The Road to Sinabung

Lava and incandescent material after a pyroclastic flow. Getty Images.

Lava and incandescent material after a pyroclastic flow. Getty Images.

We often have a tendency to believe that an eruption will come quickly after seeing an intrusion take place. Of course this is normally not the case, something that Sinabung has proven quite well. As the local Indonesian authorities are starting to issue warnings that Sinabung might be getting closer to a major eruption I thought we should take time to look at what has gone on for the last few years, and what a “major eruption” might entail at Sinabung.


Mount Sinabung is situated about 40 kilometers from the Toba system, and even if it feeds from the same deep magmatic source it does not share the same magmatic reservoir as its grander neighbor. The location at the Sunda Arc tends to give sticky magma with a capacity to build up pressure in the system, that withstanding, most eruptions from the nearby volcanoes are not big. Previously Sinabung has erupted mainly andesite to dacite.

1912 activity

Evacuation is straining the densest populated country on the planet. Getty Images.

Evacuation is straining the densest populated country on the planet. Getty Images.

The only activity in written record is an episode of unrest with earthquakes and solfataric activity in the currently active crater in 1912. This was the first recorded activity in the volcano since a minor eruption believed to have occurred in the year 1600. It is quite possible that the 1912 activity might have been the result of a reactivating magmatic intrusion. If so, it might have been what set into motion what we are seeing today, and given the time frame it would mean that there is a reservoir of evolved magma residing in the magmatic system.

Even though there might have been further intrusions after 1912 they left no trace after them.

2010 phreatic explosions

Phreatic detonations started on the 25th of August and continued all the way to the 28th September the same year. During that time intense heat from rising magma caused steam driven explosions that lofted old rock material up to heights of approximately 5 kilometers. Only one intrusive episode was reported, it took place between the 8th and 18th September followed by a small deflation episode. This was most likely not the first intrusion occurring since it happens after the main action. It is quite likely that at least one major intrusion happened a few months before the phreatic episode.

2013 phreatic episode

People fleeing in any way they can, both in vans, motorcycles and on their feet. Getty Images.

People fleeing in any way they can, both in vans, motorcycles and on their feet. Getty Images.

During 2012 seismic activity under the mountain resumed and continued in distinct episodes up through August 2013. On the 15th of September a phreatic explosion happened that raised the alert level back up to 3 and evacuation of people at the 3 kilometer evacuation zone (3 000 residents).

After that the level was lowered to 2 and people started to return home. During this period seismicity declined up until the 23rd of September when two landslides occurred accompanied by yet two more phreatic detonations. Once again the level was raised to 3 and the people within the 3 kilometer exclusion zone evacuated.

Phreatic activity continued after this with increasing strength and on the 20th of November the exclusion zone was extended to 5 kilometers and an evacuation was started that raised the amount of displaced people to 20 000. On the second of December the first deaths occurred on the mountain as nine people were killed in a landslide in the Gundaling village 12 kilometers from Sinabung.

On the 10th of December the largest ash column was ejected so far during the phreatic phase, it rose to an elevation of 11.6 kilometers above the crater. This episode probably cleared the vent for the magma to slowly start moving up the passage to the crater. During the period 6th to 13th of December low frequency and hybrid earthquakes increased significantly and harmonic tremor occurred continuously as magma started to move upwards.

On the 21st of December seismicity and harmonic tremor once again rose sharply and a dome started to extrude inside the active crater at a rate of 3.5 cubic meters per second. This puts the start of the real eruption to the 21st of December. As the extruded lava dome grew beyond the confines of the crater it started to crumble into pyroclastic flows that rushed down the mountain. Over time they grew in size.

Current development

Current evacuation map. This is not showing the extended worst case scenario 15 kilometer line. Image by local authirites.

Current evacuation map. This is not showing the extended worst case scenario 15 kilometer line. Image by local authirites.

On Saturday the 4th of January the distance of the pyroclastic flows forced an increase of the exclusion zone to 7 kilometers putting further strain on the authorities as more people get dislocated into shelters.

The day after the evacuations started the alert level was raised to 4. At the same time information was released that increases in seismicity and harmonic tremor indicated that a major eruption might be on the way, possibly within days to weeks. The authorities took steps to inform people of two new zones being created, one at 10 kilometers and a second zone extending all the way out to 15 kilometers. The latter might be seen as the largest feasible evacuation zone in the densest populated country on the planet.

What might the future hold?

Some people have seen the nearby Toba supervolcano and gone “My God! We are all gonna die!” This is of course ludicrous. The magmatic system under Sinabung does not in any way contain enough magma for a supereruption.

On the other scale are people who state that the volcano would continue with dome growth and episodic pyroclastic flows. I found that a bit dubious in regards of the long and steady build up for this eruption and the general behavior of nearby volcanoes.

Since so little is known about this volcano it is probably a good idea to look at the surrounding volcanoes to get an idea of what might be in store. Just a few kilometers away is the double volcano system of Mount Sibayak/Mount Pinto, and that might give a good clue at what might be in store.

The interier of the compound caldera of Mount Sibayak. Photograph by Eddharj.

The interier of the compound caldera of Mount Sibayak. Photograph by Eddharj.

Mount Sibayak is a 1 kilometer wide compound caldera that formed during a VEI-6 eruption as a volcanic dome was blasted away, it has afterwards had episodes where it was partially filled up by Mount Pinto, and then cleared out in an explosive eruption. Judging from the latest 19th century eruption it last cleared out in a large VEI-3 eruption.

So, if this hold true also for Mount Sinabung we could be in for an eruption spanning from a VEI-2 all the way up to a much less likely VEI-6. One should though remember that there might be a repository of 100 year old more evolved magma that might get remobilized by new hot magma.

So, no end of the world eruption within sight, but possibly a bothersome enough medium sized eruption.

A word on mitigation here, the Indonesian authorities are among the most competent on the planet. Their skill at mitigation of highly dangerous volcanoes is quite possibly unequaled on the planet. On a day to day basis the juggle around some of the most dangerous volcanoes on the planet in the most densely populated country. Normally they achieve stunning results and they save large amounts of people during each and every eruption.

