Sinabung & Tungurahua

The eruption of Tungurahua as night is starting.

The eruption of Tungurahua as night is starting.

During the night two large events took place. The first is the deadly collapse with a following pyroclastic flow that struck at Sinabung; the second is the powerful eruption that started at Tungurahua.


Farmer with the deadly pyroclastic flow in the background.

Farmer with the deadly pyroclastic flow in the background.

In a decision that I guess will be hotly debated for some time the Indonesian mitigation authority decided to lower their risk assessment for the volcano and letting people back into the 7km exclusion zone due to the diminished activity at the volcano. In the end they settled for a 5 km exclusion zone, and it is rumored that not even that distance was upheld in places.

The entire village disappeared into the ash cloud.

The entire village disappeared into the ash cloud.

During the last couple of weeks an 800 meter long lobe of brittle and very slow moving magma had formed down the valley that the pyroclastic flows has followed so far. This meant that the pyroclastic flows started from a lower point and thusly had less power and travelled a shorter distance. This probably fooled the volcanologists on site.

It is said that hindsight is 20/20, but having an 800 meter long lobe of brittle magma hanging down a mountain should really have raised concern. For whatever reason it did not do that.

During the European night the lobe failed catastrophically and came rushing down in the largest pyroclastic flow to date. So far 14 deaths have been confirmed, but the risk is great that the number will increase in the days to come.

I will leave this tragedy with one wish, that in the future dialing back on volcanoes will be done in a slower fashion to ensure that the volcano is really on the way to stop erupting. Today was unnecessary.


Screen capture of the eruption right after the start.

Screen capture of the eruption right after the start.

While people had just begun to grasp what had happened at Sinabung the next blow came as Tungurahua started a large eruptive episode. It quickly became clear that the eruption had caused an eruptive column that was between 10 000 and 15 000 meters high.

The 5 023 meters high Tungurahua in the Cordilleras has been more or less constantly erupting since August 1999. It is a medium-powerful strato-volcano capable of eruptions ranging from VEI-1 up all the way to VEI-5 from a historical standpoint.

Current Tungurahua (T3) formed in a VEI-5 eruption 3 000 years ago with a horse shoe shaped caldera formation. T1 was most likely destroyed in an even larger VEI-6 eruption. There is nothing pointing towards this growing into something like that.

Judging from the columnal height and probable ejection rate this looks to be another VEI-3 eruption and that is normal for this particular volcano. The biggest worry is the town of Baños de Agua Santa that resides just 8 kilometers from the volcano. There are also close by villages in danger.

The greatest dangers are pyroclastic flows running down the slopes and Lahars forming from the glacier at the top. No deaths have been confirmed as of now.

The eruption is said to have been precluded by small explosions on the 30th ejecting coarse black sand. But, that is not that uncommon from a volcano that has almost constantly been erupting for 15 years.


289 thoughts on “Sinabung & Tungurahua

  1. Weird report from IM: Noise disturbance due to NATO exercise: From 11:25 till noon and again around 15:05, strong noise bursts were detected by the seismic monitoring system of IMO all over the country. Few people called because of hearing thunder and feeling a shock wave. These signals are not related to seismic activity, but most likely to a NATO flight exercise that is going on around Iceland until 21. February

    And if true, why is NATO doing so long exercises above Iceland?
    Sounds like the similar sonic booms and thunder noise reported in early December by me and others, also by the IM, and that appeared in the Icelandic news.

    Carl: those 4 quakes you spoke, near Grimsvotn. Cannot find them. But interestingly, a quite moderate sized swarm has began in Torfajokull. Cannot remember such a strong swarm there. Its not deep but quakes range M1 to M2. It lies directly in center of the caldera. Maybe those are your quakes.

    They show up in SILS in the west edge of Vatnajokull, near Hamarinn, but also near stations around Hekla.

    Also, today first quake I ever remember to see located in the East Fjords. If there is a tectonic fault there is very old. Its not very far region from that old extinct volcano, that sometimes you speak of. I forgot its name.

