The cat-evolution series will tie me up for a while, so here are some reposts, including a Sunday Morning Volcano series, slightly revised, from 2019 on hazardous eruptions in and around Italy’s Campania Plain.
Pompeii sits on the Campania Plain–a rich land that stretches, between the sea and the Apennine Mountains, down Italy’s Mediterranean coast south of Rome to the Sorrento Peninsula.
The city of Pompeii was so perfectly preserved by the 79 AD eruption of Mount Vesuvius that today we can wander its streets and almost see crowds of toga’d Romans pushing past us while the elite relax luxuriously behind very private walls.
Things haven’t changed much on the plain today, though almost 6 million Campanians live there now.
Like the ancient residents of Pompeii, no Campanian today can imagine their living world disappearing so suddenly, only to reappear centuries later as a tomb and museum. For self-protective reasons, the human mind just doesn’t work that way.
But the subterranean fires are only banked at the moment, not extinguished.
All of this plain is another “Pompeii,” just waiting to happen (hopefully many thousands of years in the future).
Let us all enjoy it in the here and now, and use our scientific understanding of how volcanoes work to minimize the risks here and make effective plans that will keep social and economic dislocations to a minimum if trouble comes during our lifetimes.
So what was life in Pompeii like back in Roman times? Accounting for different circumstances, it probably wasn’t all that different from life in Campania today:
Don’t feel you have to watch this 51-minute video (found on a random YouTube search–I know nothing about its maker) at one sitting, though its warmth and beauty are very attractive, especially on a cold winter day. I’ll give you time marks for relevant points. Vesuvius, for instance, first poses for us 9:19. We visit its crater at 17:09 and get into Pompeii around 18:05. But as you can see, there is much more to Campania than that famous ruin!
The main take-away to begin with is how people here still live close together, just as they did in ancient Pompeii. And human history in this region definitely did not follow that city into extinction back in 79 AD. The passion for and enjoyment of life still run deep in Campania today.
Also, a lot of what you see in and around Naples is built out of yellow rock.
See how many light yellow unpainted monuments and buildings there are, including the Castell d’Ovo (3:54)?
That’s the Neapolitan Yellow Tuff (NYT), blasted out of nearby Campi Flegrei some 15,000 years ago during ice-age times when woolly rhinos and fur-clad hunter-gatherers roamed the Peninsula.
Naples is built on this hardened pyroclastic rock–check it out in close-ups during the “subterranean Naples” segment at 7:32.
But the NYT itself sits on an even older flow called the Campanian Ignimbrite that covers most of the region and has been found as far away as southern Russia.
Is Vesuvius a supervolcano?
No, its most intense known eruptions, including the one that buried Pompeii, have “only” been VEI 5, according to the Global Volcanism Program.
That’s three orders of magnitude below the VEI-8 threshold that many experts (like Mason and others in the source list) set for a supereruption.
Credit: Anita Di Chiara (distributed via imaggeo.egu.eu) via Wikimedia, CC BY 3.0.
But there are other explosive volcanoes here that have proven themselves capable of spewing ignimbrite all over the landscape. We’ll start naming names next Sunday.
Generally speaking, there have been as many as 18 big eruptions from various sources in the Campanian volcanic province (Di Vito and others, 2008), in addition to the NYT and Campanian Ignimbrite.
What about the Campanian Ignimbrite?
The Campanian Ignimbrite was Europe’s largest eruption in at least the last 100,000 years.
As some of the very first humans arrived, about 39,000 years ago, Campania greeted them with an eruption column almost 30 miles high and what could be described as an “ash-bearing hurricane” (Pyle and others) that buried most of the plain hundreds of feet deep in pyroclastic flows, surged up over 3300-foot-high mountains to fill in high Apennine valleys, and blocked one of our ancestors’ major travel routes into Europe back then–the Danube River valley.
As a result, everyone seems to have cleared out of the region and then stayed away for hundreds to thousands of years, until the ground cooled and soil began to build up again.
Environmental effects from this massive ignimbrite eruption were once thought to have killed off the Neanderthals, but later research (Black and others) has shown that Neanderthals were already in decline at that point.
