expound upon the subject, Guatemala and its Mayan fore-runners is divided into 3 major climatological areas. And the divisions are quite brutal. So, the Mayan civilization was always divided into 3 distinct parts. Next thing to realize is that the Mayan civilization is a highland civilization, so much so that genetic differences has come into existence in the genome. That is why Guatemalans tend to be short and stocky, since that is the favoured body form at high altitude. Even today the bulk of all Guatemalans live at an altitude spanning from 1200 meters up to 3400 meters.

But, alas, westerners like coasts, so we interpret the coastal and plains cities as the main parts when studying the Mayan civilization. A side-note here is that the pyramidal shape of the temples most likely originate from the shape of the stratovolcanoes in the highlands. And that is why we do not see them built as high in the highlands. Why build fakes when you have the originals to revere?

The volcanological view

Volcanologists are also enamoured with stratigraphic layers. Especially if they can find a layer X that terminates culture Y. Then you can analyse the ash of layer X and track it to volcano P that is known to emit ash X during eruptions. All are happy, and papers are written aplenty.

Mr and Mrs Indiana Jones in the temple grounds of Kaminaljuyu after som vigorous sciencing. Photograph by Carl Rehnberg.

So, here was my initial deal with going to Kaminaljuyu, to find layer X, get an ash sample, test it, and track volcano P.

This probably seems to be totally redundant since everyone “knows” that the Mayan societal declines were caused by distal eruptions. Well, here is my deal. Nobody has ever bothered to check for layer X, nor taken an ash sample of it.

So, as I donned my Raybans to go Indiana Jonesing, it was with the trepidation of being on the verge of doing a Leakey discovery. I was about to rewrite the volcanic history of the Mayan civilization. As mentioned, I was convinced I would find a layer with ash from a large Guatemalan volcano, most likely Amatitlán.

Before we drove the 500 meters from home to Kaminaljuyu my dear wife lathered me up in a thick layer of sunscreen. She is completely convinced that I and every other Swede are vampires that will perish in direct sunlight. This lathering normally comes with quite a bit of protestations on my part. But, alas, my wife somehow always wins these debates since I love her.

I had been told that there was even a ready dug pit showing the stratigraphic layers of the history of Kaminjuyu, and that it would perhaps be possible to get a sample of that layer at another site on the grounds of Kaminaljuyu.

As we came to the hole in the ground I looked perplexed down and did not understand a thing. Still not understanding a thing I went and looked down at the temple in its dig site, and then we went and sat down in the grass to look at Mayan priests smoking cigars in-front of the backdrop of the equally smoking Pacaya.

I still did not get it. I had found nothing. No ash-layer. No interruption of habitation. If there had been a local eruption there would have been an ash-layer, and if it was a distal eruption there would have been habitation interruption. So, no volcano to blame. At all.

When I get stumped by a conundrum I have always found that books are a good place to start. So, I started to read massively on Mayan history. And discovered that at most one of the 3 Mayan regions had been affected, and that it had only happened once.

Otherwise it seemed that the destruction had been on City or region level. As one part got destroyed others thrived. At no time had there been a civilization wide discontinuity.

Disproving a theory is as much a part of science as proving a theory, but you do not become famous by it. So, no Leakeyfication of me for this.

Tying up the ends

Graph showing warm periods around 250 AD and 950 AD. From

Kaminaljuyu came to an end due to lack of water. During it’s long time as one of the major Mayan cities it had been depending on Lake Miraflor (real Mayan name is unknown). That lake silted up and become a swamp before the water that fed it disappeared during an earthquake. The population of about 100 000 meandered away to find a climate spot more amenable with a good supply of water.

During the 9500 years that the Mayan civilization existed city after city was crushed in natural disasters in the form of large earthquakes. Kaminaljuyu itself was one of the longest existing cities in the world, and still it was most likely rebuilt about every 70 years.

Even after the Spanish occupation they have gone through at least 3 different capital cities with Guatemala City (on top of Kaminaljuyu) having been destroyed twice (1918 and 1976). And in here lies the deal, you can cherry-pick pretty much any year to have a societal downfall from the Mayan cities, because you will inevitably find a city that crumbled around that year and was abandoned.

