The VC Bar

Welcome to the Volcano Café bar, a place for all things on or off topic and inane ramblings. There has been a need of late to find a place better suited to various theories, long comments and enthusiasm. This page will be less moderated than the main article pages and cleared out every month (this may change depending on use).

Have fun and don’t forget to tip the barman 😉

3,719 thoughts on “The VC Bar

    • Fabulous! And Loihi grown into an absolute monster

      The summit caldera was result of a Laki Sized drainout ?

    • Well, looks like I made a bit of an elevation error on this map, but other than that it is still detailed…

    • Very nice for soure .. and inspires me to draw monster versions of Hawaii that does not exist on Earth.

      Next of your project coud be more like that .. or make… a Map of a future Laki like event in Iceland

      Very good maps

    • Your Big Island will be a spectacular place with ( 12 climate zones! )

    • Nice map indeed and will be so many climate zones there, and nice blue tropical ocean

  1. I got this one question (like I have always been asking), but what would the African Rift system (ARS) look like in 500,000 years?

    In my sort of opinion, the Afar region would become peninsular as the seas probably flooded the Danakil Depression and in the southern region (though that may happen in the next million years or so) and that explosive eruptions would branch into either the Albert rift or the East rift zone proper, who knows. The northern most of the explosive current activity would become more basaltic than ever.

    I have heard of talks of a flood basalt event where Nyiragongo is, but I have no idea if that is true. If that’s the case, well there’s that, but if not, a new Virunga volcano might pop up southwest of the active ones now. Volcanism will appear downrift of the areas with minor or no volcanism.

    That is my generalization of what might happen in 500,000 years with the ARS, but that is sort of my guess.

    • Don’t expect too much. The lack of active subduction in the Indian ocean means that the rift is not being pulled apart. So little spreading is expected

      • That is what I was thinking about, not too many major changes in half a million years, but a lot of minor changes could be possible. There isn’t a lot to expect from the tectonic/volcanism trend of things, yet a lot to expect from each individual volcano.

        It is kinda a paradox here, like we know what might happen to the rift itself but yet know so little of the other things in the rift itself.

    • The Danakil depression has flooded already apaprently, but there isnt a lot of data on it just that it has happened at least once. I would not be surprised if it floods proeprly for the last time in the next half million years but it could also be a lot longer too, needs a lot more study I think.

      I proposed the future LIP at Virunga. That is something that will take more than half a million years. If the Columbia River LIP is a typical example then these volcanoes live for millions of years and only a short time is in the LIP stage, CRB was active from 18 million years ago to 6 million years ago but most of the volume and big flows were 14-15 million years ago, just before the onset of VEI 8 calderas that leads up to Yellowstone. So if Virunga becomes a LIP it will be in at least a few million years from our point of view, but at a distant point it may appear that the current volcanism is the beginning of such. Or it might not do this at all, but I think there is a better chance here than anywhere else right now.

      I think there will also be a number of VEI 7s in the rift valley, maybe even a VEI 8 or two, and many other eruptions. Basically all of the existing calderas in the Ethiopian section fo rift are either undated or have a date of under half a million years, so seems they are not exactly uncommon on such a timespan.

      I also think it is not impossible that a Laki-type fissure volcano could form in Afar, a massive basaltic caldera with rift zones. Alayta and Dubbi have already got capability to erupt at Holuhraun scale, and have both done so in the last 200 years, Dubbi is actually the 3rd biggest single lava flow in historical time which is a little known fact by most.
      The massive rifting at Manda Hararo in the late 2000s also shows major rifting can happen. All is needed is a big volcano to feed those rifts 🙂

      • There is a flow of Manda Hararo that is really impressive. It is the youngest voluminous flow in that volcano. The eruption was somewhat large, but most remarkable is its intensity, sheet pahoehoe travelled several kilometres from the fissure system on both sides without turning to aa. A second wave of pahoehoe moved over the first one and has a very well defined front. Lava was channelized into a graben and forms a major lava channel that is one the widest in the world. But only once has Manda Hararo done this in recent times, no other flow like it can be seen, and it is nowhere near Laki size, it is probably not even Holuhraun size. Mostly Manda Hararo does few stuff.

        Alayta produces impressive eruptions, some of them with high fountains, which are probably gorgeous to the eye. A typical Alayta eruption might be something like 0.2 km3, going from memory, I once mapped this volcano very thoroughly in Google Earth. But that’s it, Alayta doesn’t do larger than that. The fountains are high but insignificant compared to what Sierra Negra or Grimsvotn could do on a good day. So a powerful basaltic volcano but not particularly remarkable.

