The man made earthquake swarm in Hengill volcano that happened today seems to have subsided, as it is most likely that Orkuveita Reykjavíkur has stopped pumping down water into the new drill hole that they where using today.
Over 400 earthquakes have been recorded in this man made swarm. I am not sure on the depth on most of the earthquakes. But it is in the range of 1 to 10 km from what I can tell. The largest earthquake in this earthquake swarm was ML3.4 in size, it had the depth of 3.9 km.
The man made earthquake swarm in Hengill volcano. Copyright of this image belongs to Icelandic Met Office.
I am going to post earthquake traces on Sunday or Monday. I am currently not at “home” (where my main computers are located), as I am taking this weekend off (if nothing large happens this weekend).
Two of the earthquakes from the man made earthquake swarm in Hengill volcano. This picture is released under Creative Common Licence. See licence web page for more details.
It is hard to know what happens as Orkuveita Reykjavíkur continues to pump down water into Hengill volcano. All that can be done is too wait and see what happens.
Blog post updated at 21:48 UTC on 26. September 2011.
We’ve all been looking at Katla & Hengill today, but slightly surprised no-one has mentioned there’s been a couple of quakes in direct line with the Hekla fissure:
http://en.vedur.is/earthquakes-and-volcanism/earthquakes/southerniceland/
Any slight significance to those?
They are on SISZ earthquake zone. It is not part of Hekla volcano.
Hekla is not a normal volcano. Best I can tell is that strain and stress is what sets it off. As Jon mentions it’s not part of the SISZ, but it’s fissure swarm seems to overlap the eastern end of the SISZ.
But… the SISZ can and does have thousands of quakes with no acknowledgment at Hekla.
On the other end is Hengill and it’s hydrofrack festivities. There were a couple of good pdf linked earlier and I thought that they might yield what the geothermal gradient is down there. That would go a long way in understanding what is where and whose cat was being skinned. Tracking down the sites it turns out that the pdfs were mostly about the area up around Krafla.
But… not giving up on the gradient idea, I did strike paydirt.
The Hengill geothermal area, Iceland: Variation of temperature
gradients deduced from the maximum depth of seismogenesis
FOULGER G. R. ;
Univ. Durham, dep. geological sci., Durham DH1 3LE, ROYAUME-UNI
“The geothermal gradient below drilling depths in various parts of the area ranges from 84 ± 9”C km-’ within the low-temperature geothermal area of the transform zone to 138 ± 15°C km-’ below the centre of the high-temperature geothenal area”
Saves the trouble of trying to figure it out. The discussion about the affect that pore pressure has on rock failure threshold is enlightening.
Another tidbit from that document:
“…the maximum depth of seismicity may be viewed, to a first order, as an isotherm.”
This is interesting since I have seen a slope in the quake depths deepening along the SISZ to the east. Then a somewhat dead zone near Helka, with quakes picking up again in the area of Tofajökull, normal volcano style. (scattered, but dropping more tightly down the middle). Hekla’s dead zone is just plain spooky.
Additionally, the paper mentions that aseismic areas in seismogenic regions may be indicative of ares of increased melt percentages.
“Seismic tomography and gravity studies provide no evidence for a substantial, shallow magma body beneath Mt. Hengill, though a small low-velocity body in the depth range 2-4 km beneath the NE flank of Mt. Hengill may represent an isolated body a few km³ in volume of up to 7% partial melt…”
http://www.dur.ac.uk/g.r.foulger/Offprints/Foulger1995.pdf
OMG I see a seventh order harmonic progression headed towards Hekla! RUN! …. haha just kidding
@Craig M from last thread
“As an observation on the quakes which I have been following at IMO but not in any detail. I can’t tell if they are more frequent or changes in depth but they do seem to be getting larger the longer this project has gone on. ”
http://i56.tinypic.com/2lwont5.png
Interesting plot … took me a closer look to decode the scaling. Got it: mag in blue, depth in purple. The thin time-bands are when they open the faucet, I guess.
According to the Iceland Review (in English but quoting visir.is), after the former 300+ earthquake swarm occurred in the Reykyjanes peninsula, the information officer for OR’s geothermal plant noted that because the quakes were below magnitude 3, there was “no reason to be concerned”.
Now that the recent swarm has produced two quakes over 3, I can’t help but wonder if they are still so “unconcerned”.
http://icelandreview.com/icelandreview/daily_news/Power_Plant_Causes_Tremors_Near_Reykjav%C3%ADk_0_382267.news.aspx
http://hraun.vedur.is/ja/myr/myr_str.html#img
This graph stopped updating last wednesday! Anyone know why and where i can find the most recent measurements??
Truthfully?
No. I don’t. This is the very plot that I can’t replicate since their listed formula doesn’t yield the same plot. Can I fake it? Yeah, but it isn’t useful unless you can tie it into some sort of meaning.
All the linked measurements on this page are frozen – increasingly I have found that other vedur.is pages are password protected – it is becoming harder to evaluate the implications of recent EQ activity – or am I just inept at data mining lol…..
No… but I tend to mostly ignore it and brute force my way through the quake data. The passworded pages are usually the ones with the fine grained GPS data. I don’t begrudge them locking it down, that’s research grade material and not the easiest stuff to produce.
Some of the site layout is a bit disjointed and occasionally you will hit a P/W’d page that just gives the location data for a GPS site. I usually dig around on the internet until I find a paper with the info in it.
Do not worry, that one is updated manually.
I would guess they will post an update on monday or tuesday. 🙂
Hey, I think something’s up near Kverkfjöll.
Saturday
24.09.2011 02:49:18 64.637 -16.718 1.2 km 3.5 90.08 4.7 km W of Kverkfjöll
I wonder if all those mag 3 + are not originated from the pumping…
Logically they can’t be related. But nevertheless, how very strange… 😯
Like a chain reaction?
Literally, that sounds like “playing with fire”.
How about the tremor at Katla?
Still, winds?
Really looks like there’s an overall “nervousness” among Icelandic volcanoes after the Hengill plumbing.
The Katla 3.2 was about 8 hours BEFORE the Reykjanes earthquakes, and the Kverkfjöll 3.5 several hours after the latter. So in sequence you would have to say that Katla started it all, unless of course she just knew that they were going to start hydro-pumping and that made her angry. 😀
My friends, Katla, Hengill and Kverfjoll went to party Thursday night, so yesterday they were all with hangover. There is a paper in Nature showing this to be true.
Well if there can be an exception to Eistien’s theory, then maybe our logic is is not logical . For those who have not seen the report,
here’s the link
http://www.sciencedaily.com/releases/2011/09/110923084425.htm
Sorry, that was a response to Denise-Marie’s post.