However, while difficult to reconstruct, those effects certainly weren’t something that ancient people–wherever they might live and however hardy they might be–could just shrug off:
The impact of such an eruption will be global and catastrophic. Ground-hugging ignimbrites will obliterate thousands to tens of thousands of square kilometres immediately around the caldera, whereas buoyant eruption clouds will propel volcanic ash and gas to altitudes of tens of kilometres. The coarser ash will rain out over millions of square kilometres, leaving the finer material and gas to be carried around the world by stratospheric winds. The floating ash and gas, notably the sulphur-rich components, will create an atmospheric haze that may reduce the mean global temperature by as much as 10° C for several months and maintain severe temperature distortions for decades thereafter . . .
— Troise, C.; De Natale, G., and Kilburn C. R. J. (see source list)
Chemical analyses of inclusions in the Campanian Ignimbrite suggest that this eruption could have released as much as 1.2 gigatonnes of sulfur into the atmosphere, or about 100 times the amount released by Philippine volcano Mount Pinatubo in 1991. This certainly would have cooled the planet, though exactly how much depends on the time of year because of Campania’s latitude. (Oppenheimer)
But there was another problem.
The Campanian Ignimbrite erupted towards the end of the last ice age, while Neanderthals and Europe’s first H. sapiens were also contending with:
. . . a cold phase due to a surge at the front of the North American ice sheet . . . causing a rapid and severe cooling of climate referred to as ‘Heinrich Event 4’. Thus, at the time of the Campanian Ignimbrite eruption, the Earth’s climate system may have been in an acutely sensitive phase, which could have accentuated the effects of the volcanic aerosol.
. . .
. . . While times of hardship and enforced stress may have disrupted traditional means of interaction within and between groups, they may, too, have stimulated sharing and transmission of information. These permutations in learning, understanding and ideology would have selectively affected the survivors according to their ability to adapt. In this respect . . . [some researchers] see the Campanian Ignimbrite as acting as a ‘filter and catalyst’ for human cognitive evolution–favouring innovation and cooperation.”
— Oppenheimer (see source list)
Did the Campanian Ignimbrite come from Campi Flegrei (source of the Neapolitan Yellow Tuff)?
Some geoscientists, including those who monitor local volcanoes, believe it did.
Others (Scandone and others, for example–see source list) suspect that Campi Flegrei was only a minor player and that most of the pyroclastic flows came out of fissures. Such a mechanism has been proposed for a much larger ignimbrite province that sits in a similar back-arc setting: Mexico’s Sierra Madre Occidental.
Big as it was, the Campanian Ignimbrite wasn’t the first or the last ignimbrite flow here.
Campania has been hosting volcanism for at least a million years thanks to the region’s complex geology and tectonic plate interactions.
This part of the world used to be an archipelago in a tropical sea called Tethys. Besides firing up the Campania Plain and closing off Tethys (turning it into the Mediterranean Sea), plate tectonics and associated processes have also raised limestones and other sedimentary rocks from those tranquil times up out of the basement.
They’re now cliffs that you can see in the video from roughly 30:15 on, when the narrator takes us along the Amalfitana Road.
And a little bit before that point, at about 27:07, is what I suspect might be a yellowish Campanian Ignimbrite deposit draped over a whitish limestone cliff.
Per Bellucci and others, other big ignimbrite eruptions in Campania have included:
- Two Seiano Ignimbrites, going back 290,000 and 240,000 years, respectively
- The Taurano Ignimbrite: 157,000 years ago
- The Durazzano Ignimbrite: 116,000 years ago
- The Giugliano Ignimbrite: 23,000 to 18,000 years ago
Not everyone is on board with that list.
Campania is one of the most geologically complex regions on the planet, and it’s very difficult to study because of the intense urbanization there. Experts sometimes come up with different interpretations of what little data can be collected there.
Too, each new eruption buries the rock formations that came before it, so older outcrops with clues about Campania’s geological history before the great Ignimbrite flow are hard to find.
It’s not all that unusual to find a volcanologist studying rocks in somebody’s cellar here! Deep drill holes also provide useful information, as well as assisting with seismic and volcanological monitoring.