        The most remarkable volcano in Afar is certainly Dubbi. Its eruptions often reach Holuhraun size, and without collapsing, it can also do powerful trachytic plinian eruptions. It is one of the most productive, if not the most productive, volcano in Afar. And it regularly outperforms all of its neighbours in the scale of its eruptions. It should not be surprising though. It is part of the northward migrating Nabro chain, Dubbi’s predecessors, Nabro and Mallahle, are the largest calderas in Afar. But other than Dubbi I’d day Afar is overrated. Its silicic calderas are small, you have bigger silicic calderas to the south along the Main Ethiopian Rift. It’s volcanoes are not overly productive or voluminous, Virunga is far more productive, and Afar volcanoes are actually tiny. Its basaltic systems are not too powerful, other than Dubbi you don’t have volcanoes as capable of doing large eruptions similar to those in Galapagos or Hawaii, and even less so capable of a Laki-event.

        The area does have nice monogenetic shield volcanoes, but only a few of them in Afar, other neighbouring volcanic areas are much more remarkable for this style of volcanism. The young floor of the Red Sea is almost everywhere covered in overlapping pancake structures, which are the underwater equivalent of shield volcanoes on land. So the volcanism in the Red Sea is remarkably vigorous compared to most Mid Ocean Ridges. Other than the Red Sea, such large concentrations of monogenetic shield volcanoes along a Mid Ocean Ridge are only seen in Iceland, and possibly the St Paul Rise. A lot of shields also occur in Arabia, the two youngest shield volcanoes in Harrat Khaybar are some of the best preserved in the world, and a possibly historical shield lies in Harrat Ash Shaam.

        • St. Paul rise? You mean the St. Paul’s Rocks offshore of Brazil or something else?

          • I was referring to the island in the Indian Ocean, Île Saint-Paul. It is part of an important oceanic plateau along the Indian Ridge. Amsterdam Island and Boomerang Seamount are also part of this plateau. My own estimates put the eruption rates in the Amsterdam-St.Paul Rise at 0.01 km3/year above a normal mid-ocean ridge, this makes 1 km3 every century, which is a lot. It is probably one of the most intense locations of volcanism in the world, being only 100-200 km across, but because activity happens mostly underwater it goes largely unnoticed.

          • Huh. I did not really know about that. I assume they are storing that magma for a long time until it is time for them to blow and produce massive lava flows or, if in water, produce explosive eruptions.

        • Although looking at it in Google Maps it is very obvious that Dubbi is not a productive volcano. Most of its cones are weathered, its activity has probably increased very recently due to the birth of a central volcano in the middle of the volcanic field, but before that it may not have been that much. Alayta and Alu-Dallafilla have the largest amounts of young lava, and they are probably the most productive in the Afar Region right now.

          • That is quite interesting. There is however, a larger, albeit probably less productive volcano east of the Nabro-Dubbi chain, which is the Assab volcanic field. It looks like it covers a big area but is just simply a series of monogenetic cones that cover a massive area.

          • Assab looks like a series nearby, similarly oriented dike swarms, possibly radial to Nabro and Mallahle. It seems though that its activity has faded recently, lava flows of Assab are ubiquitously eroded by streams of water. Activity in this area has probably shifted to Dubbi volcano and its surrounding Edd volcanic field.

          • There are two volcanoes in the East African Rift that I find very interesting and that are also massive like Assab. In Kenya, there is Marsabit and Nyambeni Hills.

            Marsabit itself is an old volcano that has faded, but to the northeast of it a new volcanic field has recently emerged. Eruptions from this volcanic field are voluminous and long-lived. A typical Marsabit eruption covers something like 400 km2 in lava which depending upon thickness could be something like 4-8 km3. So it is a volcano that erupts very rarely, but when it does its huge, slow, long-lived. The NE of Marsabit volcano will probably turn into a massive shield like Marsabit and Huri Hills. The composition is primitive but varies in alkalinity from basanites to alkali basalts and some samples are straddling the boundary with foidites, I checked in EarthChem.

            Nyambeni Hills is an old volcano but remains active. Its youngest lava flow is 54 km long, and covers 98 km2. It may have a volume somewhere 1-2 km3. it was erupted rapidly as a single sheet. The composition of Nyambeni Hills has set alkalinity but variable evolution, covers the entire spectrum between slighly evolved basanites to phonolites. I think it could be related to the massive phonolitic stratovolcanoes like Mount Kenya or Mount Kilimanjaro.

          • Chyulu Hills is also a curious volcano. Eruptions are not as big as Marsabit or Nyambeni but they are far more frequent. It might very well be the most productive volcano in Kenya-Tanzania. It erupts basanites, and alkali and transitional basalts.

