Stromboli Volcano Eruption Update; Pyroclastic Flows Reach the Sea

I want to note that the density calculation I made for a pyroclastic flow utilized figures and densities given in this scientific paper: Dellino, P., Dioguardi, F., Isaia, R. et al. The impact of pyroclastic density currents duration on humans: the case of the AD 79 eruption of Vesuvius. Sci Rep 11, 4959 (2021). doi.org/10.1038/s41598-021-84..., CC BY 4.0 license. (This license is linked in this video’s description). It is a good read, and I recommend checking it out. Of course, pyroclastic flow densities do widely vary (some are far more pumice rich), and part of this has to do with the density of erupting material. Basalt (lower silica) = higher density, rhyolite (higher silica) = lower density.

That is best analysis of a pyroclastic flow I have heard in memory. The super heated gas of a pyroclastic is an impressive display of its lethality. I really liked hearing about the gas, particulate water and air concentrations to better appreciate what makes up a pyroclastic flow.

A friend of mine was on a ridge less than twenty miles from Mt.St. Helens on May 18th, 1980 and watched and filmed as gas and ash shot into the sky. He told me afterwards that he didn’t realize he was any danger. He saw great amounts of ash begin to tumble, then race down the mountain. Even then he said he didn’t realize that what looked like harmless, if impressive, clouds of gas might be hot. But he said to his horror, when the front edge of the ash and gas reached the foothills it instantly lit the forest there afire before engulfing the flatter landscape in billowing clouds of what he now realized was lava-hot gas. He turned and ran downhill, away from the clouds of ash. He told me there were a number of ridges between the mountain and his ridge. Afterwards he went back and looked at the area. The pyroclastic flow had flattened and burned every bit of forest up to his ridge. He said he was probably less than a mile from the death zone. Even so he says, he was burned and choked and only just survived.

I learn something new every time I listen to this channel. You're easy to understand explanations are exceptional. Thanks very much.

I spent 24 hrs on the summit as a geologist, recording the eruptions' frequency and scale, collecting samples . Knowing the weather forecast and wind direction is vital though. Eruptions of 5 - 20 seconds duration, averaged at intervals of 15 minutes, shortest interval 7 minutes, longest 37 Approaching to the very rim of the vent was not an option. Awesome through the night experience. Wednesday's eruptions are on a much larger scale.

Thanks as always! The footage is fascinating, but also nerve-wracking at the same time. This recent pyroclastic flow reminds me of a similar pyroclastic flow that occurred, if I remember correctly, October of 2022. Thanks for the information regarding the thermal conductivity! I sometimes though about it. The way this pyroclastic flow traveled over water is also interesting. While orders of magnitude larger, there was a study that suggested that Krakatau's 1883 pyroclastic flows traveled so far because they were able to "ride" on a coat of steam created by their heat.

I really appreciate your explanations of various geology processes!! Awesome to have this video!!! Thank you GH!!

Really interesting video - I've been to Stromboli twice. First time it was too active to climb up to the top and had to settle for pizza Stromboli (it's a hot one) and the best firework show on earth... second time was for the sunset show from the summit...fantastic! Go if you are lucky enough to be able to do so...

I always wondered about the composition of pyroclastic flows. Thank you for including that!

Iceland: look at my eruptions! Aren't they cool? Italy: hold my beer, here are 2000ft fountains at Etna and a pyroclastic flow at Stromboli

This is the best explanation of the dangers of pyroclastic flows I've yet seen. Thank you.

we climbed stromboli some 20 years ago and spent 40 minutes at the summit opposite this erupting vent. Our guide told us that 40 minutes was the maximum as beyond that point statistically the chance of being killed by a larger eruption or by a large lava bomb significantly increased.

I'm sure the Leidenfrost effect plays a major role in how easily these flows glide across the water. It's riding on a layer of steam much like an air hockey puck rides on a layer of air.

Mt. Pelee on Martinique is the perfect example of why you don't mess around with pyroclastic flows. Humans who have probably have a survival rate starting with a decimal. 😵 🌋 💀

Dry standing air is one of the best thermal insulators *afaik Thx for all the information you share, much appreciated!

Especially with the warmer flows, the air temperature is enough to fry you, let alone the rock fragments. Part of my job is putting organic material in a 550°C oven (1022 °F), and it chars pretty much instantly. Your skin would take a bit longer because of the moisture content, but not much.

The side by side video of the flow crossing the water was awesome!! Loved seeing the thermal image.

Thanks for explaining in layman terms the science behind pyroclastic flow densities - I had no idea. It is stuff like this that makes your channel my primary go-to video channel when finding out about volcanism past, present, the processes, outcomes and so forth. Cheers!

Wow, I wouldn't want to be fishing too near the shore at Stromboli!🥵

I remember back in 2007, Stromboli had this massive eruption, tons of lava, etc. It motivated me to get on a plane to see it for myself. But by the time I got there (2 months later), the most reliable (arguably) volcano for eruption predictability and frequency IN THE WORLD had stopped erupting, and stayed that way for basically the whole summer. So if this increase in eruptive activity is making you want to go to see this legendary volcano, maybe hesitate. It's a cool climb, even when it's not erupting (actually, when I was there, the summit was off-limits to anyone, guide or no guide, but I climbed anyway), but still probably better when you can see it in action. But episodes which disrupt the status quo at Stromboli (i.e. which allow for a lot of magma to be released at once, rather than its usual, small and frequent eruptions) can often (as I've since learned) lead to weeks or months of low-to-no activity. So unless you're actually in Italy, or can pack up and get there in the next couple weeks, maybe wait until the steady-state behavior returns again before planning a trip. Or go somewhere else. Yasur in Vanuatu is reliable, but a lot harder and more expensive to get to (for most people...maybe Aussies and Kiwis can make a go of it though). Umm...Fuego in Guatemala's a good one, and it's close to the USA (although summer's a bad time to visit Guatemala - a lot of rain, landslides, etc....still, seeing a volcano erupt a few times an hour is a good reason to go). I have heard though, that it has gotten pretty popular with tourists, so that perhaps dozens of people per day are camping on Acatenango, and hiking over to the ridge connecting the volcanoes. So that sucks. And who knows what's going to happen in Iceland over the summer...again though, lots and lots of tourists (especially in summertime)?