Let's Know Things

This month we talk about Tonga, the volcano explosivity index, and Mount Tambora.

We also discuss media coverage, the Yellowstone Caldera, and geothermal energy.

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Transcript

The Volcanic Explosively Index, or VEI, is a bit like a Richter scale for volcanoes—the Richter scale being a means of quantifying how strong an earthquake is, and the VEI representing a method for assessing the relative explosiveness of a volcanic eruption.

The VEI was developed in 1982, and goes from 0 to 8, with 0 being the lowest explosiveness level, and 8 being a staggering, world-changing eruption.

These numbers also have names, which are often used in lieu of numbers when volcanic eruptions are being reported in the press.

Zero is an effusive eruption which measurably happened, but which has a very small plume and doesn't put much or anything into the atmosphere, in terms of particulates and gases.

One is a gentle eruption, two is explosive, at which point we're getting into moderate levels of tropospheric injections of gases and particulates, but nothing in the stratosphere yet, three is a catastrophic eruption, where we maybe begin to see stratospheric materials, but possibly not, four is a cataclysmic eruption, where the plume is 10 kilometers (which is about 6.2 miles) or more in height, and there's a good deal of stuff in the troposphere and measurable quantities of gas and detritus being churned into the stratosphere, five is a paroxysmic eruption, which is primarily differentiated from a cataclysmic eruption by the scale of its ejecta—the quantity of stuff it spits out—which goes up by approximately an order of magnitude at each step, and at a VEI 5 we're seeing more than a cubic kilometer of ejecta, whereas a VEI of 6, which is called a colossal explosion, a 7 which is called super-colossal, and an 8, which is called a mega-colossal eruption, will spit out 10, 100, and 1000 cubic kilometers of ejecta, respectively, and all have plumes taller than 20 kilometers, which is not quite 12.5 miles tall, and will put somewhere between a lot and just a ridiculous amount of gas and particulates into the atmosphere, including high up in the atmosphere, where such things tend to linger and in some cases adjust the climate for long periods of time, due to the reflectiveness of all these gases and particulates: they bounce sunlight back into space, preventing it from entering the atmosphere and warming the planet.

This method of measuring volcanic explosiveness is useful for some purposes, especially for gauging the raw amount of power in a given eruption: if we can say this one was a 1 and this one was a 5, that allows us to estimate other things about these eruptions, even if those estimates won't be perfectly accurate for any specific eruption.

That lack of accuracy is the consequence of eruptions not being carbon copies of each other that occur at different scales: some eruptions produce a lot of gas but few particulates, some are slow, some fire like a bullet and then are done, some produce a lot of fire and magma, and some just churn out smoke and ash; some occur close to the surface, some start far below the surface, some happen on mountaintops, and some occur underwater.

We do get a pretty good sense of frequency from this kind of measurement system, though, as eruptions with a VEI of 0 are happening continuously, all day every day, around the world, 1's happen every day, and 2's occur every few weeks, somewhere on the planet.

8's, fortunately, only happen every 50,000 years or so, and in some periods even less frequently than that.

At this scale, VEI 8's, we're looking at volcanic eruptions that we only know about by the traces they've left in the geologic record: we see the calderas they've formed, the mountains they've collapsed, the lifeforms they've killed off—none of them human, because the only ones we know about happened before the historical record, the most recent of which having occurred in something like 26,500 BC on the North Island of New Zealand, and the most distant we've been able to confirm with a decent amount of evidence having happened in Central Utah sometime around 30,000,000 BC—but we've thankfully not been around for any VEI 8 volcanoes going off; it's almost certain if we were, a whole lot of lives would be lost, and the global tumult caused by such an explosion would result in untold secondary and tertiary consequences, like food shortages, incredibly bizarre weather patterns, mass die offs of species, and who knows what else.

For context, the largest and deadliest volcanic eruption that has happened in recorded human history is the eruption of Mount Tambora in Indonesia on April 10, 1815.

This was a VEI 7, and its eruption led to what became known as the Year Without a Summer the following year, 1816, which was a period of darkness and cold—in some cases record cold—and because of these anomalies there were mass food shortages across the Northern Hemisphere, causing famine in China, a disruption to the vital monsoon cycle across East Asia, snowfall in usually tropical Taiwan, famines in England and Ireland, a food crisis throughout mainland Europe, which in turn led to a surge in military conflict and brigandism—and that shortage of food and its accompanying period of ill-health caused by malnourishment is thought to have caused the typhus epidemic that spread around parts of Europe in 1816 and 1819.

