Campi Flegrei, an incipient caldera event?

[Old Rocks]

Cascadia is also getting very active

Minor signs only so far in the Cascades. And those happen all the time. What is happening in Italy is not minor, and they are now on red alert.

 

[frigidweirdo]

We are seeing some very interesting developments near Naples. The best case is a release of gases and steam over a period of years, with seismic events that damage the area. The worst is a full fledged caldera eruption that would effect the whole world.

Seem to be a few of these, one in Siberia, one in Kamchatka, there's the one that already exploded in the Pacific that most people ignored.

 

[ReinyDays]

Hotspots in ocean provinces produce basaltic, very running lavas. Pretty much not that explosive of eruptions. Hotspots under continental crust produce both basaltic and rhyolitic eruptions. Basaltic, like the Columbia Basalts. Rhyolitic like the calderas in Nevada, Oregon, Idaho, and Wyoming. And those are very explosive, often producing huge amounts of ash and sulfur dioxide. Which can cool the earth several degrees for a couple of decades. Very big difference between the types of eruptions of Kilauea and Yellowstone.

The "rhyolitic eruption" at Mt Mazama took 200 years to empty the magma chamber enough to start the caldera formation ... and this is roughly equivalent to Campi Flegrei ...

Are you able to compare Mt Hood with Crater Lake? ... see how the overburden at Hood is large enough hold down the pressure coming from up from below? ... now look at the overburden at Crater or Campi Flegrei ... notice the difference ...

Here's a 90 second video of rhyolite erupting at Mt St Helens ... in 1980, the mountain had overburden and pressure built up to an explosive event ... but here in 2000, the magma is free to form domes ... this also takes place at Crater Lake, Wizard's Island sits on top of these domes ... we still have 10,000's of years of this dome building phase still to come ... (which is imminent according to mushroom's post #17) ...

Perhaps you confuse the dangers of Campi Flegrei with the extremely well documented dangers from Mt Vesuvius ... ever heard of Pompeii? ... or why the 1908 Olympics had to be moved out of Naples? ... she destroyed almost 100 American medium bombers during WWII ... what a ***** ... the danger at Vesuvius is water ... sea water creeping into the magma chamber and instantly vaporizing ... like Krakatoa in November 1883 ...

There's flood basalt from Yellowstone to the Pacific Ocean ... a lava river 500 miles long ... rhyolite won't do that ...

 

[Old Rocks]

The "rhyolitic eruption" at Mt Mazama took 200 years to empty the magma chamber enough to start the caldera formation ... and this is roughly equivalent to Campi Flegrei ...

Are you able to compare Mt Hood with Crater Lake? ... see how the overburden at Hood is large enough hold down the pressure coming from up from below? ... now look at the overburden at Crater or Campi Flegrei ... notice the difference ...

Here's a 90 second video of rhyolite erupting at Mt St Helens ... in 1980, the mountain had overburden and pressure built up to an explosive event ... but here in 2000, the magma is free to form domes ... this also takes place at Crater Lake, Wizard's Island sits on top of these domes ... we still have 10,000's of years of this dome building phase still to come ... (which is imminent according to mushroom's post #17) ...

Perhaps you confuse the dangers of Campi Flegrei with the extremely well documented dangers from Mt Vesuvius ... ever heard of Pompeii? ... or why the 1908 Olympics had to be moved out of Naples? ... she destroyed almost 100 American medium bombers during WWII ... what a ***** ... the danger at Vesuvius is water ... sea water creeping into the magma chamber and instantly vaporizing ... like Krakatoa in November 1883 ...

There's flood basalt from Yellowstone to the Pacific Ocean ... a lava river 500 miles long ... rhyolite won't do that ...

No, it only took a few days at most for the Mazama eruption to form the Crater Lake caldera. 39,000 years ago Campi Flegrei erupted in a huge rhyolite eruption that had serious climatic consequences and probably contributed to the dying out of the Neanderthals. No, there is not flood basalt from Yellowstone to the Pacific Ocean. From Eastern Washington and the Grand Ronde area in Oregon, not Yellowstone. Most of the Yellowstone eruptive material is rhyolite.

A few days
The caldera-forming eruption at Mount Mazama lasted for a few days, during which about 50 km³ (12 mi³) of magma was expelled as pyroclastic materials. This eruption was one of the largest known within the Cascade Volcanic Arc in a million years and produced widespread ashfall and pyroclastic flows that traveled as far as 70 km. The eruption's rapidity and intensity were responsible for the collapse of Mount Mazama and the formation of the caldera.