They are though facing two problems, both the volcanoes, and the amount of people needed to move. As such they have to cut the corners mightily fine and I do not envy their job, but I take off my hat in their direction. In the end they where mitigating volcanoes around the time we in the western world said “Oh look, a fire-mountain!”

Geology identification request

Photograph Johan Lindborg.

Photograph Johan Lindborg.

Reader Johan Lindborg went to the Ignaberg limestone quarry in Skåne, Sweden with his son to hunt for fossils. While being there he found a piece of stone that looked out of sorts, and now he has requested help with identifying it.

So, put on your thinking caps and help Johan and his son out with the mystery rock.


235 thoughts on “The Road to Sinabung

    • It is as I left it hanging. Seismicity and tremor points towards a possible major eruption. But no current news beyond that. Continuing pyroclastic flows and dome growth.
      I will be back with updates as soon as something comes from the local authorities or a couple of local friends of mine.

      • Great post!

        Question for those who know more about Lava domes than I do (something I have a bit of a problem with wrapping my head around entirely).

        If lava domes are fresh magma extruding from a vent, what stops them from just fully erupting out? In other words, why do some volcanoes seem to form periodic lava domes that just crumble apart and later rebuild, while other volcanoes grow a small dome, then blast it apart entirely in a big eruption (see Pinatubo).

        I understand pressure has a lot to do with this, but wouldn’t the opening of the conduit in itself relieve enough pressure that the magma would then erupt out all at once instead of gradually?

        • Two factors really.
          1. Viscosity, or how easily it the lava flows. To form a lava dome you need lava that is hardly able to flow at all.
          2. Amount of volatiles like gasses and water. The less volatiles the less likely the lava is to gush out rapidly.

          In a case with a lava dome that is slowly emerging and just crumbles until the eruption stops you have un-runny lava and low gas content. Problem here is that we do not know what is the case really at Sinabung. It could be that the dome forms a sort of plug for the escaping gasses and you get a boom in the end. It could also be that the current lava is old and “cold” and is less fluid because of that and the lava coming up is runny and gas rich, and that could really blow things up.
          Sinabung is a fairly unknown entity.

          • For the moment to me it looks a bit like Unzen, where in the spring of 1991 a lava dome began to grow at the summit after several months of increasingly intense ash emissions. The dome was precariously perched at the top of a deep ravine, and often chunks of it fell of, cascading and disintegrating into the ravine, transforming into pyroclastic flows. The same is happening at Sinabung now. Unzen never produced any large explosive events throughout the eruption, which lasted from 1991 until 1995, but there were several large dome collapse events, which produced quite extensive, destructive, and deadly pyroclastic flows. The most famous of these was on 3 June 1991 and killed 43 people including the volcano photographers Katia and Maurice Krafft and American volcanologist Harry Glicken. There are quite a number of similar eruptions, where lava domes are formed and their more or less partial collapse forms pyroclastic flows, but surprisingly many of them do not produce any large explosive eruptions. Often when we hear of some destructive or even deadly volcanic events, they are described in the media as explosive eruptions (unless the media have it totally wrong and speak of “lava flows”, as in the case of Paluweh, in August 2013), but in reality they are just some major dome collapse caused by the failure of a portion of the dome on a steep slope with rather insignifcant explosive activity.

            So far, the activity at Sinabung looks to me to be of this kind – growth of a dome, whose flank perched on top of that deep ravine frequently crumbles and forms dome-collapse pyroclastic flows, but not much, or relatively minor, true explosive activity. We’ll see whether this will build up into some major explosive activity (such as periodically happened at Soufrière Hills on Montserrat) or whether it will remain largely a dome-building eruption with pyroclastic flows generated by the instability of the growing dome.

            • Hi Dr Behncke

              So it means also that the lava extruded is not too viscous (comparatively) and that the flow is quite large ?

            • To dfm: the lava is very viscous indeed and does not form a flow, just a dome, which sometimes expands downslope into a rather short, thick, stubby lobe. The problem of lava domes is that they grow very much due to supply of magma into their interior, which makes them expand vertically and laterally; often their flanks are oversteepened and thus smaller or larger portions of the steep flanks often collapse and the collapsing material – disintegrating rock and gas – transforms into pyroclastic flows. This is still more accentuated when a lava dome, or a part of a lava dome, grows on a steep slope, especially if that steep slope consists of unstable rock. Sometimes the growing weight of the lava dome onto such unstable rock can lead to the wholesale failure of that rock, which will carry also quite some portion of the lava dome with it. This presumably happened on 3 June 1991 at Unzen, leading to a much larger-than-expected pyroclastic flow.

            • Ok I get it.
              Sorry I was not precise enough I meant lava flowrate in fact.
              But you answered that the growth is done from the inside and that the lava viscosity is very high.
              The fact is that you visualize better the growth at night because then you can really see that the dome is very hot which is not so evident because the lava color seems grey in the daylight.

              Thank you

          • I have a tremendous respect for your Indonesian collegues, and they do not seem to get excited that easily. So when it seems like something goosed them and they start prepairing for extensively extended evacuation zones, and they start talking about rise in tremor and seismic activity indicating a “major eruption” (no explanation though to what that might be) within the next few weeks, then I tend to think that something is up.

            If I ever see you writing something like that about Etna it would also perk my ears quite a lot… Just saying.

            • I hope it is much later. Etna is also to populated for comfort. You have a cool job, but I do not know if I really would like to trade with you when there is problems (not counting my lack of training to begin with).
              Yes, I do like things that go boom, but prefer the booming things to be quite aways from people.

        • I think there are two cases where we get domes forming, one at the outset of an eruption (like here) and, more commonly at the tail end of it (Chaiten, Mt. St Helens). Obviously the magma in a lava dome does not have enough gas in it to pop its top so the dome is basically extremely sticky goo that is blocking up the vent, a bit like the old magma does in the NSE crater at Etna before each paroxysm. Once you’ve got rid of it, the new gas rich stuff has a chance to let rip and this is when you will get an explosive eruption starting. At Sinabung I imagine the dome is formed from the magma that was intruded a hundred years ago and has had enough time to degas in the meantime. The new stuff is behind it. Whether there is enough of it and if it is volatile enough to blast out the dome are the 64 million dollar questions. /my 2c

          • Great explanations, and kind of what I had suspected, although I hadn’t really considered how the magma at the top end of a conduit is largely devoid of volatiles.