The downfall of the eastern parts of the Mayan civilization around the year 900 AD comes during the start of a global heatwave. And the same happened during the 250 AD low-point in the east during another global heatwave. These heatwaves did not affect the central highland parts of the Mayan empire, nor did it affect the western parts due to the cold Humboldt-current.

Here is the deal, volcanic eruptions if large and happening in statistical gluttony, will lower the temperature, and lack of volcanic eruptions increase global temperature. So, having a global heatwave is indicative of no volcano at all being the cause of the societal decline in the eastern lowlands of the Mayan civilization. In other words, there was no volcanic eruption causing anything at that time.

As the weather got colder the lowlands was re-habitated, a trend that was interrupted as something even deadlier than the climate, volcanoes and earthquakes happened. The Spaniards and their measles.


128 thoughts on “The Mayas and their lack of volcanoes

  1. Thanks Carl. I could not find any volcanic cause for Miraflor’s end, and you find the same. The problem they had has been claimed to be caused by deforestation: the building of pyramids needed more firewood than could sustainably be harvested.. The deforestation caused erosion which polluted the farming land.

    I do have to take issue with the climate plot you show. This one is, I believe, made up. You can find better ones with actual data on them. Here is one published in 2013. The slow cooling during the holocene is found in other records as well: it culminated in the little ice age. For the Maya, the bottom line that there were drier and wetter periods, but no clear temperature effects.

    • All Guatemalan lakes are happy silters. Amatitlán and Atitlán are also silting quite fast.
      Partially due to rivers bringing in ash from the constant small eruptions, from bacteria, soil, fecal matter, and an assortment of other stuff. Due to the warmth and the high amount of nutrients the process is faster than in the northern countries.

      In regards of the plot, I chose it because it was clear. But, the same temporary increases are visible in your plotline too. Yes, the general trend was towards cooling, but cooling in that area would be a boon, not a drawback. And as we both know, that cooling trend would have continued unabated into this day if not human effects had turned the tide into the spike in your trendline as we hit now. Instead of going for a new glacial-period we are going the other way. It would be interesting to know how big the temperature differential would be between a continued cooling (that would have been natural) and our current cataclysmic temperature increase.

      • The plot you give has imaginary data, curves, and dates. For instance, it has the roman empire as a warm period whereas the global plot shows it as cool compared to what was before. They very warm period 1000 BC does not exist in the global data/ My impression is that they took some dates with known issues (for instance, the 44BC cold year related to a volcanic eruption, and drew a curve through them. (Perhaps you can find what data they used! I couldn’t. The authors themselves say that they were given the data by a defunct (and unknown) organisation which never published anything!.Elsewhere they say it came from a study done in the 1940’s!)

        The global cooling rate which led to the little ice age was about 0.1C/1000 yr. We have now warmed by ~0.9C in just over a century, and are currently increasing at 2-3C/century. We are roughly 1C above expected temperatures. I wrote a bit about it at

    • Here is the data I should have used.
      The Roman warm period is stated to have lasted from 1 to 300 AD, but with the marked peaking at AD 200 to AD 300.
      The Dark Age warming between 800 to 1300 AD peaked at around 900 to 1050.
      I know that Ljungqvist pulled the data into the absurd later on, but the historical data in his initial study is pretty solid. (to be more specific, loons took his data and ran wild with it to try and disprove global warming…)

      My point is more that this is a clear indication of what will be happening soon in the tropics. Large swathes of land will become uninhabitable as temperature increases.
      P.S. I still see the warming periods in your graph 🙂 D.S.

    • Albert,

      For us lurkers (small “l”), your plot goes back about 10,000 years, whereas Carl’s goes back about 2,000 years. for some of us with less experience, it may be difficult to visualize/compare two graphs where the scale is so different. Is it possible to plot your graph so that the time scale is roughly comparable to Carl’s? Also, I’m curious, what is the temporal resolution of the Marcott et al. reconstruction?

      • The plot in the post has been updated which solves the concern I had. The reason to show the full holocene is that any variations should be seen in the context of longer-term changes.

        Here is a figure from their paper comparing different published reconstructions over the past 1500 years. This is not quite long enough for the pre-classical Maya. Note that the temperature changes over this period have been mainly at temperate northern latitudes. The equatorial regions saw little change in temperature over this period. For the Maya, the climate pressures came mainly from varying rainfall, not temperatures. As Carl pointed out, in Guatemala you can simply move up or down a bit to adjust temperature. The Yucatan is more restricted but they only moved there later.

