Eifel Volcanic Field II

Recently Nathan took you on a comfortable journey into the Eifel volcanic field. But what is the origin of this intraplate volcanism and where will the journey go?

About 400 million years ago during the Devonian, the Age of Fish, when only plants and insects roamed the land, Laurussia and Gondwana converged into the supercontinent of Pangaea forming the European Variscan Belt. It includes vast mountain ranges stretching from Portugal to Turkey. The Rhenish Massif in central Europe is one of the outcrops of this period, others are the Massif Central in France or the Bohemian Massif in Czech Republic and Poland.

The Rhenish Massif is mainly made of highly folded sedimentary metamorphic rocks, mostly slates, hence the name “Rheinisches Schiefergebirge” or “Rhenish Slate Range”.

Rhenish Massif

Geological map of the Rhenish Massif. Author Jo Weber (Wikimedia Commons)

When the Age of the Mammals dawned and Africa started to collide with Eurasia, a whole lot of volcanic activity started north of the rising Alps. This belt was termed European Cenozoic Volcanic Province by Meyer and Foulger. In the Alpine forelands extensional rift systems developed with the Rhine graben as a prominent feature. Volcanic activity of that period can be found in France (Massif Central), Germany (High Eifel, Westerwald, Vogelsberg, Rhön), The Czech Republic (Eger graben) and Poland (Lower Silesia).


Figure 1 from Meyer and Foulger http://www.mantleplumes.org/Europe.html

The ductile and tough shale and slate bedrock of the Rhenish Massif presumably was incompatible with extensional rifting. Instead the region acted as a hinge between shear rifting along the Upper Rhine Graben and extensional rifting at the Lower Rhine Basin (Illies et al. 1981).


Tectonic situation in central Europe (from this thesis, modified from Illies and Fuchs, 1983)

The Eifel volcanic field is situated west of the Rhine river near Koblenz in the center of the Rhenish Massif. Fluvial deposits prove that this area was uplifted up to 300 m since the Pliocene epoch 5 million years ago and that the uplift had accelerated during the last 800,000 years with maximal elevation around the Eifel volcanic field. Since then the Rhine river and its tributaries were forced to cut deep valleys through the Rhenish Massif, flowing past Hunsrück and Taunus, Eifel and Westerwald, Ardennes and Süder Uplands.


Uplift in the Rhenish Massif, from Meyer and Stets (2002)

The most recent volcanic activity in the West and East Eifel volcanic fields coincides with this uplift which amounts to 0.35 mm per year on average. The dome building may be a combination of widespread uplift of the so-called Rhenish Shield due to horizontal deformation from Alpine orogeny (Illies et al., 1979 and 1981; Meyer and Stets, 2002) and more locally by uplift due to the Eifel mantle plume (Schmincke, 2007).

To study the deep structures of the Eifel region the Eifel Plume project temporarily deployed a large network of seismic stations in 1997. A shear wave velocity model suggested a 100 km wide low-velocity structure extending down at least 400 km into the upper mantle which could indicate an area of increased temperature and partial melting. It remains debated whether this anomaly caused the Eifel volcanism. Other volcanic areas of the European Cenozoic Volcanic Province lack clear evidence of deep mantle plumes and the spacial distribution and timing of eruptive phases is not consistent with movement of the European plate over a fixed hot spot.

Alternative models could be a magma source derived from previous Alpine subduction or local decompression melting from passive rifting caused by tectonic deformation of the crust. Notably, the Mohorovičić discontinuity (Moho) is only 30 km deep below the Eifel while under the Alps it goes down to about 50 km which could give rise to some mantle turbulence and convection.


South-North section of the Moho beneath Europe between 6 and 9° longitude. Depth is highly exaggerated (Image by chryphia). Data from www.seismo.helsinki.fi/mohomap/

There is an overwhelming amount of literature about the recent quaternary activity of the 300+ volcanoes in the Eifel, sadly most of it paywalled or even without online access, because published in books or exotic German journals. So the following is taken from secondary literature. The eruptive history was e.g. summarized by Schmincke in Mantle Plumes (2007), Schmitt et al. (2010) (see Fig. 1 here for a map of geological map of the East Eifel volcanic field) and is nicely illustrated in this German blog post.

