The Ruminarian…

I’m going to deviate from the volcano topic for a bit… not too far, but I think that a discussion of the dynamics is important to gain an appreciation for the forces at work.

Again, the standard caveat: I’m not a geologist. There are actual geologists who lurk and pass through here. If I mess up, I am pretty sure that they will correct my errors.

While reading through “Global Techtonics 3rd ed,” I ran across an interesting rock structure called “Ophiolite.”

From Wikipedia: Ophio- is Greek for “snake” -lite means “stone” from the Greek lithos, after the often green-colored rocks (spilites and serpentinites) that make up many ophiolites. And as you know from previous posts and comments, serpentinization is the process where water is taken up into the rock structure and ultramafic rock goes through metamorphis. (remember this, I’m gonna bring it back up later)

Image: Serpentinite; Wikimedia Commons

Ophiolite is really interesting because it is a section of oceanic crust, and it’s placed in a really odd place.

Plastered onto and into continental crust.

Just so you know, continental crust is about 2700 kg/m³ (about that of granite) oceanic crust averages 2900 kg/m³ (basalt makes up a great amount of the material, and it runs 3100 kg/m³. This is the major reason why subduction zones exist the way that they do… oceanic crust drives under continental crust since it is denser. Both types of crust exist as a sort of scum floating on the denser, rather plastic, mantle, which is about 3300 kg/m³.

The big question is now did parts of the oceanic crust wind up plastered into the margins of continental crust? The answer: Obduction.

Obduction is a process where portions of oceanic crust splinter off and are driven into and mixed into continental crust material.

As as subducting plate moves along, material from its surface is scraped off and pushed into an accretionary prism… much like a pile of dirt in front of a bulldozer. Island Arcs, fragments from other continents or anything else that is riding along on top of the oceanic crust can wind up there. Due to the immense pressures the material is distorted, folded, heated, snapped… you name it. Occasionally, part of the subducting plate snags and tension forces build up and snap off slivers of the ocean crust itself. (Though rock is really good at withstanding compressive forces, it is not very good at tension {stretching} forces) These slivers get mixed in along with any terranes that have accumulated.

The Wrangellia Terrane of the Pacific Northwest, the Carolina Terrane of South Carolina, the Armorican terrane making up the Channel Islands and parts of Upper Normandy are just a few examples.

Wikipedia lists about seven different scenarios that can result in Obduction:

  • Upwedging in subduction zones
  • Compressional telescoping onto Atlantic-type continental margins
  • Gravity sliding onto Atlantic type continental margins
  • Transformation of a spreading ridge to a subduction zone
  • Interference of a spreading ridge and a subduction zone
  • Obduction from rear-arc basin
  • Obduction during continental collision

That last one (continental collision) tends to result in orogenic belts where there is severe distortion of the crust, which starts to form and push up mountains over a few million years. The Appalachians, Alps, Himalayas, Andes, Scandinavian Mountains (considered to have been connected to the Appalachians before the Atlantic opened), the Mountians of Iran, Afghanistan… all continuations of the same geologic processes of collision. (Indian Plate for the Himalayas and the Arabian Plate for the Zagros mountains in Iran) In all of these cases if you locate Ophiolite structures, you can rest assured that it came from the seafloor of some ancient ocean. Even in Serbia, Montenegro, Albania, and Slovenia coalitional mechanics have placed sections of oceanic crust… in this case, the remains of the Tethys sea. (same for the Alps).

Okay… what else do you get?

Mud volcanoes. El Totumo is a popular tourist destination in Columbia. It is one of several mud volcano structures in that area. Lore says that it was a normal fire spewing volcano until a priest drove out the evil and sprinkled holy water on it. The geology has a different story. Compression, folding, obduction structures, and of course Ophiolites. Though technically they aren’t Ophiolites until they become exposed to the surface.

Photo by photo by pattoncito on Flickr License: Attribution, Noncommercial, Share Alike

Remember the BTC pipline that I mentioned a few months ago? From the hazard survey:
“Mud volcanoes form in only a few areas worldwide, with almost half of all known mud volcanoes globally being situated in Azerbaijan. More than 300 have been discovered in the marine or terrestrial environment of the country (Guliyev & Feizullayev, 1997). These surface features are generally relatively short-lived (in geological terms), and they tend to migrate along fault lines or planes of weakness.

Eruptions can be violent and unexpected, ejecting debris many hundreds of meters into the air, and some are associated with pyroclastic flows [sic]. A further potential issue is that gases discharged by mud volcanoes may be flammable.

Over 300 mud volcanoes are present in Azerbaijan, the majority of which are associated with anticlinal fold structures.”

In all likelihood, they meant “lahar flows” rather than “pyroclastic flows.”
Notice what one of the listed hazards are… “discharged by mud volcanoes may be flammable” In other words, hydrocarbon rich.

Referring to a paper about the geology in and around the El Totumo mud volcano in Columbia, you find that there are several mud volcano, diaper structures and faults that can allow the movement of hydrocarbons. In this scenario there is opportunity for them to migrate and collect in various “pools.” This area is quite productive in hydrocarbons. (especially Venezuela, right next door)

One thing that I remember from stopping in Curaçao (formerly part of the Netherland Antilles) is the inner harbor (other than the lizards that’s charge after the cats.) Refinery operations dot the shoreline. (12.125451°N -68.927294°W)

Another feature from compressive stresses in the continental margins are diapirs and hydrocarbon seeps. The La Brea Tar Pits of California, and the Asphalt Volcanoes in the Santa Barbara channel / Gulf of Mexico are a couple of good examples. These are probably one reason why some naturally occurring microbes have become quite proficient at eating hydrocarbon products.