        The time resolution over this period is 20 years, but getting worse at earlier times. In the early holocene, they say it is around 100 years.

        The axis in years BP. 1500 years BP is 450 AD

        • On this scale this graph shows the same thing as mine does.
          All of the graphs are northern-centric since we have more data.
          On Alberts graph we still see the same cool period where the Eastern Mayas moved into the area and built cities as the climate became beneficial, and vamoosed out as soon as it became hotter.

          The point I tried to make without writing it in the article is that this is a horrible warning. You only need a very small temperature change in the tropics before it becomes to hot for humans and you get an exodus. And this is a stark warning for the coming decades as a billion people or more will start vamoosing to cooler climates.

          And a comment about Frederic Charpentier Ljungqvist. He is a climate change denier. But, he is a very honest one. So he collected pretty much every single known datapoint for the northern latitudes to contradict human made climate change. Doing so he produced one of the best evidences of said human made climate change (the graph in this article). It is as clear as the one Albert is using. And by using correct data, and correct methods he got a graph proving what he set out to disprove. And somehow his brain refused to grasp what his eyes where seeing, and he wrote that he had disproved man made global climate change.
          As I said, he is an honest scientist, but his conviction has blinded him from his own (correct) data. Anyways, I should probably be nice with my dear befuddled fellow swede…

  2. It’s the stupid season. March sees FHP making their highest number of monthly DUI arrests. ( 2017 ) Hello spring break.

  3. The YukiZE/Jaynius Gaming stream has added Hekla to their volcano cam compilation.

  4. Ahh Carl,
    I am utterly delighted with your piece. Although my knowledge of the Maya is pretty shallow your piece is precisely how I have come to view the Mayan (really central American, possibly with Amazonian connection too) civilisation. Wherever you go from Teotihuacan to Tulum and in between its clearly a fairly homogeneous society continually developing even though individual states fall and are replaced by their neighbours. Really its just euro-mediterrean culture (from Cretian/Egyption via Roman to Today) in another continent. That their civilisation persisted, with actually very little change despite all the undoubted political reversals is evident from their architecture which conveniently also tells us some of their gods and beliefs too.

    I haven’t visited Guatamala, although I did do a quick trip to Tikal from Belize (do see ATM before its ruined) and its notable how agriculturally developed (ie not jungle) the higher zones are.

    One point that was made repeatedly when I visited Mexico in the late 70’s was that every short count (?) of 52 years the Maya rebuilt the temple by recladding it completely. This of course became exponentially harder the longer the state persisted! However what it did do was to protect the inner structures. So archaeologists would arrive at a pyramid of broken stone, which was the remains of one or two earlier counts and excavate out a perfectly preserved inner core. That’s why the excavated temples look like new, they pretty well are! Sadly they are not maintained and many are now in a declining structural state. In my opinion it would have made sense to whitewash every temple once a year, maintaining a glittering white edifice, visible for miles, and also providing protection for stone and mortar. The existing pagan temples in India are very regularly repainted and I am sure the Mexican one would have been too, possibly in polychrome (which the Maya had).

    I have already had a discussion about ancient agriculture of the Maya so I won’t repeat my view that medium-term (ie a few years) food storage would not have been a problem in this area (central America) and that if the Maya followed every other civilisation from Egypt, Roman, Inca, Mesopotamian etc in power being in the hands of those who controlled the food supply particularly between oversupply and famine. I enclose a small pic of what I think is a storeroom (this from Tikal, but you can find them all over) complete with beams for putting hoisting ropes over. You can find these all over but they are rarely excavated except where they form part of a grander structure. Certainly you wouldn’t want to sleep in there when you have a nice cool breezy thatched hut outside!

    Link removed on request of commenter. The correct picture is in the comment below – admin

    • Producing the lime for the paint is one action that is blamed for the deforestation. Among others.

    • Impressive indeed!

      I think it’s worth noting that the most energetic part of the swarm at the moment is along a fault plane that became active after things started to slow down. Centered around 66.66N 18W, this is a bit west from the main activity during February and straight north from Grímsey.

      There is also a concentration of smaller quakes at a point halfway between Grímsey and Kópasker.

