Katla volcano watch anyone?

[MrSlant]

I remember when the last eruption was going on in Iceland I learned an awful lot from knowledgable MN'ers about volcanos and seismic activity, plus you all had links to the best websites.

Apparently it is not 'if' but 'when' Katla is going to erupt so anyone want to join me and educate me and save me finding all the good links again?

That looks to me like a lump of scoria badkitten.
Andesitic magma, so mid range between mafic and silaceous, and very claggy and vesicular. It looks like dark solidified foam- like a clinker.

Look closely to see if there are any glassy fragments or phenocrysts. There should be tiny crystals of feldspar and/or biotite. You'll need a magnifying loupe, and good light to see the crystals. The fragments of glassy stuff have characteristic fracture patterns.. that's obsidian.

Have a look here

Other wise it's time to bring your cat to the vet!

Marking my place to watch..

yes, scoria, I remember now!! I'll have a close look when it's daylight and look for the crystals.
We also have some obsidian and some pumice.

lol at poorly cat. That would be alarming.

I'm going on holiday in September so that's when the fecker will go off if it is going to imminently. My family were stranded in Europe by the last volcano so reckon this one is probably lying in wait for us!

Sending note to Icelandic government "Fecker will go off when Piscivirious attempts her holiday, please contact her for further details of dates".

I don't think it will go off at all, I just enjoy the speculation and being educated by OYBBK and VenusRising.

I always forget speculative threads like this make people worry, I need to put in the title "MrSlant is clueless about any of this just likes to make threads about volcanoes, your holiday is going to be FINE".

This is probably going to sound really, really stupid but... I've been reading about Doggerland recently and seeing this thread made me wonder if there is any chance that a big explosion could set off another Storegga Slide?

Couple more Katla EQ's this morning ~ she's certainly rockin' and rollin' a bit at the moment!
A poster on VolcanoCafe just posted this excellent link ~ a catalogue of Icelandic volcanoes which has lots of information about each one.

Report from IcelandReview about latest seismicity at Katla.

how not to ~ Katla is a bit of an 'unknown quantity' when it comes to eruptions and while she can have explosive eruptions, in the things I've read about her, no one mentions a Slide being set off if there was a big explosion.

Badkitten, the water's in the magma, not sitting on top of it.

Where you have magma made from continental crust that's slipped down in a subduction zone, it has about 4% water in the minerals and it causes the explosive kinds of eruptions.

The magma that's sourced from oceanic plate or at ridge margins is less than 1% sometimes much less than that water, and it makes the magma very up explosive and it extrudes out like toothpaste.

Of course silica content and gas content also determine the style of the erruption.

Depending on the topography, large scale sediment slides and collapse and cascades of glaciers can be a big worry, as is the dissolving of noxious and poisonous gases like HS (hydrogen sulphide) into melt water, in these eruptions under ice.

I'm not sure what the lay of the land is for this one in Iceland, but there are well thought out evacuation procedures in place, especially for pollution of water and poisonous gas release.

Up explosive? Unexplosive!

yeah, I understand that Venus.

GloriaSumd that link to the catalog of volcanoes is fantastic, the details and scenarios they have thought out for Katla are boggling and interesting to read. I wish I didn't have to go back to work, I could read that all day!

Place marking as I also find fascinating! Venus and BadKitten, without wanting to take away from the Katla thread, what are thoughts on Fuji-San following the Tohoku quake? It would also seem poised to cause serious disruption. I used to live nearby and friends of mine were on Ontake when it erupted last year.

I can only imagine an eruption being like a major earthquake, until you've experienced one its impossible to understand the force and intensity. although as natural events go eruptions are exciting, Im not excited about the prospect of these type and think the work that people put into understanding volcanoes is phenomenal

Thanks Gloria

I'm hoping Venus will answer that query

Well, Fuji is on a subduction zone, and its magma does seem to be swelling up, which is an indicator of increased possibility of it spewing out.

I've found this link which shows the subduction process nicely with a diagram and talks about what's happening there.

Predictions are typically difficult to make though analysis of released gas composition and changes in that, and seismic measurements would give a better idea. I don't have that data, but I'm sure it's out there!

Great link thank you, really fascinating. Even before Tohoku people were talking about a new eruption coming from the side of Fuji not the centre and how it would change the iconic profile of the volcano forever. Whilst it's not a heavily populated area it is one of Japan's most famous tourist sites and thousands (including myself!) climb it in July and August. There are popular hot spring resorts, all generated by the volcano, for miles around. It's also directly under the narita flight path, so an unexpected eruption at a busy time of year could be tragic. Did you see Aldo Kane's descent into nyiragongo? He's posted pics on social media if anyone is interested in what the inside of an erupting volcano looks like!

Bored without children, found this on Volcano Cafe, thought it was really interesting, I've started having a daily look on the drumplots for Iceland even though I have no idea what I'm looking at!

Great piece here by a scientist I happen to know on Katla - she should know, she lived and worked in Iceland for a while...

theconversation.com/is-katla-crying-wolf-icelandic-volcanos-rumblings-dont-mean-airspace-chaos-is-imminent-64920

Thank you glacierchick that was a great read, I hadn't thought that if/when she blows it won't be spouting magma. I've been looking too much at the Hawaiian volcanos recently!

Had to force myself to only look at the drumplots twice a day, getting a bit obsessed I did predict that there was a flood by looking at them on Thursday though so I'm feeing quite proud of myself .

More rumblings from Katla yesterday.

Interesting number of EQ's today.

Jon Fr's latest post.

More EQ's overnight and bigger ones too.
Someone mentions on Jon's blog that they thought they saw 'smoke' on the webcam yesterday ~ I saw that too but didn't know whether it was cloud or something.

Aviation colour code has been raised to yellow~ signs of elevated unrest.