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volcano

Late again: Monday volcano

Two weeks in a row. I’m such a failure.

This week: Sakurajima

Sakurajima (literally “cherry blossom island”) is not quite an island; it’s connected to the rest of Kyuushuu on one side by a bunch of lava flows that occurred in 1914. But the “island” itself is basically a volcano poking up in the middle of Kagoshima bay.

Sakurajima’s lava output is mostly andesitic or dacitic in composition; it’s an intermediate composite volcano, which means it tends to have the impressive explodey eruptions and pyroclastic flows.

And more volcanic lightning.

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volcano

More volcanic lightning

Check out today’s astronomy picture of the day. Very cool picture, and different from a lot of the other pictures of volcanic lightning I’ve seen since this one lacks the really striking, ash-filled plume.

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volcano

(Very belated) Volcano for Monday

It’s Tuesday, and I just remembered that I forgot to find a deadly geological hazard for Monday. Mea culpa.

The Soufriere Hills volcano in Montserrat has a minor explodey incident last Friday. For ignorant Americans like myself, Montserrat is a little island nation in the Caribbean, which we’ve been so recently and strongly reminded is quite the tectonically active area.

Soufriere Hills is an andesitic volcano, and if you check the page I’ve linked above, it’s done some impressive blowing up in the past. The page is actually incredibly detailed about the volcano’s history and it’s quite the interesting read. Anyway, the good news about the recent small eruption is that no inhabited areas were affected and the pyroclastic flows didn’t reach more than 2 km.

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volcano

Volcano for Monday

Mount Rainier is an absolutely gorgeous stratovolcano that has its own national park, and is in fact not threatening to explode at any moment.

Fun fact: Mount Rainier is the grandaddy of the Cascade volcanoes, the tallest of the bunch.

Actually, the hazard that Mount Rainier is currently presenting is of a different geological variety: like basically every mountain in the US, its glaciers are in serious retreat1and that is clogging the downstream areas with all manner of sediment. The article mostly focuses on flood risks – which are a big concern when there are people living nearby. There’s also a minor mention about fish habitat, which can also be severely altered by changes in sediment load.

Mount Rainier’s glaciers being in retreat also makes me quite sad for aesthetic reasons. Part of the beauty of these big mountains is then they’re got their white cap on, all year round. Some day soon, we may not see that any more.

1 – You know, because of that global warming thing that totally isn’t happening because it was cold outside today.

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volcano

Volcanic lightning

You can got a lot of extremely cool pictures out of a volcanic eruption. Giant Exploding Things That Could Kill You are always incredibly photogenic for some reason. But I think the coolest eruption pictures are the ones that involve lightning, such as this picture of the Chaitén Volcano erupting in Chilé.

Actually, I hadn’t thought about it much until I saw this article, and this interesting observation:

“The seismometers were actually picking up lightning strikes,” said McNutt. “I knew that I had to reach out to the physicists studying lightning.”

That’s just cool – lightning produced by the eruption was adding seismic noise with ground strikes.

Volcanic lightning would be a pretty interesting thing to study; the mechanism by which it forms is even less well understood than normal lightning. A possible model here at geology.com. Even more interesting is this article I found from last year, looking at the behavior of volcanic plumes.

A volcanic plume consists of a vertical column of hot gases and dust topped by an umbrella-like structure. A volcanic mesocyclone sets the entire plume rotating, causing it to spawn waterspouts or dust devils and group together the electric charges in the plume to form a sheath of lightning.

So basically, if you don’t get cooked by a pyroclastic flow or burned up by magma or simply nailed in the head by flying debris, don’t start feeling too good about yourself. The atmosphere might just try to kill you anyway.

Gosh, I love volcanoes.

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volcano

Volcano for Monday

Philippines’ Mayon Volcano to explode ‘within days’ – alert status has been moved from three to four, which means that an eruption is imminent. Five is when the volcano is actually erupting. Expect to see some pretty pictures of the full fury of the Earth unleashed soon, I’d say.

“Audible booming and rumbling sounds were first reported in the eastern flank of the volcano” Sunday afternoon, and 1,942 volcanic earthquakes were detected by the institute’s seismic network in the 24 hours to 7 a.m. local time on Monday (6 p.m. ET on Sunday), the institute said.

Yikes. Mayon is a stratovolcano, like Mount St. Helens, which means it will tend to have eruptions of the explodey variety since its magma is viscous and doesn’t allow gases to escape very effectively.

I’m kind of curious what the sulfur dioxide output it looking like for Mayon. The most recent PHIVOLCS report (from January 20) has it at 1051 tons per day. Sulfur dioxide often degasses out of magma, so a sudden jump in sulfur dioxide output is a sign that there’s a lot of fresh magma coming in to the area. Apparently its previous output was around 350-500 tons per day which makes 1051 a pretty significant jump.

For comparison, the last time Mount Pinatubo blew up (in 1991), the sulfur dioxide output went from 500 tons per day to 5000 tons per day.

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hoax volcano

Diappointed that it’s not the end of the world?

I know I’ve complained about this before. And I know it can’t possibly be getting on my nerves as badly as it might get on the nerves of the scientists at the Yellowstone Volcano Observatory. But still, is it me, or does Time magazine’s short article come across as just a little disappointed that we’re not all in danger of imminent fiery death? I think the question mark at the end of the article’s title (“Nothing to Fear?”) is what does it.

Yellowstone is in a very tectonically active region, whether or not there’s a giant magma monster lurking below the surface, ready to leap out and kill us all. From the YVO:

Although some quakes are caused by rising magma and hot-ground-water movement, many emanate from regional faults related to crustal stretching and mountain building. For example, major faults along the Teton, Madison, and Gallatin Ranges pass through the park and likely existed long before the beginning of volcanism there. Movements along many of these faults are capable of producing significant earthquakes.

It’s not a surprise to see things still shifting and re-shifting in the area. Admittedly, the whole thing could blow out in a massive steam explosion tomorrow and make life extremely unpleasant for anyone in the immediate area, but it is also important to note that tectonic activity in Yellowstone doesn’t necessarily mean that something’s going on in the magma chambers or even the hydrothermal system.

And while I’m spending my afternoon complaining about things, I’d just like to say: A balloon boy documentary? Please, no.

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volcano

Your volcano for Monday

Sorry, like last week, it’s a non-explodey one. Still, this makes me happy; the Valles Caldera is being considered for inclusion in the National Park System. I visited the Valles Caldera during my last field class, and it’s a beautiful area. Making it in to a national park would certainly help maintain that beauty. I even took pictures.

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volcano

Your volcano for Monday

The Yellowstone caldera, where absolutely nothing of note is going on.

I swear, if I had a nickel for every time someone breathlessly told me about the apocalyptic disaster coming soon1 to the Western US when Yellowstone explodes, I’d… well, I’d have a lot of nickels, to start. I’d quite possibly be planning for an even fancier wedding too, presumably one where I could blow a giant box full of nickels on something as insipid as an ice sculpture.

1 – This is geology. Soon does not mean what you think it means.

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volcano

Your volcano for Monday

Nyamuragira in the Congo is erupting. As it’s one of the most active volcanoes in Africa, this isn’t exactly a surprise to anyone. Nyamuragira is a shield volcano, so it tends to have runny rather than explodey eruptions.

Scientific, I know.