In todays news at Rúv News there was a report about Katla volcano. This news has a interview with a Einar Kjartansson geologist at Iceland Met Office about the earthquake activity in Katla volcano. Einar speaks about the earthquake activity in Katla volcano yesterday (3. September 2011). But he also speaks about how activity in Katla volcano has been increasing during this year and it is more then it is normal in Katla volcano. But it is important fact that Katla volcano always has earthquake actvitiy, even with earthquakes up to ML4.5.
He also says that this increased earthquake activity in Katla volcano is due to dike intrusion into Katla volcano or some other activity that is currently taking place in Katla volcano.
Flood in Múlakvísl glacier river
During yesterday and during the night there was a glacier flood in Múlakvísl glacier river. This time around it was not connected to the activity in Katla volcano. But due to heavy rain in this area and melting of the glacier in the heat that has been in Iceland for the past few days. Since then the flood has subsided and Múlakvísl glacier river is back to normal and the flood has subsided.
News about all this.
Aukin skjálftavirkni í Kötlu (Rúv.is, Icelandic)
Braut niður varnargarð (mbl.is, Icelandic)
Miklir vatnavextir í Múlakvísl (Vísir.is, Icelandic)
He, he… My two cents of provocation, only to “heat up” a tedious Sunday afternoon:
When I saw those strange cloud formations, typical at Katla, I was expecting to hear about some kind of flood. And there it is.
I know, I know, “Katla does not steam”, and again, I am not saying she does.
But, coincidentally, when those clouds (which are not “steam plumes”) appear, we see a hlaup.
I wonder what kind of microclimte causes this kind of convection that makes the “steam” rise. Yes, after all, clouds are nothing else, but steam – condensed water vapor.
Yet I need some kind of explanation as for why there could not be some kind of connection of this cloud formation and temperature gradients within the glacier.
Repeat: I am not saying that this volcano is steaming!
🙂
Since I have been travelling in this area of south Iceland today, I can say that this where only rain clouds. All the rivers in this area are considerably higher than a week ago due to the heavy rainfalls.
Today I actually saw, and much to Carl interest, a big steam column rising from above Hengill. But that was/is a well known hot spring in the area, that I see it every once in a while from here 20km east. But today it was impressive to see. Maybe because the wind was so calm and light conditions favourable to increase far away observation.
Sunday
04.09.2011 14:48:49 63.544 -19.106 0.1 km 1.9 99.0 4.0 km S of Hábunga
Sunday
04.09.2011 14:48:49 63.544 -19.106 0.1 km 1.9 99.0 4.0 km S of Hábunga
For me that is the strongest EQ at this point i have seen this summer, also very shallow. Was the flood near this area? For me i do not think Katla is able to un ring the bell and it is on a count down.
Katla’s G spot? 🙂
lol
Though I would have translated Einars sentence like this:
He also speaks about how activity in Katla volcano has been increasing during this year and it is *more than usual* in Katla volcano, for who knows what is “normal” for Katla.
Today is going to be busy I suspect. A minor harmonic tremor spike on Lágu Hvolar SIL station, it stands out from the normal background activity.
I am going to make a blog post about if something more happens if it comes this type of activity.
A question: are repeating signals on your Hekla helicorder at around 11:00 UTC human-caused?
Yes, there is a lot of noise (as so often on weekends) on my geophone. There are few earthquakes there since yesterday. But most of it is human noise.
Swarm starting again…
There is more going today then yesterday in Katla volcano. I am going to put up a blog post around 20:oo to 21:00 UTC about today’s activity in Katla volcano.
Whats happening at Jokulsarlon – the webcam shows a great deal of small ice . Has there been a lot of rain or surface run-off along with warm weather – ? Irene’s aftermath?
Irene stopped by.
Yes! It rained like hell in last 2 days, and today it was warm, maximum around 20ºC here, which is hot for September. And it was actually hot in the sunlight.
What a time for IMO site to go down!
Yeah, often seems to happen when it gets interesting…. At least the cameras are still up!