In summary, there seem to have been at least four main eruptive phases:

700,000 to 450,000 years before present: the main bulk of monogenetic volcanoes, small cinder cones and short lava flows erupted in the West Eifel and late some in the East Eifel. Their lava contained leucite (potassium rich) basalts, poor in SiO2, indicating an upper mantle source.

The West Eifel then fell dormant for several hundred thousand years.

430,000 to 360,000 years before present: In the East Eifel the Rieden complex (“Riedener Kessel”) west of the Laacher See had its most productive episode sputtering out several cubic km of lava in larger cinder cones and kilometer long phonolithic lava flows out of a 4 km diameter caldera system.

215,000 to 190,000 years before present: In the East Eifel the Wehr volcano (“Wehrer Kessel”, a 2 km diameter depression) west of the Laacher See and many large scoria cones in the Neuwieder tectonic basin erupted several cubic km of dense rock equivalent. The lava was highly differentiated phonolitic and rich in SiO2, indicating that country rock had been partially melted. During this time the first Maars were blasted out of the West Eifel volcanic field.

100,000 to 10,000 years before present: the West Eifel field was peppered with Maars still erupting the original lava, the last one to be the Ulmener Maar. Simultaneously, a new kind of lava, basanites, poor in potassium, hence leucite free, presumably from the asthenosphere, created large cinder cones and lava flows sometimes right next to the Maars (e.g. Meerfelder Maar next to the Mosenberg).

In the East Eifel only the Laacher See erupted 12,900 years ago, without doubt the most powerful eruption of all time in the Eifel probably equalling the total output of the West Eifel volcanic field. The Laacher See erupted more than 6 cubic km of magma within days, with an at least 25 km high eruptive column spreading tephra from Italy to Sweden. The magma is thought to have differentiated over several thousand, possibly tens of thousands of years, showing zonation from mafic to evolved phonolite and carbonatite. Pyroclastic flows temporarily built a dam in the Rhine river which eventually broke unleashing torrential floods, illustrated here (in German). Finally the emptied magma chamber collapsed leaving this recreational lake.


The “Loch Lochy” of Germany, the Laacher See. Image by USEBlackbird (Wikimedia Commons)

So the Eifel volcanism occurred in tens to hundred thousand years periods intermitted by hundred thousand years of dormancy. There was a general trend of eruptions starting in the NW progressing to the SE. Eruptions became increasingly voluminous and explosive with time and there was a shift of lava from an upper mantle source to partially melted crust.

Today the Eifel volcanism is dormant. As already featured in Nathan´s post abundant CO2 emission is a sign that the Eifel volcanic field is not extinct. But also seismically the region is active. Earthquakes during the past 36 years are almost exclusively confined to the upper 15 km. There is no indication of magmatic origin so far. The highest earthquake density is east of the Laacher See and west of the Neuwieder basin along the Ochtendunger fault zone on a NW to SE axis, aligned to the general tectonic setting in the Rhenish Massif.


Recent earthquakes (Sep 2012 to Jan 2013, green, enlarged) and earthquakes dating back 36 years recorded by the seismic station Bensberg, University of Cologne. Image by chryphia.

And here a 3D plot:

Since 1975 up until January 2013 over 1180 local earthquakes were reported by the seismic station Bensberg (University of Cologne) with some increased frequency in the last years.


Earthquake data from the seismic station Bensberg from 1975 to 2013 (between 5.21 and 5.472° lat and 7.25 and 7.65° lon, as in 3D plot). Image by chryphia

Helium and other noble gases that are found in high concentrations around the Laacher See are indicators of the volcanic origin of the Mofettas. Helium isotope 4 (4He) is naturally formed in earth´s crust. Another rare Helium isotope, Helium 3 (3He), is produced by fission and bombardement with high-energy cosmic rays, so what we find on earth was created before our solar system formed. In the atmosphere it escapes into space. Looking at the 3He to 4He ratio in volcanic gases relative to the ratio in earth´s atmosphere (Ra) gives a clue about the source of the magma. If it´s of deep origin, it still should contain relatively high 3He. The 3He/4He ratio measured from Mofettas from the Laacher See is 5.5 Ra, indicating an upper mantle source, but it is less than measured at mid oceanic ridges (8 Ra), thus there is mixing with 4He from the crust.