          • When you look at the volcanoes it is clear that Chuyulu Hills has erupted numerous times since the last eruptions of Marsabit and Nyambeni. Last Chyulu Hills eruption was in 1855. There is also a dated eruption in 1470, and there might be other young undated eruptions. So it is not unlikely it may erupt twice or multiple times per milennia.

            Last Marsabit eruption I would guess was at least a few thousand years ago judging from the state of weathering, but of course one Marsabit eruption counts for several Chuyulu Hills eruptions in volume, and with a few Marsabit eruptions you already have a volume as big as a small polygenetic volcano. The “inactive” shields of Marsabit and Huri Hills might be younger than nearby 2.4 Ma old Kulal volcano, which is far more eroded than any Huri or Marsabit lavas. So Marsabit and Huri have grown to enormous scale in ~2 million years, to a clearly bigger size than the axial volcanoes that might be similarly old, and this shows that the unfrequent large eruptions add up to substantial volume per time.

          • https://ibb.co/ZL28yqQ

            Found this image (don’t quite remember where it is from, maybe a paywalled paper) but shows the evolution of a shield volcano (supposedly) but it looks like, where Marsabit and the others may not further evolve unless if there is some stage we don’t know of.

          • Marsabit is at the end of its evolution presumably (it is probably going inactive), the new field to the NE of Marsabit will probably grow into something like Marsabit. I got curious and wanted to estimate the volume of Marsabit, got some topographic contours and measured areas at 100 m intervals. Looks like Marsabit has a volume of 1800 km3, making it likely into one of the largest continental volcanoes in the world. Huri Hills, right next to Marsabit, is nearly identical to it so should be the same size. Together they make 3600 km3. I think at most the volcanoes may have started growing at 2.5 Ma, but could also be younger. So it is not bad at all.

          • Their dormancies are probably on the order of thousands of years though. So the NE of Marsabit field is an unlikely volcano to erupt in our brief human lifetimes.

        • Dubbi is Heklas twin, just in the worlds hottest desert not a place named for how much ice is there 🙂 They even look basically the same…

          The last eruption at Dubbi was actually a lot bigger than Holuhraun. It began with a plinian phase in May 1861, GVP gives it a VEI 3 rating but this is a known massive underestimate as no volume measurements were given for the ash, the descriptions suggest a VEI 4-5 event. The second stage was a lava flow of 1 km3 or more, erupted from the fissure. Then there was a second silicic eruption that was followed by another lava flow as big as the first. My guess is these second and youngest flows are from September of 1861, but there isnt much information, even the best sources still guess…

          3.5 km3 of lava, erupted in a couple months. And maybe 1 km3 of trachytic tephra. The basalts are all slightly evolved but still very fluid with pahoehoe on the mountain, there was probably a massive curtain of fire, possibly twice 🙂 Not a Laki in volume but the intensity was probably very comparable, maybe even more so.

          https://www.researchgate.net/publication/233720542_Largest_known_historical_eruption_in_Africa_Dubbi_volcano_Eritrea_1861

    • You have to be careful with language as an indicator of migration. Neighbouring languages tend to influence each other regardless of actual mixing of populations. For instance, the fact that England uses the word ‘apartheid’ does not mean that the Dutch took it here. Place names can be a better indicator but do not appear as convincing here. For instance, Hekla was named that before it first erupted after the settlement era, so the origin claimed here seems less plausible. There was a significant Irish influx into Iceland, but there were also strong connections between Ireland and Norway (while England was much more connected to Denmark). I would view this with some caution.

  2. It looks like there is going to be some future Aerosol geoengineering to combat ACC, I hope whoever is running these operations knows to start small. The hazardous environmental and unpredictable weather effects make solar dimming an inconducive strategy for dealing with ACC. In my personal opinion, scientists should start with dropping solar irradiance by 3 watts/m2 at the most. The goal shouldn’t be a quick and easy fix, sustainable energy should remain the main focus
    https://www.newyorker.com/news/annals-of-a-warming-planet/dimming-the-sun-to-cool-the-planet-is-a-desperate-idea-yet-were-inching-toward-it

  3. It’s been a couple of years, hi everyone 👋 Just wondering if there’s a greater probability of earthquakes (of any magnitude) in California with all this rain? Question not in anyway inspired by watching James Bond over Xmas… although I do recall once seeing a documentary once that spoke about this but not sure how good the science was in that.

    I’m making Old Fashioned’s later if anyone wants one?

