During the last 48 hours Hekla has suffered an increase in rapid strain movements. On the images below you see two types of motion. The first type that is creating a sinusoidal movement (wave-like) is a phenomenon called earth-tides. They are normal and do not influence even the most agitated volcano. The second type of motion is rapid motion of strain changes as the mountain makes small trembles. Those small trembles are actually rapid mountain strain changes.
Rapid mountain strain changes are normally seen as a warning sign of unrest in an active volcanic system. However, I have not found any data stating that Hekla exhibits this pattern before an eruption. The only reference is Páll Einarsson stating the previous instance as the reason behind the July 2011 Hekla alert from IMO (Icelandic Met Office). Hekla then suffered an episode like this that ended with a 2.2 earthquake in Hekla proper.
Also, before the 1991 there was a set of shallow earthquakes at Haukadalur the week before onset of eruption. And during the last couple of weeks there has been another pattern of similar earthquakes, but at a slightly greater depth.
This increase in rapid strain movements might be interpreted as increased unrest in the volcanic plumbing of Hekla. But we still lack the tell-tale earthquakes at Hekla proper that normally start 30 to 60 minutes before onset of eruption. The earthquake will be in Hekla proper, or within a couple of kilometers.
Please, keep the question coming for our GPS Q&A with Professor Sigrún Hreinsdottir!
600 thoughts on “Hekla – Changes in rapid strain”
“Sometimes you wish the parents of the clueless had had their reproductive licence revoked before it was too late.” Quote from Henrilerevenant earlier on this post
NO!!!! Think of how society works. You need everyone – all intellects, to make it work even if it doesn’t work all of the time. Think of how a termite colony works (Diana back me up here please!).
I am grateful to those who can do repetititive tasks that I can not and are not bored silly by these things.
You can not have only alpha types in an organization – you need doers as well as thinkers and decision makers.
Not a rant at all, Henri. Merely my opinion but wanted to express it to afford some balance here. So please don’t bash me for it as I am not trying to change your view – you are entitled to hold a different one.
Robots? Sounds like they are human robots. Hm… do not give us ideas here 🙂
See here, my darling (no worries, Hailey!!):
Those “little critters” have got society sussed!
Termites though have a nasty habit of undermining everything 😉
I know of cases where people walked into a house and it fell in around them, quiet common is people falling through floor boards, I like animals but in their places and not eating me out of house and home, sorry I am also practical
Erm, I’d go for having a 7 of 9 working for me…
She would just assimilate you…
A terrific perspective…
We recently had it about beauty etc. Which hetero man, if not in a relation where it was decided to be faithful, would say no to 7/9 because she’s wearing “only” jeans and sneakers? I’m glad to leave Paris Hilton to skirt-fetishists if I can have that borgy bit of lava in outworn jeans… 🙂
Nah, I meant she would ass-imilate you would her drill arm…
I’m only a 2/10. Any good?!!
I’d have so many answers to that, but there might be children reading… 🙂
You like volcanoes and don’t wear high heels in bed? Sure you would…
But just to be sure you know what I meant; I’d never “classify” a human on a scale. “7of9” is the name of a character, and the actress is quite a success of what genetics can make appearance wise… Pretty sure you know, but if you’re not a trekky, the precision could be helpful…
We say ass-laminate around here.
LAKAT: Think of how a termite colony works
(Before I reply, I’d like to say it’s tongue-in-cheek, ok?)
I do. The queen gives chemical orders to the biologically neutered workers, soldiers etc who obey instantly and without questions or motivational fillips. Impose human democracy on termite society and termites would be extinct before the end of the month.
Here I think we all have to admit Henri has a point…
@ Henrile Revenant
Just an analogy, my friend (hopefully, still:)!?), not a “model”. Not even I aspire to being a termite queen…
Love you guys!
Termite queen? Geeeez you’re a hungry piece of volcanette… 🙂
Termite Queen has a certain ring to it, doesn’t it?! (But Princess Frito may not like it!!)
Bows, as always, to Princess Frito before head is on block.
And it is not yet Friday night. Oh dear!
Of course we’re still friends! My problem (please note my) is that I do not accept that the democratic principle should be applied to every aspect of human society. I do not accept the dumbing-down everywhere caused by people who want to be top dog but do not have what it takes to be top dog but still becomes top dog because there so many like him/her, then change the rules so that what they do and are is the ideal, norm and the ultima ratio, i.e. the organisation exists solely in order to satisfy their ambitions and greed. I do not accept that people who know nothing of a subject should be allowed not only to set the policies of the subject but also run the show. Gods above, we even had a Chancellor of the Exchequer who had failed at mathematics at primary education level.
The principles for a working democracy were set down by Montesquieu more than 300 years ago but since those principles limit the power of and sets boundaries for those on top, they have been set aside completely until what we have today is not democracy but the dictature of the most numerous and prolific. Democracy demands responsibility and accountability, but this is the last thing the power-hungry inept want and they share this loathing with the majority of the electorate.
We should though remember that all tested alternatives have been proven to be even worse…
I hear you.
So we rarely are getting it right.
Perhaps we could indeed learn a lot from the termites, wasps and the ants! We are, after all,outnumbered by them!!!
Study them and you may better understand the complexities of society.
Watch your feet people – disrespectful to behave that way to a higher (group) intelligence!
Things can not be perfect. And that would be boring.
Democracy is the less bad of systems, thus the choice to make.
Even if somehow I think having one big boss, king, emperor could be the most effective or good system IF that leader is a very good one. The dark side of the medal is that you’re fully doomed if he/she is an ass…
Whatever system you choose, for it to work long-term it must a) let people indulge their selfishness (a.k.a. “pursuit of happiness”), b) never let such selfish indulgence become detrimental to society as a whole (i.e. never infringes the “rights” of “Life, liberty and justice”) and c) include an altruistic and impartial watchdog that will mercilessly root out the corrupt and the corruptors.
I think all can see where we have gone wrong and why the ideal society is utopical – Quis custodiet ipsos custodes?
PS. Yes, I think the Constitutions of the United States is pretty impressive but even the “Founding Fathers” failed to solve “c)” satisfactorily and the structure is failing because of it.
For me the bigger issue is that of corporate influence.
I personally recommend that everyone who can afford to do so buys @10+ shares in the leading companies e.g. energy providers, or whatever number is required to acquire a shareholders vote.
Corporate entities are unelected and yet dicate/influence an enormous amount of national and international policy, and have only one rule to follow – that of achieving financial returns to the shareholders. The altruistic greater good of society is not their concern, unless their shareholders make it so and excercise the controls open to them at annual shareholders meetings etc. Govts are supposed to regulate the corporations, but largely fail to do so (follow the money to find the real power)…. and so democracy is failing. This would be one way for us to balance the books and give democracy a better chance of working.
My idea of utopia is somewhere near a volcano and where all the people in the vicinty are well fed, erudite, just and have Icelandic names. Moreover they would have a predilection for borderline jokes and also have internet access to all scientific papers ever written. Too small to need political organization and too curious about the world around them to suffer from complacency. – and it would have an excellent vineyard.
Looks like strain is starting to vibrate again.
And now Hofsjokull is reminding us he is there – we didn’t mention him in all the other ***jokull discussion this morning.
Also Langjökull has rather large (dormant) volcanoes.
Yes, I’m crumbling here under the weight of intellectual argument!
(Yes, strainmeters is the subject – just fooling with you.)
Above was in answer to Jamie at 12.45
@ Sloshed Signor
And would you still think that if you were not sloshed?!!
Cheers to you, my friend!
Summer Greetings from here. Officually “First day of summer” today. Nice view of Hekla today. The Sheep are about but Lambs are due any day in next weeks. http://eldgos.mila.is/hekla/
BBGM everyone, just trying to catch up here. Dean I hope everything is going ok.
Thanks Hattie im now home but over an hour im going again for 5 hours to hospital it is critical but hè is less restless now hè had also an lung infection and fever we are still Hoping thank you! Nice that you thinking at me and my father! Much love from holland
Hey Dean, good to here that your dad is less restless.Take care of yourself as it is real easy to burn yourself out when things are that stressful. Big hug.
Thanks im just back now my sister is sitting next to his bed but hè was again restless now im going to sleep we have now made an agenda so we can rest in between i can now sleep till ten or something happend in between its not easy Much love Deanne
Hugs from me, too.
it will be a difficult road to recovery, so look after yourself, which is very important, so you can stay strong for your dad, take care
Thinking of you,sleep well, and hugs sent your way.