Food shortages in New England, in North America, pushed many people out of the relatively populated parts of the continent Westward, as near-famine conditions elevated food prices sky-high, and acidic rains and ash falls even that far away from the volcano sparked many religious and spiritual movements, as did the unusually colorful skies.

Frankenstein was written this year, inspired in part by the foreboding darkness and cold, and the famous painting, The Scream, portrays the general attitude, and unusual skies, seen during this year following the eruption.

All of which is to say, a VEI 7 volcanic eruption is no laughing matter, and has consequences that extend far beyond the region directly impacted by the blast—which in this case was even worse off, as tsunamis wiped out many nearby islands completely, people and animals in the immediately vicinity were either killed by the shock wave of the explosion, by the saturating levels of ash, by the toxic gases emitted during the eruption, or by the pyroclastic flows, which are a deadly mix of rocks, gas, ash, and heat that rolls like a current from the volcano in all directions, killing anyone unfortunate enough to be caught in it.

The explosion of Mount Tambora was heard about 2,600 kilometers, which is about 1,600 miles away; and for context, it's just over 1,300 miles from London to Kiev, in Ukraine, so 300 miles further than that.

What I'd like to talk about today is a recent volcanic eruption that has dominated headlines for a few days, and take a look at some other, potential near-future volcanic hotspots.

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The article I'd like to start with today comes from Reuters, and it's entitled:

Tonga volcano eruption triggers tsunami warnings in Japan, Pacific islands

This was one of many pieces on this eruption, which is unusual, actually, as there are just a lot of eruptions happening all day, every day, and though they're mostly small, even medium-sized ones sometimes occur with little more than a below-the-fold mention in the popular press. And there are quite a few reasons for this, I think, but among them is that volcanos are not considered to be terribly relevant to the majority of people living on the planet, today, despite their destructive potential, and despite our lack of ability to do much of anything about them.

It's been posited that this latter attribute of volcanoes—that we don't have a serious means of stopping them—might be part of why they don't get the same amount of press as some other natural disasters.

There's an understood implication that if there's a blizzard, a tornado, a flood, these are things that we can immediately respond to with all sorts of preparations and safety-emphasizing behaviors. We might also be able to help tamp them down into more manageable permutations by reducing our greenhouse gas emissions or things of that nature.

Reducing our emissions won't help with volcanoes, though, and though there are a few efforts, based on a minuscule amount of research, oriented around drilling into the underground systems that feed a volcano all that stuff that eventually, otherwise piles up, pressurizes, and explodes, these are still very few, very experimental, and very uncertain in terms of whether they'll actually accomplish anything. It's a nice thought that tapping these underground resources might allow us to both generate geothermal energy and prevent the buildup of all that pressure, but it's not something we can say for certain will work yet, much less something we can actually accomplish in a reliable way.

A volcano, then, is more like an asteroid headed toward earth than a hurricane.

Thus, reportage on this topic tends to be less productive, in the sense that I suppose you could tell people to not build anything around volcanoes, but beyond that, there's not a lot of advice to offer, except for folks in the immediate vicinity, if it's a slow-erupting type of volcano. Otherwise, though, it's too little too late, and all you can really do on the ground is run—if you managed to survive the initial shock wave, flow of gases, and rain of ash.

Part of why this specific eruption has captured so many headlines, though, is that we were able to see its effects with unparalleled resolution—both in the sense of data-gathering, and in the sense of literally having images, from space, of its plume rising into the atmosphere and creating ripples, almost like chucking a rock into a pond, and seeing the effects of that impact rippling outward, but in this case on a global scale; which, frankly, despite the horribleness that often comes as a consequence of disasters on this scale, is just a remarkable piece of satellite-generated media. I'll link to some of these images, and animations made from them, stitched together, in the show notes, and if you haven't seen these yet, they're worth checking out—I think you'll understand why these images may have helped this particular eruption garner so much attention.

The location of this eruption is also relevant to its journalistic potency, I think, as it was located just off the coast of Tonga, which is a kingdom in Polynesia consisting of more than 170 mostly uninhabited islands, a bit north of New Zealand and close to Fiji and Samoa.

This is a nation defined by its coral reefs, its rainforests, and its low-lying islands.

As such, it's also ultra-vulnerable to the impacts of climate change, which is leading to the destruction of reefs and rainforests globally, but also causing oceanic levels to rise, and flooding, in some cases permanently or near-permanently, on exactly these types of islands.

