An Invitation to a Volcanocafé Scientific Project

Photograph taken some time after the October 25th 1902 VEI 6 eruption of Santa Maria, Guatemala. The eruption killed more than 5,000 people as well as causing an economic disaster by destroying most of the country’s coffee crop. The eruption column reached 28 km. Note absence of the Santiaguito cone which has subsequently grown where the post-eruption crater used to be.

Photograph taken some time after the October 25th 1902 VEI 6 eruption of Santa Maria, Guatemala. The eruption killed more than 5,000 people as well as causing an economic disaster by destroying most of the country’s coffee crop. The eruption column reached 28 km. Note absence of the Santiaguito cone which has subsequently grown where the post-eruption crater used to be.

A couple of days ago, VC reader VerboselyLaconic posted an interesting observation about the Andean Volcanos of Equador and Columbia. Here is what he said:

It seems almost a rule that when they erupt BIG, it is a lateral blast, and all but a few of them blow in a westerly direction. Now, I have no documentation supporting this, but just a cursory look at Google Earth and you will see what I mean. The place is absolutely littered with Mt St Helens look-alikes. I have compiled a (non-exhaustive) list of a few volcanoes located there, just to illustrate:

-Cerro Altar; LATERAL, W
-Chimborazo; FLANK COLLAPSE (?), W
-Carihuairazo; LATERAL, E
-Iliniza Sur; FLANK COLLAPSE(?), SW
-Corazon; LATERAL, NW
-Ruminahui; LATERAL, W
-Pasochoa; LATERAL, SW
-Atacazo; LATERAL, SW
-Pichincha; LATERAL, WSW
-Castiagua; LATERAL, WNW
-Mojanda; LATERAL, W
-Cotacachi; LATERAL, NW
-Imbabura; LATERAL, E
-Reventador; FLANK COLLAPSE(?), E
-Cerro Negro de Mayasquer; LATERAL, N
-The 3 unnamed cones to the SW of Cerro Negro; LATERAL NNE, LATERAL W, LATERAL NW
-Azufral; LATERAL, NE
-Dona Juana; LATERAL, SW
-Tungurahua; LATERAL, SW

Is this odd? Is this disproportionate to the rest of the major chains of volcanoes elsewhere? Of the 30 or 40 volcanoes located in these two countries, 22 of them have blown laterally and 17 of those in a westward manner. I guess if you must build in this area of the world, build on the eastern side of the volcanoes. You have a 57% chance of not getting shotgun blasted into the Pacific…and only a 23% chance of being shotgun blasted into the Amazon – if your mountain happens to blow. Of course, the lahars and pyroclasts may STILL get you, so there is that…

This observation is statistically significant. Roughly 50% of listed volcanoes have suffered a flank collapse, often in conjunction with a lateral blast, and of those 22 volcanoes not less than 17 (or 77.3%) have done so to the westward, in the direction of the subduction zone. Is this a coincidence, does it apply only to Andean volcanoes in Equador and Columbia, or is there a general physical principle involved, a rule that applies elsewhere? Why not start a scientific project of our own in order to find out and in the process, create our own data base!

Instantly obvious from the birds-eye view although not readily apparent from ground level, Galeras in Colombia is another volcano to have suffered several flank collapses in the past. Long-term extensive hydrothermal alteration has contributed to large-scale edifice collapse on at least three occasions, producing debris avalanches that swept to the west and left a large horseshoe-shaped caldera inside which the modern cone has been constructed. (Ingeominas photograph)

Instantly obvious from the birds-eye view although not readily apparent from ground level, Galeras in Colombia is another volcano to have suffered several flank collapses in the past. Long-term extensive hydrothermal alteration has contributed to large-scale edifice collapse on at least three occasions, producing debris avalanches that swept to the west and left a large horseshoe-shaped caldera inside which the modern cone has been constructed. (Ingeominas photograph)

So on behalf of Volcanocafé, you are hereby invited to become one of our researchers! What we want you to do is to use Google Maps (topographical is best for our purposes) or Google Earth and hunt for volcanoes that have suffered a flank collapse. Once you find one, take a screen shot – just make certain north is up! – note down its name and location, then go to the Global Volcanism Program – – and search for the “Volcano Number”.