USGS.gov+1

 

[Old Rocks]

The "rhyolitic eruption" at Mt Mazama took 200 years to empty the magma chamber enough to start the caldera formation ... and this is roughly equivalent to Campi Flegrei ...

Are you able to compare Mt Hood with Crater Lake? ... see how the overburden at Hood is large enough hold down the pressure coming from up from below? ... now look at the overburden at Crater or Campi Flegrei ... notice the difference ...

Here's a 90 second video of rhyolite erupting at Mt St Helens ... in 1980, the mountain had overburden and pressure built up to an explosive event ... but here in 2000, the magma is free to form domes ... this also takes place at Crater Lake, Wizard's Island sits on top of these domes ... we still have 10,000's of years of this dome building phase still to come ... (which is imminent according to mushroom's post #17) ...

Perhaps you confuse the dangers of Campi Flegrei with the extremely well documented dangers from Mt Vesuvius ... ever heard of Pompeii? ... or why the 1908 Olympics had to be moved out of Naples? ... she destroyed almost 100 American medium bombers during WWII ... what a ***** ... the danger at Vesuvius is water ... sea water creeping into the magma chamber and instantly vaporizing ... like Krakatoa in November 1883 ...

There's flood basalt from Yellowstone to the Pacific Ocean ... a lava river 500 miles long ... rhyolite won't do that ...

Here is a map of the source of the Colombia Basalt flows and there source. I have literally put my hands on many of the dikes in Washington, Oregon, and Nevada. There are no basalt flows from Yellowstone included in the Colombia Basalts.

 

[Mushroom]

Cascadia is also getting very active

Cascadia has always been very active.

 

[Mushroom]

Here is a map of the source of the Colombia Basalt flows and there source. I have literally put my hands on many of the dikes in Washington, Oregon, and Nevada. There are no basalt flows from Yellowstone included in the Colombia Basalts.

OK, this is a bit hard to tell, and geologists are still arguing over it.

But when you talk about "Yellowstone", are you talking about the Yellowstone Caldera, or the Yellowstone Hotspot? Because they really are not the same thing. The former is fixed in place where the latest hotspot eruption occurred, the latter is moving, and has been creating calderas since at least when it was around the Idaho-Oregon-Nevada tri-state border some 16 mya.

There is believed to be a connection between the two, but it is not direct and geologists are still arguing about it. One speculation I read about two years ago is that the explosive eruptions caused fractures that allowed the basaltic lava to move up and then created the basaltic flows over most of that region of the continent.

In other words, more of a cause and effect than one being directly linked to the other. And as the hotspot moved into older and older continental crust, the size and amount of basaltic flows reduced and changed. And remember, the Columbia River basalts predate the oldest known hotspot location, but include the hotspot eruptions through the Picabo Eruption. But the "heyday" of the Columbia River Basaltic Group was up until roughly the era of the Bruneau-Jarbridge Caldera. And it started to peter out as the hotspot moved farther East.

And the youngest active field is Craters of the Moon in Idaho, only some 15 kya. And that entire field is "dormant", not "extinct". Which means geologically speaking, they could wake back up into an active field like is seen in Hawaii "tomorrow".

One of the connections between the two covered in that paper (I wish I could find it) involved tracing the ages of the flows in relation to the Hotspot. The farther West you go, the older the basalt flows are. The farther East you go, the younger the basalt flows are. With the youngest being a mere 2,000 years ago in Eastern Idaho. And the oldest ones being the massive basalt flows we are familiar with, while the younger ones are not entirely basalt and mixed with more types of volcanic eruptions.

And a minor correction, not all basaltic flows are oceanic in origin, as can be seen in Idaho, Oregon and Washington. As the exotic terrane that formed most Eastern Washington and Oregon when Idaho was still the "edge of the continent" are truly ancient. Much more recent than the terranes that created the Cascade Range, yet the lava types are very different.

Just another thing that many geologists love to argue over. There is much speculation and theory, but still no clear answers as to why eruptions in the Western part of the states are basaltic, and on the Eastern side they are explosive. Myself, I think it points to whatever likely created those terranes in the first place when they were all just off-shore islands and microcontinents.

