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CrustalTrudger t1_j9y93si wrote

> When a volcano erupts, does this affect the pressure building up in other volcanoes?

Generally, no. At a simple level, any given volcano represents an isolated system, i.e., surface vents connected to a magma chamber within the crust, e.g., this diagram, while for a specific volcanic system is a decent generic representation to consider. If sufficient eruptable magma and conditions suitable for eruption exist (in terms of both volume of liquid, ratio of crystals to liquid, amount of dissolved gases, etc) within the magma chamber of a given system to cause an eruption, this will have no influence on other volcanoes because there is no connection between the systems.

The caveat would be if you're considering separate (but nearby) volcanoes that represent different vents or components of the same system. An example might be something like the big island of Hawaii where Mauno Loa and Kilauea effectively represent different vents of a related system (e.g., this super simplified diagram). Here we can see that while the two volcanoes have their own magma chambers in the shallow crust, they are "linked" by a single magma reservoir in the deeper crust. In detail, it's long been noted that eruptions at the two tend to be anti-correlated, i.e., one erupts which reduces activity at the other and then they switch, which many have assumed is related to competition for magma supply from the deeper reservoir (e.g., Klein, 1982). Further, there are suggestions that the eruptive process of one of these volcanoes might temporarily inhibit activity of the neighboring volcanoes through changes in the stress state induced by the eruption (e.g., Gonnermann et al., 2012).

In short, the eruption of one volcano has no bearing on distant volcanoes as there is no connection between their magma sources and the other changes that result from an eruption (e.g., changes in stress state) have a very limited spatial range. In the specific case of volcanoes very close to each other and that may share some portions of a magma plumbing system, eruption through one vent may influence (and specifically decrease) the activity of adjacent vents, but if there is a large pulse of magma that enters into all of the vents, then this "suppression" may not occur.

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Rhamni OP t1_j9yizfo wrote

Thank you! This is exactly the answer I was looking for.

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id02009 t1_j9zi7rp wrote

Follow up: how do we know those volcanoes in Hawaii are vents from the same system? Are we sure, or is it an educated guess because they're close enough?

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Uncynical_Diogenes t1_j9zm926 wrote

>same system

These systems are much, much bigger than you’re thinking of.

The Hawaiian islands are volcanic islands created by the same “hotspot” plume in the mantle as the overlying plate moved over it. They were created in sequence by volcanic eruptions from that same upwelling. It makes perfect sense for all the islands to be related, so for multiple volcanoes on one island to be related is a no-brainer.

The matching mineral composition and timing of those eruptions indicate they are related. Kīlauea and Mauna Loa’s eruptions are linked to decreases in the other’s activity for a while. Given all the evidence, there’s no need to guess; the volcanoes that make up the island of Hawai’i are linked. It would be far more difficult to adequately explain how they weren’t, if that were true.

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Ieatadapoopoo t1_j9zob38 wrote

I’m sorry, I’m not trying to be pedantic, just making sure I understand, but it does sound like an educated guess, no? An insanely solid goes off course, but it sounds like we’re just really really certain of our guess. That’s enough to convince me, just wanted to be sure I had it right!

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CrustalTrudger t1_j9zx3vl wrote

While not as unique as fingerprints, individual magmatic systems tend to have somewhat individualized geochemical profiles in terms of concentrations of trace elements and isotopic ratios so it's not "guessing" to use similarities of geochemistry to argue that two adjacent volcanoes share a source and/or have intermingling of sources in the shallow crust. Additionally, there are variety of geophysical techniques (seismic tomography, magnetotellurics, resistivity, etc) that allow us to image the magmatic systems of volcanoes which again provide evidence that these are related. The general idea that geology is all "educated guessing" (which underlies many questions and lay answers/comments in this subreddit) is pretty frustrating given the extreme care and detailed analysis many of us put into to understanding the details of natural systems.

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Ieatadapoopoo t1_ja04esr wrote

Ah, that makes sense. Thanks so much for clearing that up! I’m completely ignorant, so I had no idea what the process was like.

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imdoneanymore t1_ja09w58 wrote

You may want to read this

https://www.usgs.gov/news/volcano-watch-new-research-sheds-light-recent-pahala-earthquake-swarms

on the Pahala quakes that are happening between Mauna Loa and Kilauea. It’s all about plumbing and after ML’s recent eruption there are geologists all over the area now, because what they thought to be true is being challenged by what happened in this last eruption. It’s really interesting stuff. And a rabbit hole lol.

I live on the slopes of ML and find it fascinating.

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Ieatadapoopoo t1_ja0b8eg wrote

Thanks, I can’t wait to get a minute to dig into this :D

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JonArc t1_ja05yfh wrote

On a slightly smaller scale we've sismic imagery (think like a sonogram) of a lot of the near surface plumbing on the big island so that cover Kilauea, Manua Loa, and a few other features. If you read about the 2018 eruption of Kilauea you'll see that in action as it's all about a loss of pressure in the system.

I'd also add that the hotspot didn't just make the modern Hawaiian Islands. There's a whole chain of eroded sea mounts that used to be other islands! And the direction they go in is in the direction the Pacific plates is moving. And this is a trait we see in other hot spit volcanos. Since the souce of the heat is from the mantle it doesn't move, but the plates still move over it.