      Judging from the development since the activity picked up in January, I’d say it’s likely that the next green star will be in one of these two locations.

  5. Thanks for a great article, Carl! I’ll send it over to my wife who is still yearning to go back to Guatemala years after her month there.

  6. Off Topic: Movie Review

    “Dracula : Untold” – A very entertaining retake on the dracula tale. Set in the time of Vlad Tepes, it incorporates Vlads conflict with the Turks wrapped around the standard supernatural vampire tale. Sad ending.

    “Cloverfield paradox” – Wraps CERN paranoia with a mish-mash of 2010, Aliens, Blackhole. Very hard to keep track of the story. Ties in with Cloverfield in the last 5 seconds of movie. Very tedious.

    “Man from Earth” and “Man from Earth : Holocene” – Entertaining. Looks at how a CroMagnon would interact with moderns after living for 14,000 years. Sort of a highlander without the swords and magic. The follow-on meshes quite well with the original storyline. Not an action flick at all. Makes you think about his plight. Archeological tidbits in it match established theory. Worth the watch if you have the time.

  7. Off Topic: Movie Review

    so the best movie i’ve seen was ” 100 Year Old Man Who Climbed Out Of A Window and Disappeared” subtitles but i’m pretty sure if You can read this blog, You can read the subtitles. Laughed so much…. just loved it. Starts slow; give it time. Good Night… motsfo

    • Well, the real groaner of Cloverfield paradox was that the habitat sections of the station had artificial gravity generated by spinning that section. A plausible but dynamically limiting way of doing it. (rotation speed, radius of structure, etc…) In true JJ Abrams style, this was evident in the scenes by the sun and earth swooping past the window affecting the lighting. The groaner is that the “gravity” was acting 90 deg to the prevailing centrifugal force. And “down” was along the spin axis. Last I checked, physics doesn’t work like that. This oddity stayed true in a later EVA scene when they were on a non rotating section. Local “gravity” was still along the axis of the station.

      Caveat: Not a physicist. Just a normal person who recognizes B/S when I see it.

      • To give you an idea of just how bizarre this was, imagine going around a curve in a car. Instead of “pushing” you towards the outside of the curve, the effect in the movie would be to push you towards the seat, or the roof. If they had followed the dynamics of it in the movie, everyone would have been slung up against the wall with the window… along with anything laying loose.

  8. The post argues that the Maya collapses were local events, where one area starved but other did fine. That is an interesting discussion which has been going on since a long time. I argued that collapses were volcanically related in two out of the four or five cases. Which one is right? That is not something we will solve here! But we can find the areas of agreements. The first collapse, around 250 AD, has no volcanic cause and comes from one major city in Guatemala. In fact, this is the only case in Guatemala – all other collapses were further north. So no issue there. There is also a plausible cause: deforestation caused by the pyramid building or frequent white-washing.

    The collapse around 540 AD is a much stronger case. The major city collapses but recovered over a century, a nearby city did take over as the boss but even here, no building work took place over a 10-20 year period after 535 AD. This collapse was worldwide (even Britain was affected) , and the smoking gun is near the Maya region. Case beyond reasonable doubt.. but this wasn’t a complete collapse: unusually, there was recovery. There was cultural continuity.

    The major collapse around 800 AD was a different matter. It was a local wipe out (the local area never recovered and was forgotten), it was major (a population of millions disappeared, and many must have died) but it was a slow collapse, over decades, and nothing points at a volcano. Climate change has been claimed and this may well have played a part. A diseases can also never be ruled out. But the basic issue was over population which made the region vulnerable. The trigger may not be known but the cause is. The interesting thing is how complete the collapse was.

    The Maya empire moved north and here our knowledge is much less good because of the lack of reliable dates. We will not know why Chichen Itza fell until we know when it happened. And this time, the cultural continuity was lost. The pyramids had up to now contained a Venus alignment. In Mayapan, this was not the case. Part of the know-how of ceremonial building was lost, either because the people who knew did not survive, or because of external influence. The collapse of Chichen Itza was serious.

    Finally, the collapse of Mayapan, where the case is not closed but the date coincides very well with one of the largest eruptions of the past two thousand years.