Is it sure its just wind at Hekla? I’ve been thinking about Hekla for a week now, and I have this really strange feeling 😛 Just like I had on Katla a few weeks before the what happened in July =/
Yes it is just wind causing the raised tremor levels in South East Iceland. They have a gale warning of Force 9 dropping later to F8 according to the British Met Office here.
http://www.metoffice.gov.uk/weather/marine/shipping_forecast.html#All~All
Winfd is now affecting all tremor stations in SW-S-SE Iceland.
Well, for Carl, here it is, another Hekla transient.
http://hraun.vedur.is/ja/hekla/borholu_thensla.html
@Pieter
‘Scuse my ignorance, but what is a “transient” in this context, i.e., volcanoes in general and Hekla specifically?
I’ve been trying to get my head round the graph… Presume it means borehole deformation but without any associated tremor? Sign of a fault movement?
No, a transient is when the mountain is trying to open up due to internal pressure, it normally happens after increased activity in Hengill Spungrur Area (SIFZ = Southern Icelandic Fracture Zone), a fracturing zone that starts south of Hengill and runs all the way to where the Hekla aseismic zone starts.
It gives transients in the Burfell borehole strainmeter.
Sometimes Hekla gets affected by activity (high) in Katla, but that shows up in the Geldingáa borehole strainmeter.
I refer to the Burfell transients as aborted eruptions, since I believe them to be precursors to the real event. They during the last year grown more and more frequent, and increased in power.
Todays transients are both frequent and very powerfull. Close indeed to an actuall eruption I think.
The earthquake in Kverkfjöll volcano seems to have been just one event. I do not see any aftershocks or any other earthquakes happening after that earthquake.
Well, there was a foreshock (1,5). But I have no idea of what it means. Ans it was a deep one. (~16km)
Einstein, neutrinos et al!:
Einstein against all mediahype has not been debunked.
The neutrinos abillity for +lightspeed is actually pointed out inside the theorybuilding of the relativity-theories. It was first pointed out in the sixties and have been kind of “common knowledge” among physicists and science fiction writers since then.
The reason behind this is that the neutrino is dual-ability particle, in one state it has a very minute mass (weight) and in the other it is mass-less (As hypothetized in Quantum Electro Dynamic, google Feynman Diagram and beta-decay). Since mass is what CAN NOT travell faster then light, it was therefore theorized that in the mass-less state it would be able to travell faster then light. It is an allready known theory that MIGHT have gotten proved at CERN.
Can YOU travell faster then light then? No… But if you travell at relativistic speed (lightspeed) you will have achieved infinite momentum-energy (energy and mass is the same in this case), so your mass will bend space in the direction you travell. So even though you are travelling at lightspeed, the distance will shorten due to folding of space. (in a sense of it, hyperspace)
Now, you cannot achieve C since you need infinite acceleration at infinite energies to achieve it, but you can theoretically get close, and then instead of folding space to two points meet up you will “bend it” so the distance shortens a bit (or more depending on how close to C you are).
My point here is to show that all possible variants of “apparant” +lightspeeds are possible WITHIN the theory complex of relativity.
This is probably the worst handled case of scientific journalism ever… 🙁
Yeah, I think the idea that it’s possible that a version could be supranational has been kicked around since ’85.
And just for a side note, neutrinos oscillate back and forth through the different types as they move along.
Imagine your Volvo turning into a Jaguar and then into a Vespa and back as it goes down the road. Neutrinos are weird critters.
*supraluminal, not supranational.
Actually, they are behaving as the electrons that they are formed off as a stage in the electron photon cycle. In this case a neutrino is an “electron lepton”.
Loved the Volvo, Jaguar, Vespa analogy 🙂
Thanks Carl. I almost followed that. I understand relativity a little more after that explanation. You should take up teaching again. 🙂
Carl, This post is a true gem! Have you ever been in teaching or lecturing?
Or, it could a bunch of young post-docs who have not been in the business long enough to gain any long-term (read: historical) knowledge from the old farts (professors).
Thanks, yes, I did a bit of teaching as a ph.d. student.
Nah, the post-docs know this, it is just some science journalist running way to far with it… The same as they do with volcanologists now and then.
Please keep the space related discussions on the the space blog. It can be found here, http://www.jonfr.com/spacewatch/
My apologies Jon. I got carried away and side tracked.
Forgot that one.
I just wanted to have this discussion finnished since the journalism about it was all wrong, I kind of wanted it out of your blog and thought it quicker to explain it all to every one in here.
what’s the biggest number of green stars on the same map on the IMO site ever recorded?
I wouldn’t have thought a post about the speed of light would be any more “on topic” for a space blog than for an earthquake blog.
Your blog, your rules….
Considering that neutrinos originate in radioactive decay of K40 and U238 of the Earth as well as (mostly) in Solar processes, and that the researchers are shooting the neutrinos at another research facility on Earth, I would think that you are correct.
Geology doesn’t happen at speed of light so to speak. But some changes in rock do happen due to effects of space.
But that can be discussed without any issue on this blog.
A public inquiry into the effects of all these man-made earthquakes before this project progresses too far might be wise. Swarms of several hundred quakes whenever there is significant drilling / pumping water & CO2 cannot be good for property, people and the environment (including nearby faults and volcanoes). At minimum, it looks like some pressure is needed for more controlled processes.
If I were living in Iceland, I would want to know exactly what was going on and a say in it. And if I lived in Reyjavik or anywhere else close by, I’d be even more concerned.
Public inquiries are just a pointless waste of money. I reckon the scientist’s and geologist’s involved know more about what they’re doing then the public.
Let them experiment, who knows maybe something useful will come out off it.
Not since the experimentation is being done by a public company that MUST do the experimentation to not go bust.
If the company stops it will most likely go bankrupt. This is exactly where you need a public enquiry.
skr plot looks jittery
There are tremor pulses taking place on Skrokkalda SIL station. They are most likely from Hamarinn volcano. But for the moment, it is hard to know for sure.
I am getting more convinced that a eruption is going to happen at EL Hierro volcano. Given the earthquake activity that is taking place there at the moment. But it hard to know for sure if that eruption is going to happen in few weeks time or in 10 years time.
The latest earthquake was a ML3.3 in size with the depth of 14 km. See here, http://www.emsc-csem.org/Earthquake/earthquake.php?id=236815#
It has had a few earthquakes over the past couple days. But according to GVP it does not have much of a history of eruptions – see links:
http://www.volcano.si.edu/world/volcano.cfm?vnum=1803-02-
http://www.volcano.si.edu/world/volcano.cfm?vnum=1803-02-&volpage=erupt
But the reference to “young cinder cones” may be a bit ominous. As the volcano does not have a clear history of recent eruptions, does this mean that, if it does erupt, the eruption will be large?
Can’t really say, but the seismic activity is along a somewhat cylindrical shape (laying on it’s side) stretching out under the ocean. It could just be a smallish event, as long as water doesn’t get into the main reservoir.