So there we are today. Was this the end of it for the next 100,000 years? As long as the Brubbel squirts and the earth rumbles occasionally we can´t be sure of it. Maybe the ants will tell us one day.

And just in case: a list of webcams 😉


Many thanks to Nathan for discussion and support!


115 thoughts on “Eifel Volcanic Field II

  1. Firstly, nice, informative post! Thanks! 🙂

    Also, I’m back! I’ve been away a few months due to many things, but I’m happy to say I will be frequenting again! 😉

  2. Fine. Throw his arse in the general population. They will work it out. Karma (and justice) finds a way.

    Click to access Lam%20Luong%20decision.pdf

    BTW…. The 28 meter drop to the water from the Dauphin Island Bridge yields a velocity of about 53 mph. Not something an infant or 3 year old can handle. If the public exposure to the story is a concern, prosecute the media for jumping up and down about it and hyping it ad nauseum.

    This is also an example of the slime that lawyers are. One of their reasons for appeal was that they were not allowed to cherry pick the jury. It’s all about “fairness.” Well, how about fairness for those four kids?

    • My apologizes for the OT. This was the story that my wife was reading about in the paper when I got up this morning and was having coffee. It pissed me off to no end.

      In my line of work, I have had to go ‘behind the wire’ to work on equipment (under escort thank God) and know for a fact that those guys in general population will provide the Karmic feedback if given the opportunity. (they are there for a reason) They may be felons, but they are still people. Societies tend to self correct for aberrant behavior of the members.

  3. From the Gargle Manglated version of the link about the ‘daming of the Rhine’

    The same could be repeated one day.

    Asshats. Yeah, it could be repeated one day, GEOLOGICALLY SPEAKING. In other words, over the next few millions of years.

    Odds are, the readers you are tying to scare will have died off by then.

      • Heh…. nice video. Probably would have been better if I spoke the language, but both of my grandparents passed away before I ever knew them and they were the last native speakers. According to my dad, they used to argue with each other in different dialects, and my grandfather was not familiar with one of the dialects that my grandmother used.

        As for the video, I get the gist of what they are saying… and think that it’s probably incorrect in the message that it is sending. Footage of the Northridge California quake damage to the freeways, dead critters from an overtuning volcanic lake that releases gas when the hypoxic water reaches the surface. I found the swimmer to be reminiscent of the opening scenes of Jaws… but with no shark. I imagine the first scenes of the girl swimming in bubbles than then comes ashore and collapses is probably based on a real event. (just from the way it was presented) In which case, I feel for the girl and her family. Sulfur gases (H2S) numb the sense of smell and you can quickly get into trouble from over-exposure.

        But… it’s a good video… though probably quite alarmist for those who understand the dialog.

        I particularly liked the sheer test of the rock sample where the researcher dons a fire-fighting exposure glove to gingerly pick up the deformed sample with a pair of tongs from the hydraulic press afterwards. Almost as if he expected it to burst into flames.

      • The opening scene from that video was the most impressive part. It immediately grabs the attention.

        The ground quickly swells, you can see wispy shoots of steam coming out in an almost spray like fashion…

        There there is an air-burst? What? How did a charge get lofted above the terrain then suddenly explode?

        Sorry, I can’t even begin to envision the physics of that…


  4. I’m sorry, I guess I’m an arse. chryphia linked to a nice though somewhat alarmist video. I downloaded it and have been picking at it ever since. This is my last (I hope) jab at it.

    It’s got a really nicely done intro segment… nice in that the effects are smooth and artifact free. It’s also horrible in that it seems that whoever did the effect seems to have taken quite a bit of liberty in what (theoretically) would be going on if the event were to occur. I seriously doubt that Eifel would have this much similarity to a nuclear blast.

    First the unexplained airburst (as noted earlier), but now a precursor wave? They were first discovered in footage of nuclear blasts. There was this unexplained shock wave that traveled out in front of the blast at faster than the speed of sound. The physics of it turned out to be that the heat flash instantly raised the temperature of the air and at the same time, raised the speed of sound, allowing the wave to propagate through at the enormous speeds evident on the videos.