Oh my goodness, Dean, hope your father will get the care he needs. Ciproxin (generic:ciprofloxicillin) is a brilliant antibiotic for lung infections but I’m sure his hospital will try that one if the others fail, anyway.
This is a difficult time for you and your family. Wish you all the best.
Thank you Lakat hè is now sleep almost the whole day becomes diverse medicine and morfine thanks for the recept !
There will also be many reading this blog, who have not commented, who will be silently wishing you all the best.
Oooops…. another drop at Hekla happning (??)
I am starting to grow a bit suspicious about them, but still almost certain that it is resets. But…
Did the borhole HEKLA not exist in 2000? There are just the other three named, Stórolfshvoll, Hella and Búrfell. http://hraun.vedur.is/ja/hekla/
BUR, HEL and STO were then. BUR fell rapidly then. HEK is newer and close to Hekla.
Nothing on World Wide list that can influence, I think. Notice them “vibrations” on Burfell (increase in “aggressiveness”) but hork not shure what to make of it all.
The increase in ‘anger’ at BUR coincides with the latest drop at HEK.
Great minds think alike. Te he he
Yes! Snap! 😀
I am not sure what to make of it either, but it is strange that the vibration increased at about the same time that HEK took the dip.
When it was resetting in the first two days it fell/rose in a single clear line – now it is falling in a jagged line (hope that makes sense). Makes me think it is not resetting ….
P.S. By ‘it’ I mean HEK.
Didn’t dare to say it as I didn’t want to look like an amateur, but the strainmeter resets I have seen (in completely different contexts, and I don’t know if the whole system setup can really be compared) always lookes much clearer that that weird stuff…
Any concrete experiences among you guys?
looked. Godabunga I’m the king of typos…
That’s why I said it (about the resets/falls) – I don’t mind looking like a geological instrument idiot! 🙂
It kind of coincided a bit too much with Búrfell.
We will see I think.
GeoLoco, since new sampling methods graps were set up on the strainmetrs it has been fairly constant in progess on all three (HEL and STO always read more jagged or jumpy). This winter HEK was out, then after it came back on line a few days ago, it has been rather weird in its progress. But the “aggessiveness” is rather new showing on all of them and has strong showing now at BUR. Pure resets were marked “Valve open” a few times. * “But not expert” clause most likely applies now – Might be totally wrong ?*
Thanks. Am keen on looking back at it in some days…
look at how Bur is working with hekla’s drop.
Remember that these drops have occured very often and are mostly attributed to nearby hydropowerplants.
Historically though the hydropowerplant in the vicinity have not affected HEK.
I tell you but you won’t listen! It’s that alien device using strain as a carrier wave! Just you wait until December 21st at 21.12 when the brown dwarf passes closest to the sun. The reason we can’t see it yet is because the aliens have stealthed it. They’re so far ahead of us that while we can make airoplanes and ships invisible, they can make suns disappear. Why won’t Obama tell us the Truth? What is he hiding?
(very straight fppfMUAHAHAHAHAH!!! )
OK and I suppose there’s a Borg Cube approaching………… 🙂
Ready to wrestle with 7/9. Yes, ref to her again.
We should start training our behinds for all their experimentation. I hope they have small instruments.
there are plenty of holes to choose from and where there aren’t any they would make them, fumes from human consumption would make them puke, something to digest for you guy’s
Somehow brings us back to the mexican food thing… 🙂
I definitly want what you have been drinking… All-Galactic Gargleblasters again? 😆
There is also the Geldingaá Strainmeter, it used to be on the plot, but was replaced with HEK.
If I remember that was an old version that was not a volymetric strainmeter. Analogue, not digital. Good for reference checks.
that pic the other day of Hekla was beautiful, I think she is just over halfway there
Where did I read that Torfajökul quakes have been regarded as possible precursors of Hekla’s eruptions?
And now time for me to sign off for today… out into the cruel world of work… 🙂
Just heard first cuckoo of 2012 – summer’s-a-comin!!
That would be me? 😆
Which are you – the cuckoo or summer 😛
Former of course!
Summer is the Dragon helping with the coding…
Sumer is icumen in
Lhude sing cuccu
Groeth sed and bloweth med
And Springth the wde nu
Want the latest news on the alien invasion and singing scots? Join us on volcanocafe.wordpress.com… Said with an american radio speaker voice…
no, no, that US action movie trailer voice, much more hair-raising …
Straight to DVD, Mondaaay!
taken with humor laughing is guaranteed…
Well done! Original?
No! An English ’round song’ we had to learn in school! Goes on about bulls starting and stags farting but I can only remember the first bit!
Uhm, Henrik… We used to sing that every year last day at school… Singing prince ya know…
We did? The words don’t match my memory, but if you say so!
Sommaren är kommen
med lust och fägring stor…
Sumer is icumen in / Lhude sing cuccu = Summer has arrived / Loud, sing cucoo
Not a frightfully good match is it even if the sentiments expressed by the two songs are similar. Actually it reminds me of “Grönköpings Veckoblad” and the transpiranto poem published with every issue.
Amazing Talla! They couldn’t spell when that was written either. 😉
Hi, yes, “my” personal pair of “Haematopodidae ostralegus” (Tjaldur) birds are back a week ago. (They came with purchase of house I live in). Last year thay had tree chics feed on worms on my lawn. They are very fond of cheese but poop a lot.
I saw Hirundo rustica here (near Cardiff) on the 11th of april, and (winter) lambs several months ago, but http://en.wiktionary.org/wiki/one_swallow_does_not_a_summer_make, and trying to keep a cuckoo doesn’t work to keep the summer (http://en.wikipedia.org/wiki/Wise_Men_of_Gotham)
Where I live hearing the returning Brenta canadensis annonces the end of winter, and it’s the appearance of the Concurdees (Agelaius phoeniceus) and North American Robins (Turdus migratorius) that annonce “officially” that Spring is back.
Summer must be on its way. Check out the Daily…..
Our Delichon urbicum haven’t arrived yet – the bl**dy woodpigeons started breeding in Feb and the sods keep eating the cherry and plum buds………..then the blackbirds eat the cherries and wasps try for the plums (BUT they prefer stale ale…..tee hee)
We seem to have loads of woodies here too. Far more than usual.
I love all living things …
… apart from pigeons, swans, squirrels and red kites!
I love Red Kites! We only have one pair here so far – the only reason to go further east than Wiltshire is to see Red Kites soaring above the M4!. But I digress – the Daily Mail article only speaks about independent forecasters, not the Met Office so we can expect a sizzling May and a normal summer. 🙂
My personal shitlist start with Pigeons, Rooks, Magpie, Gulls, Starlings…
Favourite bird? Anything that eat the above birds…
Today I saw a partridge, unusual here. Made me rather hungry. Wish I had a gun with me.
Unlfying thing I don’t like: Rats. And animals that normaly want to attack me, ie. Wolverines, wild-boars and Muskoxes.
Animals I like, anything that eats the above animals. Sadly nothing eats wolverines.
Carl’s ‘sheepy-Borg’ – 10ft long, I ton weight
Ok not a true sheepy ancestor………. maybe……
I live close to the first Red Kite reintroduction site so at any given time there’s up to 20 of the bloody things circling over the village. Incidentally, last summer there were the first reported cases of kites ripping food out of the hands of schoolchildren in the playground, so the kids now have to stay indoors.
For me it’s the god-awful noise they make all day, which drives me nuts as I work from a little log cabin in the garden!
They are, admittedly, very beautiful creatures. And they eat cat-sick, which is very helpful when you have a cat that catches a rat or two every day but is unable to digest them!
I knew it, murder-sheeps…
@ukviggen: Yes, in Africa they are known for their thieving habits. I was at a game camp once when one flew in and snatched the hamburger out of the hand of a tourist at the next table. I had to admire the flying skills, didn’t miss a wing beat. The tourist was numb – couldn’t really take in what had happened and whether to get angry or think of it as the highlight of his safari. Red Kites were known for their clean-up skills and for centuries kept London, and I guess other cities, clean of stuff that could have caused disease. They died out when the industrial revolution kicked in, I think. I love all the raptors and corvids for their flying skills.
Pigeon pie. Need plenty for a pie so it’s good they breed early . :P:
I thought that “Carcajous” (Wolverines) existed in Canada only. Top of the food chain here too, and they have the reputation of having a foul temper.
Nah, we have the nasty buggers here too, and they are not any more even-tempered here.
here it is a wet Autum and doesn’t know if it is winter one day and summer the next
Finally I have internet at home.
So many things to reply.