Armed with this information, you open a photo editor (MS Paint will work), crop the screenshot and enter the salient facts. Once done, upload the image to Facebook, TinyPic, InkFrog, PhotoBucket or any other image hosting site, copy the link and post your discovery on this topic! Unashamedly copy any background information found relating to the collapse event (give credit for where you found it though). As an example, I have done this for Mount Iriga in the Philippines, a volcano which appears in one of the photographs on the Mayon article:

Philippines, Luzon, Mount Iriga (Volcano Number 273041)

Screenshot from Google Maps

Screenshot from Google Maps

Mount Iriga is a small stratovolcano that rises to 1196 m immediately SW of Lake Buhi. The dominantly andesitic stratovolcano has satellitic cinder cones of basaltic composition. A large breached crater that opens to the SE was formed as a result of a major debris avalanche that buried several villages and formed a broad hummocky deposit that extends across the plain south of Lake Buhi. This catastrophic event was at one time considered to have occurred during 1628 CE, but later work has shown that the collapse and eruption occurred earlier at some unknown date during the Holocene. The avalanche was followed by phreatic explosions that created a small crater at the base of the scarp. (GVP entry on Mt Iriga)


Good volcano hunting!


270 thoughts on “An Invitation to a Volcanocafé Scientific Project

  1. Does the activity that we are seeing will have any impact on the SISZ ?. I am really asking if this has reduced the stress around that area or indeed increased . I know we were waiting for that large earthquake to happen in that area.

      • That’s great. Have fun. If you do a fly over Holuhraun let us know if you see a new lake. 🙂

    • Have a wonderful time – keep us posted if anything exciting happens! 🙂

    • I like the plots. It looks like a deep rift?? Not what I would imagine from a magma chamber.

    • “Hope the image posts”

      I tend to use Tinypic. Once I get a full screen view of the image (right click, view image), I copy the URL and post it here. WP is pretty good about properly rendering an image as long as it has a jpg or gif extention. When the link goes to a Java or script rendered page, WP leaves it alone and treats it as “just another link to something.”

      Many image hosting entities obfuscate the image with scripting to keep people from doing that. They claim it’s to protect the image owner, but someone with a little bit of knowledge about how pages are rendered can easily bypass that and snag the image itself. They are only protecting their method of profiting off of your image by forcing people to click on their site, driving up their click count and boosting what they can charge for advertising.

      For example, digging through the web page code for the one at your link…

      Tada! What you were trying to post. 😀
      ” alt=”” />

      Now… CONSTRUCTIVE criticism (not a slam by any means).

      It is always helpful in conveying the meaning of the data in a plot by labeling the axis and units (if applicable). Try to not leave it up to the viewer to “just figure it out” … as a rule, people viewing your plot tend to have less knowledge about what you are talking about than you do. Other than that, it’s a good plot! Thank you for your effort!

      Caveat: I’ve plotted lots of stuff, and been “beaten up” on more than one occasion over how I rendered the data. I am far from an expert, but I do have a few plotting endeavors under my belt.

    • Eldey at yellow for those who wonder what da Grimmster is on about! 😉

    • Leslie, you and your family have a great visit to Iceland. Don’t forget to break in your boots before doing a long hike. (:- )

  2. Vatnajokull seems very quiet since the swarm at Reykjanes began, no?

  3. For you, my dear Volcanocafe friends, I have 3 new goodies. Plot wise. After searching for data, I finally found the gold mine.
    First is a plot of the Reykjanes ridge. I adapted the scales to really nicely show the underwater volcanic features of this region. The biggest feature is Eldey, which has a double top feature, and is the region where most of the stars are located. The swarm extends SW to the two sharper peaks.

    Next one, is Icelands elevation in general. It beautifully gives you the filling how complex it really is, and its formation features, and the big blob it sits on, legacy of the plume.

    And last is a focus on surface features. Nicely seen are the Grimsvotn caldera, Bardarbunga, Gjalp, Kverkfjoll, Esjufjoll peak, Askja outer caldera, the Pordarhyrna S of Grimsvotn and Oraefajökul. Also you can see Eya, Katla, Hekla, Vatnafjoll is nicely seen and many others across Iceland.