    Here is a frame grab from the video and the location of the apparent precursor wave as depicted.


    The guys who produced this segment of the video should be congratulated and then jailed for trying to scare people witless.

    In the video, are pyroclastic flows from a dome collapse. You sort of need a dome for that to happen. But eruptive column collapse could do it. So I guess that portion get can pass.

    • Yeah, special effects are um, kind of special. I generally just phase them out until the visual orgy is over and the science begins.

      Just a short note on the personalities involved in the video. The first guy to speak is Schmincke who was Boris’s mentor/professor and General Secretary (sounds kind of Soviet) of the International Association of Volcanology from 1983 to 1991. He looks kind of elf-like here.
      Generally, though, apart from the special effects, the documentary is pretty sensible, showing mofettas actually in the Rhine river – gives you pause for thought.

    • Yup, nuclear blast is what came to my mind immediately, really silly. The special effects scenes were from an TV drama (which I have not seen). This is the documentary that came with it.
      I would have been surprised had you not picked on it 😉

  5. offs… just lost a huge reply I had typed in to chryphia (must have changed / refreshed windows or something grr..)

    anyway the long and short of it is: absolutely brilliant post chryphia (now to be known as koryphäe 😉 )
    When I get this work shifted, I’ll attempt to recreate my post.

  6. Great post. both 1, and 2.
    -that was a bumper sticker on my old Geology Prof’s
    Diesel Mercedes (a 190D-1959) he still has it…
    The car that is..

  7. For you younger guys… beware the evils of women.

    You get harassed for putting on a few pounds. Then, after an extremely delicious supper, you are offered home made cake and ice-cream. If you opt not to take it. Good luck to you.

    Think of it as the no-win scenario. There is no correct answer or path to take. If you are lucky, you can pull off the misdirection move and get the subject changed. Honestly compliment them on how good it is. (unless it tastes obviously bad. They are quite adept as seeing though an obvious lie. So tread lightly and be truthful. If you get caught in a lie, that bit about gaining weight will be nothing compared to what you will endure.)

    • Your last resort could be a vomitorium 😉
      (A place in which, according to popular misconception, the ancient Romans are supposed to have vomited during feasts to make room for more food)

    • If you have not discovered the evils of women, you have not lived 😉 makes no sense to warn for them, they (I?) will only learn from experience in that case

  8. “Hey babe, take a walk on the loon side…”

    There have been two additional meteor events, on in the Bay Area of California, and one in/around s florida. Possibly another in cuba. None as spectacular as the Russian event.

    They roughly line up with a mag 5ish quake in the mid atlantic. It comes in at about 6km depth, so is probably just normal rift activity, but you can see where I was going by looking at it.

    Now. Since we have multiple events… think about gaussian distributions. If an object breaks up, it’s parts are likely to have a similar grouping about the source object. A rational person would start looking for correlation to known stuff… like periodic meteor showers.

    Just a thought. Enjoy.

    • I still think the events of Friday were too much of a coincidence to be all of them unrelated between each other. I just wander whether the dismissal of a correlation between the asteroid and the meteor events as a way of being politically correct and not wanting to cause panic among the population.

      By the way Tunguska occurred in the day of the Beta Taurid meteor shower. It was, very likely, one major fragment along the orbit of comet Encke.

      I am almost certain that one day the Russian meteor event, and the other minor meteor events, are going to be confirmed to be linked to asteroid DA14.

      • What I find disconcerting, is that some administrative types over there are saying that the US did it. I know kinematics fairly well, and the claims that the Russian meteor was shot down, or broken up by some sort of projectile is a bit incredulous. I’ve seen the video of the approaching projectile/object and the debris scatter after they meet. The required timing and vector control to pull that off in a turbulent re-entry setting is beyond astounding.

  9. Hi Cryphia, thanks for the post,
    I’m more inclined to the other theories than the mantle plume model, especially as the “tracking” seems to be off, I suppose the shallow moho does give this some creedence…
    I particularly liked the Excel plots of depth/ strength v time; I’ve been working on something very similar with the El Hierro set…
    The mohrovichic one is funkadelic (was that done with excel too?) 😀

  10. Warning, this is me with my loon hat on.

    Animals have been known to react to danger prior to it happening. Some society’s have even tried to make an ad-hoc forecasting utility out of behavioral changes. The problem is, no two critters, even of the same species, will react the same each time an event occurs.

