system
A chat on subreddit /r/me_irl
human
As a volcanologist/seismologist I’m with you that volcanoes are sick. I just always make a point to be the “uhhhmmmm ackshually” guy when I see people use the word overdue to describe eruptions and earthquakes because it’s usually a broad mis-characterization of how those things work to make a scarier headline/YouTube title. I’ve made a point to do this because I have a friend who gets actual anxiety attacks because she’s read too many “YELLOWSTONE WILL ERUPT SOON ITS 250,000 YEARS OVERDUE” headlines. It makes me genuinely sad that there’s people walking around terrified of Yellowstone all day because us geologists (as a field) tend to kind of suck ass at communicating with the public and there’s very few resources out there to combat the popular narratives, at least compared to other science fields.

Edit: Yellowstone is ridiculously well studied. There’s tons of real time instrumentation, including seismic stations to detect increases in the amount and size of earthquakes above the background level that is normal for Yellowstone, GPS to track ground inflation, all kinds of different things for detecting gas emissions from the volcano (a increase or decrease in emission of certain gasses can reflect movement of magma underground). It is exceptionally likely that were Yellowstone to begin a catastrophic eruption (note that it has produced many small eruptions since the caldera forming one 640,000 years ago), we would have a shit ton of warning. 

A common misconception about magma chambers is that they’re a big pool of lava underground, Minecraft style. In reality they’re just a big zone of partially melted rock where some minerals have a low enough temperature melting temp to be melted and others don’t. The preferred term in science now is “mush zone” but that’s hard to communicate so we just say magma chamber anyway. It’s kind of comparable to sand at the beach. The sand farther from the water feels wet but you couldn’t actually squeeze water out of it. The sand close to the water is very wet and if you stomp on it, you can get water to pool up at the surface. That’s sort of how extracting magma from a chamber works. The liquid exists in the gaps between solid material, called the pore space, and if the percentage of liquid is high enough (it’s super super complex and I’m not that qualified, I know people who’ve spent entire careers studying melt extraction), there’s enough free space for the liquid to build a connected network and move even tho the rock isn’t completely melted. Now, there’s no magic percentage for melt fraction necessary to extract large amounts of magma (of the specific chemical composition that causes explosions by the way, that’s another fucking complex topic), but let’s say ballpark you need something like 30-40% for Yellowstone to erupt. We can estimate the melt fraction beneath Yellowstone by using distant earthquakes. Seismic waves travel different speeds in different things. By comparing the arrival times of waves from an earthquake at seismic stations in an area you can build an image of where the subsurface is relatively slow and fast and then use that as an analogue for what the geology is. Seismic waves are slowed down by liquids, certain types more than others. That’s how we know the shape and volume of the magma chamber, roughly at least. You can also use it to estimate melt fraction… which is a total shit show that changes all the time what’s actually valid or not. For a long time, the estimated melt fraction at Yellowstone was very low, like 6-10%. A paper a few weeks ago suggested we’ve been fucking it up the whole time and it’s actually more like 15% was a pretty convincing read to me. Either way, significantly lower than the amount needed to generate an eruption. How long would more melting take? A long ass time. Years - dozens, hundreds, thousands, tens-hundred of thousands depending on a shit ton of other complex factors. Either way, likely a long ass time. I’ve read pretty good papers suggesting that the Yellowstone hotspot isn’t even hot enough anymore to generate the huge eruptions that it has in the past. 

TL;DR Yellowstone almost certainly won’t erupt for many lifetimes, possibly never again, and if it did we would have a shit ton of warning. Fuck lazy news outlets making people anxious about imminent volcano death for clicks
gpt
Neat! An actual expert! Thanks for dropping some knowledge lol. I’m endlessly fascinated, my grandpa got me into it. My grandpa has a phd in geology but he got that degree when tectonic plates were still just a theory lol so our conversations are a little… dated 😅

I don’t actually have much anxiety about the idea of a catastrophic event happening though I understand why people do. I just think it’s a neat idea lol. 🤷‍♀️ 

Honestly my favorite fun fact about volcanoes… did you know that ice volcanoes exist??? So that’s a thing lol. There used to be at least one on Earth but now the closest ice volcano is on Io, one of Jupiters moons iirc. And it’s exactly what it sounds like lmao, a volcano of ice. It’s erupts water and rock and huge boulders of ice. Oh, and they erupt gases so toxic, it’ll strip the flesh off your bones… 💀☠️