Alright… now, remember that little item from earlier? Soapstone and Talc are a couple of the end products that you can get from serpentinized rock. And along the San Andreas… that fault line that cuts down through California… has been found to exist along the fault interface along some of the more seismically silent sections.

Okay… it’s a dance about the planet. But it’s pretty cool when you sit back and consider some of the forces at work and how they make themselves known. Sure, we all enjoy looking at the volcanoes, but the peripheral stuff that contributes to their formation can be just as fascinating.



Mud Diapirism Associated to Neotectonic Transcurrent Leaky Faults in the Colombian Caribe — A PassWay to Hydrocarbon Migration” Aristizábal1 et al (2011)

Geohazards Report BTC Pipelne

197 thoughts on “The Ruminarian…

  1. Thanks GeoLurking.
    El Totumo – Wikipedia extract: “According to local lore, the volcano used to spew fire, lava, and ashes, but it was turned into mud by a local priest who believed it was the work of the Devil, and ensued to banish him by sprinkling holy water into it.”
    Some drops of holy water sprinkled around over Yellowstone, please…
    Have a nice week.

    • Hahaha!
      I don’t think it is a good idea to “sprinkle” water on lava, be it holy or not.
      But miracles are miracles…
      Thanks for the first joke of the week, Loco, and thanks, Lurking “The Ruminator”, for the excellent post!

    • It’s still the glacier run ongoing from Grímsvötn. Now at 237 cm. IMO Forsída/Vatnafar/ (allow) go to: Sudausturland / Gígjukvísl: On the Vatnafar page, IMO specialist says ”Það er enn að vaxa í Gígjukvísl og óróinn á jarðskjálftamæli á Grímsfjalli er einnig að aukast. Miðað við leiðnina þá er líklegt að hámarkið verði í dag eða í nótt. Fyrir hádegið í gær, sunnudaginn 25. nóvember, var farvegur árinnar orðinn rúmlega 200 m breiður undir brúnni. Vatnborðið í hlaupinu hefur hækkað um 150 cm, en til samanburðar þá hækkaði vatnsborðið um 200 cm í hlaupinu í janúar 2012 og yfir 300 cm í hlaupinu 2010.
      Skrifað af vakthafandi sérfræðingi 26. nóv. 11:24,
      (in Engl. – my translation, disclaimer: “The water discharge in Gígjukvísl is still growing and the tremor at Grímsfjall is also going up. (link incl. in a.m. IMO-text) Taking into account how the water is running, it is probable that the highest measurements will be reached today or this night. Yesterday morning, Sunday 25th of Nov., the river under the bridge was around 200 m broad. The water height has been going up by 150 cm now, and in comparison, in Jan. 2012, it went up by 200 cm and by over 300 cm in 2010. Written by the (IMO) specialist in charge, 26 Nov. , 11:24).

  2. Oh what an interesting post. Thank you Lurking. These anomilies in areas of subduction keep geologists on their toes don’t they? Just a daft thought. Does the occurrence of talc or soapstone help to lubricate that bit of fault so it is less likely to have a big quake? 😀

    • Breathe in, breathe out. Again. Once more.
      Now go on the site and look at your work. A nice summary that makes it quick and easy to know what was going on for those who didn’t have time to surf too much. Perfect.
      Beathe again, smile, carry on happily with whatever the day was meant to be filled with.
      Nervosity level: back to normal.

    • I thought for a moment that GeoLoco was going to break into “Machinehead” by Bush

      Breathe in breathe out
      Tied to a wheel fingers got to feel
      Bleeding through a tourniquet smile
      I spin on a whim slide to the right
      I felt you like electric light
      For our love
      For our fear
      For our rise against the years and years and years

  3. I didn’t want to loose this.

    All of us had a childhood. During this childhood, you gain skills, coordination… and importantly concepts. (some of us actually learn the basics of critical thinking, but most don’t, and those of us that do, have it drilled out of us by the school system and the entertainment industry.)

    One of the more important things that I learned… from a TV series featuring a girl with purple hair (Gabrielle Drake)… was scale.

    What had happened… was that the characters in the series had sent a probe to the alien planet, had retrieved imagery, but could not use it… they did not have a reference to the size of what they were looking at. The science gee whiz guy was explaining this to the “hero” guy with a picture of some contrivance on a gently curved surface. To emphasize the point, he pulled back on the image so that you could see the full scene, and it was a model craft sitting on the top of one of the actresses leg… and not a planet’s surface.

    That’s where I learned scale.

    Here… is Pāhoehoe. It is a hot low viscosity magma that forms a “smooth, billowy, undulating, or ropy surface” It’s also quite hot, allowing the magma to flow like this.

    Generally, you see this in Hawaii, which is where the name originates.

    So… I’m poking along with that Caldera paper, and decided to go look for some real world volcanoes to measure the size of the edifice. And I run across this… first thing that came to mind… “oh, pāhoehoe.” Then I realized that it was… large.