            I suppose I had always considered things in regards to momentum, where once you “pop the cork” things would start running downhill quickly as the conduit is set in motion. But that’s just too broad of an over-simplification to explain everything (even though it’s partially true).

  1. Hi all; nice article Carl.
    I’ve brought this forward ‘cos it took ages to ponder/ compose
    Evenin all,
    Sorry I had to duck out when the Canaries debate started to get going last night; but my tea was ready 😀
    It’s a fascinating debate, as well as being the only debate here that I even feel half way competent to get into…
    At the front of my file where I keep printouts of juicy Canaries papers I have a map (borrowed from an elsevier paywalled paper) that shows the Azores, Madeira, the Canaries and the Cape Verdes as well as the coast of Africa, the MAR and the major fractures.
    I don’t think I’ll ever really understand the numbers, my approach is to try to build a mentalmodel…
    What do we have in the region described?
    The African plate moving North and the Atlantic Ocean getting wider; there is no subduction to speak of on either side of the Atlantic… There is also a purported schuperplume feeding the hotspots in all the archipeligoes.
    What does this suggest to me?
    Of course these are wild amateur ramblings… But:
    Maybe tectonic effects are sufficient to mostly explain the volcanic situation and the hotspots/ schuperplume are “induced” by said tectonic effects…
    @ Peter, sorry I accused you of losing a decimal point; I hadn’t grasped yr frames of reference…
    @ Arjanemm, sorry I haven’t been able to dig out the Lanzarote paper; that’s why I print the good’ns when I find um…

    • I read up the chapter on Seamounts in Schmincke’s Vulcanismus again today and once again came away humbled. The book was last revised in 2000 and it is still streaks ahead of where we have got with our deliberations here. Just a couple of points, some of which you already pointed out:
      1. Seamounts are really really common. There are over a million in the Pacific alone.
      2. They form initially within a short distance of a MOR, suggesting they are pockets of melt (crustal anomalies) that remain active enough to keep vulcanism going as the plate moves away from the MOR
      3. As you point out there are loads of seamounts going up the N African coast
      4. The Canaries are huge and are kind of hard to explain merely as seamounts or residues of MOR activity, indicating maybe hot spot activity, particularly as there is no clearly evident chain of seamounts running back to the MOR.
      5. 75% of the magmatic activity in the Canaries is intruded as plutonic rock (sills and dykes) rather than erupted. This is unusually high. For most other seamounts it is about 50%.
      6. Volcanic activity seems to build the islands in an initial phase of about a million years with activity reawakening later that uplifts the islands and a lot of evidence (e.g. on Gran Canaria) for evolved magmas (including ignimbrites and trachytic dome intrustion)
      7. The lithosphere is thought to be about 100 km thick under the Canaries with partial melts forming at this depth.

      etc. etc.. so any theory we come up with has to explain a lot of unusual behavior: why the islands more prone to intrusions than erupting? Why does volcanic activity extend over a huge time period (literally millions of years) with huge intervals inbetween periods? If all of the seamounts going up the African coast are examples of intraplate hot spot activity rather than seamounts that originated at the MOR, why are they so prevalent in this region of the globe? etc. At least it seems to indicate that the current series is more likely to end as a series of plutonic intrusions rather than an eruption, so I guess that is good news. But, apart from that, it raise more questions than answers I am afraid!

        • Fascinating stuff, cracking indeed 😉 Unfortunately it doesn’t apply here as there is no bending of the lithosphere anywhere near that I am aware of, apart from the downsagging of the islands themselves and that would be putting the cart before the horse.

          It did make me think though of the Louisville seamount chain. As far as I’m aware there has not been any volcanism related to this.

          • The japanese cracking zone was 600km from the trench, so the curvature of the crust may be comparable with Hierro. The crust to the west of Hierro is devoid of Jurassics. East of Hierro the Jurassics thicken, there are erupted masses of Tenerfie etc and their eroded deposits. And IIRC the crust itself is thicker. Plus the Atlas range. All within 600km. So a curvature at Hierro sufficient to produce Hirano’s cracking might well be present purely because of mass loading.
            And seamounts on the japanese scale abound to the south of Hierro and GC.
            That recent mag 5 in my view reflects a crustal bending stress being relieved, Curiously it was at the bifurcation point of a ‘fleur-de-lys shaped’ gravity anomaly west of Orchilla Hierro. ( Gorbatikov fig 4, 6 and 10km sections). The southern limb of this structure is mirrored in the shape of the eq swarm a year ago ( yellow here: ). That pattern is more easily expalined by mechanical cracking forces than magma intrusion.
            The strong GSP motions often look to me as if the whole western half of the island is moving in concert – always north, previously east, recently west. And up. I find it difficut to believe that magma injections at the swarm sites produce such concerted large scale motion. In my view the Hirano-type cracking mechanism deserves looking at. That means a causal sequence: Cracking > GPS > gas efflux > magma eruption. To me, we seem to be halfway: no gas yet!

    • I’m gonna reanswer then.
      Hi Schteve, I had a British girlfriend for 4 years, believe me, i understand what tea is about. Anything under a PG tips or a Tetley would couse havoc. Had to be served with a few grains of sucker, a swirl of milk and served between 95 and 97 degrees celsius. After a year i managed to make it complained free.
      As of now i’m still reading upon your earlier contributions, thanks for those 🙂

    • The size is unknown, but it is most likely not that large. I think they are collecting data as fast as possible to be able to calculate the size.
      I would say highly unlikely, the rate of inflation and the lack of bradyseisms seems to exclude anything larger than a small VEI-6 as a maximum. Nothing points towards the volcano being able to have a larger eruption like a VEI-7.

      • I agree with Carl in that the likelihood of a VEI-7 is extremely unlikely. From what I can tell, Sinabung isn’t an extremely old volcano. Most of it’s eruptions have been on the smaller side of things and it hasn’t ever gone caldera. This most likely indicate that it’s still in the stage of growing it’s magma chamber.

        I think it’s important to look at the cyclical nature of volcanoes. Young volcanoes don’t go from small eruptions to devastating VEI-7 eruptions overnight. They need time to grow their magma chambers large enough so that they can actually store enough eruptable magma to create something that size. Some will never grow large enough since they don’t receive a high enough input of magma to realize the potential of a high VEI eruption.