    • It is the combined Swedish, Finnish and I think Norwegian air-force out doing weird things to prepare for the Defence of Iceland.
      And the will be booming about like maniacs for the next 18 days while taking turns at playing Russian foes.

      The Swedish part is from F21 1 squadron, so for a time there will be less fighter-jets booming over my head. UKViggen knows how nuts those guys are.

      I think that the Grimsvötnish quakes have been edited in.
      The one in the eastfjords is quite aways from Thingmuli volcano.
      I find the 2.5M at Langjökull to be fairly interesting too. I also agree that the earthquakes at Torfajökull is interesting, it is in the part that is known to have mobile magma and the part that is transected by the Veidivötn fissure. Intriguing.

      • “UKViggen knows how nuts those guys are”

        They’re all Gripen folks now – I’m sure they are much, much better behaved than the previous bunch 😉

        • Suppose ths quake is “too low” to be a sonic boom. Me think even the Gripen has troble go that deep 😉
          05.02.2014 16:13:42 63,637 -23,415 30,5 km 2,0 99,0 7,8 km SW of Geirfugladrangi, R.neshr.

          But so happened I was birdwatching 15:03 hrs and heard regular Sonic boom. No black project needed for them. Remindes of old Eagle days. No such seen today.

  2. Evenin All,
    Some action at Etna (from the flanking vent of the NSEC) best seen on the Radio Studio & and LAVE cams 🙂

  3. Here is a wiki on something I was reminded of from the 1990’s BTW, I saw TWO of the “blackstar”
    aircraft (the chopped and channeled B-70’s for lack of a better definition.) This was in 1996 on the southern Oregon coast. for several days thundering sounds, shock waves etc as you describe for Iceland- including seismic recordings (one notable thing was a high speed sumpin’
    or other going into Edwards AFB at night setting off seismographs all over southern California.)
    Here’s the wiki : .
    PS- I may be offline fore a few days due to my provider and i being at odds over some overage fees that occurred when I was in the hospital. to the tune of several hundred dollars. So it may be to the local coffee shop WiFi and that isn’t exactly a tragedy..

      • No problem at all 🙂
        I was just answering Irpsit who had found out that there was a natoish thingy in Iceland. It was actually Islander who told me all about it a few weeks ago. And it was in the papers a couple of days ago before they left from here.
        I grew up next to an air force base during the cold war. They did a lot of take of to supersonic starts every week back then, and still do when they go up to chase away the Russian bomber planes. We also have the testing grounds close by for all sorts of weird European stuff.

        So, I tend to love Blackstars and aironautical stuffs 🙂

        • Back when I was kid I didn’t even wake up when they boomed over the house. My brother though woke up one night when the outer pane cracked on his bedroom window.

        • My favorite oddball story was about an orange UFO that appeared like a receding fireball after it scared the crap out of a Shepard and his flock of sheep. Turned out to be an ASCM from a Russian test range out at sea that had locked onto the Northern coast and had gone roaring ashore at just under Mach 1. No word in the story about where it eventually wound up.

          • A story from my neighbor,when I was a kid you see, my neighbor was an Air Guard pilot -F-86D Sabres out of Geiger field
            Spokane, WA. Once,they buzzed a local
            Ski area-with the afterburners lit-(reheat which is a better definition) in pursuit of ah,something.
            He said he couldn’t say what it was- never got close enough…

          • That whole afterburner concept is pretty wild. Does it always use bypass air? If so, it’s essentially a sort of ramjet mode, augmenting the turbofan.

  4. An update on the El Hierro situation. As pointed by Karen earlier there was a small swarm right under the island. From the location of the quakes I suspect a small intrusion (there seems to be a plane-like structure – look around 22-25 s) and of course there were 2 quakes at 3 km depth and very close. Plus a rare deep quake over 30 km depth. So, not much activity, but some interesting events. TIme will tell as always.