Finally, the processes that produce and then erupt so much magma aren’t well understood yet. Such huge eruptions are very rare. None has occurred during the modern era of high technology, so volcanologists must use indirect methods like computer modelling to try to understand what’s going on underneath Campania (and the rest of the Central Mediterranean region).
What’s the risk right now?
Short answer: Very generally, at the time of writing (2019), the monitoring agency–Italy’s National Institute of Geophysics and Volcanology–reports that:
- Campi Flegrei shows “no elements to suggest significant short-term changes” (via Google Translate of week of February 12, 2019, bulletin).
- Vesuvius: the same, via Google Translate of January 2019 bulletin).
- Ischia: The same, via Google Translate of January 2019 bulletin, with the exception that the monitoring system here was damaged during a bad earthquake in 2017 and has not yet been fully repaired.
We’ll meet Ischia next. It’s a very popular travel destination, as well the least famous hazardous volcano near Naples:
Featured image: Castel dell’Ovo painting, via Wikimedia
Sources:
Agustí, J. and Antón, M. 2002. Mammoths, sabertooths, and hominids: 65 million years of mammalian evolution in Europe. Columbia University Press.
Bellucci, F.; Milia, A.; Rolandi, G.; and Torrente, M. M. 2006. Structural control on the Upper Pleistocene ignimbrite eruptions in the Neapolitan area (Italy): volcano tectonic faults versus caldera faults, in Volcanism in the Campanian Plain: Vesuvius, Campi Flegrei and Ignimbrites–Developments in Volcanology, 9, ed De Vivo, B., 163-180. Elsevier, Amsterdam/Oxford.
Black, B. A.; Neely, R. R.; and Manga, M. 2015. Campanian Ignimbrite volcanism, climate, and the final decline of the Neanderthals. Geology, 43(5): 411-414.
Branscombe, A. 2017. Deep drilling reveals puzzling history of Campi Flegrei Caldera. https://eos.org/research-spotlights/deep-drilling-reveals-puzzling-history-of-campi-flegrei-caldera Last accessed February 13, 2019.
Colella, A.; Di Benedetto, C.; Calcaterra, D.; Cappelletti, P.; and others. 2017. The Neapolitan Yellow Tuff: an outstanding example of heterogeneity. Construction and Building Materials, 136: 361-373.
Costa, A.; Folch, A.; Macedonio, G.; Giaccio, B.; and others. 2012. Quantifying volcanic ash dispersal and impact of the Campanian Ignimbrite super‐eruption. Geophysical Research Letters, 39(10).
De Vivo, B.; Petrosino, P.; Lima, A.; Rolandi, G.; and Belkin, H. E. 2010. Research progress in volcanology in the Neapolitan area, southern Italy: a review and some alternative views. Mineralogy and Petrology, 99(1-2): 1-28.
Di Vito, M. A.; Sulpizio, R;, Zanchetta, G.; and D’Orazio, M. 2008. The late Pleistocene pyroclastic deposits of the Campanian Plain: new insights into the explosive activity of Neapolitan volcanoes. Journal of Volcanology and Geothermal Research, 177(1): 19-48.
Fedele, F. G.; Giaccio, B.; Isaia, R.; and Orsi, G. 2002. Ecosystem impact of the Campanian ignimbrite eruption in Late Pleistocene Europe. Quaternary Research, 57(3): 420-424.
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Mason, B. G.; Pyle, D. M.; and Oppenheimer, C. 2004. The size and frequency of the largest explosive eruptions on Earth. Bulletin of Volcanology, 66(8): 735-748.
Milia, A.; Torrente, M. M.; Giordano, F.; and Mirabile, L. 2006. Rapid changes of the accommodation space in the Late Quaternary succession of Naples Bay, Italy: the influence of volcanism and tectonics, in Volcanism in the Campanian Plain: Vesuvius, Campi Flegrei and Ignimbrites–Developments in Volcanology, 9, ed De Vivo, B., 53-68. Elsevier, Amsterdam/Oxford.
Oppenheimer, C. 2011. Eruptions That Shook the World. Cambridge University Press.
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Flight To Wonder 