I’ve been only a day off, and two new threads already… Next week I’ll be a few days off, how many threads I have to cover by then?! 😉
If I proposed any equation for the moment, I had taken that from a Wikipedia article, no more science, education or experience there. I guess from here: http://en.wikipedia.org/wiki/Moment_magnitude_scale
I’d like to comment the older threads on the calculation of cumulative earthquake moments. Let’s just assume first, we have a clean & nice tectonic quake, so that we’ll end up measuring both the S- and P-waves properly in several stations…
Well, determining the exact location of the earthquakes is the easy part, as you’ll only be calculating time delays. After that comes the ugly part: Magnitude determination.
Provided the medium (environment of the epicenter) is homogeneous, it would be easy to determine the magnitude as the eq waves would attenuate identically in all directions. But, since there was an earthquake in the first place, the medium can not be completely homogeneous, as a crack or fault always affects the spread of quake energy (spread of energy in dependent on the direction relative to the fault).
So, what do we have now? Most likely we have a clue, there’s a fault zone or a volcano, but no DETAILED information on the innards (structure, materials, faults, cracks, magma chambers, etc.) of it. Our network has given us clean information on the location of the quake, but unfortunately the measured attenuation of the waves (our seismometer signal) does not match the calculated attenuation (only due to distance from epicenter). Why? As the ground is not homogeneous!
So, I’d guess there are a bunch of possibilities now: You could estimate the quake magnitude simply based on the strongest signal (incl. the calculated attenuation factor). Or, you could use the mean from the calculated ones and apply a common correction factor. Or, if you have some historical data on how earthquakes are seen in different seismometers and from different locations, and apply a correction factor for each station separately. And you could hope there is no sand between the epicenter and your seismometer. Sand behaves nonlinearly: Small quakes get absorbed, but strong quakes transform the sand to a “liquid”! Yes, sand starts to behave like water, if shaken vigorously enough. There’s even experimental proof of that!
I do not really know how it is done, but I’d guess it is bit like I wrote above. Add to this magmatic quakes (one of the waves missing and the other one mushy without a proper wavefront signal), and you’ll soon end up into a loop of refining a giggletygiggle signal which would be better sent to “you pick your favorite name for a place better to be forgotten”.
I’ve been doing XRF analysis and even some X-ray crystallography studies in the past. You’ll never match the peak amplitudes perfectly, it’s simply not possible due to various factors that are simply too multivariable or too detailed to be taken in to the equations. But in the end, fortunately it does not really matter! It turns up, it is enough to get the patterns (peak groups) match (relative peak intensities are close to correct ones), and the results will be accurate enough for science.
So, Lurking, I suppose you do not know what you’re doing… 😉 I’d guess, determining the magnitude of the quake is still the easy part here, as they are already given by IMO. The various equations seen here and elsewhere make it only more complicated. Looking at the Wikipedia page on seismic moments (or any other related) leaves an impression that not all needed for the calculation is told to us. If I have understood correctly, you’ll need information on the type of rocks, their strength, etc. at the epicenter. If you’re working beased on some assumptions, well, I wish you good luck!
However, I’d guess the inversion scheme proposed by Carl might work. But you’ll need serious mathematical tools for that.
I’m not a volcanologist, nor a seismologist. I’m a mad physicist who knows a thing and two about measuring, and a few more about ruining a measurement…
You know… that sand thing, It just gave me a horrendous thought.
As a seismic wave enters water, it transforms into a T wave. These are usually seen along coastal seismic stations as the wavefront comes ashore. That T wave goes into the rest of the “wave group” with the P, S, and all the various path waves (SkS, SSS, ScS2 and a HUGE group of other path nuances).
I imagine that anything approaching “wet sand” in consistency would really screw with the analysis of local quakes and be highly dependent on it’s strength (as you mentioned)
Gawd, what nightmare.
Nicely put Jack!
Liked it a lot. You have real knack of explaining things in a good and simple way. Always the sign that one knows the subject well.
If you wish to try the sand thing I have a home experiment for you.