    • Welcome back! Hope you are not flooded yourself. I strongly doubt that the rain will trigger earthquakes. There was a claim that the Haiti earthquake was related to a flooding 18 months earlier. But it is not clear how that could be related. Injecting water into a deep fault will increase the risk of a quake, because it reduces friction on the fault by lubrication. But rain doesn’t do that: it stays at or near the surface. If it is the extra weight of water, that is rather minor. Even a meter of rain only has the same effect as 50cm of sand. If that made a difference, how about the weight of a city like San Fransisco? The city is heavy enough that it measurably deforms the ground. But how about the other way? There was a claim that strong earthquakes in Tibet are more often followed by rain. The suggestion was made that geothermal heat from the quake induces rain. It seems more likely that if the re is a relation, it would be caused by dust thrown up by the shaking, acting as condensation seeds for rain. The Tibet earthquake rain was said to be mostly light rain. In summary, I think it is best in California to take the environmental catastrophes one at a time. They are independent from each other.

  4. https://m.youtube.com/watch?v=sPYyMOn19K8

    Is is a video of the 2028 Ambrym eruption. Although it is nothing special, the sound gives you a feeling of the raw power of the eruption.
    *do not get close to an erupting volcano, especially if it could produce ash plumes. The guy was probably very lucky, though.

  5. I got a question: what are the conditions (hypothetically) for komatiites to form today? We did discuss about it in another post, so i think we could discuss it again. I know that the latest true komatiites are around 90 million years ago (https://www.researchgate.net/publication/317382845_The_hottest_lavas_of_the_Phanerozoic_and_the_survival_of_deep_Archean_reservoirs), although the latest of the komatiites erupted around 85 million years ago (https://www.researchgate.net/publication/235828117_Geochemical_Study_of_Ultramafic_Volcanic_and_Plutonic_Rocks_from_Gorgona_Island_Colombia_the_Plumbing_System_of_an_Oceanic_Plateau).

    What I find interesting is that the Tortugal komatiites is actually found in an ophilite (I.e. oceanic crust exposed on land), maybe suggesting that this formed in a more oceanic setting whereas the Gorgona komatiites are possibly sub-oceanic (as there are tuff, although it is hard to say whether the komatiites erupted on land or not) and both formed during the time that the Caribbean igneous province formed (https://www.researchgate.net/publication/325570779_From_incipient_island_arc_to_doubly-vergent_orogen_A_review_of_geodynamic_models_and_sedimentary_basin-fills_of_southern_Central_America)(although it is a debate of where it formed).

    What I have found out is that they could only occur in oceanic or near-oceanic settings (powerful mantle plume under oceanic plates, maybe during oceanic flood basalt episodes), so either that they are subducted or not fully analyzed (like not taking a closer look at some of the oceanic LIP’s).

    • Hawaii is hot enough to do it, but there has still never been true komatiite erupted, although picrite basalt has the same total composition. The percentage of magnesium in the total composition of the primitive melt is not high enough to be ultramafic, so a lava in Hawaii can erupt at 1600 C but it will still be basalt.
      I guess maybe the great mass of the islands actually prevents the mantle completely melting which is what creates komatiite, so it is possible komatiite eruptions on land have always been extremely rare. Maybe an island that is formed as part of an oceanic LIP could do it but that is about it. And most oceanic LIPs are probably not real flood basalts but more like Iceland, making an oceanic plateau where a ridge is particularly active or intersects a plume.

      Along the east pacific rise or Lau basin between Tonga and Fiji where spreading is very fast, those are possible locations, maybe more likely but very difficult to observe for obvious reasons 🙂

    • And really cool timelapse of lava moving across the present-day lava lake of Kilauea:

  6. Could I ask about something. I got quite curious into hotspots lately and I was wondering about it – what would happen if a powerful hotspot (I.e. powerful as Hawaii) transitioned from an oceanic crust environment to a continental crust setting?

    There has been instances in the case of Australia (and perhaps maybe New Zealand… twice), maybe a few more, but is is all speculation. I could imagine that it would transition from oceanic island building to creating massive volcanoes on land with more varied volcanic products than if it were in an oceanic environment, because of a thicker crust. I could be wrong, but that is what I think may happen…

    • Monster Flood basalt woud that result in, I wants to place it under Scandinavia and the whole shield starts to boulge.. and rise a kilometer up

      Then later all hell breaks loose and you gets Siberian Traps 2.0

    • Place it under Baltic Sea and Jesperian scale stuff woud happen, marsian, venusian hell eruptions, Scandinavian Craton is very thick,
      But Hawaii plume Maybe able to hurt it.. being extremely powerful, our litosphere is only 3 times deeper than at Hawaiis location.

      It woud build truely enormous chambers and make Mega intrusions

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