First, Tindfjallajokull is a active volcano (the ashy type and from its history a violent one). I think it was in 2010 it had a glacial flood coming from it, I remember seeing it on the news, but it was small. But this reminds us that the volcano is active. It was also the tallest mountain in Iceland before it blew up some thousand years ago. And sometimes there are earthquakes there. Just because there are no confirmed eruptions in Holocene does not mean that there were none!
Torfajokull is another often ignored volcano. Also active. There has been at least 2 eruptions since settlement. And evidence in situ points to both efusive and violent rhyolite eruptions. The caldera is a little bit like Askja, but larger and much older. Another example of a very old caldera is at Krafla.
Even Snaefellsnesjokull and Hofsjokull are active, and there are so badly monotorized that we do not know about the earthquakes taking place there. In both these volcanoes, there are recent (think Holocene) lava fields around them. And just the size of Hofsjokull is massive, larger than Katla!
Furthermore, please take a moment to see that these 5 major volcanoes (Hekla, Tindfjallajokull, Eyjafjallajokull, Katla and Torfajokull) are quite close to each other. They nearly touch each other. Its like a crowd of 5 bad boys. And its a little bit like their 4 brothers Bardarbunga, Hamarinn, Grimsvotn and Thordarhyrna. I always asked myself, why so many large volcanoes at this region, while to their sides there is only SISZ and dead zone, without central volcanoes.
Forgive me Carl, but I am still sceptical of Hekla being a subduction volcano. I really like your reasoning, but if the microplate would be squeezed and subducting, wouldn’t that create a longer side with more subduction volcanoes. We only find Hekla there. But I think you are onto something there.
Interestingly is also to notice that if we draw a line from Veidivotn into Torfajokull and we continue southeast, then we reach Tindjallajokull. I find that interesting. And likewise, we can also draw a line from Grimsvotn, down to Thordarhyrna, Laki, Edlgjá and arriving at Katla, from where we continue to Eyja and then Westman Islands. If this means something I do not know. I am open to consider proximity in eruptions happening along these “lines”. Just like it happens along the Reykjanes peninsula, and also along the north volcanic belt, between Askja and Krafla.
Finally, this morning I had an interesting (out of the box) thought. We know that in 10.000 years since last Ice Age, we had a few eruptions happening between Hengill and Hekla (SISZ), those of Grimsnes. But the SISZ area shows evidence of many more past eruptions, like Hestfjall, Burfell (do not confuse with Hekla’s Burfell), Vordufell, and even Hrómundartindur. I wonder if one day we might witness the formation of a new volcanic cone in the SISZ, just like it happened in Grimsnes about 3000 years ago. Grimsnes had 10 separated eruptions, which create distinct volcanic vents over a wide area. The same could happen somewhere else.
The Tindfjallajökull jökulhlaup was at the end of Eyjas eruption, it could have been caused by emplacement of magma from Eyja.
Regarding Hekla, there have probably been a couple more, but they have most likely died out over time. There are some volcanoes in the area that are old and that has erupted the same odd lava around the corner, Búrfell for one. But, there was one person who suggested that it might be the corner that is subducting only, and that would explain a bit why only Hekla. Sadly I do not remember who had that bright idea, take the claim whoever is responsible!
And, let me say that I did not say it is a subduction volcano. I said that it erupts magma associated with subduction volcanoes. There could be other explanations, but one of the more likely is that something local is subducting there.
Some more information on Hekla, also stating that her products are typical for subduction volcanoes and actually not for other Icelandic volcanoes. http://www.utexas.edu/tmm/npl/mineralogy/mineral_genesis/hekla.html
They just also say here (Univ. of Austin, Texas), that Hekla has 1 magma chamber at 8 km depth, we know better!
That was me. I’m short in time. So in 2 words.
Admit hreppar plate exists. Where there are plates next to each other. There stuff happen. Imagine a proto-accetionary prism. I can imagine it in a shape that if you have some successive phases or push more push left, slide a bit etc, a slab of the prism could have broken away and been squeezed into subduction in the direction of Hekla’s feeding / reservoir / transit system and started to interact with the whole thing, sometimes more, sometimes less…
Sorry, Kids finish their milk, one already half naked, madam has “the look in the eyes”: my bathing and goodnighting skills are asked for…
We can talk about it in more detail if it interests anyone, but another moment…
push more then less, lot left
I’m having a lot of trouble with the subduction hypothesis.
-The magma associated with subduction zones gets it characteristics from the water that is dragged down into the mantle. The Icelandic crust, which is above sealevel, does not contain this water (most of the water is derived from oceanic sediment.
-In a subduction zone, crust of the water-soaked subducted slab (partially) melts only at a certain depth (normally around 75km deep). If this would be the case, enormous amounts of energy would be released due to the loss of gravitational potential energy through thrust/subduction faulting. Even on a small scale, this would be very clear and produce a typical subduction earthquake pattern with earthquakes at great depth (>20km).
-Also, under an average angle, the volcanic zone would be some 150km from the actual subduction fault, which is not very well possible.
Most important thing: I totally agree and share your troubles. That’s for in the box thinking. If I wasn’t able of this thinking and wouldn’t understand and when necessary defend the principles behind I wouldn’t have got my Randy-paper… 🙂
Thus I won’t be able to defend the hypothesis above more than utterly necessary…
But since the first time I read about Hekla I couldn’t get a clue where the subduction-type ressembling lava could originate from. So I allowed out of the box ideaing. Water: hell of a problem to explain it. But I mean, in a boundary context who knows where what water could do and go and how much would finally be needed to have a beginning of significance. Melting depth of a “subducted” piece: In the MAR / hot spot context could it act differently than what we usually know? Average angle: I don’t believe in “average”. Helps for a first approach, but in every cross section Inhad to draw or have seen, there were exceptions to average. So if in Iceland and set the hreppar thing is real I meet a mad subduction angle of a hypothetical slab of stuff going down, I mean, I already lost my pants several times so that would not shock me anymore… 🙂
Hekla is madness. I always found that if a randy has to learn something, then it’s making cross sections and imagining the structure of what lies beneath our feet in 3D. Becomes a bad habit, and turns you mad especially when you move around in the alps… But most of the time I get one or more possible mental pictures that explain more or less what’s happening on the surface. Not in the case of Hekla. I don’t get it. Besides, if anyone has something like a usable geological / structural E-W cross section of Hekla, I’d love to throw an eye on it. Probably would be rapidly healed from fooling around with partially subducting thingies… Or not, but then with suitable arguments…
Pieter, thanks for even reacting and taking it seriously. That fire mountain will really turn me loco with it’s weirdest behavior.
Don’t forget with subduction zones there is an interaction of wet- and dry-magmas; the hydroxyl acting as a flux lowering the melt liquidus
just from the guts, is it worth going on thinking about subduction related stuff (sensu lato) to explain things, or is that so far out of the box that it leads to the psychiatric section of the next hospital?
When I was looking for “Hekla + 3D” – as I am always willing to help out a friend – I found this: http://www.designconnected.com/lighting/table/Hekla_p3900
PS: I’ll keep on the search…
the spiral formed sill explains it all.
The Hreppar microplate anyway is also mentioned in this article preparation of a field trip – by an known Icelandic volcanologist, Freysteinn Sigurdsson: http://www.norvol.hi.is/~thora/summer2003/notes/WVZ.pdf
I have a harder time imagining the region without the hreppar plat than with. But it’s really tough to say much about it when you are an Alpine randy and just hobbying around with Iceland.
And here is someone (Foulger) also talking about subduction – if I understand this right, about an old slate of former oceanic crust – and Iceland in one article: http://www.gps.caltech.edu/uploads/File/People/dla/DLAjvgr05b.pdf
This could be interesting mat. (esp. p. 16 ff.): http://www.geodesy.miami.edu/articles/2005/Iceland2005.pdf When they are talking here about a “rigid block”, the Hreppar plate, and “overlapping”, wouldn’t this mean some sort of subduction? (my caveat: not me being a specialist here)
In my – laicistic when it comes to volcanoes – mind, the Hreppar plate could be an answer to a lot of my unanswered questions. When tourists came to me whom had been given the explanation, that Iceland, that was so simple, here is America – and on the other side of this fissure in front of you (normally they could chose about this one near Reykjanes / Svartsengi / Gunnuhver http://commons.wikimedia.org/wiki/File:2006-05-22-155112_Iceland_Hafnir.jpg and the famous diving gjá in Thingvellir, I am actually not really sure, if it is this one: http://commons.wikimedia.org/wiki/File:2008-05-25_13_45_35_Iceland-%C3%9Eingvellir.jpg ) – there is Europe, I tended to laugh and said: “Stop, it’s not so easy.” And explained, that there was something
in between .