The state the sand enters is a sub-set in between liquification and superfluidity called non-newtonian fluid. All you need is corn-starch, water and a sub-woofer. Or you look at this youtube clip.
http://www.youtube.com/watch?v=scbPKjU8Ssg&feature=related
As you now understand the difficulties involved, I’ll drop the final one: The same knowledge on the environment of the epicenter is needed if you want to calculate the cumulative moment or stress release for the quakes involved.
So, basically I think the whole issue lies on a bed of guestimates!
Somehow OT, but did someone realized the EQ swarm on in the German-Czech Border Region? According to german volcano blogger Marc the depth varried between 10km and 3km. Some informations about that cheb area (german, so please stress aunty googles translator: http://www.vulkane.net/vulkane/cheb/cheb.html
EQ Map here: http://www.erdbeben-in-bayern.de/aktuelle-beben
Quite impressive swarm!
Yes i realized it.. here is a report from a german newspaper.. (use google translator)
http://www.freiepresse.de/NACHRICHTEN/TOP-THEMA/Beben-im-Vogtland-erreicht-Staerke-4-0-artikel7749386.php
These?
http://i51.tinypic.com/1z2h8o7.png
Dunno. There was mention of “magma on the move.” But I don’t know of a volcanic structure in the area. The nearest thing I could find were some mountains to the west… but I don’t think they are volcanic.
Beats me.
Last known eruption 8000 B.C.
I’d like to know the source of that.
“The youngest volcano at the Bohemian territory was active before some 850 000 years”
Komorni Hurka Volcano
50.100833°N 12.336667°E
http://wikimapia.org/11781870/Komorni-Hurka-Volcano-Kammerb%C3%BChl
That was probably the silliest volcano I have ever seen, only Goethe could have gotten off on that one…
I guess the real question is when does a cinder cone become a volcano…
Don’t forget the rootless craters…
The caldera without a volcano (I think it was Boris who came with that one) is though my personal favourite. I guess that Godabunga could be one of those, the little teasing minx 🙂
Laacher See is a nice example of a volcano crater with out a mountain.
hiya guys. watching the katlacam just now, something VERY odd turned up. I made a gif of it..
http://makeagif.com/i/6HXh7p
you can see a light seemingly illuminating the cloudbank from WITHIN it.
probably nothing, but I thought I’d show you all anyway.
hmm interesting.. but i think it is a lens reflection or something 😉
yeah, probably. lol
Isn’t that where the alien base is?…..calm down i’m kidding!
It could be a shaft of sunlight, caused by a gap in the higher cloud. The shaft of light illuminated the lower cloud for a short while. I think 🙂
Odd – it’s very bright for reflected sunlight and goes on a long time for lightening / static electrical discharge from the clouds.
I also suspect “shaft of sunlight” … what else could it possibly be but that?
Is that near Maria Lage? And is that unusual for that area? I don’t think the Eifel volcano’s are waking up?? 😉
its not the Eifel, its more East, in Czech, but near the border to Germany.
Ah, thanks. I just saw it in the German article: Vogtland…
yes, about 450km east from eifel.. (i live there, near eifel)
😉
IMO back online.
Whats on the katla cam now? looks unusual
Sheep 🙂
Sheep and fog.
lol …. I knew I get that answer when they walked past
It was something like the white light Mark referred to, probably just the camera playing tricks
If its not the alien base, unlikely, its probably a static electricity discharge in the clouds.
What is that white thing passing by? I have seen it often!
No, I don’t mean that sheep 😉
There is a false earthquake on IMO earthquake list. It is clearly a error as it has the size 10,7 ML. Please ignore it.
What? You mean there was no asteroid impact?
Very glad indeed that was false, it would have been very inconvenient for us humans, plus going back to the stone age would be very boring….No Internet.
Nope. I just slammed the door of my car, when I drove by 🙂
Sorry, just the after effect of bean-stew again…
Whatever it was it must have been inside the SIL-station. I guess someone put a piece of dynamite in it.
Because a 10,7 would be something like a kilo of dynamite at zero distance 🙂
Hilarious though, if it had been a 10,7 the only way we would have been knowing about it is that Iceland ceased to exist and my house would have collapsed…
Please stay off the bean-stew 😉
Oh because I felt this huge shaking that ripped off my head. Just before my death, I said WTF it’s a M11.0 earthquake.