    So, knowing that animal behavior can be widely varied, what are we to glean from a monstrous sized pod of dolphins spotted off the coast of San Diego? (i.e. much bigger than is normally seen)


    I haven’t found out which direction the pod was moving, but it might be worth while to watch the area where they were coming from… or to go fishing where ever they are headed. (if you can get there first) They could simply be heading towards a food source. (The Gulf of California is known for large squid events)

    But it does make you wonder. Were they headed south? Should we watch the Cascadia?

    • Hmmm, I know mankind often does not comprehend animal behavior, let alone intelligent animal behavior. Maybe they team up due to food shortages caused by overfishing, maybe some anomalies in currents, winds or temperature has moved their feeding grounds, maybe a few years ago it has been an exceptionally good year to make baby dolphos or maybe Yellowstone is going to erupt cataclysmically.

      I don’t believe animals can sense what is coming any better than we can, but by falling in the pit of the hindsight bias it will always seem that way if you want to.

    • I don’t believe animals can sense what is coming any better than we can

      I do. Especially Dolphins. They “see” by echolocation. Audio figures very heavily in their existence. Another ocean going creature, the ray and likely also sharks, can sense the electrical impulses that drive the muscles in some prey. (Dunno about the range though). Birds see in four colors. (red blue yellow and something out there in the ultraviolet). On more than one occasion I have run across dogs that know something about a person that they don’t like, that turns out to be an indicator of some not nice trait about that person that turned up later. Another issue with dogs is an uncanny ability to hear you fiddling around with a package that they equate with food. No matter how quiet you are.

      Back to the Dolphins. With as sophisticated as their sense of hearing is. It is entirely conceivable (to me) that in the course of looking for fish, they could have run across a sound along a trench that they instinctively equate with bad stuff happening. Just because they don’t construct buildings or write novels, doesn’t mean that they don’t communicate. It could be that they have an oral tradition that is just as elaborate as ours. The oral tradition of some islanders in Indonesia dictated that when the earth shakes like it did…. to move to high ground. Many (if not all) of them survived the tsunami.

      This still does not rule out that the gigantic pod isn’t headed off for food.

      • I recall all the fish that got stuck in a harbour on the West Coast after the Japanese quake last year. I reckoned they were heading away from a huge sound or pressure wave, which would have been amplified under water. But that was after the event… Perhaps this lot didn’t like the asteroids falling into the water???

        P.S. only playing with ideas here – no evidence required

        • Provided that any hit the water. Not out of the question. The Airburst over Russia was able to trigger the seismos, and the surface of the earth is about 2/3rds covered by water. If an event happened out in the open ocean, only sea dwellers would probably know about it. (or those on cruises who are not busy wading though feces)

        • Seen in the Loon Press™: “well, last time it happened, it was around the same area, San Diego. shortly after came the Japan quake. so, a week or three should tell if it is related to anything like that.”

          This video was shot off the coast of Mazatlan (Mexican West Coast) and uploaded to Youtube 26 Mar 2011. The Tōhoku earthquake and tsunami was on 7 April 2011. (opposite side of the Pacific Basin.)

          This is located near the entrance to the Gulf of California. 2 reasons that would be an okay place to hang out… The Gulf of California would be a good shelter from tsunami coming from Japan, and there is plenty to eat there. (for a Dolphin)

          • from wikipedia:
            Dolphins are social, living in pods of up to a dozen individuals. In places with a high abundance of food, pods can merge temporarily, forming a superpod; such groupings may exceed 1,000 dolphins.

            I remember seeing a superpod on the Kaikoura coast when I was a kid. It was one of the most amazing sights I have ever seen. It was early morning and they were backlit by the sun and all of them were jumping for fish or just the sheer joy of it. Absolutely stunning.