PS: Germans like something, which is called “Schachtelsatz” (a sentence in form of a box, or a lot of boxes one inside the other actually). And this above here is a very fine example. 😆
My thoughts of the subduction zone signature, is not that of current activity.
The region around and associated with the Iapetus and the Rheic Oceans were slammed together and torn apart a few times over the last few 100 million years. An island arc was sheared off and became the micro-continent of Avalonia. It in turn, has been torn apart, and pieces of it can be found on both sides of the Atlantic. When Avalonia was forming as an island arc, it was most likely the byproduct of a subduction zone… since subduction zones tend form island arcs and back arc basins.
So, the mechanics of the subduction process have been at work in the area in the past.
In comparison to the majority of volcanic islands… Iceland is way too thick. 40 to 45 km in the region of Bardabunga, and lesser in the areas around that, have been postulated by some papers to be the result of a staking of crust segments. Possibly a layer of oceanic crust overlaid by continental crust.
My reasoning is that a shard of this subduction zone material is in the mix of stuff that makes up the basement of Hekla, and what is seen is a re-mobilization of that material.
That’s how I square Carl’s subduction magma idea.
Yes. Anatolia, Tethis… Colliosion-spreading successions lead to weird structures.
A paleo partial subduction that brought a piece of something down where it interacts with the magma that comes up. Maybe several pathways, some that lead up so that the magma nearly don’t get affected by that thing, and some where there is interaction.
I’m not sure if I get all of your reasoning. You’d say the “subduction” happened in times when things were under water? I have no good idea of when which part of Iceland was under / over sea-level…
Pieter you are of course correct, but…
Iceland is not a large scale subduction zone.
If you just scale it down and go with average chrustal thickness you are fairly well close to the scale of Iceland. And since it is thinner and admitedly hotter you would get a golden case of slow quakes. And those are recorded all the time in the Hekla area.
There is another thing with subduction magmas except the water (that could equally well come from the ocean here). And that is the grade of extreme fractioning of the magma, it is after all rather extreme in the evolvememnt part…
Nice collection of papers!
I think that Lurking has a good point in how it should be working.
I though thing that Hreppar is in a sense of it on the way to become stacked, there the process lurking describes is still ongoing.
A site for those interested in what is up along the San Andreas and other interesting parts of the US.
April 19, 2012 – PAPUA NEW GUINEA – Mount Lamington is a stratovolcano in the Oro Province of Papua New Guinea. Local community of Popendetta reported smoke and ash emission on March 25. No official reports have come in yet. Lamington is an andesitic stratovolcano with a 1.3-km-wide breached summit crater containing a lava dome. After a long quiescent period, the volcano sprang suddenly to life in 1951, producing a powerful explosive eruption during which devastating pyroclastic flows and surges swept all sides of the volcano, killing nearly 3000 persons. The eruption concluded with growth of a 560-m-high lava dome in the summit crater. The volcano last erupted in 1956. -SYFN
Could you indicate your source?
That’s a reply to luisport.
Tyler what is false? This news?
Yes, because it came from the site, extinctionprotocol.
Papua New Guinea / Mt Lamington
According to setyoufreenews.com, Mt Lamington volcano in New Guinea is showing some signs of becoming active. According to the brief news, locals from the community of Popendetta reported “smoke and ash emission on March 25″. No original source or other reports could be located so far to confirm new activity.
Mt Lamington volcano is an andesitic stratovolcano with a 560 m high summit lava dome that grew during 1951-56, following a brutal reawakening with a major explosive eruption in 1951, which produced lava flows and devastating pyroclastic flows, and killed about 3-4000 people.
(source : volcano discovery) http://earthquake-report.com/2011/12/31/worldwide-volcano-news/
So, now it’s true?
Luis: There are more experts dismissing this eruption.
For further information, take a look over Erik’s blog (see Raving’s links) at
In one of the comments, Boris said:
“As discussed below, this report about Mount Lamington reawakening is FALSE – the prime source of its diffusion has been a web site called “Extinctionprotocol”, which unfortunately is doing its share in spreading highly debatable information. One thing that I particularly noted is that the author of the site insists that volcanic activity is globally at unusually high levels (which it definitely is not, it’s rather low level lately), happily and intently feeding the latent 2012 hysteria. Let’s try to keep away from that one … “
I would take this report with a very large grain of salt. The Smithsonian GVP has no reports of activity. Having looked at the setyoufreenews site, I would not place much faith in anything reported there. In a quick search I did not find any creditable reference to the supposed activity.
A pleasure to meet you.
But i saw it in earthquake report, not in extiction protocol
The net is full of traps.
You often come with valuable info. Maybe this time was an exception and you fell in one of the traps. I guess we all know that very well from own experience.
I was not there you know… LOL
Earthquake Report referenced Volcano Discovery which referenced Setyoufreenews.com which, to me, appears to be in the same league as Extinction Protocol.
The easy thing with these kind of stuff is check national news of that particular country. But I do not know how to find news from Papua New Guinea
if it was in the news there, it would have come up in Australia, it didn’t, I am always on the look out for things EQ and Volcanoes
A good idea is to check who’s behind the site. If he or she looks anything like this, stay away:
Male proprietor: http://www.damninteresting.com/wp-content/uploads/2005/11/tinfoil_hat.jpg
Female proprietor: http://www.crystaleves.com/wp-content/uploads/2012/02/tin-foil-hat-woman.jpg
15 Years of Icelandic Earthquakes and Eruptions in 4 Minutes
by hjalli Plus10 months ago
This video shows just over 15 years worth of Earthquakes and Eruptions in Iceland since 1996. Dark colors indicate deep quakes, while bright colored ones are shallow. The size of the circles indicate the quake’s magnitude.
Stars indicate eruptions.
At 24 frames per second and one day per frame, every second of this video shows the seismic activity for almost a month.
All in all the video shows 242,724 Earthquakes and 7 volcanic eruptions.
Work in progress. See also “Earthquakes and Eruptions in Iceland 2010” that focuses on the Eyjafjallajökull Eruption: vimeo.com/10708403
Such an amazing video!
You can clearly see how earthquakes happening under Eyjafjlajokull for several years pointed to a long magma intrusion under it. We can also see that happening in Kistufell (Bardarbunga), at Hengill, Krisuvik, Askja and Katla, as preparing to eruptions
And those quakes south of Hofn, they happen often than we think!
Such a mystery spot
1139701 19/04/2012 13:01:22 28.1489 -16.2158 1.5 mbLg ATLÁNTICO-CANARIAS
More wait and see what will happen next …?
Thanks for that.
A very tenacious riddle…
Could this earthquake be related to the text below.
ML 3.2 Region PYRENEES Date time 2012-04-19 17:02:41.0 UTC Location 42.59 N ; 0.86 E
Depth 1 km
,,We have identified a 50-km-long active fault scarp, called herewith the Lourdes Fault, between the city of Lourdes and Arette village in the French Pyrénées. This region was affected by large and moderate earthquakes in 1660 (Io = VIII–IX, MSK 64,), in 1750 (Io = VIII, MSK 64) and in 1967 (Md = 5.3, Io = VIII, MSK 64). Most earthquakes in this area are shallow and the few available focal mechanism solutions do not indicate a consistent pattern of active deformation. Field investigations in active tectonics indicate an East–West trending and up to 50-m-high fault scarp, in average, made of 3 contiguous linear fault sub-segments. To the north, the fault controls Quaternary basins and shows uplifted and tilted alluvial terraces. Deviated and abandoned stream channels of the southern block are likely due to the successive uplift of the northern block of the fault. Paleoseismic investigations coupled with geomorphic studies, georadar prospecting and trenching along the fault scarp illustrate the cumulative fault movements during the late Holocene. Trenches exhibit shear ,,
The BIO Las Palmas (Oceanographic vessel), who made some extensive bathymetry last week, measured the depth of the cone at 86 meter.
Lunch is over – back to work. TTFN
Don’t know; I can’t find confirmation in IEO’s site but found a report of the water sampling:
Click to access PR_130412_volcanohierro.pdf
Found this: http://www.avcan.org/?m=Noticias&a=noticia&N=918
But no reference to a scientific report so a bit vague for comfort.
19.04.2012 18:20:58 65.145 -16.390 10.7 km 1.7 81.12 3.8 km SSW of Herðubreið
MJO is looking a bit spiky.
Hi! Yes, I saw that – but can’t see a reason for it. Worth keeping an eye on. Honestly I’m going to need as many eyes as an insect soon with all this volcano monitoring! 🙂
LOL, Doh! I get so bad that on more than one occasion, I have been so absent minded, that I have grabbed my reading glasses and stuck them on over my bifocals.