Not that there is a lot of potential for that, on average these quakes are about 11 km deep.
Okay, what in the flying @#$@#$ is El Hierro doing?
Any takers? Carl? Jack? Jon?
http://i53.tinypic.com/cqb9v.png
Note, that’s depth v time v mag. The top label on the plot is incorrect (depth v depth v mag). Deepening quakes seem a bit odd.
No, I don’t think the island is sinking.
Well, interesting plot.
The median may be sinking, butI guess you did notice the spread is also increasing? So, I’d say, it’s not sinking, but the activity is spreading to new depths (both towards surface and deeper). What this means geologically, I do not know, as I am only an amateur.
My guess, but remember that I am not familiar with that volcano.
I think that what you are seeing is quaking between two magmatic-reservoirs, one “shallow at 10 km, and then a deeper below at perhaps 20 km. I think what we are seeing in the end of your plot is widening of the conduit between them.
At least there is a high probabillity of a conduit opening.
I guess we will have an eruption in a few weeks there. Next stage would then be quakes that start to migrate up from 5-10 km as the new magma that has entered the system during the last days reach critical pressure.
Eh… only since I already did the plot.
El Hierro, September quakes color coded by date. 4D rotating plot.
http://www.youtube.com/watch?v=4Nz9udmbEs0
Okay, I am not offically scratching my head… Odd movement over time to say the least. Large movement over area, and small movement down. Must be either one hell of a slipfault at low angle, or the largest magma-reservoir on the planet…
earthquakes El Hierro – http://www.01.ign.es/ign/layoutIn/sismoListadoTerremotos.do?zona=1&cantidad_dias=10
http://www.facebook.com/pages/Actualidad-Volc%C3%A1nica-de-Canarias-AVCAN/163883668446
El Hierro: See also this one, it’s in Spanish language, but should be understandable. http://www.01.ign.es/ign/resources/volcanologia/HIERRO.html
Since this seems to be of interest, I’m cross posting these from the other blog just in case it was missed.
These are all quakes there in 2011.
Profile view looking North
http://i52.tinypic.com/dyt8nk.png
Profile view looking East
http://i52.tinypic.com/5an71c.png
Perspective view, looking to the Northwest.
http://i56.tinypic.com/263wzg5.png
I wonder… Might that be quakes in and around the magmatic reservoir as it fractures due to magmatic intrusion?
Then it has a hell of dusy of a magmatic reservoir..
Slightly OT… http://volcanogeek.wordpress.com/2011/09/24/a-curious-thing/
read it and her article sounds interesting indeed, I have no xp with Yellowstones Observatory and the info they publish…is it true??!?
You can see a disturbance right before the webicorder goes nuts. Looks like a malfunction to me. As for the rest of the network I don’t know.
http://www.isthisthingon.org/Yellowstone/daythumbs.php
Jon,
I have read somewhere that ice core analysis in Greenland and the Antartic has revealed that there was a large volcanic eruption in 1809 which led to a decade + of cold weather. Do you know any more about this? And does Greenland, itself, have any volcanoes – I cannot find any reference to any (active, dormant or extinct)?
Have they got their dates right? Seems a bit odd, because it was 1815 that Mount Tambora erupted: –
“The eruption created global climate anomalies that included the phenomenon known as “volcanic winter”: 1816 became known as the “Year Without a Summer” because of the effect on North American and European weather. Agricultural crops failed and livestock died in much of the Northern Hemisphere, resulting in the worst famine of the 19th century.[6]”
http://en.wikipedia.org/wiki/Mount_Tambora
What is worrying is Mount Tambora is: –
“has been raised to the second-highest alert status as its activity has been increasing since April, the Jakarta Globe reported on Friday”
http://hisz.rsoe.hu/alertmap/site/?pageid=event_desc&edis_id=VA-20110919-32378-IDN
So far nobody seems to know which Volcano erupted in 1809.
http://www.sciencedaily.com/releases/2009/12/091205105844.htm
As for volcanoes in Greenland, a hotspot with some geothermal activity has been noted.
Here is a pretty good geology account, with no mention of actual volcanoes in present time. Of course much of Greenland is under ice and surrounded by a solid sea of Ice.
http://www.geus.dk/program-areas/raw-materials-greenl-map/greenland/gr-map/anhstart-uk.htm
and this suggests geothermal activity beneath the ice.
http://www.sciencedaily.com/releases/2007/12/071212103004.htm
Here’s an article, anyway
@Diana & Wial, Thank you for finding the articles for me; much appreciated.
They raise a lot of questions. With satellite images, it would be difficult now to miss a large volcano, or remains thereof, on land, so presumably the missing volcano is under sea or ice.
How accurate is ice core analysis – to decades, years, or months?
I have a feeling it could have been a volcano under ice. I doubt it would be an equatorial volcano like researchers seem to say. I immediately think of volcanoes in Kamtchacha (the area is remote, so it would be easy to skip traces of a large eruption) or even Bardarbunga in Iceland, which has a remote location. The tephra seems to have been larger in Greenland. Alaska is another spot, but been so much researched I doubt they would miss a large eruption there. In 1808 there was actually reports of an eruption in Kamtchacha, as well as another in Taal in Philipines and another in the Azores, but all were not larger than VEI3. It is difficult to find that Krakatoa-sized eruption!
I would here like to venture a completely other guess.
Think sub-aquatic eruptions here. 6/7 volcanos are after all below water lever. Some of them are the largest on the planet. The size of the central azores caldera could hold all Icelandic calderas, Toba, Krakatoa, and a few others and still host a ball for Yellowstone…
But, if it was onland I would look at either Kamtjatka or Aleutians. Greenland seems a bit far-fetched. Might also have been in the antarctic, they have a couple of brutes that are poorly known. But, nah, should have been noticed really. Ocean… 🙂
Good thinking!
Where on our planet can a very large eruption have occured without 1) it being observed, directly or indirectly, in 1809(?), and 2) have left no visible traces for us to find with all our modern equipment?
Even if there are quite a few locations on land that meet the first criterion, land is almost certainly ruled out by the second. Next consideration – a very large maritime eruption would have resulted in an ocean-wide tsunami (especially if in a location such as the Mediterranean Sea). Are there any records of such a tsunami? If not, the conclusion must be one of the following: 1) the eruption was deep enough to produce a neglible tsunami (quare; in that case, how come it has left traces in ice cores?), 2) the researchers are mistaken either to the year or in their estimates of the size of their hypothsised eruption.
Nah, a large eruption at the Kerguelen Plateau would not have caused any significant tsunamis. Most underwater eruptions don’t you know.
I am still trying to track the original source for the mysterious disapearing Island outside of Kerguelen.
