Posted on by Jón Frímann

Currently all is quiet in Iceland

At the moment it is rather quiet in Iceland in earthquakes and volcanoes. When that might change is impossible to say. But in the last few days there have been minor earthquake swarms on the Reykjanes Ridge. It is not related to volcanism, but rather tectonic movement along the rift zone.

There is continued minor earthquake swarm activity in Katla volcano. But it has quieted down from about two weeks ago. For the moment, the glacier floods seems to have stopped.

Other then this minor earthquake activity, everything is quiet in Iceland.

115 Replies to “Currently all is quiet in Iceland”

  2. These Volcanoes may be Quiet, but they are never empty.

    And Cliché has it that when ever someone claims nothing is happening, fate spits back a calamity right in their face! Ha Ha!

    Don’t worry. KATLA Will give us Trouble this year. I am certain of it.

    But like Sir Jon says, it’s a question of time.

  3. I totally agree with abowe, the next eruption is near(er), and probably some larger quakes too. But I hope they do no serious harm, if and when.
    Last calendar year we had one large eruption (but two if magma-type/vent-location is considered), this year we have had one large ash eruption (and two sub-glacier events producing two floods). Thats two in two years (plus two probable). Last centurys average was one eruption every three or four years (not exact count, just rough estimate on actual and definate eruption-events). But we can expect increased activity next forty years, some experts say, espcially in “hot-spot” around Vatnajökull but should Katla be in this “estimate” too?
    Just my two pennies.

  4. I reckon Katla still receives the influence from the Icelandic plume.

    Scientists say the plume is narrow to about 200km width, and centered over northwest Vatnajokull. This includes right on spot Grimsvotn, Hamarinn and Bardarbunga, and related fissures of Veidivotn and Laki. Within range we find Also Askja, Oraefajokull, Esjufjoll, Kverfjoll and Hofsjokull (all with large calderas).

    Near the edge of the plume, at about 120km away, we find Torfajokull, Krafla, Hekla and Katla/Elgjá. All these volcanoes have had very powerful eruptions in their past.

    All the remaining volcanoes in Iceland have rather small eruptions in comparison, and less often.

    So yes, Katla is probably fed by the hot spot plume.

    1. Small? Please remember the massive lava flow from Theystareykjarbunga. Or the massive lava flows from Langjökull shield volcano (+ Prestahnukur). Brennisteinsfjoll volcanic system has also the capability of producing almost 10cu km of DRE. I highly doubt that there is any volcano on Iceland-mainland which is not fed by the ‘hotspot’. Even Snaefellsjokull is a side-feature from this process.

  6. Ok. Well, I think “one big mantle plume theory” maybe wrong. The rift zone crossing Iceland would in time look like “S” in shape (updraft in Northern Hemisphere spins things this way due coriolis-effect). Instead it looks like flipped “h”. Is this then not really caused by “sink” of Icelands whole mass (as suggested by some geology featured, seen in east-fjords) but material driven down or under-it then re-heated (cooking the sinking materiel) and thus rising again, in many places (then many plumes, giving off both regular and irregular “puffs”), then not one plume feeding all. I just put this up here because there is so little otherwise happening re Quakes or Imminent Eruptions. Just my thoughts now.

    1. At 60 Ma the hotspot is predicted to have been beneath West Greenland where there are volcanics of this age, for example on Disko Island. At 40 Ma it would have been beneath East Greenland which may explain the anomalous post-drift uplift of this area. On this model the North Atlantic igneous province, initiated at approximately 60 Ma, was a result of rifting of lithosphere that had already been thinned by its proximity to a hotspot, rather than the arrival of a plume head.

      In contrast to this interpretation, however, there is considerable doubt, on the basis of geochemical and geophysical data, that the Iceland hotspot is fed by a
      deep mantle plume (Section 12.10). The Iceland hotspot is therefore something of an enigma.

      Global Tectonics 3rd ed.

      There is chemical evidence that Iceland’s Hotspot may have a more shallow origin. Given the chaotic arrangements of the plate fragments (Hreppar and Tröllaskagi) and micro-continents (Jan Mayen)in the area, that there is possibility that a segment of continental crust (less dense) is sitting on top of a segment of oceanic crust (more dense).

      Melt from the bottom of this arrangement may be responsible for the hotspot or it may have a deeper origin.

      What is known for sure, is that the area under Vatnajökull is about 40 km thick. For an island, that is a bit high.

      http://my.opera.com/nielsol/blog/show.dml/10513421

      1. Thank you very much. Seems I now know more on this, some of this I recon to have aware of (from other sources), but nevertheless nice map of bondaries. Since Katla Volcano seems maybe picking “up steam” today (and “false awakening if Hekla Volcano this morning) but all not that defnite due approaching rainstorm from the West of Iceland, I just stay watching my PC.