    That’s about one kilometer from side to side. Okay… maybe I’m seeing stuff. Lumpy mud looks about the same in a mudflow… but there is not really an equally large supply of water to do this. Hmm.

    Take a wild guess where this ancient landform is.


    If thats what I think it is… that thing must be capable of some nasty stuff. That would have been a phenomenal flow if I’m correct about what it looks like.

    39.151263°S – 175.676232°E

    Sub-comments so far:

    tgmccoy says:
    November 26, 2012 at 06:25

    Kind of like the Newberry Obsidian flow but that looks ever larger…
    One impressive flow…

    Bruce Stout says:
    November 26, 2012 at 07:19

    yep, it’s lava and it’s less than 20,000 years old… looks more like porridge!

    Michael Ross says:
    November 26, 2012 at 08:19

    And once you’re done with Tongariro, have a look at p. 345 of Lockwood & Hazlett…


    • …you can also just look at candle-wax on a table… Depending on the wax you have the same looks at mm scale. Or at custard when for cm scale. Some “key-features” or elements return at many scales. From microscopic to astronimic. And I loved playing with scales during my studies. Explaining orogeny by metamorphic structures in minerals under the microscope. Planar deformation features in quartz as a proof for the Chicxulub impact… Polens, spores, foraminifers that allow conclusions on the climate, and then correlate the whole thing with Milankowitch cycles… When science completely turns into phylosophy…

    • @Geolurking

      Has Tongariro ever had glaciers? You sometimes see compacted ice and rock debris that looks like this on Alpine glaciers at the end of summer before the onset of winter. OK in the Alps it is obvious that there is still some ice involved. But here if the ice has melted it may leave debris that has yet to be eroded – then add a hefty sprinkling of volcanic ash on the top of it.

      • Actually… I don’t know. But I can guess.

        Right now, Ruapehu is the only mountain on the North Island with glaciers. Poking around Google Earth, you find that they are all above 2350 meters elevation.

        Making an assumption that glaciers could exist down another 500 meters during the Ice Age, you find that parts of Tongariro are above 1750, but not very much. If there were a glacial accumulation there, I don’t think it would be very large at all.

        • If the flow is on the south side of Tongariro (sorry not been to check), the ice could have accumulated in a col above 1750 and flowed out. I guess the north side would get too much sun so be too warm.

          If it’s not the remains of glacier debris, I guess rhyolite flows slowly enough to start resembling an ashy glacier 😦

          • It’s all about viscosity AND scale. A lava that is sufficiently viscous on the human scale to form an “aa” lava flow (I tried it wearing boots asnd went “Ah! Ah!”, because it was rough and lumpy!) can have the arcuate flow lines and lobes of a pahoehoe flow when seen on a larger scale. (Did I upload photos from Tenerife … Yes.) is a photo of a Recent (last few thousand years) brown lava flow on El Teide, Tenerife seen from above, with clear “pahoehoe”-like flowlines.
            This (earlier) photo though shows the flank of the same “pahoehoe”-textured brown flow from closer up, when it is seen to have an “aa” texture in human scale, particularly if you compare it to the underlying dark-grey “pahoehoe”-textured flow (which also has a gas-venting tumulus disrupting the generally flat-lying pahoehoe structures.
            You may well need to open both photos to original resolution to see the structures in sufficient detail.
            (Yes, I am a geologist. The photos of rocks are a bit of a give-away.)
            I’ve added a “geotag” to one of the photos (I forget which) to give location information. It’s the first time I’ve used Flickr’s geotagging, and I’m not terribly impressed with their mapping. The Google map has much better imagery.,-16.635532&spn=0.009868,0.021136&t=h&z=16

    • @ Mike, do you mean the debris avalanche from Taupo, 9500 years ago? I was kind of surprised it was so young..
      btw… Does anyone else have this problem? Not that long ago I used to think 9500 years ago was so ancient, it was pretty well beyond my comprehension. Now I think 9500 was just around the corner.

        • I was at a lecture by Jerry Coyne (“Why Evolution is True”) a couple of days ago, and realised for the first time in several months that I didn’t have ANY pieces of billion-year-old stromatolite fossils in my pockets.
          By my perspective, that’s recent. (The billion years, not the couple of days.)

          • ha… great!! Someone who just possibly could have been carrying around billion-year old stromatolite fossils in his pockets. Fantastic. Welcome to the club!

            • You know people who don’t carry billion-year old fossils around in their pockets – amongst the sweet wrappers and expired bus tickets? How … quaint! (in the words of “Scotty”)

  4. Several earthquakes in Vatnajokull, mostly around Grimsvotn, and also some increased tremor there. I don’t think it is wind. The weather is cold and very calm today, even in the glacier.

    Its showing slight increasing tremor in 2 stations near Grimsvotn. I think this tremor is due to some gradually increasing geothermal activity or glacial movements, probably linked to the recent glacial run. And the earthquakes confirmed the volcanic unrest under Vatnajokull. Also, some new quakes in Hamarinn, one new quake in Esjufjoll and the recent major quake in Kverfjoll. Definitively, there is some hotspot action going on.

