Complexes and Super complexes
This is a world where only the best dominate, where the unskilled are left behind, and where the average scorn. Volcanoes are no different, the best volcanoes last the longest and produce the strongest eruptions. So what makes a volcano strong? Can we find our missing piece to our Wah Wah springs mystery? Let’s see!
We are familiar with how volcanoes are formed and Hector already went into detail on regional processes that make calderas but let’s get into more local processes. Just because the larger setup is favorable for calderas doesn’t mean you will see an abundance of these volcanoes.
Right now everything is busy geologically speaking, we have to 2 powerful and expanding hotspots with a rapidly expanding rift above a superplume. This shows that the next million years will be interesting! But we won’t live that long. We also have developing volcanic complexes that look to be capable of producing large eruptions in the future. I have got 4 for you guys and with these volcanoes, we’ll talk about what part of their backgrounds and make-up that makes them strong candidates.
Tatun Volcanic Group
Let’s start with a familiar volcano, I have already written an article about this volcano detailing the threats and the background of this volcano. So you should probably read that first to get a good picture of this system. Simply put, this volcano has around 3,000 km3 of magma in its upper chamber and unknown amounts beyond that in its plumbing. So this is a big boy but its origins are more mysterious. This volcano has been active since Pliocene so it’s got some age but what keeps it from being a strong contender for a large caldera-forming eruption in the near future is that it doesn’t have a lot of evolved magma, it is becoming more explosive, so it would seem that this volcano could become very nasty in a 100,000 years or so.
What makes this volcano a strong candidate for future caldera formation? Beyond its size of course. First, it has an abundance of water to tap into, the proportion of dissolved water at this volcano is at least 3% and it’s right next to the sea as well so that’s not an issue. Second, this volcano has a deep source and its magma is more viscous due to the abundance of crystals in this area. There are only a few things that keep this volcano from being more explosive.
The first issue is that the magma degasses too quickly when approaching the surface and leading to effusive eruptions. This volcano seems to be in a vulnerable area locally, it seems like it’s too easy for magma to erupt here and because of that, there aren’t any really large eruptions here. Despite being bigger than most volcanoes on the planet, it has only produced 1 known Plinian eruption. Progress is being made, an eruptive pulse has ended and that will give this volcano some time to evolve it’s magma. Its magma is already volatile due to it being rich in water and other gases, and rich in crystals. This will give time for local Tectonics and the overall setting to change. Slight changes are all that is needed for this volcano to become more explosive and that is the new trend at this volcano.
This could relate to the eruption of Wah Wah springs in the sense that the local area became weak and magma could erupt through it easily. Local settings in volcanoes seem to affect not just how the magma has erupted but the volume as well. The local setting of most volcanic regions are constantly changing but the most subtle details keep certain complexes quieter.
I don’t think the Wah Wah springs volcano was anything like Tatun, Tatun would be as different to the Wah Wah springs volcano as you can get. But with a weakening setting and a strong and buoyant magma chamber, this could be how the setup for the eruption began.
Clear Lake Volcanic field
This volcano is depressed, it is almost as big as the Long valley Caldera and the USGS seems to believe it could be in a pre-caldera evolutionary stage, but if you type it’s name on google scholar you’ll get more results for Medicine lake! So not a lot of attention is given to this volcano. This guy would seem to have a PR issue. Located in Northern California, it stands alone with no volcanoes nearby.
This volcano is just as old as Tatun and it has more evolved magma. It has 1,400 cubic km3 of magma within its chamber and it could actually be in an eruptive period right now! The past 10,000-year lull of activity doesn’t mean the eruptive period has ended and in fact, it could continue for another 200,000 years.
Why hasn’t this volcano produced a caldera-forming eruption? It has the volume, the magma, and the water. Now, this is where the issue of this volcano being underrated comes in. I don’t have a lot of data to really work with. There is one fact however that is interesting, recurrent calderas usually have an understudy or a partner. Vesuvius for Campi flegrei, O’a caldera and Corbetti, Long valley and Mono-lake, you get the idea. As Hector has already brought up, bigger volcanoes crush and absorb their weaker neighbors but that isn’t this in the end.
First issue is simple, the fact that there aren’t any volcanoes or an abundance of smaller regional faults nearby means one thing. This volcano is likely in a locally stagnant location and has the opposite issue that Tatun has. As it doesn’t seem to be as frequent as an eruptor which would explain the more evolved magma.
The reason for this could be related to the fact that the San Andreas and Hayward faults are in the vicinity of this volcano. Contrary to popular belief, just because there is a huge fault system nearby doesn’t mean it will help volcanic activity. Tectonic faults and volcanoes have a much more complex relationship than the layman would think. These faults aid or combat the processes that help with volcanic formation(Let’s call it volcanogenesis!) and without an extensive local fault system(at least from what I could gather) there doesn’t seem to be anything to help with caldera formation.
The tectonic faults in this area are not set up in a complex fashion and are region also these faults don’t seem to do much for this system. External variables would seem to be essential to caldera-formation after all ejecting trillions of tons of material at speeds in excess of 250 mph all the way to the upper stratosphere might require some external help. You can’t simply have a massive magma chamber and expect to see a large eruption and this volcano is an example of that.