  8. Thank you for the update Jon. Quiet is good. It gives me time to read (and get on with household chores!)
    Please can someone give me some good suggestions to read about the Icelandic Plume and other theories? Of course I can Google but I would rather have recommended reads.
    Thank you all.

  9. quake at hekla!

    26.07.2011 06:04:39 64.015 -19.604 14.5 km 1.5 63.04 4.0 km NE of Hekla

    now the wuestion is: tectonic or volcanic?

    1. Well that’s an interesting quake! It’s checked now which makes it even more interesting…
      Tuesday
      26.07.2011 06:04:39 64.017 -19.586 19.6 km 1.2 99.0 4.9 km NE of Hekla

  11. The GFS weather model is simulating cyclonic weather around Katla until end of July:
    rain and fog will be dominant – no clear view:

    Cheers Philippe

    1. Heres the Katla Meteogram:

      http://www.meteoradar.ch/forum/forum_uploads/incoming/20110726_093602_Philippe_Zimmerwald_frei.gif

      You see the situation until 2nd of August on Katla summit (from 1000m up to 10000m):
      – humidity (green)
      – temperature (red)
      – winddirection and force (windbarbs)
      – vertical lifting (violet, in hectopacal/h)
      – precipitation

      In case of an eruption you have an idea about the conditions on summit in which direction the ash plume is blowing.

  12. Strange..The quake doesnt show on Jons helicorder. After all it was a 1.2 and that should have been visible. I highly doubt it to be a tectonic quake due to its location.

    1. It did show up. But it is not looking like your normal tectonic earthquake. This time around it appears that this earthquake was created by magma. But it had a irregular shape and form.

      But there is also a chance that there was a noise at the same time as this earthquake took place and that is why it looks so messed up on my geophone.

      1. I do see it on your geophone Jon, but the shape looks different to an earthquake. If it wasn’t for the IMO saying a quake happened at the same time I would have thought it was just noise. 🙂

        What size/frequency of earthquakes are usually noted at Hekla before an eruption there?

      2. As Gandalf1 said. If it werent for the IMO I would have thought it to be noise. And it seems to be quite bad weather at Hekla at the moment (windy) so maybe thats why it got distorted.

      3. It’s weird though, there doesn’t seems to be any wind noise on the geophone before or after the event.

      4. I didnt check the wind data just based my assumption on the fact that the camera was wiggling and there were fast moving clouds in the foreground. 😉

      5. Maybe the noise was caused by something else.. truck or peoples, less likely however because the earthquake had to happen at the same time as the truck passing by or something 😛

        Sander

  13. Think this answers seismometer question,

    “Seismology
    An important method for imaging large-scale structures in Earth’s interior is seismic tomography, by which the area under consideration is “illuminated” from all sides with seismic waves from earthquakes from as many different directions as possible; these waves are recorded with a network of seismometers. The size of the network is crucial for the extent of the region which can be imaged reliably. For the investigation of the Iceland Plume both global and regional tomography have been used; in the former, the whole mantle is imaged at relatively low resolution using data from stations all over the world, whereas in the latter, a denser network only on Iceland images the mantle down to 400–450 km depth with higher resolution”

    The station s publishing the “tremor graph data” are targeting the lower end of the classic 1 hz to 6 hz tremor range but obviously they have a second net from which they don’t publish the data.

    2. Well “imminent eruption is possible” is a bit far fetched.
      Last known eruption was around 550 BC. In order for magma to reach the surface I would say it takes alot longer time for this small swarm. It more seems like there is an intrusion of sorts.

      Not sure if the depth is recorded but that would be a good pointer. I bet Lurking could do a very informative plot of these quakes to see if there is a sill formation going on.

      But i would be surprised if these mag 1-3 quakes were able to reawake a volcano that hasnt erupted in over 2000 years.

      If an eruption is coming I think it will be some time yet. Geologically speaking a blink of an eye but in our perspective quite long.

      2. The depth is listed, most of them are around 10-12km, with some at 6km but also some at 27km

        Sander

      3. I tried to plot lattitude vs depth and longitude vs depth in Excel, graphs don’t look as nice as lurkings graphs do but what it shows is a large blob of earthquakes around 10km, not realy an upward trend is visible

      4. The narbo volcano took a series of 5m earthquakes to wake it up but then it had been asleep for a lot longer than Hierro.

    1. Dont think I would like to be that close. It could have found in ignition source!

  16. I really like the Iceland plume discussion. Pieter you are right, the potencial for large eruptions also happens in western and north Iceland, but less often. It could make sense that these areas are still fed by the plume once in a while, thereby explaining their less often eruptions, but still large ones.