        One caveat to note here is that this is for standard stratovolcanoes.

        Also – one thing I disagree with in terms of Bradyeism, is that I don’t believe all volcanoes with the propensity to form a VEI-7+ eruption show intense bradyeism. Sure most, probably do, but I wouldn’t imagine Tambora would show intense bradyeism with it’s extremely deep magma chamber. I would believe it’s much more common in post-caldera resurgent domes than in standard stratovolcanoes that have a potential to go big.

        • I would believe that it actually did. Remember that Tambora most likely had an upper magma chamber that was eradicated during the eruption. I have a huge problem seeing another mechanism behind the eruption than piston like collaps.
          The walls on the caldera is ultra-step, and unless you are a world-class mountain climber you need to go by helicopter as I did. And the bottom looks like any other caldera I have seen.

    • Hello Tyler!
      Good one! I guess I should make a post on this one of these day when it is calmer among the erupting volcanoes, feel free to remind me.
      Evolved magma is magma that has had time to fraction so that the heavier elements have sunk to the base of the reservoir, this leaves more boyant cilica-rich chrystals to rise to the top of the reservoir, and cilicic magmas are often more explosive than unevolved magmas like basalt.
      Hope this helped a bit.

    • From a more thermodynamic oriented point of vue.
      When the magma moves up due to density difference, the surrounding conditions (pressure, temperature) will change also (a bit like there less oxygen when you go up a mountain). So his will trigger some chemical reactions, some gases will leave the bulk of the flow and some chemicals will diversify (some new minerals will appear (precipitate) only for this and that pressure and temp conditions). This is how volcanologists can retrace the magma “history” by stuying its components.
      This is usually not very abrupt changes, meaning that for instance some species can cohabit with different chemical ratios.

  2. Will be interesting if Sinabung does give us a large blast. Hope everyone gets out of the way in time.

    • Problem with Indonesia is that you kind of never wants a blast there. Not with millions living in the surrounding parts.

    • And here I have a question about density: Erik writes “…in magma with upwards of 7 weight percent water at ~30 kilometer depth pressures, the density is only ~2.0-2.2 kg/m3. This is much lower than the surrounding continental crust, which is ~2.7 kg/m3…” Is that right? Rocks on the surface have a density of 10 kg/dm3 (ores), and that without the depth pressure on them. 2.7 kg/m3 is not much more than cardboard….

      I did not dare asking the question on the Eruptions blog in case I am overlooking something, and seeing that several critical pairs of eyes had scrutinized Eriks post already…

  3. The Columbian Volcano Galeras had lava dome. So as I understand it, as the pressure builds up there is a 100% chance that an eruption shall occur?

    In Iceland, what is going on at the Hveravellir volcano?

    • Yeah…a 100% chance… but over what timescale?

      That last bit is where people get wheel-wrapped. Ya see, there is also a 100% chance that it will not erupt… over a certain timescale.

      I can make 200 predictions that it will or will not erupt in the next fifteen minutes, and be most likely correct in the not erupting predictions. Probably approaching to 100 percent of the time.

      The hard part is figuring out which fifteen minute window when the “will erupt” prediction will be correct.

    • Hydrothermal events at Hveravellir, and in regards of Galeras… Who knows, it might erupt, and it might not. It depend upon if the pressure is sufficient to in the end blast the dome away.

    • I think there is a party. Them “jólasveinar” have as of tonight returned to the High Mountains (from the human settlements) and may have stopped by the Liquer store for supplies!
      – Explaining: We have our own Christmas Santas, so the North-American Santa (in the RED uniform) is not needed. Our Icelandic ones are in Dark Brown outfits, them red ones are suspected be fake.. Saves too on foreign currency.Íslensku_jólasveinarnir

      • Not to forget the Jólasveinavarnir that keeps track of them and warn the general population when they are up and about based on information from the IJO.

        *running like a nut from the Icelandic Cod on the way to connect with my head*

        • No running possible. I goes even uglier. We can drop all over, says IPHO.
          Currently unknown if tetonic or hot water effect says BPFAEO.

          We (IDO) have upgraded that “cod” and I belive this (video below) was just one exercise accidentally caught and smuggled out. None others have been seen since, as all surrounding boats were also sunk…. :mrgreen:

          In this “official demonstration video” (below) one of them upgraded ones (here role-played by a sperm-whale) is seen making a practice drop in unspecifed area in north of Sweden (starts at 0:54). Note how them montains look just like swedish ones.

          *IPHO = Icelandic party holding office
          *BPFAEO = Better prepare for anything everywhere office 😉
          *IDO = islander defence office

          • Nope, IPHO was my favourite. I am going to hold you to it though, holding the party until I get to Iceland again 😉

            (Stuck on phone… mundane life)

            • Ok, at present we have “real” White Winter-in-the North,
              so you just can drop by anytime you like
              and we are mostly off “whale season” 🙂
              But no eruption forthcoming, SFAIK

            • No winter here either. Just the 5th day of rain… I am quite literaly going nuts soon. Or maybe grew mildew…

            • in wales all the natives who developed suicidal tendancies as a result of continual rain have long since died off resulting in a genetic skew toward those who don’t mind a bit of mildew between the toes 🙂

            • Same here, there are nobody left who is not predisposed to having snow in the winter…
              1 meter of snow in the morning? That is just normal and business as usual. Mildew in the beard is not normal… 😦

              There is though hope, the forecasters are trying to raise hope with promises of -7C on thursday. I hope so, otherwise the city will be floating out to sea soon.