      • I agree with that. I meant it a bit different then what I wrote down. Every animal responds based on what it’s sensors register, and what evolution and learning processes have programmed it’s brain to make of that. It’s not like animals have a sixth sense or super-disaster-sense, they have senses that can be different from ours in function or sensitivity, leading to surprising conclusions sometimes, which is where our lack of understanding of behavior kicks in.

      • Seasonal migration is the most probable reason. Although the quality of the video is too bad to even guess the species one candidate could be the Pacific whitesided dolphin: http://www.cms.int/reports/small_cetaceans/data/L_obliquidens/L_obliquidens.html Numbers in California have been described an order of magnitude higher during Feb-April (northern hemisphere winter) while peak abundance in Washington/Oregon is highest in May (beginning of calving season), suggesting seasonal north-south movements. So my best guess is they avoid the cold months in the north Pacific following the California current:

      • The footage is timestamped stamped “am” If so, California is missing.

        … might actually be a good thing.

        But, the stamp seems to actually be the broadcast caption. It’s Probably footage from the previous afternoon (There’s no California under the sun, so it’s probably setting). South it is then. Anybody along the Oregon/Washington Coast? Whats going on there?

          • Okay, ignoring the possible Nostro topic and Ray Mabus…

            IF there is something that spooked the Dolphin… it has to be pretty signifiant to make a pod 7 miles long and 2 miles wide, seek shelter. What could pack that much power? I’m thinking that another megathrust event could be in the offing. Aleutian Chain, Kamchatka, Marianna Trench, something in Indonesia/Philipines/Japan. Or… a mass wasting event in Hawaii. Several years ago, a Mag 7.2 dropped the coast SE of Hilina Pali a few feet. Purportedly, there is a collection of rubble/seamount keeping the foot of is braced.

            Either way, the Gulf of California would make excellent shelter for pretty much anything in the pacific basin.

            Note: this is just wild speculation on may part. There is nothing authoritative about my musing.

        • I, err.. have been hanging out on the loon site too long.

          I was always taught that you train how you fight. For this reason the Combat Systems Training shifted from open ocean “war at sea” scenarios to Littoral warfare when the likely threat shifted.

          So… Whiskey Tango Foxtrot?


          For those that wonder what I’m yammering about. The purpose of these targets is to condition the shooter (Law Enforcement) to using lethal force against the people depicted in the silhouette without hesitation if they are perceived as a threat.

        • I don’t doubt that animals are more sensitive to disaster than most humans are, but there is no way they would be able to predict an earthquake or landslide prior to it occurring. Why is this?

          Not counting foreshocks, there aren’t any major precursor signals to events like these. Birds and animals are good at predicting bad weather since they’re sensitive to phenomena and weather patterns that often occur prior to bad weather. Low pressure, temperature change, and other similar signals occur before many types of disaster. I don’t believe there are many precursor signals to events like these, since both landslides & earthquakes are simply pressure releases from strain that has been existent for hundreds of years.

          • There is also a possibility that there is a peizo effect as material is getting close to the failure point. Something as yet un-observed by us, but that a critter with the correct combination of sensors could detect.

  11. Nathan and Chryphia! I did write a comment right at the beginning. It was the first but seems to have disappeared (More likely I didn’t hit “Post” properly.
    Anyways I did say thank you and how we are blessed in Volcano cafe with the likes of these two who write and post in a very professional manner.
    As to animals sensing events. I have commented on this frequently. Biologists have tried to link animal activity to being precursors of a quake but it is far too difficult to set up these obsevations as yet. My take on it is that for instance ants could react to minute changes in the magnetic fields in a quake zone. .Therefore ants on the San Andeas fault would be used to the “Normal” settings and as the rocks under stress may alter the magnetic field so the ants may behave in a certain way… Would the same species of ants react if they were on another fault? I could rabbit on but it really does get complicated thinking about what reactions they may make and also how the hell a nest could be observed without human interference and so ruling out other possibilities for behavioural changes.
    Lets face it they may just decide the nest is too hot, too cold, too dry or wet or just they want to move on….
    Animals in water, such as Dolphins, also are far to difficult to study on a day to day basis so that a clear picture of behaviour prior to a quake events over a long period of time would be almost impossible to monitor given the distances of travel involved. Animals in captivity really are usually under some stress or other factors that may not give accurate observations.
    If I was younger and given the chance though I would love to spend some years researching this idea…
    Ideally we need some graboids , active, sensitive and definitely not domesticated. 😀

  12. Hi

    Here is a new plot for Iceland.
    I have made a summary of earthquakes for Iceland in January and up to February 16th.
    In the first part of the video, business as usual with the day by day animation, size of dots according to magnitude, age of the quakes color coded (blue=old, red=recent).
    In the second part a simple rotation (with a touch of rocking chair effect 😀 )
    In the third part, I’m making a zoom on the Hekla zone.