    The first part of the video shows an event by event animation starting on January 1rst.

    The left side of the colorbar gives the date.

    Dot size is proportional to magnitude. The scale is given on one side.

    Terrain elevation is shown (see right side of the colorbar)

    The following sequences are a 360 rotation showing all the events and some vertical rotations.

    The last sequence is a zoom centered on the last event.

    Data is from IGN and NOAA, made on Gnu Octave.

  5. For those in the \uk – Julia Bradbury’s Iceland walk prog on BBC4 right now – she’s going up Ejaf …. the one that went off, It’s a repeat but well worth it

  6. I am a bit under the weather from vegetable poisoning. Had planned to write something but not really up for it today. If any of the Dragons feel like pushing on the buttons and post something from the Stockpile please feel free.
    (going back to the sofa to drink tea and watch another episode of Eureka)

    • The A4’s are magnificent locomotives. 4464 Bittern and 60009 Union of South Africa have been putting in some impressive performances as of late. 4464 did Torbay Express in 2012 and those 90mph streak trains last year. 60009 was the primary power for 2013 Winter Cumbrian Mountain Expresses and also did a Royal Duchy this past June over the Devon Banks.

      I also like GWR 4-6-0 Castles and 4-6-2 LMS Stanier pacifics.

  7. OT: Bug Splat.

    From the article (and specifically about Mars) “Before-and-after imaging that brackets appearance dates of fresh craters on Mars has indicated that impacts producing craters at least 12.8 feet (3.9 meters) in diameter occur at a rate exceeding 200 per year globally. Few of the scars are as dramatic in appearance as this one.”

    Now… given Mars’ proximity to Earth, it would not be too far of a reach to assume that the impact frequency for Earth is likely very similar.

    • Okay, appears that we got the answer to what the reaction would be to the mistake they made with Sinabung.
      After checking the list I can say that it is not 19 new volcanoes that has been placed on alert. They have raised the alert for about 10 of them, that is all. Some like Soputan, Lokon-Empung (both Tondano), Merapi, Kelud and Anak Krakatau (among others) where already on the second highest alert or allready erupting (highest alert).

      I guess it is an understandable way of trying to make sure that they will not underestimate there volcanoes again. Probably after considerable discussion they changed their Operations Manual a bit. The Indonesians are good at what they do, and they learned by their mistake. Cudos for them.

      On a personal note. Everybody can make a mistake, even tragic mistakes. Heck no I have made more than my share. What makes the difference is to learn from them. I would like to compare this with L’Aquila, the mistake was not made by the scientists there, the mistake was to punish them. Good safety can only come from an environment where you get to learn from your mistakes, without fearing retribution. In the end it is an (almost) impossible job being done by people who do their utmost to protect people and sometimes mistakes will happen, but most often they do not make mistakes and large amounts of lives have been saved.

      It is important to understand that during Sinabungs ongoing eruption the authorities in Indonesia have saved far more lives by their actions than was lost by one mistake.

      • Thought that the victims at Sinabung had strayed into the 3km exclusion zone which had not been lifted and people had been returning briefly to their homes even before the wider restricted zone had been lifted, albeit for a short time. Was the error local communication?

        • That is true, but the PVMBG also issued dispensations and limited the exclusion zone, and that way they sent a not intended message that the volcano was “safe”. At least that is how people interpreted what they said.
          And that set the stage for when the largest PF so far came rumbling down.

    • If it’s deeper than about 3.5 km, I’d say probably not… and thats allowing an extra km of slop in my estimate. Water crosses the supercritical point at about 2.5 km depth. Below that, it can’t form steam. However, that doesn’t mean that some form of water isn’t being pushed around down there. In that case, it’s entirely possible. … and just as likely not.

      If it is superheated water, and it gets pushed above that 2.5 km depth, we could get a new Maar to look at.

      Note: 2.5 km is not the actual depth, but I’m too tired to go back and recalculate it. However, it is close to that.

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