LOL! My eyes are really bad – I have to remember where I put my glasses in order to find them by touch. If I can see – I have them on!
Same for me..Blind as a bat
assuming you are short sited like me there is another option – get your camera phone, and zoom to the max, then look at the screen and you get very rudimentary vision over a greater distance than you can normally manage 🙂
Keep checking the webcams everyday, but never lucky to get a nighttime eruption…
That was awesome.
impressive!! Interesting to note that electric discharges start immediately within seconds of the initial burst.
Hey GeoLoco guess what.
You are number 2 in the top recent commenters, right behind Carl.
Now, why does that not surprise me? Randy!
hey that´s brilliant..I did notice that GeoLoco did come back with a “bang”….oops, I am sure he will come back with a risque comment about this, watch this space…. LOL xx
You show a nice example of living with risks instead of risk mitigation and immobilism in front of a hazardous situation.
On the other hand, what else can I see behind that than a compliment. Pretty cool to enter the scene with a bang – my imagination provides a little film about a wrestler entering the hall with a hell of a firework. Then standing still, a bit like The Rock used to do, with a dark expression in his face. Down there in the ring are some pole shifting 2012ers hoping that Mardok will fall on the Bang-dude. Then Bang-guy takes his shades off and starts to speak: you guys now watch at the big screen of the arena. I hacked the computer and you’re gonna read volcanocafé, look at lurkings plots and listen to Carl’s explanations why the amount of energy for your shifting-fantasies would have atomized us when I did it in the past… Mouahahahaaaaaaa…
Maybe Sissel has some planty medics to cure me… Hope so, somehow. Or not. Whatever…
I dedicate that score to our grand master Marsh.
GeoLoco is your job Risk assessment or Risqué assessement ?
Right now it’s explaining someone how to build a house in a slope. I must be an alien. That dude seems not to be bound to the same rules of physics as the ones I know in my world… Sometimes I wonder I we all have to obey gravity or if it’s just one of my fantasies…
Recent, yes. Very nice.
In tough times it’s good to allow oneself these little pieces of joy that helps taking things with a smile. But I’m not sure I’ll hold the pace… 🙂
Over the year I hope I’m still number 6. I want to win my number 5 man to man, eyes in eyes with our friend Carlos. Would be a shame to do it like “behind his back”.
Just checking stats because not so much is up. 2 people found this blog looking for “dating site badbadoo” ????
2 with dalek dog
1 each with images of beach balls
usgs double couple
blog redirecting to dating site
small living room with stairs
Thanks Spica, what a reief! I was dreading that you would come up with someone looking for Spanish “come to bed eyes” after my rather mad comment while back.. 🙂
oh no, sticky keyboard syndrome again…reief -should be relief.
Western Turkey seems to be having a swarm of EQ at the moment.
Eastern Turkey does aswell.
Turkey, does seem to be as busy as ever, a very dynamic land mass. Squeezed as it is between the Arabian and the eurasian plates. If it helps, checking on google earth gives a reasonable historic record of the +2M EQs using the Layers/Gallery/Earthquakes. Also using,
http://services.google.com/earth/kmz/realtime_earthquakes.kmz and checking the Tectonic plate boundaries displayed in ”Places”, results in the display of the reasons behind all this activity. Turkey it seems is a micro plate in it’s self.
maybe of use in explanation.
Hi Judith, am getting ready to go out for dinner, so have to make this quick. Have you heard if you can go on vacation yet? I hope so. Got to run TTFN.
Going for sure now, catch you all later.
Hope all is going OK with you and yours Hattie…. @ Judith…how is your husband? Has he got the all clear for the holiday…I really hope so. All the best xx
Hi Debbie, just returned from supper and a walk down the beach, things are going good so far, thanks for asking. This blog is a special place,with special people. Hugs.
Thanks for asking we still dont know about the holiday but he is walking better now on his foot . x
On the Hreppar discussion: what is interesting to observe is how each side of it behaves.
Assuming the microplate is real, we have at the 4 corners: Hengill, Hekla, Bardarbunga and Langjokull. Two of these corners are some of most seismic places in Iceland (the junctions at Bardarbunga and Hengill), while the other two are some of least seismic places (Hekla and Langjokull). Curiously they are in opposite sides.
Now the sides:
The south side of the microplate is highly seismic, because there is a slip-side motion (the SISZ)
The eastern side has massive volcanism but reduced seismicity (dead zone and Bardarbunga system)
The northern side has massive long dormant volcanoes (Tungnafells, Hofsjokull, Kerlingarfjoll and Hveravellir) and interestingly (unlike SISZ) no slip-side earthquakes.
The western side is generally dormant (almost like the dead zone) but had massive efusive eruptions and large earthquakes on the past.
This suggest to me that the Hreppar microplate, if real, is moving in some sort of interesting motion (some have suggested a twisting rotation), and its possible to even have a 3D motion, one side moving upwards, another moving downwards (to fit Hekla subduction magma). That means my house is rotating and tilting when compared to the rest of the world 😀
I am no knowledge in models, this is just what I have observed around Hreppar, someone else might explain this accordingly to Hreppar movements.
If Hreppar moves or rotates or tilts, I think it is not because of itself, but because of the rifting occuring on both west and east sides. Because inside Hreppar (which is a very small space anyways), there is still the SW-NE alignment of mountains and old volcanoes.
You’ve all seen this paper by Dr Gillian Foulger (Durham University) about Iceland sitting on a much older crust, I hope. (It is always worth another read!)
Any discussion about Iceland throws up so many anomalies and this helps to point out some of the whys. Many more still remain.
Here it is:http://www.dur.ac.uk/g.r.foulger/Offprints/OlderCrust.pdf
Thank you for the paper.
Always welcome. Thanks for all your and other regular contributors’ info/input, too!
(This is such a nice, friendly place to feed one’s mind.)
Irpsit… Would you know the map co-ordinates (or locations) of the borehole strain meters?
I am glad you can provide so much on-the ground experience and information, living in Iceland as you do, and I enjoy your posts and look forward to more.
I am asking because of the difference, between the drop of strain of Burfell 2000 eruption, compared to what seems to be an increase at the moment. I am trying to visualise the movement and pressures of the landscape and imagining the vectors underground. Thanks in advance.
I never imagined this twisting-tilting 3D movement. But would fit nicely with a part being (or having been if we take Lurkings vision that there’s not too much present action in these ways) pushed down at an unusually steep angle under Hekla.
That was a very useful way to describe that hypothetical microplate.
And the possibilities that opens to wildly imagine links (at least on a time-line) between so many of our fetish-volcanoes… I have to hold back, you would immediately put me in a new category of 2012er… 🙂
you meant to say you feel the the earth is moving under …..magic
Anyone have noticed a quake swarm near Baker volcano, Washington state? http://quakes.globalincidentmap.com/
These are tectonic, not volcanic. See the following site and note no quakes listed as associated with Mount Baker.
One more thing: today I was hiking here at the region, and at one moment, I saw Hekla with a clear steam-like cloud moving from the same site which someone else a couple days ago also saw something similar.
For a steaming-sceptic person like me, this was a clear surprise.
The sky was clear at that time, and judging from where it came, and was the wind was blowing, I believe that it was steam and not a orographic cloud (clouds that form on top of mountains)
One note: I know well Hekla summit. The place where I saw the “steam” coming is to the southwest of the summit (right side as seen from the west), this is where the 2000 eruption happened, and where last summer I saw hot ground steaming when I hiked Hekla.
PIC link: http://imageshack.us/photo/my-images/3/dscn3817j.jpg/
This was also the site of 2000 eruption where ground is observed to still be hot and steaming if you hike there.
I saw it for only 5min. The sky was clear around Hekla. And since this is the 2000 eruption site, I have my clear doubts that this was just an ordinary cloud. (Please note I am the most sceptic cloud person).
If this is true, then magma has come to the bottom of Hekla, and it is warming the open conduits at its top, where steam might be released ocasionally.
It is a MUST now to observe Hekla carefully with the webcam. I am not sure, but I think this was also the site was the person here a few days ago also reported some “steam”.
Hi Irpsit, that sounds exciting and definitely worth keeping an eye on…it is noted that you are the most sceptic cloud person,, which makes it sound all the more credible that you have spotted something of significance…we shall see!
I must say that sometimes I can see similar steaming (but much tinier) if I go closer to Hekla, within 2km from its base, where the road goes by. With binocular from such a close location, and from the southwest angle, you can see that spot steaming a tiny bit all the time (and of course you can see it much better if you walk to its top).