  5. Great post Lurk. When I was living on Oregon’s south coast there is a large formation of
    Serpentine to the south.HWY 101 is built on it they have no end of problems with it sliding…
    a good chunk of the Sislyous and Klamath mountains have large Serpentine/Olivine deposits
    had a big green rock in my garden for a water feature…
    I remember one storm that 101 slid and we in Port Orford were now “the end of the line” for a while.One enterprising Fisherman started a run between Gold Beach and Port Orford..
    Just like the old days when “Coasters” were common..
    His name was Robbie Armstrong.He was killed in his new boat when forced to go out on the
    Rogue bar to get in position for the short, artificial crab season of ’99
    His new boat was “Thistlehead (he was Scots ancestry. ) his old boat that his son still works is
    the “Irish Rose” named for his wife Cecile …
    Hard way to make a Living…

  6. Breaking cover to say hello to everyone for the first time… Not a professional, just a volcanoholic. I’m particularly interested in mud volcanoes. Thanks to GeoLurking, it’s a very informative piece for me.

    • Welcome !
      Just a lurker myself. I break cover now and again too ! Particular interest is El Hierro but it seems to have died recently….which is bound to now stir it into life again.

  7. Doing business related paper work- had to let my brain out to play it doesn’t like being cooped up on a nice day-had that problem through -out school-one of the reasons I was a Biology major.-had dreams of becoming a field biologist or a forester. Then I learned to fly.
    Anyway here is a good paper on basic Vulcanology a lot of good basic stuff.
    I bawling along a Google trail looking for Pahoehoe in Oregon and found this..
    Also a bit on Pahoehoe in Oregon:
    Sometimes I think of myself as an ‘ol Bluetick hound…
    Sniffing out things that interest me…

  8. @GeoLurking. Interesting article. Never knew I was seeing obduction – or the results thereof – in my Alpine holidays.

  9. @ Geolurking: Getting back to the Jaupart and Pinel paper… just a thought: perhaps this downward propagation of fissures proposed in the model helps explain the rapid ascent of rhyolite magma at Chaiten? Shame that no network was in place prior to the eruption. It might have taught us a lot.

    • I don’t think so. Chaiten erupted out through the middle of the existing plug. Nothing really fancy was going on there other than a re-awakening. All the structural features that make up Chaiten were already in place.

      From modeling the heat loss in volcanic system, I’ve found that they don’t like to cool down, and can stay at elevated temperatures for quite some time.

      Here is a generic Chaiten after 9223 years of cooling following a 900°C eruption event. That area still above the solidus temp would essentially be the “mush zone” where fractionization would continue.

      All it would take would be a quantity of fresh magma rising up into it to re-mobilize the material.

      NOTE: This is a highly simplified model and does not feature a magma storage area.

      • Err… did I miss the point?

        I think you had a pretty good thought myself. I imagine that when this thing was being built that it may had something to do with it… but with all the rest of the mountains being pushed up and stuff running over each other, I don’t know if there would have been an opportunity for the stuff in Jaupart and Pinel to come into play.

        I really liked being forced to look at a theoretical Chaiten. I didn’t actually consider how hot it still was until I noticed that it had only been about 9200 years, 😀

        • um, no, sorry about that, I wasn’t insinuating you were trying to teach me a point, I was alluding to the slightly um, .. graphical nature of the chart.. (just file this under one of the posts one would like to delete if one could).

          Very glad you took the trouble to look at Chaiten. That’s pretty cool. And this was a volcano that nobody really had on their radar.

        • It’s a generic model. Upon closer look at the summit, there appear to be three separate plug sizes in the pre-eruption Google Earth image.

          Converting the elliptical area to equivalent circles… I get 885 m, 417 m, and 1905 m diameters. (1905 m probably being from the last huge eruption)

          What I don’t know… is what the vent size is. If you assume that the vent size is represented by the diameter of the plug, it might help in ballpark estimating just how much heat from the eruption could still be in the vent,.. and whether it’s a mush zone waiting for a gob of magma to re-activate it, or if it really is dormant.

          The temperature plot that I did only served to illustrate the concept. This might be worth looking into with reasonable starting estimates.

          No harm no foul.. I just wanted to make sure I understood the post correctly. Had a rough day, never did get to go to sleep last night.

          Morons roaring up and down the street last night, and when they weren’t, the wife was fiddling with stuff on her night stand. Got pissed and went to the couch… got cold, went back to bed. Woke the wife up, who started fiddling with stuff on her night stand, then the cars again. Tried to doze in the computer room (I am adept at sleeping in a chair), Got cold again. Noticed it was 04:50… made breakfast, ate, went off to the mechanic who tells me that yes, I have toasted another engine. Yay. I can’t seem to get above 321,868 km without loosing a cylinder. Grr….

          • oh cripes.. 😆 you’re life is not dissimilar to mine at the moment. Try having a marital at remote distance like I did last week. Not fun. But I just think my wife and I might be getting somewhere (after a few sleepless nights.. maybe we get credit in the karma stakes for not sleeping, it’s gotta have some pay-off somewhere). … and 321k for an engine is not all that bad, though I guess with your job you are doing these miles in a few years.

          • Do you get diesel powered cars (cars not trucks) in the States? Somehow I remember that they weren’t available. Great for mileage.

          • Grrr.. guess I’m still tired. Posted my response insider your post by accident.

            If I could get a European version… on the cheap, it would be cool. Our EPA is dead set against the consumer here.