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QuiteAffable t1_ja3h7n2 wrote

For a similar example look to the hotspot that created Yellowstone park

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kvakerok t1_j9zgnej wrote

To summarize in laymen terms it's more like a pimple squeeze than a balloon deflation (balloon being planet earth).

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FlameSkimmerLT t1_j9yzxxd wrote

Oh interesting. About your example, then, why do the connected system Kilauea and Mauna Loa erupt at such different volumes? I believe Mauna Loa tends to erupt much more lava.

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OpenPlex t1_j9zao8u wrote

> At a simple level, any given volcano represents an isolated system, i.e., surface vents connected to a magma chamber within the crust, e.g., this diagram, while for a specific volcanic system is a decent generic representation to consider.

Why does the magma in that image travel up as lone tendrils? What's the physics of that?

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the_muskox t1_j9zem6q wrote

The magma is exploiting fractures and other weaknesses in the overlying rock to ascend. That's much easier and faster than just melting its way through several km of rock.

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CrustalTrudger t1_j9zfwyg wrote

Yep, and in some cases the pressure building from the magma itself and gases is sufficient to push the overlying rocks into a stress regime that's right for tensile failure, so it's not just exploiting existing fractures, but sometimes also making new fractures.

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dmscvan t1_ja0ip5y wrote

After your explanation, I’m curious about what might be going on when two nearby volcanoes erupt at the same time. For example, I do fieldwork near Rabaul, Papua New Guinea. Though it’s before my time, I believe the eruption of Tavurvur (which destroyed much of Rabaul at the time) in 1994 (the exact date might be off) also had another eruption of a possibility new volcano nearby (my offhand guess is ~50-100km away).

I know that Tavurvur and the newer volcano are both on the rim of a much, much older caldera, which now makes up Ataliklikun Bay. So I’m wondering then, is it likely that they have the same magma chamber and the release at Tavurvur wasn’t enough to hold the pressure, and a new opening was needed?

To be honest, I may have some small details a bit off about this event. I’m a linguist not a geologist or volcanologist. This is all from what I remember reading and talking to people about. I had always assumed they had the same magma chamber, but I actually know nothing about how it works, and your comment had me wondering. FWIW, Tavurvur (and not the other volcano) has been active on and off again for quite awhile now (though it’s been about 10 years since I was last there, and I’m unsure of the current situation).

TIA

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CrustalTrudger t1_ja0kf5l wrote

There were simultaneous eruptions of Tavurvur and Vulcan (this is discussed in this Wiki link). Importantly, these (and another volcano) all represent different vents that are part of a single system, so it it definitely analogous to the Mauno Loa and Kilauea example in a sense (though I don't know that much about the detail vent system or structure for the Rabaul Caldera and associated vents). Importantly (and as discussed a bit in the Gonnermann paper I linked in the original answer), there is always the potential that if the influx of melt into a magmatic system is significant enough, you can definitely get simultaneous eruptions in adjacent vents (i.e., the mechanism that potentially drives eruption in one or another vent they present can be overwhelmed if there is just a lot of magma).

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dmscvan t1_ja2291k wrote

Thanks so much for this explanation! And the links you provided have more information than last I looked into it. (Though I don’t have access to the paper after leaving academia, I can probably get it.)

I have a couple stories about the 1937 eruption and they have oral history of older eruptions as well. It’s really interesting to me to understand more of the science behind the volcanos. Cheers!

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ground_App1e t1_ja0fyil wrote

Genuine question: Why is all the popular media always talking about the ring of fire being set off then?

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CrustalTrudger t1_ja0h4i8 wrote

Because (1) potential disasters brings clicks and thus ad revenue and/or (2) Earth Science is a subject that typically takes a back seat to the "big three" STEM fields of biology, chemistry, and physics, so even at the lay level (i.e., whatever science folks get in primary school or college), people tend to be incredibly misinformed or completely unaware of even basic aspects of how the Earth systems works.

To clarify, for either earthquakes or volcanoes, there is effectively no mechanism for triggering either type of event along significant portions of the various plate boundaries rimming the Pacific (i.e., the "Ring of Fire"). There are very specific and limited mechanisms by which earthquakes and volcanoes can trigger each other, especially over large distances, but these are exceedingly rare, require very specific preconditions, and are very hard to demonstrate even if they operate.

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AphroditesAutomaton t1_ja1ypn0 wrote

When novarupta in Alaska erupted around 100 years ago it drained a nearby volcano (Katmai or something like that?). They first thought the drained volcano was the one that erupted, but it was another crater around a mile away I think. NPS has a good article on it: https://www.nps.gov/articles/aps-v11-i1-c2.htm

Correction: the erupting crater was 6 miles from Mt. Katmai!

Novarupta was largest of 20th century BTW.

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stephenph t1_ja25jyp wrote

So how about indirectly causing a chain reaction of multiple volcanos...

I am thinking of an earthquake on a large fault (say the cascadia fault) setting off multiple volcanos along the fault line. Or would a volcano going off always lower the stresses on connected faults?

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[deleted] t1_ja00lfm wrote

[removed]

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the_muskox t1_ja080dv wrote

> For example, the eruption of Mount Pinatubo in the Philippines in 1991 is thought to have triggered the eruption of nearby Mount Unzen in Japan.

Do you have a source for this? They're on separate magmatic arcs.

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