    Data from IMO and NOAA, made with Octave (Linux version)

  13. So a few weeks back I had mentioned that I wanted to map out large caldera boundaries on Google earth. I worked on the project, and I’m now done. So want to hear something mind blowing?

    I only mapped out caldera systems that are potentially active, and have created eruptions that could have potentially reached VEI 7 (or at least come very close). Thanks to Geolurking’s plots, just about every caldera is larger than 7 square Kilometers, with most being larger than 10 square Kilometers.

    So how many total calderas would people guess I mapped? I’ll post the answer later on. Note – most calderas were found simply by scouring the GVP database. That being said, some were added through other means (scientific texts, etc).

    • Well over a 100, so I would guess 150 😉

      But do we worry about the calderas that have actually happened or the ones which will happen in the future 🙂

      • & that would be Holocene. In which case the overall number could be a lot higher if you include the hopefully extinct / long time dormant ones – say, 1,000.

    • My guess disappeared so here it is again: well over 100, so possibly in the region of 150.

      But do we need to worry about the calderas that have happened or the ones which have yet to happen 😕

      • Honestly, I don’t think we need to “worry” about them at all. Maybe I’m an oddball, but ever since I wasn’t a kid, I haven’t understood the idea of “worrying”. If there is something that could cause a problem that is within one’s control, then instead of worrying… do something about it. If that problem is out of your control then it’s not worth worrying will only serve to stress yourself out more than you normally would be.

        That being said, being aware & informed is the most important thing. Chances are, none of these will erupt in our lifetime, and if they do, they probably won’t be caldera forming eruptions.

        • I claim to have learned something from every ship that I have been assigned to.

          1) – Crisis Management
          2) – It can get worse, (and Murphys law says that will happen sooner than later)
          3) – Contingency Planning. What are you going to do when it all goes bad? (because it will)
          4) – All the planning in the world is no good If the Universe is out to get you.

          And last, but not least (actually #4 but I had to tie 1,2,3 together nicely)

          Grace under Pressure. Think, then act.

  14. M5.6 earthquake just off the coast of Tokyo at 35km depth.

    Perhaps this is Lurking’s dolphin alarm? I don’t know a ton about earthquakes, but if this is a precursor quake, then things could get ugly. I highly doubt it is however since I believe it’s too deep to preclude a megathrust.

    • 5.6 is pretty commonplace for Japan. I was even surprised that the largest over the previous week had been a couple of 4.6s and a 4.7. Japan is so seismically active it has several quakes a day.

    • 5.6 is a toad fart for Japan’s quakes.

      As for something to alarm the dolphin, I could be totally wrong. It may be a feeding or breeding event.

      My stock in trade is staring a thousand feet down the road, hour after hour, only to find out that the people that I were trying to get ahold of (Friday) in order to coordinated them pushing a new firmware load down the network, but who couldn’t be bothered to answer the phone, contacted the site and pushed the firmware down this morning. Of course I didn’t find this out until I had driven the 200 km to the site to do the firmware flash. 5 hours of my life… gone. >>poof<<. Never to return.

      On a plus side, I did get to see the formation of an ass chewing (totally unrelated). Another contact (different site) was livid that security personnel had left a female clerk alone in a building with two convicted criminals… un-attended (or guarded). The contact is a prior CPO (much like myself) and is going to make sure that the administrative side of that organization is made aware that this young lady was placed into danger. I don't care how well behaved they are, they are guarded for a reason. How do I know he is going to report the event? He's a CPO. We live for ass chewings. Especially if it fixes a problem.

      Enough ranting for now.