            The vehicle I had prior to these two… I had for 14 years. Of course I killed the motor in that one also… and had it replaced. Kept it in great shape other than literally wearing out the motor. Then a Hurricane ate it.

          • As for good night’s sleep… it’s looking up. It’s raining and miserable out side… just the sort of thing to cheer me up and let me sleep like a baby.

            I love inclement weather.

          • Lurk have had sleep depravation for last 6 weeks. wife was sleeping like a
            Basalt plug, I have some arthritis try not to take too much antihistamine and
            pain pills (Ibuprofen ). Wife is a combo herbalist and medicine woman sometimes.
            (she is a direct descendant of Pocahontas) . Tried the followng: Hot lemon with
            ginger tea then a couple of Taurine 1000mg.
            worked .
            We have a house full of morons across the street -adult foster care.the Morons
            aren’t the clients they are the ones who own the place..
            Papa fond of running/tuning Harley at 9:00 pm and daughter playing Rap
            while waiting for 10:00 pm… who runs a Diesel tuner Dodge…

          • Heh… as I have mentioned, in a previous life I was really into my job. Electronic Warfare. As such, I know the general physics of how to make things… not work.

            I occasionally sit around thinking about what I could do with a nice fat high voltage capacitor bank and a well positioned coil to dump the charge through…

          • Poor Lurking, tgmccoy and Bruce. Nohthing worse than having da marital just before bed time. So many ways a wife can inflict torture. 😀 However I am pleased I don’t live next to Lurking. So many ways he could make life hell!!!

  10. Good morning everyone. @ IngeB… Thank you for your comments about activity under Vatnajokull. Certainly there seems to be extra heat causing ice melt. Grimsfjall signals are not the usual steady “pulses” that have been seen since the last eruption.. I wait with interest to see if more activity happens.

    • The rise in low frequency tremor on the 21/11 could suggest a magma intrusion perhaps that has led to this increase in ice melt? Possibly a failed eruption?

  11. Good morning everyone, and thanks again for the welcome. Cup of coffee to hand, here comes my pesky question (and apologies for rambling length) ….

    I’m interested in particular in the mud volcanoes on a group of three islands just off the coast of Sabah, Malaysia on the island of Borneo that generally go under the name of the largest island, Pulau Tiga. This might sound familiar because the first series of the US and UK versions of Survivor, and possibly others I don’t know about, were filmed there. From what I gather, there’s not much volcanic activity in and around Borneo in general. Malaysian Borneo only gets one entry on the GVP, Bombalai Hill; I don’t know if there are any in Indonesian Borneo, GVP doesn’t show any. Anyhow, Pulau Tiga doesn’t get a mention so maybe they don’t count as ‘proper’ volcanoes. You can find them at 5 43 25.46 N and 115 39 13.38 E on Google Earth.

    I have read a report of a possible eruption on Pulau Tiga that involved flames. It happened just before the Japanese invasion in World War 2, and was described as ‘a fire at sea’ (seen from the Kuala Penyu coast about 11km from the islands). The viewer also wrote ‘I could see a clear red glow in the sky, there was something unusual happening … There was undoubtedly a fire of some kind or another out at sea; every so often I could see a shower of sparks flying into the sky. The source of the fire wasn’t moving … The event happened just before Christmas [1941] … years afterwards I was told by geologists that it had been a mud-volcano erupting on Pulau Tiga … I would often fly over it in later years … and look down on the big wide circle of different vegetation that had grown in the crater of the volcano …’

    I was wondering about this, and whether he was misinformed by the geologists. The Japanese didn’t arrive in that area until 1 January 1942, so it’s unlikely to have been a ship on fire as a result of hostilities, though of course it could have been a ship at anchor and on fire for some other reason. Is it possible for a mud volcano to erupt like that? Could the hydrocarbon gases have combusted naturally via something like a lightning strike, maybe? Or could human activity/fire-making etc have ignited the hydrocarbon gases? Would this cause the gases to send up showers of sparks rather than just explode them? I know in the chaos of wartime record-keeping would have gone to pot, especially with the imminence of invasion, but is there any record of this eruption (if it was one), maybe established by later research?

    I’ve done a bit of googling and I can’t find out much about the mud volcanoes of Pulau Tiga at all. Geology of North-West Borneo: Sarawak, Brunei and Sabah by C.S. Hutchison shows them on p252 (Google Books preview, just after a mention of a trench (?subduction) and ophiolites on p250, no p251 available on preview.) Maybe they haven’t attracted much research. Anyhow, if anyone knows any answers, I’m all ears. Cheers.

      • Hello Renato, and have a good day at work. I’m lucky to be able to work from home, so the caffeine addict in me is well fed!

    • Hi Rebecca, i’m one of the regulars and writers of VC.

      First of all Borneo has a few volcanoes, these are not mentioned by the Global Volcanism Program’s website (but are included in the their book, Volcanoes of the World 3rd edition). These are much like Bombalai, mostly pyroclastic cones and fissure vents. More importantly, these are focused on the NE corner of Borneo.

      The mud volcanoes of the islands you mentioned don’t appear to be on any reigonal fault lines. Mud volcnaoes are usually not related to ‘normal’ magmatic volcanoes, as they do not have a magmatic source, there source is usually underground gases such as methane.