By the way…
I have a very simple solution for the Cumulative Seismic Moment plot ending in July. I guess that it froze during vacation time, and nobody has seen it at the IMO yet. I guess they will get around to reboot it one of these days when they realize. Or more to the point, when they see that we are harping about it here. I have noticed before that when we find an error and talk about it for a couple of days it mysteriously fixes itself… 🙂
I would not be surprised to see it up and running tomorrow monday or tuesday.
I do not think they are hiding anything, the IMO has never done that as far as I know. I guess they would be beaten up by angry sheep-hearders if they did hide something. And remember that everyone on Iceland is related to each other (albeit a bit far sometimes). Against popular belief Iceland does not have the population of China… 😉
Interesting thought experiment.
If you take Iceland’s 100,250 sq km of land area, divide it up into 8 x 8 meter blocks, and put one person in each box, you could accommodate the entire population of China, and still have room for a volcano.
New blog post is up! 🙂
Is global warming causing more earthquakes & more powerful quakes? Chart: Earthquakes vrs Arctic Ice Loss …
http://twitpic.com/6g5e63/full
Correlation does not mean that there is causation. I doubt this.
I would say that there is a correlation between the global warming, and the totally unrelated instance of there being more seismometers deployed…
There is also the hitherto unknown correlation between my increasing age and more earthquakes. 🙂
One should always be carefull of overinterpretation and over-patterning.
Equally possible that rising magma causes warming, at least on a local level.
Done a bit of research. Germany does have extinct volcanoes but these are some distance from the epicentres of the earthquake swarm. However, there is a mountain range in the region called the Ore Mountains on the German / Czech border. These are not described as volcanic but do have ignacious rocks in them (granite and basalt mentioned) so some volcanic activity in the past. They were later fractured and folded by the collision of the European and African plates.
As has already been said, there is a lot of geothermal activity (hot springs) normally associated with volcanic activity. So either the earthquake swarm is a result of movement of the plates (we even get the odd earthquake in the UK attributed to this) or something interesting may be on the way.
I read somewhere that scientists no longer use the term extinct because volcanoes previously thought to be extinct have errupted. They prefer to say not errupted for a long time. (I am paraphrasing from memory).
Not erupted for a long time equals (more or less) dormant, i.e. sleeping.
I would like to translate some things from the quakes in Germany:
http://www.freiepresse.de/NACHRICHTEN/TOP-THEMA/Beben-im-Vogtland-erreicht-Staerke-4-0-artikel7749386.php
“Beben im Vogtland erreicht Stärke 4,0” -> Earthquake in Vogtland reaches Magnitude 4 (on the Richter Scale).
“Es sei damit das stärkste Beben der aktuellen Schwarmbebenserie, die seit Ende August immer wieder die Region erschüttert.” ->This is the strongest Quake of the Earthquake-Swarm, which rattles the region since the End of August.
“Gestermann sagte, die Fachleute hätten derartig heftige Erdstöße nicht erwartet. “-> Gestermann said, the professionals (seismologes and geographers?) did not expect such strong quakes.
“Die Stärke liege am oberen Ende der für die Region typischen Erschütterungen.” ->The reached Magnitude lies on the upper Level (of Magnitude) for this region.
Then it is said, that the Region has frequent swarms and the last one was in 2008, so this seems to be normal activity in this part of Germany.
“Die Region ist vor allem für ihre teilweise heißen Quellen bekannt, die für Heilzwecke genutzt werden.”
-> The Region is know for its hot springs, which are mostly used for Healt-related Cures. (Heilzwecke in English?)
http://www.vulkane.net/vulkane/cheb/cheb.html
“Neben den Vulkanen der Eifel zählen die Vulkane in Böhmen zu den bekanntesten Feuerbergen in Zentraleuropa.” ->Next to the Volcanoes of the Eifel, the ones in Boehmen belong to the most know Volcanoes in Central Europe.