    My bottom line: Carl is right regarding the early years of the Maya in their Guatemala heartland, but the society became more fragile at later times. And I find it curious how little innovation took pace after the move north. Almost everything they did was in place by 200 AD. The only real addition at late times seems to have been the development of sea trade. That continuity gives the impression of a very regimented society, where everything was written in stone. A good way to survive in marginal conditions, but a poor way to deal with sudden change. Perhaps the very aspect of their society that made it so stable was also the cause of its collapses. And perhaps (speculation alert) this rigidness came about only after the first disaster of 250 AD.

    • It’s been going on for a couple of days. Lots of small and medium size quakes along the southern caldera rim. The south side finally seems to be moving again. Judging from the cumulative seismic moment and the average rate, the south side should produce an M4+ any time soon. In order to keep up with the average rate, I think the equivalent of a single M4.5 would do the trick. To stay proportional to the north side, it could even be a bit larger than that.

  9. Been watching this area after the 7+ earthquake. Had USGS lsited 4.9 in Papua New Guinea at the base of the collapsed cone of Bosavi, 1.1 km depth.

  10. Admin comment!
    Comments propagating climate change denialism will be removed. The same as any other conspiracy theory.
    Also, all links going to climate denialism conspiracy sites will be removed.
    The debate about climate change is over. An overwhelming majority (above 99 percent) of the worlds climatologists have spoken on the subject.
    Volcanocafé is a place of learning and scientific debate about verifiable data regarding volcanoes in particular, and science in general. Avoiding science and scientific data, or invoking conspiracy theories is not appreciated.

    • A bit out off the loop here, but is this in regards to any specific episodes here that I’ve missed?

      Nothing against it though, as I totally agree with the statement.

    • If it’s “over” then it ain’t science. But, I do agree with the sentiment of keeping it about volcanoes. BTW, the only conspiracy theory I have regards the State of Florida, but I don’t have the statistical skill to prove it. I have the requisite evidence, but that’s a crap-load of data to dig through numerically. I also don’t have a good temporal analysis routine to make anything useful of it.

      • Science is never over. There is always room for new theories and adjustments as new data come in.
        Or for that matter new interpretations.
        It is what scientists do every day.

        • True, as looking at the data from a different angle. Even ten years from now we will have a somewhat more complete puzzle.

          Held up for approval by the wordpress deamon – admin

      • Exactly. 😀

        You know I’ve generally always been a contrarian, but I don’t use this blog as a personal soap box. Not my place to do so.

        I just wish I had the mental fortitude that I had when I did the moon-moonie article.

    • …You would have loved Holmes and Wegener at the start of the 20th century. They had this crazy theory about how WHOLE CONTINENTS are moving. …99% of the scientific community were in agreement then, too.

      Caveat: I am not a denier, I just question everything. It is how I learn.

      Especially when told that such a politically-charged and world-impacting theory is settled.

      • Not quite the same. Wegener had his idea but lacked a plausible mechanism. He had some unlikely ideas which could not possibly work: the idea lacked a physical mechanism. Later, Holmes came up with the model of mantle convection and that took about 25 years to be taken seriously, when the predictions it made about the ocean floor were beginning to be confirmed. Science went slow but methodically on this. The physics of CO2 is well known, and to be blunt , the current models do not differ all that much fro the calculations that were done a century ago. The predictions were made, and the evidence was found in the 1990’s, from areas as wide apart as breeding season of birds to thermal expansion of the ocean. We are now 20 years later and the evidence has not changed, just become stronger. That is why the science is settled: the model works and the predictions it made were found to be correct. Anyone wanting to challenge this should go through the same procedure: make a model that fits the data, and make testable predictions.

        Anyway, scientific discussions are fine. But I am not willing to engage in polemics which were started purely to keep Koch industries in its wealth.

        • “…Anyway, scientific discussions are fine. But I am not willing to engage in polemics which were started purely to keep Koch industries in its wealth…”

          Hear Hear!!

          Released from Spamalot – Admin

      • I was under the impression that in the UK, and possibly europe, the idea that the continents were once one was generally accepted. Certainly reading old textbooks in the 1950’s that were from the turn of the millennia that was the impression one got. The geological continuity across the joins is pretty convincing. That there was no mechanism known was a hitch but by no means was this a fatal one. For example the size, age and energy output of the sun was known and not in dispute even when the mechanism was unknown. In the US it (both postulates) was not accepted, not least because it implied a rather long age to the earth, rather more than the bible suggested so was ….