      Hope this helps, as mud volcanoes are not my forte.

      • Mud volcanoes are much more strongly associated with regions of rapid sediment accumulation than they are associated with magmatic volcanoes. If sediment accumulated faster than water can be expelled from it (and particularly when clay minerals in the sediment metamorphose to compactify themselves AND expel water), then the water starts to carry some of the weight of the overlying sediment. If a conduit to a lower-pressure area opens (faulting over a forming anticline ; an un-cased oil well), then the water will flow, entraining sediment from the wall rocks to form the “mud” of a mud volcano.
        Volcanic regions are often regions of rapid sediment accumulation (between the volcanoes), and also have significant ground movements. So it’s no great surprise to see extensive mud volcanoes in the Indonesian archipelago (the infamous Lusi volcano, about 100,000 displaced people in the last few years). The mud volcano that I’ve climbed (while drilling an oil well along side it) in Azerbaijan is in the foredeep of the Caucasus mountains and their subduction zone, and this is another major area for them. But the Mississippi-Missouri delta and it’s submarine delta-front also has mud volcano-like processes (including natural oil and gas seeps), purely due to sediment accumulation ; but they get planed flat by flooding and slope collapse every few centuries. (My Azeri volcano is on a peri-Caspian delta top and has clearly suffered marginal erosion too ; but it’s flow rate is rapid enough to accumulate faster than it is washed away.)

        • Hello gravelinspector! Thanks for the information, and my head is now full of images of intrepid Azeri volcano clambering. Were you able to mud bathe in the top of your one?

          • At sunrise on New Year’s Day, well below freezing and in a Muslim country … the idea of stripping off for a dust-bath didn’t appeal. The presence of a cemetery on the top with some sort of shrine (natural gas flame ; heretical remnant of Zoastrianism? I don’t know. ) decreased the desire further.
            I don’t know how long the summit of the volcano had been used for burials, but when the sun rose high enough to see the ground, there was no difficulty about identifying bits of human bone in the dirt around the various erosion gullies. (I resisted the temptation to add to my fossil collection – I don’t need airport hassle like that.)
            Oh, sorry, I should add that it’s a Scottish mountaineering tradition to watch sunrise from the summit of a convenient hill on New Year’s morning. Being a quarter way round the world is no reason to not stick to the habit.

      • Wow wow wow! I stop for lunch and what a treasure you have found Shérine! Thank-you so much, and thanks to Lucas too for his information. Am still digesting (lunch and PDF both!!) …

      • Shérine’s PDF is great for loads of reasons! It tells of the seismic event during which the mud volcano islands of Pula Tiga were first formed – a big earthquake on 21 September 1897, which also caused two other islands to form as well, one near Kudat up in the very north of North Borneo (some 200km northeast of Pulau Tiga, and called Ruby Island in the report), and the other some 50km southwest of Pulau Tiga at Mempakul/Lambeidan opposite Labuan Island. I wonder if these latter two islands still exist?

        Clearly a lot of burning went on at Pulau Tiga during the 19 February 1941 eruption, so that answers some of my questions about combustion pretty conclusively! I was interested to read that “We understand that there have been for many years at about the position of this explosion, two small mud volcanoes of a type which are not uncommon in the B.N.B.H. Klias Peninsula”, so there are/were other mud volcanoes in the area of the peninsula (the peninsula is shown in the figure in Geology of North-West Borneo: Sarawak, Brunei and Sabah by C.S. Hutchison that I mentioned above).

        I rather think the December 1941 eruption of which I have a report must be a separate one from the February 1941 one. The writer is quite particular about the date, mentioning mid December and then ‘just before Christmas’, and he mentions it in relation to the preparations for the expected and imminent invasion. Pearl Harbor happened earlier that month and the Japanese were sweeping across the region. I guess his account (he was a District Officer) didn’t make it into the colonial records as no-one was filing reports like that when they were busy with all their defence measures. The writer speculates whether it might have been a Japanese munitions ship catching fire – these wouldn’t have been that close to the NB coast in Feb 41, certainly.

        Thanks so much Shérine for finding this terrific document. Also I’m chuffed because I know of the Mr Speedy who filed one of the reports in the PDF, so its like meeting an old friend!

        Not so sure I’d want to go on holiday to Pulau Tiga though, having read all this …

        • Regarding other mud volcanoes in Sabah I kept coming across some big’uns at Tabin, which has seven in all. This is from the Tabin wildlife resort site (

          “In all, mud volcanoes can be found in five separate volcanoes in Sabah – the Klia Peninsular including the more famous one in Pulau Tiga. But these are little more than just a few feet across, certainly nowhere as impressive as those in Tabin. There are about two in the Tingkayu area in the Semporna peninsula, two north of Sandakan some of which are located on turtle islands and one that had come and gone – Pulau Hairan, another football size mud volcano which erupted in the middle of the sea on 15 April 1987, catching many fish and lobsters by surprise.”

          • Interesting stuff ukviggen – I had no idea there were so many in Sabah, or that they could come and go like that. I suppose the sea just erodes them away as they are soft mud. The Tabin one in the photo looks very impressive.

            My inner Beavis (or is it Butthead?) loves your use of big’uns, by the way.