This might actually help the system produce a large eruption in the long term IF it can get a large amount of magma. An infrequent eruptor gives the volcano a chance to get an even bigger magma chamber, more buoyant magma, and more pressure. A setup like this could result in either a large eruption or an average complex with a substantial plutonic body. How does this relate to Wah Wah springs? This could be how the volcano assembled such a large magma chamber since this eruption was probably the closest to being a VEI 9 as we’ll ever get. The chamber that generated this eruption would have to be in the tens of thousands range to produce such a large eruption. In order to get a chamber so large, only a relatively small portion of magma would be erupted preceding the big one. The volcanic activity could create a regional fault system if it was intense and persistent enough.
The First Issue
So we speculated on how the volcano got so big and why it suddenly became vulnerable without thermal rejuvenation. We still have yet another question, what kind of volcano could produce this massive eruption without an intrusion, we haven’t anything like this with other calderas, regular complexes, and just about every other volcano.
Wah Wah springs was in a completely different league then other “supervolcanoes” may I dare say that this was hypervolcano? I don’t believe a traditional complex produced this eruption, I am not omniscient so I could be wrong but if an average complex could do this, I am thinking it would be more common. Well, there are a couple of volcanoes that could actually earn the title super or hyper volcano. There is a magma body capable of producing a large eruption like this volume-wise, and it’s our first super complex.
Altiplano–Puna volcanic complex
Do I really need to say any more? Everyone has examined this massive system with a magma body consisting of 500,000 km3 of magma. This incredible body within the central Andes is responsible for so many volcanoes and calderas, it’s crazy. This might be the first thought one might have when considering a system that could produce such a large eruption. It has the volume and history. Was the Wah Wah springs volcano on a magma body like altiplano?
The Wah Wah springs volcano was part of the Indian Peak-Caldera complex so it is possible that there was a similar magma body in this area. The deformation at Uturuncu is probably caused by migrating magma within the Altiplano-Puna complex so this would follow through with the system needing no thermal rejuvenation for the generation of pressure. With enough pressure, the decompression caused by the eruption could rejuvenate some of the magma.
Now this magma body seems to be past its prime surely this couldn’t produce a similar eruption to Wah Wah springs? I am not sure. Let’s forget how molten the system since sometimes it doesn’t seem to matter. If Uturuncu’s uplift is caused by the buoyant magma and not magma intrusion and this could be a problem, to say the least. The magma could degas and APVC could end its supply before the volcano erupts.
What does matter is if the magma chamber can handle whatever pressure this body throws at it. Something that could help with this would be to study on the systems past caldera forming eruptions and see if they had thermal rejuvenation. Historical precedence for eruptions without thermal rejuvenation could mean that Uturuncu may become scarier to say the least but if there is no historical precedence then it is unlikely that this system could produce an eruption like this in it’s dying moments.
Cerro Bravo-Cerro Machin complex
This is the most underrated volcano in history, in my opinion, This system is big, REALLY big. If you know about the two volcanoes that make up this system’s name you already have an idea how huge this system is. For those who don’t know just look at this picture.
Yes. This complex consists of more than 9 volcanoes, five of which are 4500-meter+ tall stratovolcanoes, this is a huge and very mysterious system. An article was released by the Journal of Volcanology and Geology concerning this system but I don’t have $35.99 lying around to pay for it. The major volcanoes of this system are the aforementioned Cerro Bravo and Cerro Machin, Nevado del Ruiz, St Isabel, and Romeral. The products of this make up a massif.
This volcano has so few articles dedicated to it it is ridiculous. I know I sound like a broken record at this point but it’s true! Think about it, Nevado del Ruiz and all of its history and background is just a pretty small part of this system! The recent activity of Ruiz is part of the heightened activity of the whole system. Elevated seismic activity has been noted from the volcanoes of this complex and a portion of this system is under inflation.
Needless to say, there is a LOT of magma beneath this system although I don’t know how much exactly though I think it’s safe to say that it’s a little more than 1,000 km3.
I don’t know how much of the magma has consolidated in it’s chambers but I am sure it’s a lot.
The Magma at this system seems to be more concentrated than Altiplano but it is not as evolved and this system may be the beginning of a similar-sized magma body but it is still not as big. I don’t know much about this system because there are and I’ve counted, less than 5 studies dealing with the system as a whole and not just the individual volcanoes of the complex.
I am not aware of any other active supercomplexes, these massive systems could be very easy to miss. Volcanoes tend to form together and sometimes some are very close to each other without being related in the slightest but it would seem that isn’t always the case.. I believe the Wah Wah springs volcano was like this system and I also believe it also provides the answer on what the “The Missing Piece.” is. Think about it…these are massive systems and depending on how one would define a volcano, you could say technically that these huge systems are one volcano. After all, the calderas, cones, and stratovolcanoes are all connected to a single source, a single source causes recurrent eruptions at the vents with distances of over 40 km. I think I’ve got it.
To be Continued