    If you want to see any particular Icelandic region, just tell me and I can zoom in.
    Hope you like it, since it took me a while to plot it. 🙂

    • Very informative, thank you! That last picture really brings home one fact – how Iceland was formed:

      7 MY BP, the hotspot was under what is now Langjökull, ~4-5 MY BP, it formed Hofsjökull and since at least 2 MY BP Vatnajökull.

      Nice job!

      • Good one Leon. Thank you. Those diagrams really explain how Iceland rift “works” and has changed and it’s relationship with the “plume” .

      • Both have provided telling data. Very good!

        Now, if the casual reader will note, the RR segment has moved from it’s original “landfall” location to it’s current. Eventually, it will likely move to a new “landfall” point lying along the Westman Islands and treking up through the Hekla area.

        • There are two possible alternatives if we speculate. The first is the MAR shifting to a line through Katla – Eyjafjallajökull – Heimey (K-E-He). The second is a much shorter shift, roughly through Hekla and Torfajökull (H-T).

          Seeing that there already exists a rift from Bardarbunga to Torfajökull, that Hekla is a rift feature and that the MAR at Reykjanes Ridge seems to chug along nicely, the path of least resistance would result in the H-T line opening up.

          • How long in your best guess would this take for the MAR to shift ? Its been happening for a long time now.

          • Quite some time. Your best estimate would probably be to compare the ages of the systems in Snæfellsnes and Reykjanes, since Snæfellsnes is where the MAR used to make landfall in Iceland.

            It’s been so long that I looked into it that I have forgotten the references for it.

    • Thank you so Much Down Under. I think the visual of what lies under Rekjaynes ridge is vital to help understanding what may be going on. It certainly looks like it’s still “bubbling” under there. I may be detecting a slight slowing of the quakes but still pretty active.

      Bon Voyage to Leslie i really hope this holiday in Iceland is wonderful for you and your family. Have Fun and bring back lots of pictures. 🙂

    • Your number two is… WOOT.
      Seriously it is giving food for though. It shows the hotspot extending in a totally unexpected direction towards Höfn.

  4. Just met the “great grandson.” Pretty weird. I spent most of the visit being drug around the house by the “tooth monster” who wanted to meet and greet everybody.

  5. Hi.

    I was checking for seismic data on BORG station in Iceland (IDA Network), located around 150km from the epicenters.. i did noticed a continuous recording at ~6Hz, since i dont know the station, if its common to get these recordings, or its local noise, does the IMO data corresponds to this? i´ve been mislead in the past when checking for volcanoes seismic data.

    Its a small amplitude recording..

    To check for seismic data from BORG Station, just download the day file from the following link:
    Open the file with your favorite software, i recommend SeisGram2K. Only >M2 eqs will be visible on the station.

  6. Would like to know how Cotopaxi is doing while we take in this exciting Icelandic activity.

    I’m also taking note of how Iceland has more activity in summer.

    • From what i gather there – report of low energy emissions rising to no more than 500 metres above the summit to the west. and continuing tremors. Seems to be bashful and hiding behind the clouds most of the time though.

      • Should also add that it seems there’s been some ongoing activity at Reventador, with incandescent material reported on thermal images, should probably keep an eye on this one too.

    • Very Cool! It puts the parking lot cam into perspective so that you get an idea of what the image is actually looking at!

      • It was in a comment at Erik’s eruptions blog, and i couldn’t not share it.

        Honestly it’s kind of creepy to me. I keep picturing what it would be like to be standing in that parking lot looking down on the vents and not knowing when the bomb under your feet is going to go off.

    • This is brilliant! As Lurking says it tputs the whole area into perspective. Some power being released there. If an eruption happens then is this going to be a huge flank blow out? (Makes mental note not to park car on that car park!

    • Now that is a nice real-time cam. Better than the parking lot actually 😀

      • The scary part is that you can see where the doming is going on, and also see how the camera shakes now and then.

      • My wife asked me a couple weeks back why I always had a tab open to a parking lot webcam.

        Waiting for it to blow up, I said.

        Look of disbelief, then she replied that no one’s going to car bomb an empty mall.