  12. This at least l o o k s like it would be something special from Iceland. – But: Disclaimer for Daily Mail and others: It is n o t what it looks like. It is just the sun shining into a gas and steam cloud streaming upward from the high temperature field at Námaskard / Krafla volcano, b.t.w. a “must” for every Iceland tourist. 🙂 See: (but better be upwind of these .wink:) and

  13. Hi

    here is a day by day animation for earthquake density in Iceland for October and November 2012 up to the 24th.
    On the right, color bar shows number of EQ, date is also shown

    you can get a good quality video by seing it directly on YT

    • I always like your quake animations. 🙂

      There are two concentrations in the north still to be recognized. The first is still in Eyjafjördur trough – where two tectonic structures meet (Tjörnes Húsavík Fault-System and Eyjafjördur / Eyjafjördur trough), the first one directed to the southeast, the second NNE.

      The second one is in the fjord – or actually more a bay – called Öxarfjörður (from Wikipedia). And I have a theory about this and would like to have your opinion on it: I think there could be a small submarine eruption ongoing in the fjord which would be part of Krafla volcanic system (acc. to p. 16 in this text: The fissure swarm of Askja central volcano by A.R. Hjartardóttir ). There you can see that the fissures of Krafla are reaching out into the fjord more or less to the location of the now ongoing quake swarm there. And if you have a look at KVO station, which is sitting smack boom in the Krafla caldera, you can see a ongoing action (which has been there for months now) . I don’t think it is manmade, because it is not regular enough.

  14. Poking around in the archives (when I should be working – VC is addictive, oh dear) I’ve just found Nathan’s post on the mud volcano at Lusi, woohooo.

    In the comments GeoLurking wonders about the combustion too. He also wonders about the wisdom of petrochemical pipelines near mud volcanoes that are known to erupt and catch fire.

    Petronas are just completing the Sabah Oil and Gas Terminal (SOGT) in Kimanis Bay, “for the purpose of receiving, processing, storage, metering and exporting the oil and gas” produced in Sabah. (reference

    Guess what else is in Kimanis Bay? Yep, you guessed it: Pulau Tiga mud volcanoes!!

  15. Ya have to love distractions. The most pervasive distractions come when you notice something out of the corner of your eye and realize that you were sort of already looking at it.. but weren’t quite aware of it at the time.

    That is the case with Rebecca’s island… Palau Tiga. Provided I am looking at the correct one.

    5.721944°N – 115.649722°E

    It turns out that Palau Tiga is on the margin of the Kinabalu batholith. A rather jostled bit of material that has become… or is nearly welded to, the Palawan Continental Terrane.

    You guy remember that right? I mentioned it in “Sleeper Fish… A look at the Taal and Laguna de Bay setting.” This is the other end of that structure. While the dead South China Sea spreading center was pushing the Palawan Continental Terrane southeast, the Kinabalu batholith got caught up in it and it appears that parts of it were joined to the southwestern end of it… or at least in part.

    Along the northern region is the also dead Borneo-Palawan Trench… a no longer active subduction zone. And natch… Ophiolite fragments are in the mix… mainly down in the suture region. To be honest, it’s quite possible that the “Continental” part of the Palawan Continental Terrane runs out because midway down the island of Palawan, you get a large collection of Ophiolite and then it transitions into “Collisional sediments: melange and outerarc basin sediments” as you move towards the Kinabalu batholith end of it.

    So… you get the same overall structure that make up most mud volcano regions… collisional tectonics and massive forces squeezing the rocks, some of which choose to act like toothpaste.

    Now… how do gases from a mudvolcano catch fire?

    A couple of ways that this can happen.. three actually, but one is grasping at straws.

    First, methane and natural gas, both hydrocarbons, are the primary flammable material. Denser stuff is possible, (tars, asphalts, even crude if the conditions are right). But how do you light it off? Well, static electricity is a possibility. One material rubbing against another is all that is needed to strip charges from one and transport them somewhere else. But in a brine environment… anyplace there is saltwater, that’s hard to accept. Anytime you have some sort of mineral dissolved in water.. especially any kind of salts, the conductivity goes through the roof.

    (That’s one reason that anything over 30 volts could potentially kill you, your conductivity can get pretty low if you are sweating enough.. enough to make that dangerous)

    The third way (only because I want to get it out of the way) is peizo-electricity. That’s the electric charge you get when you whack the right kind of crystal. Under stress… specifically shock stress, some crystals inside of rocks can release a sizable electric charge. Quartz is notorious for this. Try holding a peizo starter for your bar-b-que grill against your leg and triggering it. You’ll see. (I don’t actually recommend this because it will knock the s@#$ out of you… voice of experience)

    The second way… and held to last just to confuse the reader… is phosphine. Chemically, PH3.

    From Wikipedia: “a colorless, flammable, toxic gas. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like garlic or rotting fish, due to the presence of substituted phosphine and diphosphane (P2H4). With traces of P2H4 present, PH3 is spontaneously flammable in air, burning with a luminous flame.”

    Further: “The origin(s) of atmospheric phosphine is not certain. Possible sources include bacterial reduction of phosphate in decaying organic matter and the corrosion of phosphorus-containing metals.”

    And where do hydrocarbons come from? Decaying organic matter… at depth, in ancient sediments as they are slowly turned into coal, crude oil, natural gas.