 

[Mushroom]

Minor signs only so far in the Cascades. And those happen all the time. What is happening in Italy is not minor, and they are now on red alert.

Oh, there are plenty of signs. And there were multiple eruptions in that range in the 20th century.

The problem here is that we are in a region of the planet with written records only going back a few hundred years. We actually have written records of volcanic events like Pompeii some 2 kya, but only very ancient Indian legends and what geologists can puzzle out in the Cascade Range in the past two centuries.

For all that people know of the Mt. Saint Helens Eruption, another that is largely forgotten even though there is a National Park on the site is Mt. Lassen. Which also has the distinctions of being not only the first eruption in a US state, it was the first captured on film.



Once again, what throws people off about these is the timelines. Geologically, something happening 2,000 years ago or 10,000 years ago was the blink of an eye ago. So close geologically they are almost the same event. Most people simply can't comprehend events on time scales like that.

Where as I look at things mostly in the time scale of hundreds of millions of years.



When I talk about exotic terranes joining the continent back when the coast was in Idaho, I am being literal. Back when the Eastern US and Europe were conjoined, Idaho was the "West Coast". And all the land making up the continent to the west of there down to Arizona are recent hitch hikers that have been picked up.

And yes, go back around 400 million years, and you really could have oceanfront property in Arizona.

Exotic Terranes are a particular fascination of mine, and one of those things that I have seen people getting glassy eyed trying to comprehend. That huge islands and microcontinents the size of Florida were once off the US coast, and slammed into it making up the coast we know of today.

 

[Mushroom]

No, it only took a few days at most for the Mazama eruption to form the Crater Lake caldera.

And much of this is largely speculation, but based on very good science.

But volcanic collapses and the calderas they leave behind are just the end stage of events that took place over hundreds to thousands of years.

I still remember the awe I felt as a kid when standing on the edge my teacher showed us the extent of the Owyhee-Humboldt Caldera. And that was in the 1970s, when only "radicals" were connecting that to Yellowstone and that the entire Snake River Plain was remnants of a single "moving volcano".

I think the best explanation I heard for the Mazama Event is that it likely was the end of an eruption cycle that took place over a dozen or more years, then ended with the collapse. But the collapse itself was amazingly brief, probably measured in hours to days.

Which matches Indian legends, of a battle between spirits that went on for years with the spirits throwing great fireballs at each other. And the war ending when one night the evil spirit was forced back into the Underworld and the good spirits collapsing the mountain on top of him.

 

[ReinyDays]

What a geologist has to say ...



ETA:

 

[toobfreak]

We are seeing some very interesting developments near Naples. The best case is a release of gases and steam over a period of years, with seismic events that damage the area. The worst is a full fledged caldera eruption that would effect the whole world.

What amazes me is that in a region populated by some of the biggest, worst volcanos on the planet, they are shocked at the formation of a geologic caldera.

I'm no geologist, but none of this seems surprising and is following right along the laws of entropy.

It seems clear that in the future, releases of pressure will go up, some of which could be catastrophic.

I'd be moving out of Italy right now.

 

[Mushroom]

What amazes me is that in a region populated by some of the biggest, worst volcanos on the planet, they are shocked at the formation of a geologic caldera.

I'm no geologist, but none of this seems surprising and is following right along the laws of entropy.

It seems clear that in the future, releases of pressure will go up, some of which could be catastrophic.

I'd be moving out of Italy right now.

Not sure where you would go to then.

Don't go to the US, there it will someday be much worse. As in literally overnight the US will become one of the most impoverished nations on the planet.

And that is not the only one, as there is also the Long Valley Caldera in California.

And here is the other two with the Valles Caldera in New Mexico.

Yes, three super volcanos in the Continental US. And two more in Alaska.

Those are so large, there is really nowhere you can get to and avoid the consequences. Every one when it goes off will seriously impact most of a continent directly, and have global effects afterwards. As in a 10-25+ year long volcanic winter.

But compared to the timeline of humans, these are extremely rare events. The most recent was almost 28,000 years ago in New Zealand, at roughly the same period of time that humans discovered how to make ropes.

 

[toobfreak]

Not sure where you would go to then.

Yep, MR, I've known all about that stuff for a long time. The thing is that we have a very poor fund of understanding of how these super-volcanos work since they are such a rare event, so there really is no telling just what will happen where and when, but by a lucky happenstance, if there is any "least bad" place to be in North America, I am already there.