        Further explanations didn’t change that look one iota.

        • Nobody who is not a volcanoholic themselves will ever undertand us.

        • … well, when I met the great grandson today, I was chatting with my grandson and I was quite enthusiastic about the fact that he lives inside of the Rio Grande rift. He didn’t understand my interest. He was more stoked about finding a 4 year old can of soda in his suitcase that he had left here years ago.

          • We’re going camping in Kings Canyon National Park here in a couple of months. I was checking out the road vie Google Street and found this:

            This isn’t the GS pic but this view made me shoot soda out my nose.

            The satellite view blew my mind.

            36.821361, -118.822643

            Wow, more gray rock, Wife says, deadpan.

            Two kids didn’t look up from their books (at least it wasn’t phones this time).

            Middle son, though. . . Patiently listened to my explanation of dikes and sills and if this ones magmatic, holy crap that must’ve been exciting. I used to think he was humoring me, but now I think he’s interested but doesn’t want me to know.

          • Re Kings Canyon – that place sends chills down my spine . Had to work a fire twice there .
            nasty place for a four engine Douglas firebomber. Amazing geology though…
            would like to see it again-from the ground someday…

          • Speaking of 4 engine behemoths… I made a comment to my wife about the recent Indonesian crash of a C-130. “You sort of have to work at getting one of those to go down”

            Was I very far off the mark? That airframe is used specifically to do “Hurricane Hunter” missions due to it’s ruggedness.

  7. There has got to be a paper out there somewhere discussing the role of regional tectonic stress in relation to flank collapse direction.

    to the archives!

    Retrieved from the Akismet Limbo /Lugh

    • There might be. The last “interesting” paper of that nature that I read had to do with the location of the islands in the Canarys. It seems that each one may be at an inflection point in the bend of the oceanic crust where one island loads down the crust, causing the next over island to form at a weak point in the crust.

  8. Dear Volcanoes of this World,

    If it may be permitted, we, small and insignificant representatives of the species of ape-like creatures that sometimes climb your mighty edifices, have a humble request to make of you:

    Please, great as the current plethora is to us volcanophiles, one at a time!!! Otherwise, we do not have time to explore your mysteries, present them to others and together enjoy the mighty shows you put on for our benefit.

    With the greatest possible respect, thank you!

  9. Emerging out of lurking mode to thank everybody rescuing the site and contributing – out of the Rift energy flows, have to expect some quakes and fountains I guess. Speaking of which, as I rearrange my bookmarks – any suggestions for Watching? How do you organize you bookmarks and windows to all the fascinating webcams, drums, maps?

    • Lol. Being not very organised…With difficulty! I tend to group cams and plots etc together per Volcano or region. I have Icelandic, Bob.. Japan, S.America etc. Etna,…Vesuvius…Europe…Africa….NZ….But my Favs Volcano file Is HUGE! with many sub divisions so I have Iceland as a file on it’s own and of course before all these… VC.
      It does get messy especially when there is an eruption so I am constantly reorganising. One tip….Check links & cams weekly. They either cease working or are not as useful as an eruption subsides so I delete these. As we get more organised on our new VC site links will added under the appropriate headings at the top. The master Daleks are sorting this out as they have time.

      One Note….I do like to see all the Lurkers here. Please don’t be afraid of commenting even if you think nobody will be interested or that you don’t know enough. Rest assured, speaking for myself, I am way lost with some of the discussions on here.. There are some BIG brains out there but also many more average brains. All that we expect is a fascination and interest in Volcanology. I love discussing simple things such as where people live and maybe if they have ever visited or had experience of a volcano on a tourist level. Most importantly there are NO stupid questions. Nobody on here knows EVERYTHING about volcanoes and if we don’t know we all ask questions.

      • I salute this. I remember about a year or so ago when I started to comment. I was a complete novice then and I am still a newbie now, but thanks to all the commenters here tgat replied my stupid questions and all the informative posts, I was able to rise a level or two of the begining stage. 😉

      • A Lurker writes: Always watching, reading & learning, but keep myself to myself [most of the time].

