Volcano thread

[bjdeming]

Afar TV got a really good video of MErapi (Java) doing its thing last night:




I learned while reading up on this Decade Volcano that, all around the world, volcanoes that push up real sticky lava which accumulates at the summit in a crumbly dome that regularly sheds pyroclastic flows are said to be having Merapi-style eruptions.

Merapi does this most of the time, in the midst of millions of people. The summit area is a no-go zone but sand miners go up there anyway because volcanic ash is a very good source of silica for electronic chips and poverty is widespread here. They frequently lose their equipment and sometimes their lives, but many are willing to risk it.

(PS: These days I'm not active at Patreon, despite the note at that link.)

 

[KakashiHatake2000]

Oh interesting

 

[bjdeming]

I have no idea who the author of this letter to the editor is, and a quick online search isn't helpful. Given the content -- an in-depth discussion of the tsunami risk from Kick-'em-Jenny, it sounds like someone who knows what they're talking about.

Note that the Gulf Coast isn't mentioned. <Layerson speculation> Certainly islands and other land close to the volcano are most at risk. The only context where I've seen the US brought in is for a Hunga Tonga-style megablast, but from other reading my impression is that volcagenic tsunamis, when recognized as a risk at all, aren't well understood; neither are submarine volcanoes.

For that matter, neither is Hunga Tonga's big boom. Until that is figured out, chances of another one at another submarine volcano that, like HT, is frequently active in a "normal" way, must be considered as not zero. </Layperson speculation>

 

[bjdeming]

As far as I know, this study doesn't announce anything really new, despite the dramatic and IMO rather misleading headline, but it does report a welcome new proof of technology that could greatly improve volcano monitoring.

Again, I have done no in-depth reading on the Cascades, but of course I looked them up when I moved here. It's a surprisingly complex picture but my general impression is that scientists know about the bodies of partial melt that the headline refers to as giant magma bodies.

Those in the Cascades have their own properties, but basically there is partial melt under probably all dormant volcanoes and elsewhere, too -- say, between Albuquerque and Socorro in New Mexico.

But that doesn't mean that it will erupt. It just means that hot stuff from the depths has found its level of neutral buoyancy. Much more often than not, it just stays there and freezes into rock.

The processes that can bring it up are a whole 'nother story, and as this layperson understands things, not completely known.

Also, it's expensive to monitor volcanoes and that's why only known troublemakers are likely to get networks.

Mexico's El Chichon and Pinatubo in the Philippines were not known troublemakers before they went off. Neither was Vesuvius, dormant some eight centuries before its Pompeii eruption.

There must be other volcanoes out there -- dangerous because no one knows about them. The success of receiver functions in this study, if verified, means that volcano monitoring costs at individual volcanoes can drop and so more possible troublemakers can be monitored.

This is pushing past my knowledge envelope, but it might also mean that preeruption processes can be studied in greater detail, too. That would improve eruption forecasting a lot.

 

[bjdeming]

There has been some sensational media coverage about a volcano, relatively dormant for 700,000 years (GVP notes two possible active episodes, in 1902 and 1993, but with ??), suddenly waking up and showing signs of an impending massive eruption.

Fact-checking shows that some scientists tested a type of InSAR monitoring on a long-dormant volcano in southeast Iran that is the only member in its volcanic field still emitting fumaroles, and they picked up a transient episode of inflation from 2023 to 2024 with it, which was indeed scientifically exciting.

In their report they say that it could be due to either hydrothermal processes or a minor and very deep magma intrusion that affected Taftan's big hydrothermal system.

That's all.

But they included an image that someone with no background in volcanology and who hadn't fully read or understood the technical text -- I don't understand the details sometimes but usually get the gist -- could interpret as a "massive explosion" when it's really just a diagram of the ongoing fumarolic activity (image is CC BY-ND-NC-SA 4.0):

This baby is only dormant, not extinct, and it's one of the few Pleistocene volcanoes that GVP lists despite it not having a confirmed eruption since the last ice age ended.

But it doesn't sound to this layperson that any magmatic trouble is brewing there in the foreseeable future.