The pressure cooker

It will come as no surprise to regular readers of Skeptophilia that I have a peculiar fascination for things that are huge and powerful and can kill you.

I'm not entirely sure where this obsession comes from, but it's what's driven me to write here about such upbeat topics as giant predatory dinosaurs, tornadoes, hurricanes, massive earthquakes, supernovas, gamma-ray bursters, and the cheerful concept of "false vacuum decay" (which wouldn't just destroy the Earth, but the entire universe).  I'm guessing part of it is my generally anxiety-ridden attitude toward everything; after all, just because we don't think there's a Wolf-Rayet star nearby that's ready to explode and fry the Solar System doesn't mean there isn't one.  I know that worrying about all of that stuff isn't going to (1) make it any less likely that it'll happen, or (2) make a damn bit of difference to my survival if it does, but even so I don't seem to be able to just relax and focus on more positive things, such as the fact that with the sea-level rise predicted from climate change, it looks like here in upstate New York I may finally own ocean-front property.

It's also why I keep regular tabs on the known volcanoes on the Earth -- on some level, I'm always waiting for the next major eruption.  One of the potentially most dangerous volcanoes on Earth is in Italy, and I'm not talking about Vesuvius; I'm referring to the Campi Flegrei ("burning fields," from the Greek φλέγω, "to burn"), which isn't far away from the more famous mountain and seems to be powered by the same magma chamber complex that obliterated Pompeii, Herculaneum, and Stabiae in 79 C.E.  Both Vesuvius and the Campi Flegrei are highly active, and near the top of the list of "world's most dangerous volcanoes."

The problem is, the three million residents of Naples live right smack in between the two, only twenty-odd kilometers away from Vesuvius (to the east) and Campi Flegrei (to the west).  (For reference, Pompeii was nine kilometers from the summit of Vesuvius.)

The Campi Flegrei, looking west from Naples [Image licensed under the Creative Commons Baku, VedutaEremo2, CC BY-SA 4.0]

The problem is that volcanoes like these two don't erupt like the familiar fountains of lava you see from Kilauea on the Big Island of Hawaii, and the recent eruption on La Palma in the Canary Islands and the one near Grindavík in Iceland.  The most typical eruption from volcanoes like Vesuvius and Campi Flegrei are pyroclastic flows -- surely one of the most terrifying phenomena on Earth -- a superheated mass of steam and ash that rush downhill at speeds of up to a hundred kilometers an hour, flash-frying everything in its wake.  That the Campi Flegrei volcanoes are capable of such massive events is witnessed by the surrounding rock formation called the "Neapolitan Yellow Tuff."  A "welded tuff" is a layer of volcanic ash that was so hot when it stopped moving that it was still partially molten, and fused together into a solid porous rock.

A video of a pyroclastic flow from Mount Unzen in Japan in 1991

The Neapolitan Yellow Tuff isn't very recent; it came from an eruption about 39,000 years ago.  But there are signs the Campi Flegrei are heating up again, which is seriously bad news not only for Naples but for the town of Pozzuoli, which was built right inside the main caldera.  The residents of Pozzuoli have had to get used to regular rises and falls of the ground, some by as much as an alarming two meters.  In fact, between 1982 and 1984, there was so much uplift -- followed by magnitude-4 earthquakes and thousands of microquakes -- that the harbor became too shallow for most ships to dock, and the entire population of forty thousand was evacuated until things seemed to simmer down.

In fact, the reason the topic comes up is a study out of Stanford University and the University of Naples that appeared this week in the journal Science Advances, that found this terrifying swell-and-subside isn't due primarily to magmatic movement, as was feared -- it's the bubbling of superheated groundwater.  The study looked at the composition of the "caprock," the rock layer on top of the formation, and found that when mixed with hot water it forms something like a natural fibrous cement.  This then plugs up cracks and prevents groundwater from escaping.

The whole thing is like living on the lid of a giant pressure cooker.

Of course, unlike (I hope) your pressure cooker, the rock doesn't have the tensile strength to manage the pressure fluctuations, so ultimately it breaks somewhere, triggering an earthquake and steam eruptions, after which the caprock settles back down for a while until the cracks all reseal and the pressure starts to rebuild.

This is all pretty scary, but it does point scientists in a direction of how to mitigate its potential for harm.  "I call it a perfect storm of geology -- you have all the ingredients to have the storm: the burner of the system -- the molten magma, the fuel in the geothermal reservoir, and the lid," said Tiziana Vanorio, who co-authored the study.  "We can't act on the burner but we do have the power to manage the fuel.  By restoring water channels, monitoring groundwater, and managing reservoir pressure, we can shift Earth sciences toward a more proactive approach -- like preventive health care -- to detect risks early and prevent unrest before it unfolds.  That's how science serves society."

Which is all very well, but I still wouldn't want to live there.  I visited Italy last year and loved it, but the area around Naples -- that'd be a big nope for me.  When we were in Sicily, itself no stranger to seismic unrest, one of our tour guides said, "We might be taking a risk living here, I suppose.  But those people up in Naples -- they're crazy."

That anyone would build a town on top of an active volcano is explained mostly by the fact that humans have short memories.  And also, the richness of volcanic soils is generally good for agriculture.  Once Pompeii was re-discovered in the middle of the eighteenth century, along with extremely eerie casts of the bodies of people and animals who got hit by the pyroclastic flow, you'd think people would join our Sicilian tour guide in saying, "no fucking way am I living anywhere near that mountain."  But... no.  If you'll look at a world map, you might come to the conclusion that siting big cities near places prone to various natural disasters was some kind of species-wide game of chicken or something.