  10. Actually found Hakone drums from the closest two stations to the caldera, tho none is actually inside the caldera. But any slightly elevated activity or tremor is recorded nicely.
    First one is the activity around the phreatic detonation, and the second is latest. It is a one hour display.

  11. just a minor mention that this site seems slower than the wordpress with respect to loading pages

    Retrieved from Limbo /Lugh

    • It is slower, and we are looking for solutions. This is one of the things that comes along with having to move in a hurry when being kicked out of one’s house by squatters. Meanwhile, we are learning how to do things and we’ll get there, just bear with us.

  12. I’m surprised at how much the cafe has become part of my entertainment/education/life. I have a feeling of like-minded attitudes. While this transition to a new host must have cost our Daleks a lot of time and effort, it seems to have really sparked a lot of new participation. One problem that I have though, is that I thought many of my old “friends” had disappeared but then I realized they had all taken this opportunity to change their names. Does anyone have a cross-reference of old names to new names?

    • Well, I am me. Through some quirk of fate, I wasn’t forced into a name change. Do keep in mind, that many of the name changes were forced by the act of becoming a valid user here, and that the previous name was just rendered un-usable by the transfer to a new host, and was an unavoidable occurrence. How exactly I was able to retain my name is beyond me. It could be that I still had access to the email account that I had when I initially made my account and just requested a password reset.

      • GL, I forgot my PW and waited. Suddenly, there was no longer requirement of signing in to post or reply. When I answered in reply, it said I was registered as Biologique with wordpress. Great, I was able to reply from then on without signing in. I thought you folks had arranged thing so we could post with original name. (: – o)

  13. finally starting to fly regularly. Working for three different companies,
    but you gotta do what you gotta do. Have a flight down into the John Day area then to Boise Idaho, back to Baker city Oregon. very interesting geology. I will make sure I have my camera. I’m flying a
    Cessna 172 with 160 snarling horsepower, so I will have enough time for sight seeing even in a straight line,,,

  14. Hi. My first post here.

    I thought I’d join in with this project and I was scanning Sumatra on Google maps for volcanoes that have suffered a flank collapse (I started off in Chile but it’s a bit difficult to tell the difference between a deeply-eroded crater and a glacial valley, so I switched to somewhere with a more tropical climate) when I found this very strange depression.

    According to the Google Maps scale the diameter is about 10km.
    Here’s the general situation:

    As you can see it’s just to the north of Payakumbuh (about 40km) and to the east of the Sarik-Gajah volcano.

    Some satellite views:

    Does anyone here know what this is? Is it a volcanic caldera? Is it just a valley that happens to be approximately circular? Something else? If you look at the first topographic map I posted there’s a roughly crescent-shaped hill about 1km across which sort of resembles a scoria cone down in the south-east of the depression.

    And north-west of that there’s a tiny cone-shaped hill. These two features are probably the most prominent things in the crater, aside from them it’s relatively flat. The hill has a scar of bare earth running down from the summit, which looks a little like a lava flow.

    Does anyone have any clues as to what this feature is? If it is a volcano (or was, it’s clearly not very active given that the valley floor is densely-populated and everything inside is so heavily eroded), why is there no information available about it online? Considering its size I would have thought there would be at least something on it.

    removed the IMG tags, no need for the tags just the url /Hobbes

    • Download the GVP’s google earth overlay. I use it all the time – it displays all active holocene volcanoes in real-time on an interactive google earth map, which can be clicked on to provide an overview.

      With that said, this could very well be a very old caldera, but it also could be a tectonic or erosional feature. If you look long and hard enough, you can find a lot of areas in Indonesia that fit this criteria, especially when you go further east into the less populated islands. Part of the problem with a country like Indonesia is that they only have so much funding, so they have to allocate that funding towards the research of more recent volcanic features, and more active volcanoes. With over 75 active volcanoes, it’s difficult to justify researching what may be extinct volcanic features.

      • And that is where we can do a bit of useful stuff.
        We could perhaps with a bit of luck find information to see if it is a volcano, and if it is an active volcano with a long repose period.

      • Thanks, I really appreciate the quick reply. I’ll try to get the GVP overlay.