  4. And here we have White Island crater without ANY steam! For those who want to scrutinize the crater floor for lava dome spiders and other extrusions:

    • Seems like there is a few small earthquakes and a bit of hydrothermal activity at Yellowstone. Nothing out of the ordinary really for a large volcano like Yellowstone.
      But, I bet that the tinfoilers are having a blast now. Especially since there has been two papers during the last week about Yellowstone and the media have followed the procedings quite thoroughly…
      Rest assured, if anything warranting a post happens it will be written… 😉

  5. That is a terribly tense situation around Sinabung. There has been a meeting of the emergency services yesterday, apparently 21360 people have been evacuated by now.

    giggle translation of the current volcanic situation:
    “Volcanic activity is still dominated by the eruption is followed by the hot clouds glide to the southeast and high eruption 300-4000 m, the number of days eruptions for the 20 events. For hot clouds glide range as far as 3000-4000 m. Volcanic activity is still high status level IV (Beware)” :

  6. I was unaware of the current activity at Galeras as we speak here. It was just featured in BBC’s volcano hell show. That is how I learned about it. I believe the dome exploded off the top of the volcano in 1992. Whether the lava dome is there now I would doubt it because there is much activity going on currently.

    Should an eruption happen in Iceland this year I would like it to be one of the unusual suspect volcanoes..

    • on latter item. I agree, mostly. Unusual suspects be most exciting, but usual suspects more practical for learning

    • Trivia, what phenomena was first seen (and noted) by the geologic community at Galeras? Hint: Now days it can be used as a precursor indication that the edifice is getting ready to do something.

      (does not include or pertain to gerbils)

    • Galeras built a new lava dome in 2004-2005, which was blown out during a series of later explosions, and it has sporadically sputtered on since then. Nothing big, just a reminder to keep off the active cone (which lies within a caldera), while it is threatening to explode. The tragedy of January 1993, when nine people – including six volcanologists – were killed was not due to a large eruption, but to the fact that these people were on the cone, some even within its crater, when it suddenly produced a phreatic (vapor-, not magma-driven) explosion. On a geological scale that was a minuscule event, but for those people it was Armageddon.

  7. OT, but in Iceland. This idiot pilot was apperently show boating from what I heard. Amazingly, the co-pilot got out of the crash alive.

    • That sort of wind field is already in place since Midwinter or so. Bringing one storm(-depression) after the other towards western Europe.

      Since Midwinter we’ve here (Brussels) a mean wind speed of 6.0 m/s, normally that is between 3.0 and 4.0 m/s. There is actually never a moment when the wind stops blowing. And we don’t sit in the way of the most storms like the UK.

      Also the waves hitting the European Atlantic coast have already several (think 10+) people killed who were walking on the beach and got taken by surprise.

      an example of such wave


        Two people were caught in the UK – an 18 year-old photography student who has not been seen since he set off up a coastal path on the south coast, and someone on a disability scooter that was pushed off a path. The water doesn’t have to be very deep to pull someone in.

        A Chinese girl was pulled off the prom one year and disappeared when a wave randomly came across during a normal high tide. This is exceptional though. The prom has been undermined and properties flooded, windows broken etc

      • Most of these waves generate at the 200 fathom line and moves inwards if the bottom conditions are right, the highest rate of occurance in Europe is around Key Biscayne. It occurs as a wave train consisting of large swells are being retarded as they are braking on the 200 fathom line and at the same time encounter a wave of similar size coming at an angle, this will give the energy (wave amplitude) of 3 waves or more. It is also known as a rogue wave.
        Let me remind people here that it is a more rare occurance that someone gets killed like that then to win a million Euro-lottery (which is insanely unlikely to begin with). I reiterate, you are more likely to die by putting on your socks in the morning.

        On the other hand I would stay the hell away from the 200 fathom line in Key Biscayne during a westerly to southwesterly large storm swell… Literally thousands of people on ships have died there due to rogue waves over the centuries. I would though not hesitate to take a walk along the shoreline there, after all the gravest danger is out at sea.
        It is the same as with a volcano, you are way more likely to die a few kilometers away from let us say Hekla in comparison to being 52 kilometers away (that was a seriously unlucky farmer).

        • Do you mean the Bay of Biscay? Because I thought Key Biscayne is in Florida?

          And rogue waves are very rare indeed and it is even rarer to get caught by one, but it seems that in the latest series of storms there have been some huge (deadly) waves hitting the coast. So I think it you just have to be aware for it when a train of (south) westerly storms is coming in, but otherwise you’re fine.

        • 2 people were washed away this week end in Biarritz, one did not make it out…..
          The big wave surfers are waiting right now on the Belharra spot….

      • I find it hard to believe so many people stood there for so long watching that!!!! After watching the Japanese tsunami (yes I know this wasn’t a tsunami but a severe storm surge) I would have starting moving away as soon as the first wave came in so far through the harbour entrance and I would have been running when the next one broke over the wall. Mind you I have lived by the sea for almost all my life and occasionally seen massive rogue waves come inshore even in relatively calm weather.
        Always respect the sea and never take you eyes off it if you are close to the waves.

  8. And volcano wise it seems that 2014 will be a very interesting year, if the first week will be an indicator.

    Has somebody actually heard something about the Japanese volcanoes? Especially Snoopy Island and Sakurajima?

    • Sakurajima is sakuriajiming and Snoopy is slowly growing and is not so snoopy like any longer. So, nothing new there.

  9. In regards of comments on typos:

    The last couple of days it seems like people have really gotten into nitpicking on typos, I am kindly asking people to back down on that. I remind everyone that most people in here has English as a second or even a third language. Repeated comments and jokes about peoples spelling will just make people stop commenting.
    If the typo is making a train of reasoning un-intelligable, please help out, but for the love of god an obvious typo is not the end of the world. Use common sense.

        • do not think this was yellow card, or very pale. rather like hand movement of the referree of (all) back off and give slack. the typo gohst also lives at my place

    • If it’s glaringly obvious, I occasionally sneak in and fix it with no elaboration. If it seems as if the person is trying to make a statement by their choice of spelling, I leave it. The issue is I have to be ultra cautious due to the international flavor of this blog since I may not catch what the author is getting at. So, I usually leave it be unless it’s obvious.

    • Quilty too. I just want to let everyone know i didn’t do it because i was nitpicking. Everyone with some knowledge about the subject would have red over the mistakes just fine. I just was afraid someone new might miss the point abit cause it is a recurring term in volcanology with importance.
      I’ll never become a spelling nazi. Simply because i need those or a spell checker since i’m partly word blind and dutch. 🙂

  10. It will be interesting to watch how the events at Sinabung will evolve. I keep getting impressed by their mitigation efforts and efficiencies.