But I never saw it from where I live, 45km away. That indicates that the steaming is now increasing much more. Guess why.
But Hekla is so tricky, that it can go back to business again.
Irpsit, Is the linked photo from today, what time?
Photo was taken today at 12:04
(my photo has a recorded time of 12:08, I confirmed my camera clock is 4 mins ahead of time)
Photo data: File name: dscn3817j.jpg
File size: 147580 bytes (4000×3000, 0.1bpp, 244x)
EXIF Summary: 1/800s f/5.9 ISO160 81mm (35mm eq:450mm)
Equipment Make: NIKON
Camera Model: COOLPIX S9100 Camera Software:COOLPIX S9100V1.0
Maximum Lens Aperture: f/3.6 Focal Length (35mm Equiv): 450 mm
Image Orientation: Top, Left-Hand Horizontal Resolution:300dp Vertical Resolution:300dp
Image Created: 2012:04:19 12:08:29
Exposure Time: 1/800 sec
Exposure Program: Normal Program
ISO Speed Rating: 160
Ok. I was looking at Hekla now and then today on Mila webcam, direction is about 45 deg offset from your vantage point, and saved screenshot at 12:40, then it was clear.
I belive cloud was possibly further away, more to the south, out of webcam view, and be Cumulus forming and subsiding. They do so often. No proof, only my point of view.
Onto strain charts. “Scale Graph Overlapping” on units vs time (made myself) of HEK and BUR strain charts for the last days, shows the Sumatra quake (12 April) gave peak amplitude (útslag) of about + / – 40,000 units (1 sps) Uncorrected ( barometric pres.?)
BUR is “about normal in amplitude” last four days, only slight increase, but has had “agressiveness” from about 17:00 UTC on 16 April, then subsiding much after about two days, to about half value now tonight.
HEK strain has fallen total more than the charts appear to show (due scaling of them) of about 80,000 units “down” from 05:00 UTC on 15 April and until tonight. As I write this 23:00 UTC more fall is not visible.
I also have a suspicious cloud foto and one with a little surprise
The first one makes me think of a hot vapour cloud and the second well its just a scare 😉
Nice, odd refraction buenamusa, how did you get that?
I guess it was the rising sun shining on a water spot on the lense, cool eh
The first pic is from April 2 and oops sorry it was the setting sun.
First photo is only clouds. I am so used to see those clouds!
Second is camera refraction.
ahhh I just thought it looked odd the way they were hovering over the top of the mountain. It’s beautiful anyway and how I envy you. It has always been my dream to go to Iceland ever since I was in jr. highschool but I have never been able to get there. some day I hope it will come true. Today is my birthday 51 so I will have to make a wish.
Best Wishes Buenamusa. Many happy returns!
“Happy Birthday To You, Happy Birthday … ” *music*
Have a wonderful Birthday day..
Happy birthday, have a good ‘un!
I bring it sung in a jazzy adaptation from Marily Monroe’s version for “Mr. President”…
oh oh oh! SOOOOOOOOOOOOOOOOOOO Funnnnnnyyyyyy SPICA Thanks for the song I loved it also made my day. You guys are wonderful here and sooo funny I can´t imagine a day without reading what everyone has to say here. Un Beso Muy Grande para todos…mmmuuuaaaah kiss, Lorien (sounds better than Lori)
Thank you Jay. I have never heard that before “many happy returns” I wish I could return to being 21.
And thanks KarenZ as well
30 years ago we didn’t all have internet… 🙂
lol yes yes you are right! you just made my day I am so happy to be 51 and have internet as my oracle to answer the constant questions that pop into my head and to talk to people all over the world. Thanks to everyone for the greetings….Really great!!!
Belated Happy Birthday from me too!
as to the 2nd pic, if you ever get one like it for real, she will blow within 48 hours
Is it me or is the BUR strain really shooting up?
It is higher than it was on Tuesday although not so ”agitated”. It’s definitely not you Tyler, unless as previous comments suggest, you’re in league with unidentified forces or creatures?
Stórólfsvoll has also increased considerably.
Might be because its an approaching New Moon. Seriiously.
Because the up and down behavior in the strain is due to tidal forces (2 times up per day every 6 hours), And probably just like ocean tides, they are larger during New or Full Moon.
Hmm, since the Sun exerts a gravitational pull on Earth hundreds of times greater than the Moon, can you fit the observation to zenith and nadir, noon and midnight? Also, can you fit it to coincide with regular tides? If not, you’ll have to come up with a mechanism that explains the difference in timing between “earth tides” and regular tides.
Henrik, earthtides do exist.
You can actually see them on Búrfell all the time.
Why does the sun not give tides? Because it is a static pull, the moon is motional pull. If the sun started to move I would hork in my pants… 😉
We should though note that an earthtide has never ever caused an eruption. Period 🙂
Why is this important? Because if you are correct, a correction can be applied that removes tidal influences from the observations and leaves pure Hekla-strain for us to ponder.
The earthtides are actually easy to remove, they are the sinusoidal wave on Burfell. With a bit of good will you can handmap them away.
The final corrected strain has all of these things removed, but those are not open data.
Ooo! “Not open data”. A conspiracy! 😉
More like they have not thought about making it public I think. And, the data on the normal strain-rate is enough to see if Hell Opened Up™, Ice-cream soled at convenient Places along the Road… 🙂
First tides are much more affected by Moon rather than the Sun. Tides are not exactly correlated with Moon ascending near Zenith or passing close to the horizon, there is a lag of a few hours, but between tides there is a near exact 6 hours between them. Because the Moon pull is larger than the Sun, and sometimes they occur at same time, tides are significantly larger in new/full moons. If you observe the ocean every day, every hour, for a full month, you will clearly see that. Full tide is often several meters higher than low tide, and if, for example, there is hurricane storm at new or full moon, then flooding becomes unusually extreme. This is well known. Also the tidal effect also pulls the ground upwards and the atmosphere, this has been studied and confirmed, the effect is even larger as recorded on the Moon surface itself. I don’t understand the aversion of some people to disprove tidal effects. They are so well known. We talk here about the Moon, not of planets, which have tiny tidal effects (at most a few tiny mms). So, the tidal effect is recorded on SILs and strainmeters, you must look past this waving up and down, and realize that near new/full moons, data might get a little bit more up and down. About earthquakes occuring more often near full or new moons, there are some studies showing that, but the effect is somewhat little and often lost within background noise.
Good evening all.
I would like to rock the boat a bit. Something popped in my head earlier his evening. Alot of volcanoes in Iceland are calderas, why is Hekla not….. yet.
What type of signals would show “if” Hekla lost her feet?
Jamie… http://en.wikipedia.org/wiki/Hekla has a good description, you may wish to read. Especially ”Geology” ie: ”Hekla has a morphological type between that of a crater row and stratovolcano (built from mixed lava and tephra eruptions) sited at a rift-transform junction in the area where the south Iceland seismic zone and eastern volcanic zone meet. The unusual form of Hekla is found on very few volcanoes around the world…”
Yeah I know how she was made, I live across the street from her. I just wanted to know why she has’nt collapsed in on herself like Katla, Askja, Grimsvötn, Tindfjallajökull, Torfajökull, and Krafla.
What I ment to say Jamie is that it’s a fissure.
I think they need a shallow chamber and release a large amount of magma.
You need a massive eruption, either explosively to collapse the mountain, or a large amount of lava to empty its chamber. Or even better you need a shallow chamber.
Hekla is a young volcano and apparently it did not suffered these kind of eruptions yet. And its chambers are mostly located deep.
Only a part of the Icelandic volcanoes have calderas. Langjokull (seen from above), Hofsjokull (well defined, large and ice filled), Tungnafells (small), Grimsvotn (lake-filled, within the glacier), Bardarbunga and Katla (big calderas, well defined but ice filled), Tindfjallajokull (small and very eroded), Oraefajokull (small, almost like a large crater), Torfajokull (easy to spot but very eroded), Askja (the perfect one, ice free), Krafla (very eroded but easy to spot too)
Hekla, Hengill, Eyjafjallajokull, Krisuvik do not have calderas
Kverfjoll also has a caldera, and Esjufjoll it seems so, but both ice-filled.
Snaefellsjokull I think it does not have a caldera, only a large crater.
Reposting here as I think it got lost above:
”Irpsit… Would you know the map co-ordinates (or locations) of the borehole strain meters?
I am glad you can provide so much on-the ground experience and information, living in Iceland as you do, and I enjoy your posts and look forward to more.