It was reported by a variety of ships in slightly different locations during the 1810s and 20s, and was even on the naval admiralty charts for a while. In the 1850s the admiralty sent a survey ship, but by then they could not find an Island, but they found som shallows around the area in question.
But, it could have been pretty much anywhere except in the mediterranean. One place it could have been is actually Jan Mayen who has an abundance of underwater volcanos if one look at a naval chart.
Sounds eerily similar to the Ferdinandea/Campi Flegrie del Mar story:
http://www.volcano.si.edu/world/volcano.cfm?vnum=0101-07=
http://en.wikipedia.org/wiki/Ferdinandea
I found this “Poster” showing the progress of the IDDP .
It only records up to 2009 when Magma stopped any further drilling at Kafla. However I found it very informative and explains exactly what the IDDP are trying to achieve.
http://iddp.is/wp-content/uploads/2010/07/3901_10_yr_later_poster.pdf
The equipment is amazing but I do wonder if they may meet magma again at Hengil.
I hasten to add that I am an informed..ish Layperson and in no way am I in a position to criticise . However I will be interested to find out their findings after these concentrated ‘quake swarms in Reykjanes Peninsula.
I am sure the Icelandic Government has it’s fingers firmly on the pulse of this ongoing experiment.
Well, I am in a position to criticize.
You see, I’m some babbling idiot on the internet. It’s my job.
But, looking at the gradients and the depths they are operating at there should be no encounter with magma. It doesn’t mean that they won’t change the stresses down there or eventually cause something stupid. See, they are human, and like all humans, we tend to do stupid things.
🙂
🙂
Ace! 🙂
Hehe, remember that they met magma (and took a sample) at half the depth that they expected at Krafla, so there is a possibility they could at Hengill too, especially since Hengill inflated roughly a decade ago… 🙂
Another babbling internet idiot here 🙂
@Diana,
You are very diplomatic.
It is interesting that the magma at Kafla does not appear to have been where they were expecting to find it – it was much closer to the surface. Is this because the nature of magma makes its precise location difficult to detect?
Don’t forget two things. There was a long period of eruptions some decades ago in Krafla, in rifting episodes, so it is natural that the magma is still way up. Also I expect that that magma has not too much pressure, due to the recent eruption, so any deep drilling in 2008-2009 did not result in anything like earthquakes or eruption. The volcano was actually calm after the eruptions in the 1980s.
Actually, the eruptions in Krafla some decades ago, started only a couple of months after they were building the first power station (and probably drilling) in the Krafla volcano. Could that drilling have triggered the volcano? I don’t know. It is a nice coincidence. And actually they were very lucky that the lava just 1km away flowed northwards rather than southwars towards the new power station.
In Hengill, drilling is not new. But this is the first time that they are doing deep drilling. I am not surprised that they are actually triggering a lot of accumulated strain there, and that they could hit magma further up than expected. If that happens, I wouldn’t be even surprised that they would trigger a minor eruption.
Also remember that the Blue Lagoon is actually the result of a drilling accident in Reykjanes (but a beautiful accident)!
As knowing Icelander authorities, I doubt they have a foot in that experiment. They were so oblivous to the bank practices before the crash in 2008. Also authorities don’t understand nothing of science, they trust in what scientists tell them.
The Icelander authorities have a duty of care. I hope they are watching this one very closely. Especially as so little is known about volcanoes and earthquakes – the science is still in its infancy. And especially as it has a direct impact on them.
Karen:
I entirely concur with you .
Don’t forget the inflation a decade ago in Hengill… New magma you know.
I hope Burfell strain plot is someone kicking it
http://hraun.vedur.is/ja/hekla/leidr_thensla_burfell.html
@ Karen Z (from last night)
I’m 99.9% sure Greenland has no active volcanoes, the tertiary volcanics there are roughly the same age as those in NW Scotland, ie dating from the opening of the N Atlantic and are of similar suites, being of the same volcanic province.
The 1809 event appears to have been ‘somewhere in the low latitudes’
This may be relevant if you’ve not already seen it
http://bprc.osu.edu/Icecore/dai00-1.pdf
A
There where actually a bunch of reports of a new Island close to Kerguelen in the 1910s and 20s… But when the admiralty got around to send a surveying ship they didn’t find it.
No, that is not kicking. It is true transients on a massive scale.
It actually follows exactly the trend I calculated for Hekla to take if she will have an eruption between december this year and may next year.
Business as usual for Hekla that is. I am as always more worried about Hekla than I am about Katla.
@alan c. Thank you; much appreciated.
There seems to a starting trend of rapid uplift at Hekla, but we still have to few data-points to say for sure. If this uplift continues for a few day more then we will know if we are seeing a final phaze of hyperinlfation before an eruption. But it is not shure that we would see that due to Hekla being so different from anything else, and is allready a very bloated and nine months pregnant volcano drunkard… 🙂
And here is the link to Hekluvöktun for those who do not have it:
http://hraun.vedur.is/ja/hekla/
If u didn’t see it, I saiud it here yesterday, Carl.. Nå går Hekla snart 🙂
Sorry, I missed that.
Satt nog på planet hem då 🙂
Helt sikkert 🙂 Har bare hatt på følelsen i det siste at noe kommer til å skje med Hekla 😛 Kan ikke si hva det er da, men hadde den samme følelsen med Katla kun ett par uker før det her som skjedde i Juli 🙂 Carl, Har du twitter?
Nej tyvärr har jag inte Twitter. Varför undrar du? 🙂
Hehe, har fått dilla på twitter bare 🙂
Why do you think that Hekla could be more dangerous when she would be erupting than Katla? Is it because of this 1104 event? But then, it was rather a long time since she’ d done that before (about 250 years), and now the last eruption was just in 2000. On the other hand, of course volcanoes seemingly have a lot of possiblities to surprise the scientists as was last the case with Grímsvötn …
I meant mainly dangerous as in more likely to erupt. But, one should always remember that Hekla stands for 70 percent of all ash-downfall in Europe during the last 9000 years.
What one should though know of Hekla is that Hekla is the only main-line volcano in Iceland that sofar hasn’t had a caldera forming event. And at the rate of eruptive behaviour the magma-reservoirs under Hekla should be severely weakened by now. I would not be surprised if she had one sooner or later.
I would though like to say that at the current rate of inflation she is as likely as Katla to have a VEI-4 eruption, the amount of magma inserted into the system is by now twice the amount of 1991 and 2000. The amount of magma was actually passed in 2006 when IMO released a warning about her being ready to erupt. Also, you have lateral filling trending via a dyke towards Isakot, with a possible secondary reservoir there. So a regional fissure would not be impossible.
But, the main reason for Hekla being dangerous is that she erupts so fast from first sign (2000 she erupted exactly 61 minutes after first sign) that she is the most likely volcano to kill people. This due to people hiking onto the top all the time. There is no possibility for anyone on the top to get to safety in time. Katla will give ample warning (most likely). So even a small eruption is very dangerous in that sense.