    OT, this made me chuckle. My self-proclaimed “Vulcan-prophet” aunt contacted me and had to share the latest vision (at which point my automatically started rolling), mind you that aside from the ’96 “predictions” for a “sub-glacial blast this fall” she’s never been anything but vague. Anyhoo, in yesterday’s message she went on in her usual tone about “a large-ish eruption that we’ve been waiting for years”, the usual stuff (heard that one at least thrice in the last ten years) and then that deary adds “but then Öræfajökull is gonna stunn scientists by going St Helens on us”.
    I think you can guess at which point I busted out laughing. I’m just glad that she communicated via email this time or I’d have had to deal with an irate mother…

    I guess the only true part of all this is that IF any Icelandic volcano went St Helens scientists sure would be stunned. (^_-)

    Well, it is time for me to get outside into that brisk -20°C Kentökký air and drive home (and somehow convince the missus that she needs to get up and go to work)

    • I be surprised too if Öræfajökull did go St.Helens on us, but Eyjó style more likely, it has shown small quakes in recent months, but nothing much. I do not know if fresh injection might hit old fragmented pot and blow it up. Possily it can, but it´s not usul for Iceland.

    • Nah. I prefer to sit here and laugh at them. If they cared for accuracy, it might be different. But they don’t. All they want is someone to look at them… like most media, they are attention, wh@#$.

      • unfortunately they appear in “oldest profession on earth”
        might there be market for non-bullshit news network,
        but then you are up against all government
        and/or private agencies & contractors on this planet,

        • I come from a newspaper familly, as such I am saddened that there are so many newspapers that do not take their work seriously. It is one thing that a journalist now and then get a fact wrong, it happens when you have to publish a daily newspaper, but one should always strive to make as few mistakes as possible, and to hand to write as unbiased and accurate as possible. The bias should remain on the political comments page.

        • Ain’t gonna happen. Goebbels proved how effective it was at pushing or bending the news to fit the message.

          “Goebbels soon established: Press, radio, film, theatre, music, literature, and publishing. In each of these, a Reichskammer (Reich Chamber) was established, co-opting leading figures from the field to head each Chamber”

          (Yes, It’s Godwins Law, but illustrative of my point. No accusations about anyone in this forum have been made, so I think I should at least get a pass in broaching the subject)

          • I know, I just find it sad that not everyone is trying to uphold the standards that I am used to.
            I was a small child when I was “indoctrinated” into the obligations and rigths of the free press. But, I guess our morning papers are rather different in comparison to many other papers. The afternoon press here though is rather horrible.
            People who wish unbiased news prescribe on the morning paper, and people who wishes to know what famous idiot made a boob-job will buy the afternoon tabloids.

          • It’s no better in broadcast. I have long berated “Vodka Bob‘s” holier than thou attitude, despite his being a class “A” asshat that is not better than the people he frowns upon in his news casts.

            Meanwhile.. I got a chuckle out of the reporting of a fire in Phuket. Classic. Even funnier since I have been there. Until he died, an acquaintance of mine ran a computer shop there. (Survived the tsunami that wiped out his shop only to be killed in a scooter accident 2 years later. R.I.P. Tracer.)

            HA!! Weather twit on TV just stated that temperatures are going to rise “astronomically.” So where ever that is, better be prepared for everything turning to plasma. Stars typically run about 5,778 K for the the photosphere of Yellow Dwarfs. (Well, that is the closest meaning of what the twit said.)

            If you ever make it there, it’s gorgeous.

  11. M 3.8 on the Reykjanes Peninsula, looks like near the Bláa Lónid Lagoon. Perhaps a failed try of Splashdiving?

    • I have always wondered what the average temperature is at Bláa Lónid Lagoon. Does anyone have an answer to that?
      I would love to be soaking there at this moment as I have a very badly aching hip today. Have to make do with the bath but it hurts a lot just climbing in. 😦

      • Hi Frances

        It’s generally about 37/38°C as I recall – just perfect!
        If you’ve been in a while and feeling slightly cold then you can find some hot-spots near the inlets.

        Slap the old mud (sorry, I mean invigorating salts and minerals) all over your face and away you go to heaven.

        • Thanks for the reply ukviggen. Oh that does sound a lovely temperature! I am now off to try the benefits of a hot bath with mineral salts on the aching hip. I think (and hope) that the problem with the hip is just being exacerbated by the constant damp weather we are getting.
          All I need now is a mud pack from the Dead Sea or somewhere similar and I can imagine being in Iceland! 🙂

  12. Lively Iceland map today. One approx. 3,8 R (unchecked) in Rekjanes Volcanic Field, but not felt here. Likely I was grinding, burn and brewing coffee (!) so must have missed it.
    And I promised Carl nothing would happens soon!
    Of note is quakes in many different places. Even Old Shield Volcanoes like Lyngdalsheiði and Þingvellir National Park…. I no longer can say nothing is happening, but I can be wrong. But its just January, too early to tell if this developes like January 2010, but I ask to them plotters, to dust off their excellent plotting skills and analyse swarms, if they look curious.

    • Thingvellir is most likely just hydrothermal events, but I would not rule out a new geyser or some such sprouting forth.

      • Nope. No hot springs in THINGVELLIR, you mean Hveravellir ?
        (Thingvellir place is gigant cracks, Graben and lots of cold water)
        Period. True! Nearest hot springs are 12 km away, at Nesjavellir,
        but quake was removed (likely ghost)
        *throws a fresh cod to north-east Sweden with great precision*

    • Rough quake, I think, downgraded to 3,5 R. These ocurr frequently but do not need be volcanic connected. Tectonic movement likely, in my view.

  13. Carl, I translated your post to Indonesian language. May I post it in my blog? And can I post it on an indonesian forum like Of course I will cite you as the source.

    I edited the translation though, your idiomatic english is somewhat hard to translate to Indonesian language.

    Thank You,
    Izzuddin A

      • I don’t know if WordPress has any bandwidth or access restrictions Carl will have to answer that one. If they are off of tinypic, just copy the link and go for it. But remember that tinypic images are prone to wandering off to the bit bucket after a period of time. (few months) I only use tinypic for stuff that doesn’t have to stick around for a long time. In a year or so Tinypic images won’t be there anymore, making archival reads of any associated material devoid of pictures. All main articles here use local WP hosting in order to avoid that problem.