What we have here, then, is a disaster blowing up a part of the world to which we're paying more attention right now, if often only in archetypical generalities, and that disaster is causing secondary disasters like tsunamis—giant waves—that are rolling through some of these inhabited islands, in addition to the uninhabited ones. Consequently, we've got livestream videos shot on phones and security cameras from some of the afflicted areas, and like the satellite images of the eruption, the media generated as a consequence of this is just staggering and frightening and unbelievable in the same fashion as a train wreck: you can't look away.

As mentioned in that Reuters piece, tsunami warnings were also issued for other Pacific islands, for Japan, for Australia and New Zealand and the west coast of the United States and parts of South America.

It's still early days, but it's already been reported that several people have drowned as a consequence of large waves washing up in the Americas, and we've yet to get good numbers from Tonga itself and the surrounding islands, as many communication services are down as of the day I'm recording this, and relief flights have had trouble landing because of all the ash, in the air and on local runways, but it's a fair bet there will be quite a few deaths and injuries, alongside all the infrastructural damage, there, as well.

The 21st century, thus far, has been pretty fortunate—all things considered—when it comes to volcanic eruptions.

We've have a fair number of VEI 4s, including one in Iceland that famously disrupted European air traffic for several weeks and one that killed 39 people in the Philippines.

There was a VEI 5 in Chile in 2011, which disrupted flights in the Southern Hemisphere for a while, but beyond that we hadn't seen something that officially measured up to that VEI level in recent memory; again, this is an imperfect system that measures only certain things, and many of the 1's, 2's, and 3's of the 21st century were more deadly or destructive than the 4's and 5's, because of where they were located, their emissions, or because of their adjacency to humanity or other life.

Initial assessments of the Tonga volcano suggest it might be a VEI 5 once all the data rolls in; at the moment this is not confirmed, and there's a chance there could be further eruptions following the currently most explosive one that occurred on January 14th and 15th, but right now it seems like this eruption is putting relatively less gas and other materials into the atmosphere than other, recent, big eruptions, but that the explosiveness of its eruption—the shockwave it send around the world—was substantial, in part because it was underwater, but located just close enough to the surface that it wasn't significantly dampened by too much earth above it, which allowed it to vaporize surrounding water near-instantly, turning it into steam, which amplified the eruption's shock wave.

So as I mentioned earlier, eruptions differ in many ways, and this one would seem to have been especially loud, but less impactful in terms of emissions—thus far, at least.

So while VEI numbers are still being tossed around and debated, it could end up with a relatively lower or higher number, depending on how much weight is given to these specific attributes, once all the data is parsed.

This volcano has been long-watched, as it's simmered in the past, and was actually doing quite a lot of simmering leading up to this main explosion, beginning in December 2021.

But there are numerous other volcanoes around the world that are being actively monitored, because they seem likely, according to various criteria, to erupt at some point in the relatively near-future, and because if they do, they could either be especially powerful, or cause a lot of damage because of their location.

Of the currently active volcanoes we know about, Mauna Loa, which is one of the volcanoes that make up Hawaii, is considered to be the largest, and has historically been quite active.

Much of that activity, fortunately, has been non-explosive in nature: it bubbles up lava, which is neat to look at and generally less destructive than the alternatives.

Its most recent eruption was back in 1984, though it's been actively monitored since 1912, in large part because it's so close to so many humans, and because it has a measurable history of periodically erupting explosively and powerfully.

It's one of sixteen volcanoes that fit criteria established by the International Association of Volcanology and Chemistry of the Earth's Interior as part of a UN program to identify what they call Decade Volcanoes, worthy of further study in order to avoid future devastation by these natural processes, and though that program never got full funding and thus, never really accomplished the full expanse of research they wanted to achieve, they were able to get a bunch of smaller programs going, and bring international attention to this, and fifteen other volcanoes considered to be worth watching located around the world.

Also on this and similar watch-lists are Mount Fuji in Japan, Mount Hood in the US state of Oregon, Mount Paektu in North Korea, Mount Ruapehu in New Zealand, Tungurahua in Ecuador, and Anak Krakatoa in Indonesia, whose name means "Child of Krakatoa," Krakatoa being the site of one of the biggest eruptions to have occurred in recent history, and which formed this smaller volcano in 1883, post-eruption—and this new volcano is considered to be unpredictable in a worrying way, like its predecessor.