      • Ot on the subject of Chewing arses..
        In my office I work with a very lovely classy, southern belle.. Her father was a US Army
        Two Star. Now retired. He worked his way up from private. No Academy. Well the other day one of her clients tried to pull a fast one on her and make her the fool.
        Big Mistake. She gave the Client a reaming like I have never heard. Voice not raised,However the client got the the point- kind of like being hit with a velvet covered hammer. Now the Owner of my outfit is a retired USCG CPO himself. He said:
        “That chewing was a work of art I haven’t heard anything like that ever.”
        The lady must have paid attention to what her father was saying over the phone or was the object of “constructive criticism” as the Boss calls it…
        I’ve gone toe to toe with Bosses and Co-workers,but she is only one in that office that
        I would really not want mad at me…
        (Kind of like my wife..)

        • I gained the respect of my fellow ‘goat locker’ residents when I and another had a difference of opinion. I calmly sat and answered the other guys comments and each time I did, he became more livid. At one point he was literally hopping up and down, inviting me to fight. I asked him what problem would it solve? This went on for about five or ten minutes. Eventually he gave up, and sat down, panting. Everyone in the mess was rolling laughing about it. My guys didn’t have to maintain the MG sets, and his guys didn’t have to deal with Nixie. (torpedo countermeasures set). The only reason my guys were saddled with it, was that we had no sonar techs, and since it had ‘SLQ’ in it’s designation. (my main system had the same designator)

          Side Story: When I first reported on board, this system was only operable from the winch room located at the rear of the ship. Shouting down on an intercom is a very cumbersome way to operate it. My initial task was to get the remote unit (up in combat) operating. Since I had never seen or worked on one of these before, I sent off for a tech-assist. I and the NSWC guy found that the remote unit was sending signals aft, but they weren’t getting there. Using a TDR (a mondo cool device that can identify problems in your cabling within a few inches) “Time Domain Reflectometer” we found the break about midway to the rear compartment. Seems that someone had taken a screwdriver to make a hole for a CATV cable in one of the cable stuffing tubes and had severed my line. A bit of splicing later, and it was up and running and OPS thought I was a miracle worker. ‘No Sir, just a tech’

          I didn’t want the space, but gear is gear, and it beat having to deal with the MG sets. I later blew one up by dropping a massive load onto it. The way the system was designed was for one MG set to be able to handle the system. In ‘idle’ mode (normal operating) it drew so little current that the brushes tended to wear faster than normal. The electricans had taken it upon themselves to have only one MG online to handle both my gear and another systems current draw. The only problem, is that when my system went to full on, it could easily demand 150 amps, instantly.

          That, coupled with the other system, was far over what the MG set was rated for.

          Instant equipment casualty. (I had warned them what my system would call for if I to go to full on.) This was what had spurred the MG system to be given to the guy I was arguing with, and that was what the argument was about. As a general rule, the Operations Department Heads on this ship were junior to the Chief Engineer both in rank and position. This one had immediately cowed and agreed that OPS would take over responsibilities for the MGs. This was a lower echelon disagreement between two divisions within the department.

          In a way… it’s sort of a good thing that he lost that argument. Months later, when it came time for his retirement ceremony, I covered a time-crunch by doing the invitations using my (relatively) uuber computer skills to make a some really nice programs for the event. Had I lost the argument, I probably would have still carried a grudge and passed on stepping up to compensate for the personnel depts lapse.

          To this day, our wives still communicate with each other.

    • I guess the missing comment reapeared again? Right?
      Yesterday this happened to many people here, the comments did not land in the spam box but just went “missing” and reapeared on their own later. I assume this is a wordpress server problem. But please let us know if it happened to one of you, even though we probably cannot do anything to prevent it. (In case the comment was spammboxed and set free by a dragon, there should be a line below, telling you so.)

  15. As I was sitting here, reading my favourite blog, the age old debate of ‘Katla or Hekla?’ popped into my head.

    Now, at any other time, if somebody had of said Katla, I would have called them mad. But, I don’t know… I feel like Katla has gone eerily quiet at the moment, even Godabunga is only working part time! 😉

    I reckon we’ll have the answer by the summer.

  16. Pingback: Sheepy Dalek on a saturday | volcanocafe

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