        • I believe the drift hypothesis was more accepted in the US than in the UK. Especially Cambridge (the UK one) was conservative on the issue and would not include it in teaching.

    • Comment Removed

      Opinions are always welcome, peddling pseudoscience isn’t. Let’s not join the ranks of the flat-earthers barking up the wrong tree that’s long since been deforested.

      We’ll leave the discussion there.


    • Please see earlier comment from Carl:

      “Also, all links going to climate denialism conspiracy sites will be removed.”


    • Carl, what is your opinion of the Grand Solar Minimum groups? Are they completely barking or do they have a point regarding imminent cooling because of low solar activity. They also seem to think there will be an up tick in volcanic activity.

      • The idea that low sunspot number = cold weather was based on the Maunder minimum coinciding with the little ice age. But now we know that the little ice age lasted 500 years, not 50. So that relation is no longer valid. I have gone through the statistics and have not found a significant relation. So first, the idea that we are heading for a period of quiet sun is still speculative , and second the idea that it will cause cooling is based on suspicious data.

        Science addresses this by turning it into predictions. You have a model. First, does it fit the past? Second, if I extrapolate it, is there a prediction I can test? The model here does not fit the past well, but if we forget about that, we can test the prediction of imminent cooling. This has in fact been predicted several times in the past, but the cooling failed to come and instead we got rapid heating. The last four years were the hottest on record. But we are currently in a weak solar cycle. What does that say about the model and the prediction?

        But people tend not to think in terms of scientific evidence. They tend to think in almost unshakeable convictions. This is very useful on some issues but in this case is leading to us being badly unprepared for what is coming. The point of not publishing comments that bring up fake science, or link to such sites, is that most of these comments/sites just aim to establish power, not to have a scientific discussion. If you try to present arguments, you find it is answered with dodges. Most of those people are not worth our time. It does hit some people who have a real question which is a pity. Sometimes it is just a matter of how a question is phrased.

    • I have been here a long time. Really enjoy the articles and as a geologist find the back and forth entertaining. As a scientist, I willing read and try to understand conflicting opinions on a wide range of topics. That said I find the automatic censoring of “climate change denialism” somewhat childish. In that particular field, the “known” may outweigh the “unknown” but to call it settled science is simply incorrect. This is your website and you can set the rules but should reconsider blanket deletes. Do not stifle debate and access on topics that you think are “settled” as that is the only way science progresses. If you are so sure about the current level of climate study, allowing people to comment and even supply links to opposing views will only strengthen your case if the opposing views are so patently incorrect. Just my opinion – delete if you wish

      • Open discussions are welcome, including this one. But we have had some experience where the opposing view point isn’t looking for a discussion, just in having the last word. Whenever the topic of climate change comes up, there is the standard comment that pops up from a denier. It is what they do. So we have had the policy that discussions and questions are welcome, but they should be based in science. We don’t do politics. And that has meant that some comments, especially those linking to the anti-science sites (which you will know about), will not be published. And I agree with that. (BTW I do not know what was in the comment that triggered this but can guess.) We have no reason to engage or link: that just gives them unwarranted publicity.

        I work in science and I know from experience that scientific argument and political debate do not mix. You say that the science is not settled. But that is not what the far side is interested in. They play on emotions and whether a fact is real or fake is not important to them: it is whether they can use it.

        I went into the problem of CO2 in some detail last year (, and there we did not have to stifle discussion. There were valid points raised. But in the second part I recounted the story whether the myth of volcanic CO2 came from ( (It is the the end of the post), and that shows the process of fact distortion and myth making. Where people have real question, I a happy to engage. Where the purpose is to distort, I am not willing to provide a vehicle.

        The funny thing is that few businesses still deny the reality of change. Even the oil companies accept it. But it has taken on a life of its own.

        End of sermon/rant. Back to the real world. How is the climate doing in your area?

  11. Favourite past time relating to the Mayans, looking up Yuri Knorozov. An interesting and sad story.

  12. My firewall has just thrown its toys out of the pram when I tried to access Magma Indonesia – Live Seismogram and also the webcams from Badan Geologi. Anyone else having the same issue?