        Note for authors or anyone thinking about writing an article, if you need your images pushed up to the server, any of the dragons can handle that. It’s done in the editing process.

      • The images are all on our WP server that does not have any bandwith limitations. So feel free to do it any way you wish.

    • Hello Izzuddin!
      Please feel free to reblog it, just remember to credit me, and post a link here to the blog post. I love seeing myself in other languages! 🙂


        • Sounds like a good idea to add the volcanology terms so that it is easier to understand.

          I would like to thank you. It is not every day I get translated into a new language.

          • Someday I may translate your post to ngoko Javanese (with the accompanying rural and rough stereotype, in comparison to English, the language of global intellectuals :p ). 😀

            On the other hand, I wonder if Bone Idle is a Batakese… He(she?) seems to be quite familiar with Brastagi region.

  14. Niijima / Nishino shima is still growing. The small snoopy island seems to take some height

    it seems new area seems to get even to the old island
    The 2 vents are still there and seem active

    source Japan coast guard

    • The new part of Nishinoshima is probably having a larger amount of mass by now since it is higher than the old part.

      • yes, too bad we do not have any other info, but it is very remote. However the eruption seems to go on at a traquil pace.

        • And even if it threw a fit and delivered something around a VEI-4 it would still be in one of the few parts of Japan that would not affect people at all.

  15. Warning for all. Karma is up to something. This is so out of the ordinary that there has to be something at play. My parts are sitting at FedEx. 580 km away in Memphis. It’s pretty obvious I am not going to make the call down town. But a change that radical means that really bizarre things could be at play. Could be a volcano, could be a quake. Might even be a coup somewhere or a tank farm explosion.

    Keep your eyes peeled for signs of the weird.

    • Now ponder this… I am one of the most scientific guys around, and this place is all about science. And still I have had to hand out a Psychic Point for answering a riddle one minute before it was posted to Lurking. As such Lurking is my personal Black Swan proving that some people just can do that (he has done it a few times more). The most fun thing is that Lurking is about as scientific about it as I am.

      But I am pretty certain that Lurking this time is playing at something much more scientific and sinister, he is playing with the other side of the Black Swan. It is my only scientific rule to date that I have had the honour of fomalizing.
      It is all based on Douglas Adams wordplay on probability theory, “The Improbability Theory”. I played extensively with it from a mathematical standpoint when I was in my twenties and discovered that the often omitted fact that a Bell curve has no ends have profound effects. In fact, the outlayers far out there will always outnumber the statistical probability. It is also most likely the only mathematical equation that is easier to formalise in words than mathematical language beside Newtons most famous law.

      I call it the Law of Miracles:
      “There are so imprabably many improbabilities that improbable amounts of improbabilities will happen to you improbably often”

      Now read what Lurking wrote and you will start to see what he actually meant. Or he actually meant what he wrote ad verbatim.

      • Well, how did Popeye put it? “I yam what I yam and dat’s all dat I yam”

        I got a text message from a friend up on Long Island. “It’s in the 20’s in Pensacola!” My responce → “Yeah, I noticed that.” He sent me a screen shot of his systems management screen for the building he operates. “External Temperature 5.6”. He’s quite happy that the delivery of 4000 gallons of heating oil was delivered yesterday. Their tanks were running low and there would be quite a few unhappy tenants if the boiler shut down.

        The news is jumping up and down about how odd the cold weather is… but I distinctly remember freezing my arse off 20 years or so ago here. (I’ve mentioned the frozen bunker gear before).

        Carl is quite correct. But my fascination with the Black Swan is spotting evidence of them before they occur. Technically, that would make them non Swans since by definition, you don’t see them coming. If I ever see one, odds are I will wind up being Casandra about it though. Casandra is a tragic tale. Perfect prognostication with the curse of never being believed.

        Where the Normal distribution fails is that it doesn’t have fat enough tails. Stuff goes bad much more often than one would expect. In Carls link to the Hitchhikers Guide snippet, the bowl of petunia’s epitomizes the Human condition. It’s a personification of “the guy.” The person who dutifully takes his child by the hand and trudges across a field of volcanic ash to get it to safety. He’s the person that stuff always happens to, so he grits his teeth, bears down, and deals with it.

        Notice that the adults stride is arbitrarily shortened to match that of the child. This is a person in a parenting role. They obviously have their wits about them. All hell is breaking loose around them and they are patiently coaxing the child along.

        • Or go well… The law of miracles kick both ways. It will of course not make you win a million in a lottery, but now and then you might get something good in an unexpected or even ludicrous fashion. I remember once when I was a student I was as poor as a student can be and I was waiting for an airplane that didn’t come. I was also about as hungry as a student can be. Out of the fog of the airport came a dude and sat down and hauled out a bottle of whiskey, for four hours he regaled me with stories about his life whilst imbibing me with the whisky. In the middle of the night he got up to go to his airplane. As he got up he hauled out his wallet and handed me all the swedish cash he had and that he could not exchange in the middle of the night, and he just wandered off leaving me quite surprised (and drunk) with something like a fortune for a hungry student in my hands. Many years later I saw him again on the news when he was hauled off in hand-cuffs for the Madoff scandal. How’s about that for a law of miracle event. I am the only one to date to make a profit on him.

          What I find hilarious with the cold in North America (not that freezing your arse of is funny) is that at the same time as you guys are freezing we have record warm weather in Europe and large parts of Russia. So, on average the weather is AVERAGE.
          In my case I should have about a meter of snow now and -25C… Instead I have the sixth consecutive day with rain, +5C, and a bloody flood-warning for the river system. It is the first winter flood-warning issued in January for obvious reasons.

          • Carl that is our Northwest weather! sounds like Seattle. We are short at about 10cm of rain for the winter and we finally are getting a bit of moisture this week. but our cold isn’t here either.
            I wouldn’t like to be in Michigan right about now.Called a friend who is a retired Coast Guard
            CPO who was saying that the weather is supposed to break this week…

          • here it was 35 + and now I have a heater going with 10 deg, one part of Australia is very hot, no rain, cold in another and so it goes, all the ships down south are on their way, Sinabung is is getting ready to blow its top and another nearby volcano is rumbling.
            I have been thinking, volcanoes seem to get active being a certain distance after there have been a lot of strong quakes in nearby subduction zones and others who get further away go to sleep ??