I am asking because of the difference, between the drop of strain of Burfell 2000 eruption, compared to what seems to be an increase at the moment. I am trying to visualise the movement and pressures of the landscape and imagining the vectors underground. Thanks in advance.”
Apologies I think I’ve found them… http://hraun.vedur.is/ja/hekla/Stadsetning_stodva_31052011.jpg
Again, when does a crater become a caldera? The sloppy practice of calling every structure atop a volcano larger than a few hundred meters a “caldera” is really getting on my nerves. Some of those you list as “calderas” definitely are not calderas but craters, and many of the remaining ones have been created by processes other than those normally associated with caldera formation.
Good question. I am not an expert so this is pure conjecture on my part. To develop a caldera, the weight of the rock at the summit has to exceed the weight-bearing capacity of the rock / magma reservoirs beneath it so the rock at the summit drops down.
This might be caused by a) emptying of part of the magma reservoir; and / or, b) the supporting rock getting too ductile due to heat from rising magma.
So I guess that the warning signs for a caldera would be: deformation, EQs and increase in ground temperature. Pretty much the same signs as required for an impending eruption. If more is known about the weight bearing properties of edifice, there may be more specific signs to look for.
Sudden de-gassing may be important – suspect that fracturing of gas reservoirs could be an indicator.
The experts can now shoot this down or add more detail, as necessary ……
Not an expert… but Hekla has quite a few magma “chambers.”
The area around Hekla encounters a lot of continual rifting stress. Rather than being a probe of magma that snakes it’s way to the surface and the continues to build in one spot over the millennia, Hekla opens up as a rift every time, since that is it’s essence. Because it never has a chance to heal and suture the ends of the fissure and form a proper cone, it’s maintains it’s fissure characteristics.
Does this preclude a caldera (s) or just make the process of developing one more protracted?
I would think that it would preclude it.
There is never a long enough stay time for a consistent “chamber” to form. Each comes along, does it’s thing, and what’s left becomes a pluton. All you have are intermediate accumulations of segregated chambers. Some might mingle, but that tends to be the exception rather than the rule.
Dunno what what the current “chamber” count is at, but it’s pretty high.
Right now, Hekla is too young and erupting too frquently according to my understanding of the phenomenae.
a bit OS- fracking the way it is carried out now could subside how much land???
Fracking can’t subside land. It can lubricate faults by increasing pore pressure, but in itself, can’t make land subside.
Only gravity can to that.
So another question on the chambers of Hekla. When the word “shallow chamber” is used, how deep, btween top of the chamber to ground are we talking, and how deep would it be called deep chamber?
From the guts, some will come with magnificent links and references and correct if necessary: shallow I’d say everything from 0 to maybe between 5 and 10 km. Then, deeper than 10 it starts deserving being called deep.
Remember the thickness of the crust for comparison: oceanic 5-10 km, continental 30-50km, a bit more in the Himalaya… 🙂
I think this may be relative and not absolute usage, Jamie. Furthermore, I don’t think there are any fast rules to define exactly when a magma chamber is to be considered “deep” or “shallow”. My impression is that it is rather subjective and depends on the volcano, thickness and type of crust plus the observer.
what I meant, was there is gas and whatever there in a layer, once it is taken out the layer above would collapse ?
@ursh removing water from your kitchen sponge won’t make it collapse as such, it might make it subside ever so slightly if you had a weight on it to start with, but the water (before you remove it) won’t be supporting the weight above unless it was under pressure – and couldn’t get out at the sides. So similarly the gas/oil removed won’t have been holding the weight of the sediments above, just spread out over a larger area of sediment/sponge (think only a drop of water in the middle of your kitchen sponge, won’t leak out if you put a weight on top, and comparing the shape of the sponge plus weight – before and after adding the drop of water doesn’t seem to have any difference). Or at least that’s how I see it. I am not an expert – porosity of the rock, the type of sediment and alll kinds of other things might affect it and I might be wrong, but I think fracking effectively increases the porosity slightly and maybe the minor earthquakes it apparently generates are tiny amounts of subsidence but nothing really noticably on the surface.
There are areas around Long Beach, California where the surface has subsided from oil extraction. Out in the central valley of California similar effects have been noted due to the extraction of water for irrigation. In oil fields the effect can be mitigated by water injection.
Caldera or crater collapse?
Well, those two terms may sometimes look interchangeable but as a general rule a caldera is always from a much more powerful event and by definition a much less common event. You can have a crater collapse without leaving a huge depression. The same can not be said of a caldera!
It is a question of force i.e. the explosivity index (VEI) which is key.
http://18.104.22.168/content/4/1/11.abstract (Latter uses the dreaded super volcano term but is from GeoScience so still useful, folks)
Thank you Jamie!
The answer is fairly complex, but I know exactly why Hekla has not gone caldera (yet). But the answer is fairly long, so I will do a post instead on it.
2012-04-19 23:41:09.2 34.34N 16.60W 80km 4.4mb MADEIRA ISLANDS
Interesting perhaps, any connection to the proposed feed to the Canaries?
A question GeoLurking, as you may know.
Re: Moment tensors, as I gathered from your excellent, article/post ”focal-beach-balls/”. Often when viewing regional MT maps, it appears difficult to recognise the extensional and orientation due to many tensors suggesting conflicting displays. (I realise there are slight distances between each recording, although depths are often similar.)
Any idea how that is?
In any bed of material, there are going to be conflicting stress and strain values. Also, in any given bed of material, the structural soundness (how resilient it is to cracking) is not generally uniform. In other words, some rock is weaker along one axis as opposed to another. It has a tendency to fracture along a certain plane. This happens at the crystal level, and at the larger (macro) level.
How the solutions come out depend on what the dominant stresses were, and how that interacted with the material.
When you see those “historical” solutions (when they don’t give you a specific one) you can look to see which orientation(s) are more prevalent. That will at least clue you in to what was most likely.
Personally, I tend to ignore the historical ones. They can only tell you what is most likely, not what actually happened.
Separate hot spots as far as I know. But both facilitate movement of the African Plate.
Thank you to you both.
Small earthquake swarm NW of Hveragero
My internet connection sucks tonight so going to watch a show for a bit, have fun everyone.
If it is being streamed across the Internet… shouldn’t that be a “Slow”?
Dude, sometimes I’m afraid of you… 🙂
Oh, that probably was sooo much of “not english”. …fear your… might have been better.
Should hopefully have my new (Gr)avatar up now.. At the craters of fimmvorduhals last summer.
So who thinks Hekla will erupt in 2012? Surely it can’t take much now to set the beast off?
What a mountain she is by the way. Unless you’ve been to Iceland, and seen her – from the side especially – you just can’t grasp her size!!
Oh… I think I can.
But it would never be the same as being there.
To me, Helka is amazing from the dynamics of how it works. It is the Yin and Yang of Fissure vs Stratovolcano…. not fitting either but being both.
Helka took the red and blue pill and told Morpheus to pack sand.
…and others would have taken the blue pill and told Morpheus to leave as they want to be alone with Trinity…
To slow people I recommend swallowing the blue pills as fast as possible. I mean, who wants to end up with a stiff neck?
Erm, sorry, that fat mess is not my fault or intention. I didn’t think the hork I wrote had to be pointed out in any way…
Personal experience hath spoketh
Nah, I’m nearly afraid of that stuff… 🙂
I fixed the leaking bold issue.
New gasket or diapers?
lol. Ok from now on a slash / in the right place will remind me of diapers. And it leaked from GeoLurkings comment not from Geoloco.
Well, eventually we’ll all get to that point in life.
Tall and strong we stand our whole life through, and then we need to get our bottoms cleaned by others. No idea how to prepare for that. One of the big challenges in life. Sometimes I think one should not miss the moment to end things by one’s own will. Someone very close asked me to organize that with him and accompany him after a cancer that made him paraplegic went on taking his upper body and wouldn’t have stopped until the end. Geeez this determination and strength in the eyes. The damn communists didn’t dictate him his life, and fucking cancer didn’t dictate him his death. Heaven how I don’t fell like letting someone else clean my ass. Lizards hiding behind the moon, think twice before you try to stick your instruments up my digestive system…
Yeah, GeoLurking. Terrific guy. I’ll start calling him GeoLeaking… Nah, better not, he’ll plot me some curse, or plot my alps away…
GeoLeaking has certain… completion potential.
In a much younger age, my cousins and I would see who could hit the far tree.
Celestial lights — northern lights this season
The latest map from IEO can be found on the link below.
An interesting article on the technology they used. Unfortunately the screen dump does not show enough detail to interpret the map. Pity as it also looks interesting.
At the moment we still dont know if we can go on holiday it all depends what the specialist says.