 

[westwall]

Hm.

Campi Flegrei (Phlegrean Fields)

Campi Flegrei (Phlegrean Fields) Volcano, Italy - facts & information / VolcanoDiscovery

www.volcanodiscovery.com

Birth and growth of a volcanotectonic fault during the current volcanic unrest at Campi Flegrei caldera (Italy) - Communications Earth & Environment

Spatial analysis of seismicity within the Campi Flegrei caldera suggests it has become progressively clustered since 2023 around a central plane which is consistent with the development of an extensional volcanotectonic fault

www.nature.com

I track some of that. But not all of it. Sounds like the caldera rocka are predated from prior earthquake damage within (2023) and that this may not bode well if it blows again.

When I hear “caldera” my brain sees Yellowstone going boom. The one in Italy may be smaller but stil constitute a potential extinction event?

A bit further in the above quoted piece (the “abstract” above) is this disturbing forecast excerpt.


Id.

Yikes.

I did some more looking and see that if Yellowstone’s caldera were to blow, it would probably be an extinction level event for humanity.

By contrast, while not an ELE event apparently, if Campi Flegrei caldera were to go super volcano on us, Milan would be flattened and Earth would probably go through a Temporary climate cooling ( 1–3 °C globally, for a few years). It would constitute a major agricultural disruption—but not mass extinction.

The above is distilled from GPT. I haven’t checked its sources.

Anyway, I find this stuff fascinating and this one in particular somewhat concerning.

Before you get a caldera eruption like that you will see the entire region raise up. Several hundred meters at least, so no. No caldera eruption is imminent.

You could still see a nice Plinian eruption though

 

[Old Rocks]

Before you get a caldera eruption like that you will see the entire region raise up. Several hundred meters at least, so no. No caldera eruption is imminent.

You could still see a nice Plinian eruption though

Yes, a lesser than caldera eruption is the most likely outcome if it erupts at all. However, given our present knowledge about caldera eruptions and how they occur, I would not dismiss the possibility of such an eruption.

 

[westwall]

Yes, a lesser than caldera eruption is the most likely outcome if it erupts at all. However, given our present knowledge about caldera eruptions and how they occur, I would not dismiss the possibility of such an eruption.

I would. Before a caldera eruption occurs, the entire area undergoes a period of expansion called "regional tumescense" as magma is injected into the sub strate. Long Valley, and Yellowstone witnessed a bulge that was close to a mile high before they erupted.

No regional tumescense, no caldera eruption.

Simple.

 

[BackAgain]

Before you get a caldera eruption like that you will see the entire region raise up. Several hundred meters at least, so no. No caldera eruption is imminent.

You could still see a nice Plinian eruption though

Good to know. Thanks.

 

[westwall]

Good to know. Thanks.

You're welcome.

 

[toobfreak]

I would. Before a caldera eruption occurs, the entire area undergoes a period of expansion called "regional tumescense" as magma is injected into the sub strate. Long Valley, and Yellowstone witnessed a bulge that was close to a mile high before they erupted.

No regional tumescense, no caldera eruption.

Simple.

That makes sense considering that everything I've studied on the topic indicates that the actual magma chamber driving the volcano action is usually far larger than just the caldera region alone.

And given that the crust is 30 miles thick, long before enough pressure could accumulate to lead to a localized caldera collapse, the overall general pressure increase over the entire region would have to swell a much wider area by a significant degree. In fact, the volcanic explosion is actually a mechanism by the Earth which seeks to release that pressure, making the volcanic release before the pressure accumulation unlikely.

 

[westwall]

That makes sense considering that everything I've studied on the topic indicates that the actual magma chamber driving the volcano action is usually far larger than just the caldera region alone.

And given that the crust is 30 miles thick, long before enough pressure could accumulate to lead to a localized caldera collapse, the overall general pressure increase over the entire region would have to swell a much wider area by a significant degree. In fact, the volcanic explosion is actually a mechanism by the Earth which seeks to release that pressure, making the volcanic release before the pressure accumulation unlikely.

Correct. Just to give you an idea of the scale involved, and why the expansion must take place first, Long Valley Caldera, which erupted approximately 750,000 years ago is 20 miles long, by 11 miles wide, but over a period of about a week it erupted over 600 cubic kilometers of ash.

That deposit, called the Bishop Tuff, has measurable quantities in the Mid Atlantic Ridge.