There's another potentially devastating volcano that receives a bit more press, in part because of its association with a well-known national park, called the Yellowstone Caldera.

And this volcano, we know from geologic records, erupted something like 640,000 years ago, as has been—since we've been tracking it, at least—increasing in elevation by as much as 6 inches, which is about 15.24 centimeters, a year, which is an imperfect and indirect, but often utilized means of estimating the pressure inside the magma chamber beneath this type of feature.

That said, most experts say that reporting about this caldera is more hyperbolic than actually worrying, as pressure measurements have been decreasing, the pressure in the magma chamber isn't directly correlated with eruption, and much of the reporting was predicated on the false idea that volcanoes can be "due" for eruptions after a certain period of time, which isn't the case.

More likely than volcanic eruptions at Yellowstone, it would seem, are hydrothermal explosions, which are a separate thing that are also destructive, but usually in a different, less globe-influencing way that massive volcanoes. You wouldn't want to be near one, but it's less likely to lead to acid rain and famine if it happens, even on a large scale.

That reporting upon, and general sense of explosive inevitability surrounding, Yellowstone, is actually a useful template for what we often see with other volcanoes; especially big ones, and especially ones that haven't erupted in a while, but which are technically still active, with the requisite might-blow-up-at-some-point conditions still in place.

Yes, these volcanoes could go off at any time. No, we're not great and knowing when. Yes, folks in volcanically active regions tend to be aware of that risk and are as prepared as anyone can be for such a disaster, but no, not as aware and prepared as they might be, especially in cases where the volcanoes haven't erupted, or haven't erupted in a big way, in a generation or more.

This is why programs like that one introduced but not sufficiently funded by the UN are considered to be important by folks in this space: because it should help us better understand these geologic happenings in a way we don't yet, but need to if we're going to learn to predict them more effectively, and learn to live with them in the way we'll eventually have to, as they don't seem likely to go away any time soon, our planet still being internally active, and likely to remain so long into the future.

It's anyone's guess as to whether this educational undertaking will happen any time soon, though, as there are plenty of other disasters that are perceptually more pressing, and even those aren't getting what they arguably should be getting if we're taking them seriously as a globe-spanning species—so it could be that a Big One volcano goes off and redirects some of that funding, but until and unless that occurs, and the potential danger represented by these things is made abundantly clear and politically viable to address, there's a good chance they'll remain fairly random-seeming and spectacular, in the sense of being media-driven spectacles, rather than being fully-understood natural events we can learn to live with and maybe even ameliorate to some degree.

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Show Notes

https://www.reuters.com/business/environment/tonga-volcano-generates-tsunami-us-tsunami-monitor-said-2022-01-15/

https://en.wikipedia.org/wiki/Volcanic_Explosivity_Index

http://ete.cet.edu/gcc/?/volcanoes_explosivity/

https://geology.com/stories/13/volcanic-explosivity-index/

https://en.wikipedia.org/wiki/List_of_largest_volcanic_eruptions

https://en.wikipedia.org/wiki/List_of_large_historical_volcanic_eruptions

https://en.wikipedia.org/wiki/Year_Without_a_Summer

https://en.wikipedia.org/wiki/1815_eruption_of_Mount_Tambora

https://www.usgs.gov/faqs/can-we-drill-yellowstone-stop-it-erupting

https://www.discovermagazine.com/planet-earth/major-blast-in-tonga-create-tsunami-and-heavy-ash-fall

https://www.bbc.com/news/world-asia-60007119

https://thehill.com/changing-america/resilience/natural-disasters/553219-scientists-urge-eruption-plan-as-worlds-largest

https://blogs.scientificamerican.com/rosetta-stones/the-underappreciated-threat-of-volcanic-tsunamis/

https://en.wikipedia.org/wiki/Mauna_Loa

https://www.npr.org/2022/01/15/1073328387/tonga-hit-by-tsunami-after-undersea-volcano-eruption

https://en.wikipedia.org/wiki/Decade_Volcanoes

https://en.wikipedia.org/wiki/List_of_large_volcanic_eruptions_in_the_21st_century

https://en.wikipedia.org/wiki/2022_Hunga_Tonga_eruption_and_tsunami

https://www.insider.com/volcanoes-around-the-world-that-could-erupt-2020-2#mount-yasur-vanuatu-10

https://en.wikipedia.org/wiki/Yellowstone_Caldera

https://twitter.com/hausfath/status/1482467701436006400

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