Yes Katla can probably have a VEI-6 or a regional fissure eruption like Elgja, but it is not very likely statistically speaking.
Also please remember Hekla has a different type of lava from elsewhere in Iceland, as far as I know she’s the only erupter of acidic/calcalkaline material -which is more viscous than more basic types thus more explosive.
Thank you. Yes, this could be really dangerous.
Plus the country to the west of Hekla is rather populated and open whereas the mountains Eyjafjalljökull, Tindfjallajökull and Þríhyrningur would be giving sort of a small protection against pyroclastic surges and the like coming from Mýrdalsjökull.
Or, this has a few more GPS stations to show:
http://hraun.vedur.is/ja/hekluvoktun/
Here are new pictures of Fimmvörðuháls area on Eyjafjallajökull volcano. But this pictures show the changes that have happened in the one year since the eruption did stop in Eyjafjallajökull volcano.
This blog post is in Icelandic.
http://sigsig.blog.is/blog/sigsig/entry/1193512/
Haha, guess what Giggle translate for the title of this article is:
“Major changes in Merapi in 16 months”
Fimmvörðuháls = Merapi!!!!!
:-)) At least they got the type of mountain correctly…
Has to do with a heck of a lot of people trying to get Giggle to understand Merapi. In the beginning it translated Merapi into “More graphic accelerators”… The sentance “Explosive eruption at More graphic accelerator has started”, was more of the entertaining I have seen… 🙂
😉 Think we could get enough people to suggest that a correct translation of Hekla is Capitol Hill?
It would be hellishly much cooler if we could convince Giggle to translate Katla into “The White House”…
@ Carl
Jag vet inte, ni unga blonda svenska killar och damer! (I’m being cheeky again!)
To the point, I can’t find in the IMO pages available, any long-term – ie 3month+ish – plots of anything, BUR strain would be good for a start, ‘cos there was a transient a week or so ago I think and it’d be good to see long-term trends; so much data the grey cells can’t remember all of it.
Nu är jag ju varken ung eller blond… 🙂
I have accumulated data since december for Búrfell, and if I had been Lurking I would have constructed a beautifull plot of it… But now I am not sadly.
The long term trend is towards heavier and more frequent transients, and they have started to group together into several spasms like what we are seeing now.
Om ursäkt typ sir!
Inget att be om ursäkt för 🙂
Haha, have you started to learn Swedish out of interest in young Blond swedish women?
Back in the 80’s I knew a young lady from Vaxjo! Dark haired tho’ Anna-marie A*******!!
An anomalous situation, according to Carmen Romero, volcanologist and professor of geography at the University of La Laguna, but that does not necessarily lead to a rash now. A view shared by Ramon Ortiz, a volcanologist at the CSIC and coordinator of the scientific committee that advises the IGN now on seismic activity in El Hierro. For Ortiz “now there is a probability of about 20% of an eruption to occur.”
http://www.abc.es/20110925/sociedad/abci-hierro-peligro-201109250534.html
I would be seriously confounded if El Hierro was starting to give rashes… 🙂
one has to love Giggle translations….
(at least this one was readable, spanish is seems to be simpler as icelandic :-D)
20% of an eruption shouldn’t be so bad now, should it?
Excellent! 20% of a VEI 6 is only a wholesome VEI5, nothing to worry about. 😉
Does it start to come smoke out of Hekla before an eruption? 😛
No, it goes from nothing to everything within minutes. A slight sulphuric smell has been reported during the hour before the start of eruptions.
Ok, so that smell is kinda the first sign of an eruption? Or can u see it on something else before that smell?
Normally, it starts with a quake between 2 and 2,5M (and sulphuric smell), then shortly after you have a massive transient down on the Búrfell and one up at Geldingaá. The Geldingaá transient will be about a quarter of the Búrfell transient. Then you will have massive harmonic tremoring as magma gushes upwards together with a small quake-swarm between 0,5 and 2M. The entire time of this is an hour or less. 2000 eruption from first sign to full blown eruption with a 10 kilometre ash-column took 61 minutes exactly.
There is some evidence that water might disapear in some creeks. I have hypothetizised that the transients at Búrfell is a sign of impending eruption, if that is true remains to be seen.
Otherwise there is no other signs to be had at all.
If you are ontop or close to the mountain you will not have time to get into safety. There is no way to predict an eruption there known to science except GPS uplift over time, and perhaps the transients at Búrfell.
Nothing on this planet can get me up to the top. Nothing.
Haha, you’re saying that u would never ever go up to the top of Hekla? Well, thats scary…
Can I ask how long the eruption lasted?
Feb 26 to march 8.
I am not normally especially afraid of anything, but that seems just crazy to me since it is so close to erupting…
To be precise.
I would happily hold a course on dancing ontop of Katla without even feeling worried. I would if needs be share the vicinity with a polar-bear and only feel slightly worried. Then you start to understand my feeling towards Hekla. Irpsit is a brave man who climbed it…
Carl, when I climbed Hekla one month ago, I was really scared but I went anyways, knowing I could die. Actually the next day, an earthquake 2.5 happened on Hekla, but nothing followed. I imagine how scared were the hikers that morning. I experienced a 3.0 of Katla when I was hiking in Thorsmork a couple of months ago.
About the risk of hiking Hekla. Yes, you have the risk of death. The hike is easy but takes 3 hours up and 2 hours down. If Hekla starts the earthquake, you could run within 1 hour to the highest parking lot at 800m, but few jeeps can drive there, because the track is steep.
But from the top, the first 20min down its over a lava field, and so you cannot run down in case you would feel a quake! You have to walk there with care, the rocks are loose. But after that, you could easily run down the slopes of the mountain because it is pure ash and sand, and so its very easy to run down without breaking a leg. We actually did it, we ran down after reaching the top to see how long it woulf take: 70 mins to the highest parking lot, 90 mins to the lowest parking lot.
The trouble is: when the eruption starts, all the rocks will fly upwards and will eventually hit you. You would stand to absolutely no change if you were still running down the slopes at that moment. The first rock flying down on you would kill you!
I think it is even dangerous to be driving at bottom of Hekla when the eruption starts. I think you could drive fast to escape it, but the road there is very bumpy. I really hope, that when Hekla starts there is no one hiking the mountain.
With Katla, you would expect much more warning, but now the danger of climbing Katla is that the ice cap is very fragile and full of cracks and depressions. You can die falling into the many cravesses.
I forgot to say. Clouds (fog) hangs very often at the top of Hekla, even in good clear days. It comes as fast as it goes away. So, when you hike Hekla, you have to bring a GPS or at least a compass/good map, to not get lost in case the fog remains thick. There are also snow fields to cross, rough lava fields, and steaming areas. Go there a while after it erupts, that’s the less risky time to climb it.