    • Very interesting video, thanks Irishzombieman. I never would have believed that solid rock could do that; I guess if you’re in the right place at the right time, they kind of do! I know that wide-ranging temperature changes leads to this but it is impressive to see the rock popping violently like that.

      • Probably a prudent feeling to have given the scenario.

        This last weekend, I saw one of the grandkids at a get together at my stepsons new place. He was there to see his brother who was in town from Texas. (the one that owes me photos from inside the Rio Grande Rift region)… anyway, this other grandkid, is the one who had a shocking startling experience with H2S. When younger, one Easter he had found an egg from the previous easter and it evaporated in a vigorous puff of yellow dust onto him. The shriek and his reaction are still remembered to this day.


    This webcam is …. interesting right now. It’s dark in Japan right now, but this webcam seems to be set to display stuff at night. Earlier today, I saw steam rising clearly here, but right now, it looks very chaotic, I can’t tell what’s going on except that there is a LOT more steam than there was before.

    • It goes in waves. Now it looks like it did during the day. And it is also good to remember that during the night mist in the mountains form more easily, so the steam will look like more steam naturaly in the colder night air.
      That being said, the general trend of steam is definitely increasing.

  16. So I decided to cut together all the cotopaxi drumplots from the last month. I’ve loaded them into two pictures in order from the oldest to the newest. Worth looking at to see the changes here. I think there have been more “popper” style quakes recently, but less intensive tremor than during the middle of june. I still wouldn’t call them proper full scale poppers yet, but there definitely has been more sharp-quake followed by tremor recently. The images are quite large (long), so i didnt want to post them in here. View them at the links.

  17. One thing worth mentioning regarding Hakone: In the last 10,000 years, it has had a lot of phreatic eruptions without magmatic eruptive sequences. I wouldn’t be entirely surprised if all that came out of this is a few phreatic eruptions as that would be fairly fitting based on its recent history.

  18. I made a comparison in real up to scale, between 4 well known volcanoes. Above are Hakone and Pinatubo – Pinakone 😀 (I dont know why I cant stop comparing those two), and below are Tambora and Cotopaxi.
    The baseline of Hakone is not really that much smaller than Tamboras, and the same goes for the caldera. It is a notable difference, but Hakone measures up nicely.
    Cotopaxi tho is smaller than those 3, but it has packed an 8km3 ejecta punch in its best times a few k years ago.

    Looking at Hakone, its resurgent dome is actually the size of the Pinatubo caldera.

    • I like this. Might try this with relief maps.

      Cotopaxi, I think, is the oddball, being much higher overall and more prominent in its surroundings. It’d be interesting–for fun and nothing more–to superimpose Tambora’s caldera onto C’s edifice and calculate the volume above.

    • If you look back over the past month or so, seismicity is pretty interesting here. It seems there are long-ish periods of quiescence that are followed by bursts of intense seismicity. The most intense seismic period was about 3 days ago, which is around when the supposed first minor phreatic eruption occurred.

  19. Am I the only person who cannot see pictures/plots that are posted here? I can see YouTube links, but, for instance, I cannot see any of DownUnder’s graphics. 🙁 Do I have to change settings somewhere?

    • Talla H, I can see all the graphics now, but a few days ago I couldn’t see some of them. This evening I decided it was time to update ‘adooby flash playa’ (didn’t want to write the proper name for it) as I was starting to get irritated by not being able to see – well, live streaming from webcams for example. Could it be just that updates are required? Having said that, I have actually been able to see Down Unders’ grapics before I updated – I was wondering if it was just teething problems on the new VC site.

    • The last graphic posted by DownUnder is on a server. If that is in an adblock program somewhere it will stop it from being displayed. The adblock that I use currently does not block it by default. If you have manually added a block on an ad hosted on that site, you may be blocking other content from it.

    • a headline from for the NT news, (Northern Territory News, Australia) reads as follows about the above article
      ” Premature eruption stops route”

  20. A rumbler at or close to Hakone overnight (checked the arrival times).

  21. isn’t raining here, got some snowflakes in my clothes, but on the whole it is sunny and cold -7 to 10 deg, another couple of days the same and then up to -3 to 12 deg. well it is winter, like your new post, there is such so much we don’t know about our planet, thanks to you all of us going on a voyage of discovery

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