The activity at Fogo is still ongoing.
Question for Professor Sigrún Hreinsdottir:
Two years ago, there were basically three types of tremor displayed:
* The regular kind with fuzzy red, green and blue worms counting from top to bottom
* The kind that were influenced by nearness to power stations or traffic such as Reynihlid or Sandskeid
After her May 2011 eruption, Grimsfjall SIL joined the Godabunga group. Today, most – but not all – show the same type of activity ranging from some degree to far more intense. If we discount those that show weak changes and focus on those showing the most clear and unequivocal Godabunga-like activity – alf, ask, aus, bre, esk, hvo, kre, kvo, mid, mjo, mko, rju, sly, smj, ski, skr, snb, vat & vsh – what is it that we are seeing? Nineteen, twenty-one if god & grf are included, stations showing an increas in “Godabunga-like” activity? Is it due to observer-induced changes such as new equipment or changes in sensitivity/settings, instrument malfunction (over such a wide area!?!) or is it a real phenomenon and if so what?
PS. I have ruled out seasonal change as 2010 and 2011 did not exhibit this pattern.
1695 Psalmbook. Israel Kolmodin & Johan Olof Walliin. Same song that I told you that you had sung untill your throat fell out
Den blomstertid nu komma
med lust och fägring stor.
Nu nalkas, ljuva sommar,
då gräs och gröda gror.
Med blid och livlig värma
till allt som varit dött,
sig solens strålar närma,
och allt blir återfött.
De fagra blomsterängar
och åkerns ädla säd,
de rika örtesängar
och lundens gröna träd,
de skola oss påminna
Guds godhets rikedom,
att vi den nåd besinna
som räcker året om.
Man hörer fåglar sjunga
med mångahanda ljud,
skall icke då vår tunga
lovsäga Herren Gud?
Min själ, upphöj Guds ära,
stäm upp din glädjesång
till den som vill oss nära
och fröjda på en gång!
Du milde Jesu Kriste,
Vår glädjesol och sköld,
Ditt ljus och hägn ej briste,
Uppvärm vårt sinnes köld.
Giv kärlekseld i hjärta
Men dämpa lustans brand;
Vänd bort all sorg och smärta
Med mild och mäktig hand.
Du Sarons blomster sköna,
Du lilja i grön dal,
Ack, värdes själen kröna
Med alla dygders tal.
Av Sion må hon fuktas
Med nådens dagg, att hon
Förskönas och befruktas
Som ros på Libanon.
Välsigna årets gröda
Och vattna du vårt land.
Giv oss nödtorftig föda,
Välsigna sjö och strand.
Av himlen drype fetma,
Bespisande vår jord,
Och flöde nådens sötma
Till oss av livets ord.
I sort of figured it would be the song from Dunderklumpen.
I did not know that Dunderklumpen theme song was a church-psalm
Depends on the Church….
Well, the Dunderklumpen psalm is not really a church psalm.
But the lyrics I posted is one of the oldest psalms in the Swedish Lutheran (protestant) Church. It’s been one since 1695. Still sung every summer on the last day of school. You could wake me up in the middle of the night and I could sing it without even waking up…
Lovely as it is, and similar as the sentiments expressed are, it does not match the song in Middle English posted by Talla:
Sumer is icumen in,
Lhude sing cuccu!
Groweþ sed and bloweþ med
And springþ þe wde nu,
Awe bleteþ after lomb,
Lhouþ after calue cu.
Bulluc sterteþ, bucke uerteþ,
Murie sing cuccu!
Cuccu, cuccu, wel singes þu cuccu;
Ne swik þu nauer nu.
Sing cuccu nu. Sing cuccu.
Sing cuccu. Sing cuccu nu!
Summer has arrived,
Loudly sing, Cuckoo!
The seed grows and the meadow
And the wood springs anew,
The ewe bleats after the lamb
The cow lows after the calf.
The bullock stirs, the stag farts,
Merrily sing, Cuckoo!
Cuckoo, cuckoo, well you sing,
Don’t ever you stop now,
Sing cuckoo now. Sing, Cuckoo.
Sing Cuckoo. Sing cuckoo now!
Yesterday evening there was a discussion here on strainmeters in Iceland. I think I’m in need of some kind of explanation of how strainmeters work and how to interpret the readings!? I might not even be the only one at loss?
To start somewhere, it seems to me that there is a zero strain value on the charts (0e+00), and from there strain can move either in a positive or negative direction. This leads me to interpret the current Hekla strain as negative high (whatever that means) but with low activity? Am I completely off target or is strain measured somewhat like EQ P-waves where you have a positive and a negative value ( beach balls)
Can anyone explain? Carl?
BTW. I seen on the Icelandic page for strain that they have a new page in the works and will be open shortly. Maybe we will be able to check the archives again.
All verrrrry quet. Just like an Angel flew by. Ah, remeber – Schleepy Dalek Bar opening or Spot That Lava competition later today! *hopeless at it*
Nice webcam view of “Lady-H”
some activity near Katla?
The 3.0 is still of poor quality… But hey, Katla is always so worth watching…
yeah, now its gone:)
Bird must have hit the antanae
or a flying sheep….
I’m with cowboy on that one. Sure must have been one of the flying killer sheep.
The Name that Lava will posted my 18.00, and that is blogtime 16.00.
If that picture ever finnishes loading. Sigh.
Carl, did we ever decide on a date for the BBQ? I think we did, but I forgot.
14 july 🙂
Heh, yeah, I had a friend describe it to me a few years ago, said it was one of the oddest things that he and his brother had run across in a movie theater. To this day they still haven’t figured it out…. but it was un-nerving.
That same friend is going to be returning with a stone from Edinburgh… as requested. He found it odd that I would ask for a stone rather than some other item… such as a sweater from Scotland.
Swedish movies are… well ehm… pretty far from the concept of Swedish Sin reallly. We go actually more for weird than smut… Against popular belief
That is unfathomable! But the rabbit (or whatever) is obviously a Reading fan so it’s OK by me!
Anyone of a certain age remember ‘The Singing Ringing Tree’? It terrified generations of British children. It seemed to go on forever and no one understood a word. There was a fish and a dwarf in it, as well as the tree, and a girl.
I will not be around tonight, serious case of real life.
I will pop in tomorrow and give out the points.
Hope it’s serious but not bad.
anyone with a good understanding of fracking able to give an opinion on my comment up the page – I think the analogy of a kitchen sponge is roughly right but if not I’d be interested 🙂
The water is pumped down under a lot of pressure, and is containing chemicals to get out what is interesting. So it’s not just like a sponge soaking water and giving it out…
But: the main problem in my opinion is not related to stability. It’s about linking aquifers or opening a passage to them, and then polluting groundwater.
The pressure applied and type of rock usually concerned makes it much different from when you want to create a volume for a water circulation in hot layers for geothermal electricity production en example. At least if I understand it right and you’re talking about fracking for shale gas exploitation.
The “chemicals” and additives used in fracking are primarily concerned with propping open the cracks that are generated from the fracturing. Once you have gone to the trouble of breaking the rock, it does little good if you release the pressure and all the holes close back up.
As for aquifer contamination… the biggest hazard is poor sealing of the casing. Generally the drilling engineer can tell what the formations porosity is like from the status of the drilling fluid (mud) that is used. Loosing fluid to the formation is a clear indicator that the strata is taking the fluid. In this case, they take other action to seal the formation and maintain the well integrity.
Once you get the product flowing, the last thing you want to do is loose it to a shallower formation. Big time loss of money there.
In order to do the frack, the dynamics of the formation are looked at and the fluid is pumped down… the well pressure is then raised above the fracture gradient until the formation breaks.
This is about as far as I can go with my limited knowledge… I do recommend that anyone interested to read up on it rather than buying into hype.
Before fracking… there was nitroglycerin. It’s been done for years.
Shooting an Oil Well With Eighty Quarts of Nitroglycerine, Pennsylvania
I go with you on most of it. Just that for the aquifer contamination, there’s the risk of having fractures leaving the horizon of interest, and leading to another layer with another porosity… There the drilling engineer has no more control, it’s no more a question of seiling, and at this stage you realize that you loose fluid quite late.
I’m not against it as a principle. It’s just that the question remains of at what costs / risks should exploitation be done. And we know that those who do this are amongst the most money driven lobbies. If well and cautiously done it can be an option, under very interesting geological circumstances. But some seem to begin to quickly come to that solution. Like anything planning an preparations needs time and money. They have non of it in spare. And when they started investing, they will not quickly abandon a project, even if it starts looking sub-optimal.
I’m not green hyping… 🙂