    • I occasionally get messages how a secure connection failed. I just avoid the site until that clears. It’s likely cache poisoning or an injected redirect or the like,something a hosting ISP can fix simply by reloading the site script. Any site that gets enough attention will attract opportunistic malware. You can also try clearing your browser cache and history.

      • I just checked the site and it’s fine via the East Coast of the US. Sangeang Api appears to look fuzzy caterpiller-ish, but I’m no expert.

  13. Nice little swarm at ‘Greip’ today as well as possible intra-plug quakes. Not sure they are connected to the southern rim fault due to their location and depth, but I suppose it might be a mixed bag…

    • If you compare with the location of the eruption quakes instead of the mapped caldera rim, you will see that the quakes do line up with the southern rim fault. Here is a plot:

      Grey dots are from the eruption, blue dots are all post eruption quakes. The larger green dots are from March 2018. Most of the activity is along the south side. There is a handful of intra caldera quakes and another handful of northern quakes.

      If you look at all the post eruption quakes, you can see that there is activity in all the same regions as during the eruption, plus a line of intra caldera quakes that was not present during the eruption.

      • Thanks for that Tomas, it does indeed fit along the southern rim fault. Your plot is far more accurate than my quick map plot, I’ll make a note to tweak my mapping code to improve accuracy.

        What did you use to plot the data?

        • I use matlab for all my analysis and plotting. Maybe it’s a bit overkill, but since I have access to a license through work why not use it 😉

          There should be (mostly) compatible freeware tools, but I haven’t tried them.

  14. … local news is reporting a non standard traffic/alcohol incident in florida. 60,000 lbs of beer have overturned somewhere on the Interstate near mile marker 45.

      • Speed limit in that area is 70 mph. Not a lot of merging traffic, mostly strait and open. Sporadic dumbarses. Steep shoulders if you leave the roadbed. If you do, then your pretty committed to ride it out.

          • For Florida;
            Under 21 → bac .02 (No drink at all)
            Over 21 → bac .08

            But, they also have an “open container” provision that has gotten more than a few people busted. Roughly, if there is a container for alcohol in the vehicle that has been unsealed, you can be nailed.

            I’ve personally been on the scene of a traffic accident where it was obvious that the flipped vehicle was at fault for crossing the center line, but they charged the vehicle he hit with the accident because he had an open container in his car.

            That open container rule cuts down on pickups with empty beer cans in the bed.

            What part of Florida has tge highest dui convictions? S Florida. Hillsborough and Broward Counties.

            The truckload of beer was (likely) doing normal speed for that section of roadway. (As posted). I know of a couple of FHPs favorite “hidey holes” in that area where they like to shoot radar. It’s pretty well monitored for speeding.

            This guy probably lost focus, drifted too far and panicked when he hit the rutting along the road edge (put there to get your attention) and over corrected.

          • As for the flipped vehicle, my job was to keep him from falling as we cut the seat-belt and EMS was stabilizing him.

            NO fatalities!

            Stupid side note not pertaining to this or anything, really…

            During my last tour, I had to attend a DUI court as a command representative regarding one of my instructors. I was amazed at the skill of his lawyer. By the time the trial was over with, the Judge had actually yelled at the State Trooper for his disregard of safety in making the apprehension. The instructor was acquitted of the charges, but personally, I know he was flat out guilty. It was his character. Why did the judge yell? The trooper testified that he had done 90 mph after turning around to catch a guy doing 50 in a 45 mph zone… which was also a school zone during the daytime.

            The acquittal was due to vagaries in metabolism and the timing of the various BAC tests. The lawyer invoked enough uncertainty to make it questionable.

      • Most of the single vehicle fatalities in the area are from intense rainfall and the vehicle meeting a tree on the other side of the drop off.

      • Oh, and I would like to add that an overpass just east of there has been hit by dump trucks on two separate occasions. Each one was driving with his dump bed elevated. The first was,a fatality when the cab was shoved up into the bottom of the bridge, the second guy survived but hit it within a few weeks of the completion of repairs from the first mishap.

    • this one interests me. There was an article a while back that this seamount is alive and possibly a risk to erupt in the near (geologically speaking) future.

      • If the earthquake happened at 361 km deep then it probably has nothing at all to do with there being a volcano on the surface above that spot. Even diamond bearing kimberlite eruptions don’t source from that deep in the mantle.