Not a game I want to play.  Such phenomena make me feel very, very tiny.  I'm very thankful that I live in a relatively peaceful, catastrophe-free part of the world.  Our biggest concern around here is snow, and even that's rarely a big deal; we don't get anything like the killer blizzards that bury the upper Midwest and Rocky Mountain states every year.  Given my generally neurotic outlook on life, I can't imagine what I'd be like if I did live somewhere that had serious natural disasters.

Never leave my underground bunker, is probably pretty close to the mark.

****************************************

Brain of glass

Because my other option is to go on a crazed rant about how my country is being run by an amoral sociopath, and about how even given that fact thirty-some-odd percent of Americans still support him and/or idolize him, I decided to look instead at a more cheerful topic: the remains of a young man who got fried by Mount Vesuvius on August 24, 79 C.E.

That eruption gives new meaning to the word "colossal."  It was what geologists call a Plinian eruption -- named, in fact, for author and philosopher Pliny the Elder, who was also killed that day -- one that instead of producing the fountains of lava you see from volcanoes like Kilauea, produces pyroclastic surges composed of ash and superheated air that can reach speeds of one hundred meters per second and temperatures over a thousand degrees Celsius.

In other words, once you see it coming, it's too late to do much besides sticking your head between your legs and kissing your ass goodbye.

(If you want to watch a fantastic -- if terrifying -- ten-minute simulation of what Vesuvius would have looked like from Pompeii on the fateful day, check this out.)

In any case, the eruption in 79 C. E. killed at least twenty thousand people -- probably more -- and released an unimaginable amount of energy in a very short time, estimated to be one hundred thousand times more than the atomic bomb that destroyed Hiroshima.  The city of Pompeii was basically flattened where it stood, and its inhabitants flash-cooked and then encased in ash, which is why researchers have found molds and casts of human bodies (and one dog), still in the positions they were in when they died.

This discovery, though -- the news of which I once again owe my pal Andrew Butters, author and blogger over at Potato Chip Math -- is unique, and is as fascinating as it is gruesome.  A team at University of Naples Federico II discovered the remains of a twenty-five-year-old man in a temple in Herculaneum dedicated to the Emperor Augustus.  He was face down, still lying where he fell.  But when the researchers took a look inside his skull, they got a surprise.

His brain had turned to glass, so quickly that his individual neurons are still visible.  Pier Paolo Petrone, who led the research, said in an interview with CNN, "The brain exposed to the hot volcanic ash must first have liquefied and then immediately turned into a glassy material by the rapid cooling of the volcanic ash deposit."

Here's how the team explains what happened, in their paper, that appeared last week in the journal PLoS-One:

In AD 79 the town of Herculaneum was suddenly hit and overwhelmed by volcanic ash-avalanches that killed all its remaining residents, as also occurred in Pompeii and other settlements as far as 20 kilometers from Vesuvius.  New investigations on the victims' skeletons unearthed from the ash deposit filling 12 waterfront chambers have now revealed widespread preservation of atypical red and black mineral residues encrusting the bones, which also impregnate the ash filling the intracranial cavity and the ash-bed encasing the skeletons.  Here we show the unique detection of large amounts of iron and iron oxides from such residues, as revealed by inductively coupled plasma mass spectrometry and Raman microspectroscopy, thought to be the final products of heme iron upon thermal decomposition.  The extraordinarily rare preservation of significant putative evidence of hemoprotein thermal degradation from the eruption victims strongly suggests the rapid vaporization of body fluids and soft tissues of people at death due to exposure to extreme heat.

Without further ado, here's a microphotograph of the neurons they found:

Vesuvius remains one of the most dangerous volcanoes in the world, and will have another large eruption at some point -- not if, but when.  And this time, it isn't a couple of towns with twenty thousand folks in the bullseye; right downslope from Vesuvius is the city of Naples, which has just shy of a million inhabitants.

The good news in all this is that volcanologists have gotten much better at detecting the danger signals prior to an eruption -- much better than, for example, the seismologists have of predicting when an earthquake might occur.  But as humans have shown time and time again, we really suck at taking the advice of scientists, preferring instead the reassurances of people who honestly don't know what they're talking about, and the time-honored maxim of "everything will be fine, just like it always is."

Which brings us full circle to Donald Trump and his brazen, idiotic, selfish *Gordon lapses into mumbled obscenities* comment not to be "afraid of COVID" or "let it dominate your life."  Despite the fact that worldwide, a million people have died (i.e. the population of Naples), and twenty percent of those have been in the United States.

Okay, I feel a rant coming on again, so I better stop here. 

**********************************

One of my favorite TED talks is by the neurophysiologist David Eagleman, who combines two things that don't always show up together; intelligence and scientific insight, and the ability to explain complex ideas in a way that a layperson can understand and appreciate.

His first book, Incognito, was a wonderful introduction to the workings of the human brain, and in my opinion is one of the best books out there on the subject.  So I was thrilled to see he had a new book out -- and this one is the Skeptophilia book recommendation of the week.

In Livewired: The Inside Story of the Ever-Changing Brain, Eagleman looks at the brain in a new way; not as a static bunch of parts that work together to power your mind and your body, but as a dynamic network that is constantly shifting to maximize its efficiency.  What you probably learned in high school biology -- that your brain never regenerates lost neurons -- is misleading.  It may be true that you don't grow any new neural cells, but you're always adding new connections and new pathways.

Understanding how this happens is the key to figuring out how we learn.

In his usual fascinating fashion, Eagleman lays out the frontiers of neuroscience, giving you a glimpse of what's going on inside your skull as you read his book -- which is not only amusingly self-referential, but is kind of mind-blowing.  I can't recommend his book highly enough.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]