“Der letzte Ausbruch fand hier vor ca. 10.000 Jahren statt, also in etwa zeitgleich mit dem Ausbruch des Laacher-See-Vulkans in der Eifel.”->
….The last Eruption has taken place around 10’000 Years ago, most likely at the same Time as the Eruption of the Laacher-See-Volcanoe in the Eifel (At the End of the last Glaciation->Glacial Rebound Effect->Landrise?)
“Die Wissenschaftler sind sich sicher, das sich in 35 – 25 km Tiefe ein Magmenkörper befindet, der in die unteren Schichten der kontinentalen Kruste intrudiert.”
Scientist are certain, that at 25-35km below the surface, a magmatic body is intruding into the lower sheets of the continental crust. …
The article goes further in explaining, that curently there seems to be no sign of any danger or eruption, and that most likely the intrusion will somewhen stop and cool down inside the crust.
There’s that ‘10,000 years ago’ (8,000 BC) thing again. That’s HOLOCENE.
What volcano? Where? (Lat and Lon if no name.) If it’s Holocene it should show up in somebodies list somewhere.
This is a bit frustrating.
http://volcano.si.edu/world/region.cfm?rnum=0100 lists only West Eifel Volcanic Field (incl. Laacher See) in Germany. It erupted 8300 BC and 8740 BC (both were explosive).
Wikipedia knows a few German volcanoes: http://en.wikipedia.org/wiki/List_of_volcanoes_in_Germany but none of them are in the east. And none is listed for Tzech, Austria or Switzerland. Poland has a few, though.
There’s an extinct volcano area closer, Vogelbergs Mountains (see http://en.wikipedia.org/wiki/Vogelsberg_Mountains).
Wait!
http://cs.wikipedia.org/wiki/Kategorie:Sopky_v_%C4%8Cesku
Nothing really there yet, but a few are close.
Evidently that runt of a hill is the 10,000 year old volcanism.
http://cestovani.kr-karlovarsky.cz/en/pronavstevniky/Priroda/Prirodnizajimavosti/Pages/PrirodnipamatkaKomornihurka.aspx
There is one thing that amazes me with the text.
First of all, the most well known volcanos? Hm, I haven’t been able to find well-known volcanos there. Just Lurkings piddly little hill. Second of all, if you have volcano that is showing the least bit of activity in the northern half of europe you bloody well know the culprit by name.
Something is fishy with that “wellknown volcano”. Let us say it had happened in Sweden, then we could have pin-pointed which of the six stonedead volcanos was doing the miracle dance.
No name = No volcano
The problem i think is, that all of the Volcanoes in Central Europe are “extinct” since the end of the last glaciation, so what remains of those volcanoes is most likely heavily eroded, doesn’t show any signs of activity, is only known by a few and so forth. I think not even all germans know that the Eifel is Volcanic in origin.
I’ve done a little research on my own and came up with the following:
http://www.daserste.de/wwiewissen/beitrag_dyn~uid,18urcjcbwm5xcsim~cm.asp
and:
http://www.geo.de/GEO/natur/58550.html
i think it’s best if you use google translate for this: but in short the article mentions the following:
– The Region “Vogtland” is seismically on of the most active areas in Germany/Central-Europe
– The last known Eruption has taken place around 300’000 Years ago (so the 10’000 is totaly wrong for the Region around Vogtland)
– The Earthquake swarms have a repeat-cycle of about 6 Years
– In the Year 2000 there were more than 10’000 registered Quakes
– Vogtland sits on top of two tectonic fault zones, that intersect each other (Egergraben and Marienbader Verwerfungszone. )
– In a Swamp in this Area a larger amount of CO2 and other volcanic gases are beeing emitted, which indicate, that the crust must be quite permeable(/brittle?) (gases: CO2, Helium and others, which indicate that the gases come from a very deep source)
– No large Magmachamber/Body was found in the last years
– It is belived that a Sill Intrusion is taking place at a depth of 25-35km, from which it is possible, that small amounts (Blobs/bubbles?) of magma are rising further, and thus releasing the Gases which are emitted/meassured on the Surface (Swamp)