There were some earthquakes and tremor, but as Carl rightly said, just at very short notice before eruption starts. Here comes description of 2000 eruption by Institute of Earth Sciences, University of Iceland: http://earthice.hi.is/page/hekla26feb2000.
Problem is that there is not enough time to get down from the mountain between first warnings and eruption set-off, just as Carl mentioned, too. Also, most people hiking don’t think about carrying a walkie-talkie – and there seems is no portable phone connection on the mountain, so that it would be almost impossible to get through such warnings. – They intend to use emergency rockets to warn hikers in Þórsmörk (i.e. around Katla) (http://www.almannavarnir.is/upload/files/almv_baekl_EN_vef.pdf – warning signals), but I don’t know if that is also planned in case of a Hekla eruption. Could be a good idea though, so that at least people hiking on the lower slopes could escape.
I would use air-bombardment sirens.
People have a tendency to run like hell when they hear them. And they are also heard for a long distance. And, they are also pretty cheap.
Just a note. As Carl mentioned, the first indication that something was happening at Katla took exactly 61 minutes.
This is very true. But that was also detected on seismic gear.
From the time the quakes crossed the threshold of human perception (feeling it in your feet) until it popped the cork was about 10 to 15 minutes.
Provided you were standing right on top of them.
ERRATA, not Katla – Hekla
And Jon, is it still wind that shows on your helicorder?
Hope so but they look like earthquakes to me.
Haha, I understand.. 🙂 But what about right after an eruption, would u then dare to climb on top?
Well, if I had really good asbestos clothes…
I guess all the lava would be a bit hottish…
Very funnny 😛 You know I didn’t mean like right after an eruption, but like maybe a year after or so?
Ah, I thought you was thinking about inventing skiing on molten lava 🙂
Yes, then I might actually dare to do it. But then I would still look very carefully at the GPS-plot first since Hekla has erupted with very short spans in between at times.
Magnitude ML 4.2
Region AZORES-CAPE ST. VINCENT RIDGE
Date time 2011-09-25 17:29:08.0 UTC
Location 37.22 N ; 15.93 W
Depth 40 km
Distances 609 km W Queluz (pop 103,399 ; local time 18:29:08.5 2011-09-25)
508 km N Machico (pop 12,567 ; local time 18:29:08.5 2011-09-25)
462 km N Camacha (pop 8,635 ; local time 18:29:08.5 2011-09-25)
Actualidad Volcánica de Canarias (AVCAN)
Meneo importante entre Azores y Gibraltar a unos 450 km de la costa portuguesa, de 5.4 segun el IGN y de 4.2 según el EMSC que seguramente se notara en todos los sensores….hacia tiempo que no teniamos algo tan potente por esa zona…
IGN => gn2011suvt 25/09/2011 17:29:02 37.5100 -16.3700 10 5.4 3 AZORES-CABO DE SAN VICENTE
EMSC =>17:29:08.0 37.22 N 15.93 W 40 ML 4.2 AZORES-CAPE ST. VINCENT RIDGE
http://www.emsc.eu/Earthquake/earthquake.php?id=236893
http://www.01.ign.es/ign/resources/sismologia/www/dir_images_terremotos/detalle/ign2011suvt.gif
http://www.01.ign.es
Luis:
That is the probable location of the 1755 Lisbon EQ, isn’t it?
Yes, and i’m scared!!!
It is common for earthquakes to happen on faults that have broken in the past. It does not mean that they are going to make a new Mw9.0 earthquake soon.
Jon, infortunatly the return period of this fault passed, and we in Portugal know that we will have a Big one soon… It’s very scarying!
Luis:
No reason to be scared.
Let’s face it: there are thousands of problems that come ahead of earthquakes, most of them soluble, so let’s just concentrate on those, instead of flying to others which will, most probably, never occur in our life spans.
Abraço, amigão.
We cannot prevent earthquakes or volcanoes. There are also so many other factors (depth, proximity to populations, geology of region – as showed by the Virginia quake) that affect how damaging a quake is. Worry about what you can change or else you may miss the truck you are about to walk in front of (and I think statistics would back this up – more people died after 9/11 by taking the road than if they continued to use planes).
@Renato Rio
“soluble”
Sorry, I had to snicker at that one. Made me think of a whiskey sour. I know you meant solvable.
@Luisport
I tried to respond to this last night but my phone and catcha had an argument and I told them both to piss off and went to sleep.
“scared”
There is nothing that has occurred that should invoke this level of fear. A quake 80km down poses little more threat than a fault saying “I’m still here.” What you should take away from this event is an awareness of the faults presence. At this depth, it’s below the crust. (oceanic crust remember) By the time whatever force caused this quake manifests itself on the surface, it could be 1000 km from where the quake occurred… if it ever gets to a point of being able to do that.
Imagine my surprise when a Mag 6.0 happened slap dab in the middle of the Gulf of Mexico a few years ago. That area is supposed to be seismically dead. At least according to the USGS. It took some digging but I found out that the whole Gulf of Mexico is covered with ancient transform faults of Jurassic/Cretaceous age. One of them even passes within 10 miles of my house. (Port St Joe Fault)
If it had not been for that quake I never would have learned that.
Use this quake as an opportunity to learn more about what makes them happen. It’s an enjoyable process and tends to make you the “go-to” guy when your friends have a question. I was immediately text messaged by a friend up in New York when the VA quake occurred. He know I would have an answer, or at least a clue as to what had happened.
Meanwhile, fear nothing. Be rational, and run like hell if you see a pyroclastic flow coming.
Thank’s Renato, we will see the evolution of this situation in Azores and in El Hierro.
2011-09-25 19:35:14,2 63,654 -19,069 1,1 3,4 30,19 8,4 km N af Hábungu
only 30% tho’
In addition to the poor quality, nothing can be seen on Jons Geophone.
Weird. 30 %?
How come it doesn’t show?
I think its one of these 2 red dots. Due to the low quality they may dont put a star on it?
Should be the one to the right. In the caldera itself.
?????
Strange – according to the GPS position it should be here: http://maps.google.de/maps?q=63.654+-19.069&hl=de&ll=63.801894,-19.335937&spn=0.515328,1.766052&sll=51.151786,10.415039&sspn=11.72253,28.256836&vpsrc=6&t=h&z=9
Far away from the Caldera.
My fault, its the red dot on the right within the caldera.
According to http://hraun.vedur.is/ja/alert/2011/sep/25/049.html this was only a 1.4 quake, which fits much better.
But we can see a red spike in godabunga graphic
http://hraun.vedur.is/ja/Katla/god_trem.gif
Pretty quite – which graph are u talking about?
All graphs, but Gri and Skro look quiet.