    • and almost all of the accessible (for us) seismos on Muana Loa are down even though it looks like a tremor happening on one. TRAD

      also, it’s been a long time since weather has permitted a view or Klyuchevskoy. This from today:

      • It is not the seismos that are down, but the database, I think. It is affecting both Mauna Loa and Kilauea. They may be recalibrating.

        • I read their update for today and they said the earthquakes are at the crust/mantle boundary and far below the swarms from sliding of the island under gravity. Seems like a magma recharge event happening now, maybe in a few days or so there will be another lava lake overflow like in 2015, or maybe more lava at pu’u o’o. Or maybe a new intrusion and small eruption like in 2011 and 1997. During the mauna ulu eruption there were a lot of smaller eruptions from short lived vents in addition to the vents at mauna ulu, so maybe what has been happening since 1983 is like that but in slow motion.

          Actually I have a theory that once the east rift zone stops erupting then the lava lake at the summit will start building a shield and eventually overflow the caldera like what happened in the middle ages. probably not as extensive because a large volume of lava has been erupted at pu’u o’o but probably enough to fill the existing caldera and overflow to the southwest, probably within the next 100 years. So I dont think the constant lava in kilauea is going anywhere anytime soon.

    • That looks like its going to bung up the works nicely. I have a feeling the next one from Shinmoedake is going to be a more lively event.

  15. Given that there is a 450m depth of water above the crater, it would take an exceptionally lively eruption to produce any visible effect at the surface. Likeliest hazard might be a danger to shipping from loss of buoyancy above the vent

  16. New green star at Kolbeins ridge and some more 2+ quakes in the area. New wave of activity initiated?

    • I mean they called Catania a ‘small town’…

      I dont know if it is just because the first decade of the 21st century was unusually active, but mt etna has been really quiet since 2015, I wonder if it is developing a shallow magma chamber under its summit craters (not like a really big chamber, one similar to what was apparently there in the 17th century up to 1669) If that is what is happening then maybe the later part of this century will have some interesting scenarios regarding where eruptions occur (possibly including large eruptions within the inhabited lower flanks of the mountain) I mean theres loads of pyroclastic cones on the lower flanks of mt etna so its very obviously done this sort of thing before.

    • Doubt that Etna is splitting into two. But here are the latest earthquakes (if the image uploads properly 😀 (a while since I tried it))

    • Boris uses a lot more than eq data to monitor Etna e.g. CO2 emissions, VT, tilt etc. So wait until INGV says anything before getting excited.

  17. The downside of the cold winter weather across the northern hemisphere is that the arctic ocean has been much warmer than normal (or whatever counts as normal these days). The ice cover in the Arctic this winter is at a record low. The Bering sea is mostly ice free. Even north of Greenland there is some open water – in winter!

    • When the Vikings colonized Greenland the climate was much warmer. They reportedly had sheep and maybe even cows and horses there and maybe were able to cltivate some plants…. Is in known anything about the arctic ice sheets in those times?

      • I had been wondering about that. The north coast of Iceland is very sensitive to warm/cold period because of the currents (the division between warm and cold currents is not far). The earliest mention of sea ice there is from 1145. There are very few records from before that so it is hard to know what happened before that time, apart that sea ice can’t have been common because many early settlements were on the north coast. In the 1300’s thee traditional sea route to Greenland,along the 60 degree North had to be abandoned so at time sea ice was worse than it is now. But before 1145 it may have been comparable to now.

        A reconstruction made a couple of years ago (published in Nature) has arctic sea ice extent (summer) around 800 AD at 9.5 +-1 million km2 (40 year average). The latest 40-year average is around 7 million km2. At face value that would suggest the current ice cover is less than that during the Viking settlement of Iceland, but it is not clear to me that the numbers are comparable. However, distribution of sea birds in the Pacific and North Atlantic suggests to me the sea routers were mostly closed during the holocene. At the moment they are opening up.

      • The Greenland colony was prosperous enough to offer a farmstead and many cattle for a religious leader to come and run their church.

    • It is seen over a large area of the mountain so it is not clear to me where it was. The signal is largest on the seismographs on the south flank but the sensitivity will differ between instruments

      • Found it. It was south of the island, halfway to Lo’ihi. I am wondering whether part of it may have involved an underwater landslide

Leave a Reply