        • I’m quite happy for the hard freeze. It prunes back the bug population.

          However, I won’t make the same mistake I did several years ago in another arctic blast. I set a water hose up to spray a fine mist into the air overnight. I wound up with a couple of tons of ice in a large lump in the backyard.

          That lump stayed put for several days and blocked the driveway to the garage around back.

          • Well… if you cover it up with sawdust you could really mystify your neighbours come summer… (and keep yourself cool as you BBQ).

          • This was years ago. Jackson has since seized the property and resold it for taxes. Funny how they never did change the mailing address when requested. One of those corrupt bastards made a bit of money off of that.

            I hope all their Yazoo clay gets damp. It’s not quickclay, but it has an ungodly expansion coefficient.

            “It’s a thick, extremely dense clay that has an affinity for water. If it’s exposed to water for long periods, it swells. If it dries out, it shrinks. It swells and shrinks A LOT, as much as several feet in a few extreme cases, and nothing can stop it. If the drainage around a house isn’t done correctly, water will pool around the uphill side (causing that side to swell) and the downhill side will dry out and shrink. If the house has a well-constructed post-tensioned foundation the soil will tilt the entire house. If it’s a typical poorly constructed post-tension foundation only the ends of the house go up and down which cracks interior walls, exterior brick, and sometimes causes roof leaks.”

            I’ve seen tractor trailers that were snapped in two due to the buckling of the highway from this stuff. It’s nasty. As for the house… it’s the only wood frame house that I know of with a 50 foot 10″ I-beam running down the middle of the attic. That was my dad’s way of stabilizing the structure. All the rafters were tied into it.

  16. Great post Carl! Very clearly explained. Hope this may get a definition as soon as possible so that nearby people can finally take a breath.
    Big hugs from Rome to everyone in VC!
    Best, Rio.

  17. There was a combined explosion / pyroclastic flow at Sinabung. It clearly went outside of the 5km zone. I do not think the PF went outside the 7km zone, but it was borderline.

    • Wow, Sissel, good catch there! When there is just clouds to see in 99% of the time, ash or weather, I sort of get tired of looking and probably miss the best moments.

  18. Twice I had to drive off into the median on the way home. When you have emergency vehicles coming up from behind, you get out of the way. Luckily every one was playing right and yielded to them. In bumper to bumper traffic it helps if you get out of the way in unison.

  19. And after 15 days Sinabung has made it into the VEI-3 family. It is actually pretty astounding since the major eruption has not really started. But if the major eruption does not start it will take a loooong time to get to a VEI-4 equivalent, if it ever does that.

    • After 44 pyroclastic flows yesterday, Sinabung seems to be relatively quiet today.
      The webcam not showing continuous activity as per yesterday.
      Calm before the storm? Or signs of a wind down?
      Do you access to the seismology reports?

      • Did you miss the large one that just ran down to the 7km zone boundary?
        I get my hands on a few of them, but I have not seen the latest. But I do not think that it is winding down. It looked more like a large part of them dome went down yesterday and now there is less material that can go down.
        Hopefully I get fresher data during the day.

        • Missed that 7KM run.
          This means that the exclusion zone to the southeast will need to be pushed out to 10K’s – maybe more.
          You are starting to talk about tens of thousands of village people now.
          Our family has a hill-station house in Berastagi line of sight to Sinabung. Fortunately not in the southeastern path.

          • I think that Surono will wait for an increase in seismicity or changes in the mountains leveling. But, they will most likely not hesitate if they see a need.
            I can only repeat that they are good.

            I am a bit jelous when I hear about the hill-tation house. I take it you are not there currently?

            • Kabanjahe town is around 12 – 14 k’s south east of Sinabung. There’s a largish population there.
              I would be nervous living there.

              Here’s a view overlooking a neighbours house – when the Sinabung was quieter.
              No one is at our family hill house – it’s to get away from the Medan heat and humidity. There’s a caretaker however he’s not getting up on the roof and clearing the ash off anymore.

              Link fixed. Spica

    • “it will take a loooong time to get to a VEI-4 equivalent, if it ever does that.”

      You know better than I that it’s all about the rate. Puyehe got on with it quite determinedly.

      • I know, one should also take into consideration the columnal height.
        It was just a way of putting it into perspective. I just fervently hope that Sinabung does not decide to make the jump to VEI-4 in the same style as Grimsvötn did.

  20. And to continue to complain about the weather… This is now the seventh consecutive day of non-stop raining. Now with the added benefit of fog and rain at the same time. The grass has started to grow again, and below the balcony there is a nice collection of mushrooms. Could someone from England come and collect your weather… please?

      • I saw the temperature in your neck of the woods on the news here… Not even a swede would go to the beach at those temperatures (maybe a Finn would…)

    • Hi Carl. Please stop moning about the rain.
      We had rain three times last “summer”.
      First for 14 days, then 35 days and finally another 30.
      It will go down in annals as year without summer … 🙂

      • Even though we had the best summer ever I will still moan a bit. A bit of moaning makes life a little bit better. 🙂

        • I couldn’t agree more Carl. If one MUST put up with bad weather then a good moan certainly helps relieve the frustration.
          And guess what? Out walking today and saw this strange grey shape form on the path in front of me!!! After a great deal of thought I concluded it might be my shadow. 😉

      • According the the gnews… California is concerned about the lack of water. They have almost no snowpack in place for the spring thaw. Look for water issue there (lack of) later this year.

  21. I wonder if the lava dome at Sinabung will just grow and collapse repeatedly or if the volcano will actually blow it out.

  22. Pingback: Jalan menuju Sinabung | Izzu

  23. Lots of data and figures covering Sinabung´s activity from November 2013 to just a few days ago:
    Image and video hosting by TinyPic
    The caption reads: “Appendix 1. Seismicity G. Sinabung 1 July 2013 to January 2, 2014
    Earthquake eruption and fallout increased since December 30, 2013, but is still dominated by the quakes seismic Hybrid.”

    • The volcano next to Sinabung is Gunung Sibayak, it is because the lack of distance I used it as a potential model for how Sinabung might erupt.

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