A satellite? 🙂
Probably an error.
Sunday
25.09.2011 19:35:14 63.654 -19.069 1.1 km 3.4 30.19 8.4 km N of Hábunga
You beat me to it Sissel! It’s not showing up on the trmor graphs yet and it is unverified.
@ Jon. Little wind so I am presuming the activity on your webicorder is your noisy neighbours slamming car doors. Am I right?
Sorry Diana, my timing was very very bad – thought the quake just had happened. Time for bed.
Sleep well all of you!
You beat me to it Sissel! It’s not showing up on the trmor graphs yet and it is unverified.
@ Jon. Little wind so I am presuming the activity on your webicorder is your noisy neighbours slamming car doors. Am I right?
I think this 3.5 will be downgraded to 1.5 or something like that. It doesn’t show up on the tremor graphs. I don’t know why they have detected this and nothing shows in the tremor graphs.
askja plot – ask – has picked up something this evening
http://hraun.vedur.is/ja/oroi/allarsort.html
Could it be that the 3.4 is really really deep though?
No, it would still have to appear on tremor plots or helicorders.
Good news. I have gotten the permission to install a geophone close to Katla (really close to it) volcano and in Eyrarbakki village on the South Icelandic Seismic Zone.
I am going to post more details on this later in a blog post. But I have to have a fund raiser so I can buy the hardware for this installation. But a geophone close to Katla volcano really improves my ability to see what is going on in Katla volcano.
Kudos, Jón.
Just about in time when I’ll be able to resume donations.
That’s pretty seismic in itself! I have to apologise though, I’m on sickness benefits at the moment otherwise I’d be donating, hopefully in the near future this will change.
WOW! Well done Jon! I shall certainly be donating my usual small amount. Every little helps! In fact I have just thought! I have some old vinyl music records . I will sell those on eBid (NOT eBay…Far too expensive) and the proceeds will all go to Jon’s Cause. If anyone is interested in old music stuff I sell it here… just google … The Allsorts Cupboard. I am on Youtube too. Sorry about the plug Jon but it’s really on Topic because this is where your donations from me comes from!!! :))
I hasten to add I am on a very small old age pension! I am not in business and this selling helps me pay for little extras!
Hi Jon – cash strapped myself, but what I can do (and everyone else who reads this blog) is make sure I use your amazon link for any shopping I do in the run up to christmas. It does not matter how you go to Amazon i.e what ad you click on – any purchases you make at Amazon after clicking on an amazon link from here will give Jon a commission on the sales made. Its an easy way to ‘give’.
Great Jón, I’m in for a few £’s.
But, if your geophone lands on my roof in the UK, I want my money back 🙂
Oh my Godabunga, that made my day *rofl*
My blog went live today, http://reviewdrugpolicy.blogspot.com/ what do you think?
Hm unusual turn.
http://hraun.vedur.is/ja/Katla/gps_austmannsbunga.html
A single point is not yet a turn.
That is not a turn, that is normal for Aust, it does this odd dance up, down, to the right and to the left, and twist and turn.
Sigrún had a wonderfull plot where you could see the lateral motion, it looked like a dancepattern. I wish she put up the graphs again so we could look at that. It was a motion plot overlaid ontop of a map that showed the movements in an exaggerated way. If you see this, please put that one on your Katla page. It was awesome and very pedagogic!
Pieter, you need to look at long-term plots. You usually tell me to do it 🙂
I know, but it is still a significant 3cm drop in about 2 days.
With +/- 0,5 cm 1-sigma error bars the 3 cm drop is still within the +/- 3-sigma error, so it is not yet that significant. If it continues, then it becomes significant, as the magma has to go somewhere…
Check page http://notendur.hi.is/runa/eyja_gps.html
Inflation can now be seen in many stations.
It is actually a bit slowish with the exception of AUST and ENTA.
I like to compare with the ultrasteady uplift of Hekla… She has been going like this since 2000 and no relaxation.
http://strokkur.raunvis.hi.is/~sigrun/HEKLA.html
Could this chart show increasing contactions of the ‘pregnant’ Hekla or is this rise usual behavious? Sorry, I have only just come across these charts so have no knowledge of their usual behaviour.
Do you mean the contractions (transients) on the Borehole strainmeters, or do your mean the GPS-plots?
Transients, not normal, that is a sign I think of the mountain trying to rip open. Sign of nearing eruption if you will.
GPS is normal, it is also a very good sign of upcoming eruption since it shows the filling of the magma-reservoirs under Hekla. She was filled enough for an eruption allready in 2006, and has just gone on getting more pregnant. By now she is onto month 18 in her pregnance, baby-size 79cm and hitting 18kg.
Oh dear, so sorry, I meant to add this link so that everyone knew what i was talking about. Put it down to tiredness please. And thanks very much for the reply Carl.
http://hraun.vedur.is/ja/hekla/leidr_thensla_hella.html
Then I will answer better Newby:
Look at this plot instead:
http://hraun.vedur.is/ja/strain/str_corr/index.html
If you look at Búrfell you see very sharp spikes that are 40 times as large as normal. Those are called transients, and a transient is when the entire mountain is trying to “unzip” itself.
Currently something is missing for it to go off, so it just works as a tension release. But if there was high tension and an earthquake occured we would have an eruption.
The pressure is allready there, the magma is there. It just takes the tension being high enough, and an earthquake (in theory).
Hekla has been only 60 minutes away from an eruption since 2006 when the magma reservoir was reloaded from the 2000 eruption.
The power and intensity of the transients are growing and they are coming more often. That is a probable sign of being close to an eruption.
Many tanks for the explanation.
As I’m not in a position to help with funding at the moment, I’m plugging the blog via my twitter account, might be an idea for Twitterers who visit this blog to do the same, be brazen and ask for a RT from you followers too.
Just noticed on Twitter that someone is stating the conductivity is increasing in Mukalvisi River and inflation is going on in Katla. Could someone confirm this and does it mean eruption is near?
I think they are refering to news from a few days ago.
There is since friday no large GPS-movement, but the inflation has been going on for a long time now. And the conductivity briefly went up a few days ago, and at the same time there was a sulphuric smell.
Check Jóns post before this one and you can read about it.
Caveat: Conductivity might be up again! But I have not checked it. If it is up again I bet Jón will tell us in a while.
Its indeed going up – but only very slightly.
That was myself, it has happened before without an eruption occurring, so I wouldn’t get too excited or concerned. It’s just yet another symptom of something going on. As is always made clear on this blog Katla could just as easily go quiet again.
Has anybody’s guesses for eruption dates changed? Mine are:
Hekla: December 2011 – February 2012
Katla: April 2012 – July 2012
These are when I guess the eruptions will happen. 🙂
Nope, mine are still:
Hekla: December 2011 to May 2012
Katla: June 2012 to Decemer 2022
Krysuvik: Somewhere next year to 2050
Askja: 2013 to 2033
Bardarbunga: 2014 – 2034
Grimsvötn: At least 4 times the next 25 years, minimum 2 years untill next eruption.