    And… a link to an applicable paper. (most of the annotations for the image come from this)

  16. Update on Plosky Tolbachik from KVERT:

    “According to the data by observers from Kozyrevsk and Lazo Villadges, ash explosions and lava flows are noting at Tolbachinsky Dol, at the area of 1975 Severny Proryv (Northern vents) eruption. Probably a lava intrusions towards the summit caldera of Plosky Tolbachik volcano too but the volcano obscured by clouds at now. Ash fall was noted at Krasny Yar (35 km from Klyuchi Village to the west): a thickness of ash was about 4 cm.”

    • Thanks for all the info posted on Tolbachik. ( A volcano i never heard of before yesterday) And thanks dmf that we can now “order” those plots. How cool is that. Welcome Newby and lurkers.
      I am usually always around just busy in rl´s work and other things and so quiet when i can’t really contribute anything valuable.

      • Oh and mud volcanoes. I saw a mudhole in action near Yellowstone years ago. But know more like nothing about them. Last year when i watched the ROV Herkules in action they were also diving on the southeast coast of spain looking for evidence of a mud volcanoes, which could not be found. They explained that especially submarine mudvolcanoes are often of organic origin. When lots of organic debris is coered by layers of sand or other material the gas ( Methane) which starts being produced creates mud volcanoes. Does anyone know more about this?

      • Hi Spica

        Well there is that huge data file from IMO that Lurking gaves a few weeks ago and that I’ve updated since.
        To explain how the density plots are made, you define a zone with the lat/long coordinates and create a regular grid. Then you advance along the grid, stand in the middle of the current interval and look on both side to see if there is an earthquake nearby. If so you increment the interval counter.

        So you can play a bit with the settings, in particular the grid definition. Too small will show you individual dots, too large will show big zones. For the last video I made a day by day lookup, but the lookup frequency could be 2 days, one week, one month or &àà quakes for instance, so we can pretty much play with the settings.

        As we have now the whole data for Iceland, it’s just a matter of selecting the right zones and time frames.

    • Oh yeah, i shiver already.
      Could you send mail please,got some other stuff on my mind as well. I ll be back later after a dentist appointment.

        • ‘Entrain’ is a lovely word.
          It is one of those that is almost impossible to use without your hands involuntarily performing sweeping gestures, especially when talking hydro- or aerodynamics.

  17. Good morning to all can someone look at the el Hierro Cam meteorales im at my i phone but i am seeing something but what??? Is their smoke?? Or does the sun gives me a wrong sight? At my phone i cant enough see if it is normal ?? I have no pc today friendly greetings Deanne

  18. A very old man is sitting in a restaurant. Next to him a group of youngsters. One has a sort of red punk haircut. The old man stares at him as he’s quite fascinated. After a while the young guy has enough and asks the old sack if he has never done something wild. Says the dude: oh, some years ago I got cooooompletely drunk and f.cked a chicken. I was just wondering if you were my son…
    Lunch time. For those in my time zone: bon appétit.

    • Renato… you see weird stuff on the Internet. Several years ago… I ran across a photo of a man doing just that. Aside from the disgusting aspect of it… it was the silliest thing I had ever seen. The expression on his face gave an air of “okay, now what?” To his benefit, at least there was a “lady” present. (only used to connotate gender, the moral turpitude negates any positive characteristic of the individuals depicted.)

  19. A reminder about the Mastin et al equation. According to the text, it has an error factor of about 4 either way (high or low). That means that the plot that I did earlier, represents the trace right down the middle of that estimate.

    Tolbachik does not have an updated VAAC report, so that means that there is no longer a direct hazard. On the high side, it could have made it to VEI-3… provided that my linear interpolation accurately represented what the volcano did. (not likely)

    It is just a ballpark estimate.

  20. Meanwhile in Vatnajökull:

    The glacier run from Grímsvötn has been subsiding a lot, though the water in Gígjúkvísl bears still a lot of conductivity. Commentary of IMO’s on duty specialist (from yesterday): “Hlaup úr Grímsvötnum veldur óróa á jarðskjálftamæli á Grímsfjalli. Óróinn er mestur á hæstu tíðninni (blár ferill). Óróinn náði hámarki í gær og hefur farið hratt minnkandi síðan og bendir það til þess að allt vatn hafi runnið úr Grímsvötnum. Hlaupvatn er enn til staðar undir Skeiðarárjökli þannig að búast má við að hlaupið haldi áfram í Gígjukvísl.
    Skrifað af vakthafandi jarðvísindamanni 27. nóv. 11:18 ” (My transl, caveat: The glacier run from Grímsvötn causes tremor on the SIL device at Grímsfjall. Tremor er most intensive at the highest frequency (blue line). The tremor reached its peak yesterday and since has been going down fast and this indicates that all the water has left the Grimsvötn (lakes). The glacier run continues still a bit under the glacier Skeiðarárjökull which means that it will continue to run into (the river) Gígjukvísl.) This does not mean that Grímsvötn are now dry!

    BTW: There is still a lot of conductivity in the river Gígjukvísl (572), which is also mentioned in another IMO report from today: Water height is now at 111cm, 60% down from 26 Nov. These data together imply that the run could still be going on for some days.

  21. Sorry people,i experienced a minor collapse today and my laptop died in the afternoon while i was trying to write a post.
    So it took awhile but now ….
    New post is up!

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