And at least one surprise volcano the next 25 years.
“And at least one surprise volcano the next 25 years”
The Lake Dellen complex?!? 🙂
Torfajökull, Öraefajökull, Krafla, Esjufjöll, Hengill, Vestmannaeyar, Eldeyarbodi, Geirfuglasker, Prestahnukur, Hromundartindur, Brennisteinsfjöll, Theistareykjarbunga, Kverkfjöll and a few others… I would be more surprised if one of those didn’t make a surprise eruption, than if they did. Or we get a brand spanking new volcano or some such. We are talking about Iceland after all.
Ah, I forgot… Svartsengi!
There will though be no eruption at Thingmuli… 🙂
…and Lake Dellen. http://www.runemasterstudios.com/graemlins/images/cheerleader.gif
Henrik:
I am feeling very slow now…
What in the name of Godabunga is Lake Dellen?
(Cute waving Pinup on the picture you linked to though)
I’ll go along with your dates Carl . In fact I can be even more precise. Each will erupt in the early morning hours when I am asleep, or when I am away from my PC or I have died. 🙂 So I am expecting to miss the start of each eruption!
I agree with your bets.
Possible in next months, but not guaranteed:
– Hekla late 2011 to 2013 (VEI4), can happen any time soon, but could be also much later away: I think Hekla is already breaking its pattern from last decades
– Katla 2012 to 2015 (most likely within next 2 years) (VEI5), at least 5 weeks away, I am waiting for a rush of deep quakes coming upwards
Sometime in next decades:
– Grimsvotn, several eruptions, every 4-5 years, then goes back to a long sleep, I expect also a major eruption of Bardarbunga this century
– Askja, fissure eruption, sometime in next 20 years (VEI2), not before 2013
– Next 50 years : major fissure in dead zone (possibly Veidivotn-Hamarinn), also possible near Kistufell, likely warning will be a period with several deep quakes at Bardarbunga
– Next 100 years: Kverfjoll (VEI4), still years away, it will gradually increase in activity, could have much larger eruption if Bardarbunga feeds magma into it
– Circa 2050-2100 Oraefajokull (VEI5), still years away, it is starting giving some swarms once in a while, and very strong earthquakes before the next big one
Sometime this century or in next centuries:
– Maybe this century or next: Esjufjoll (explosive, VEI4)
– Maybe this century or next: Krisuvik (fissure eruption, VEI3), just because we have swarms doesn’t mean an eruption in soon; this region has been sleeping for 700 years, and has been quaking for decades!
– Sometime in next centuries: Prestahnukur
– Sometime in next centuries: Hengill
Probably no eruption this century:
– Krafla, Snaefellsnes, Hofsjokull, Tindjafjallajokull, Torfajokull (unless fed by Veidivotn), Grimsnes, Westman Islands
Actualidad Volcánica de Canarias (AVCAN)
¿QUÉ TIPO DE VOLCÁN SURGIRÍA EN UNA ERUPCIÓN TIPO BASÁLTICA MONOGÉNICA EN LA ISLA DE EL HIERRO?
Queremos compartir con vosotros un estudio que hicimos en la Punta de Orchilla (El Hierro) sobre el volcán Orchilla y una pequeña erupción fisural anexa al mismo.
Becerra Ramírez, R., Dóniz Páez, J., Guillén Martín, C. (2010): Geomorfología de los volcanes de Orchilla y de la erupción fisural del NE (El Hierro, Islas Canarias). En: González Cárdenas, E. et al.: Aportaciones recientes en Volcanología, 2005-2008. Pp 141-150. ISBN: 978-84-614-1025-5
http://www.uclm.es/profesorado/rbecerra/volcanes-El_Hierro.pdf
Rafael Becerra Ramírez (Grupo GEOVOL. Universidad de Castilla-La Mancha
I think I found out about the strange small earthquake center to the south of Katla caldera. Following this map http://www.mbl.is/mm/gagnasafn/popup/mynd.html?img=2004/11/28/GRRAGGHO.jpg, it should be Gvendarfell í Mýrdal, a lava dome (rhyolite?). See also: http://www.raunvis.hi.is/~mtg/pdf/Katla_gos_bradnun_06.pdf , esp. p. 13 (in Icelandic).
This map shows lava domes (most likely a rhyolite ones) in Katla volcano. They form when magma gets trapped in the crust for a long time.
Yes, I know how they are formed. But the question is, if this cluster of small earthquakes which we found between Katla caldera and Reynisfjall is under some lava dome like Gvendarfell. There are some of these quakes to be seen on the IMO right now (63.5° – 19.3°): http://www.vedur.is/skjalftar-og-eldgos/jardskjalftar/myrdalsjokull/
seems hickup in IMO hau tremor chart, last update 14:10, bad thing as small EQ 11:01 was “only” 14 km SW of Hekla …
New blog post about Katla volcano later tonight.
Thanks for that Jon, look forward to it! 🙂
I noticed some interesting. While Katla eruptions seem to occur most often in late summer and autumn, Hekla seems to have eruptions more often around winter and early spring. This could fit well with your predictions, Carl:
Hekla in winter, late 2011 or early 2012
Katla in late summer 2012
While for Katla, I can understand this trend; in late summer ice pressure is reduced; for Hekla, I don’t know why she tends to favor winter eruptions.
But we can’t forget about global warming now.. 😛 Maybe Katla will erupt next weekend, since it’s supposed to go back to summer again.. At least here in Norway 😀
Well, this is just a trend. I am not fully sure whether this is just a coincidence (number of sample is small after all), or if there is really a trend and a reason.
Hekla, eruptions since settlement:
Jan-Feb-Mar xxxxxxx total 7
Apr-May-Jun xxxxxxxx total8
Jul-Aug- Sep xxxx total 4
Oct-Nov-Dec xxx total 3
Katla, eruptions since settlement:
Jan-Feb-Mar x total1
Apr-May-Jun xxx total3
Jul-Aug- Sep xx total2
Oct-Nov-Dec xxxx total4
I think I can answer that, but it is basically a guess.
During the winter the mountain is being cooled down, and that makes the surface slightly less ductile. We are talking about fractions of a fraction here, but it might make a difference. It might also have to do with changes in water-levels due to downfall staying in frozen form instead of turning into water.
But I am guessing here…
And btw, Jon, I think everyone can put in 10 euro’s for u.. I’m gonna do it as soon as I get my thing from the bank… We can all afford this… We are readers of a very interesting blog. And if this blog didn’t excist, we wouldn’t know that much about volcanoes…
Have u tried to get some scientists to help u out or anything?