    How about your theory, Yet another lurker? Do you still that the plume is not the result of a moving hot spot, but rather only related to the tectonics of the two plates? Do you think there are several irregular patches of plumes, like around Hekla, Katla, Vatnajokull, Krafla…? Or that there is still a main plume with several side plumes feeding those volcanoes outside of Vatnajokull. After all, it is under Vatnajokull that the main anomaly of thick crust is, so it suggest that the main plume is there. To support this model that there is a main plume feeding other volcanoes like Katla and Hekla, please read the paper at the end of my comment.

    I don’t know about the moving hotspot theory. Scientists speak about volcanism, 60 M years ago in Greenland, but this is probably related to the initial opening of the Atlantic rift, which was occurring then. This is my only objection to the plume theory, otherwise I think it makes sense.

    Another thing: I still think we will watch an eruption of Hekla in soon, before Katla goes. Now I think Katla will go most likely next year or in 2013. And I think Hekla is going to be stronger than average; I remember someone saying that the inflation now is already larger than in 2000. We have seen that also with Grimsvotn last year.

    This morning, I read a paper that suggested in the future the volcanic activity in Vatnajokull will decrease, and the activity in Hekla and Katla will increase, as part of a periodical cycle in volcanic activity from the Iceland hotspot (they also spoke about the plume feeding those two volcanoes, Hekla and Katla): “Holocene volcanic activity at Grímsvötn, Bárdarbunga and Kverkfjöll subglacial centres beneath Vatnajökull, Iceland, Bull Volcanol, Óladóttir 2011”

    1. I strongly enhance the theory of Iceland being a LIP which once was beneath Greenland. My explanation: Iceland has rhyolitic lava’s. This is very unusual for hotspots and/or spreading centers which normally erupt basalt. Some hotspots do indeed erupt rhyolite but this is only where the hotspot is located beneath a continental shield. What happens is that the basaltic magma slowly turns into rhyolite while penetrating the shield.

      Ofcourse, Iceland is not beneath any continental shield, but in my opinion it once was; the Greenland craton.

      For the future my best guess is that the Icelandic LIP will continue it’s way eastwards and Iceland will develop into another ‘Kerguelen-like continent’. Or, incase it reaches Europe, something like the Deccan traps.

      1. I like this conception of Iceland’s birth better …

        http://www.platetectonics.com/book/page_10.asp

        And since there is a spreading plate boundry running through the center of Iceland, I like this future scenario better …

        http://www.platetectonics.com/book/page_5.asp

        In particular, “As North America moves westward and Eurasia eastward, new crust is created on both sides of the diverging boundary. While the creation of new crust adds mass to Iceland on both sides of the boundary, it also creates a rift along the boundary. Iceland will inevitably break apart into two separate land masses at some point in the future, as the Atlantic waters eventually rush in to fill the widening and deepening space between.”

        Two Iceland’s in the future for the price of one. 🙂

      2. Yes, Iceland will ‘break apart’. But what you’d get is a situation like the Walvis Ridge and the Rio Grande Rise. Two ridges originating from one hotspot, which has also produced the basalts in Namibia and Latin America (Rio Grande Shield)

    2. Thanks for your interest, I read it. Very interesting, informative and short. Seems good work already done. Rather than say yes or no to any of your questinons, I may think of “hot spot” rather like “Big Nail” with sharp end down, scraping deeper core due Larger Plate Movement (?) or acting like conduit (?) from the deep down levels to upper levels, then this melting on edges or in-beween “Nails” (such as minor-plates have tumbled and lying like sideways?) The deeper the “Nail(s)” the more warmth it can transport or scrape up even? (Just an idea I got from how varied Icelandic magma seems). You get my drift?
      I am not expert in any of this stuff. But can this be proven, the warmth transport rate calulated and thus possible Volcano activity calculated or predicted?
      Hope this will not be acted upon as “nail in the coffin of theory”. Its just an idea of mine, maybe nothing too it. I am totally prepared to return to “silent reader” of this blog, if it makes no sense.

    1. This is interesting.

      “The magma reservoir feeding Hekla is located at a depth of 5-9 km. During non-eruptive periods the volcano is virtually aseismic. Eruption-related seismicity starts only 30-80 minutes before its onset.”

      http://www.volcanolive.com/hekla.html

    2. I see no inflation in either location.

      How do you figure there is inflation? What specifically are you looking at? When did this inflation start? How much inflation do you see (in mm)?

      You do realize that only the data plot labelled UP can show “inflation”, and that there is also noise in the data, right?

      1. The fact that Hekla is inflating has been known for year, what he refers to is the small anomaly in the vertical direction which measures about 8mm. This could ofcourse be due to noise, but if it becomes a trend it’s interesting to watch it, since we have seen these sudden uplifts before.

      2. Yeah, that’s what I meant for the supposed inflation. This could be noise, just a normal variation from the volcano, or the start of a more steep inflation trend. Like it happened a couple of weeks ago.

  18. The Hekla earthquake as seen in GoogleEarth 3D view … shows the proximity to the volcano … locations of Hekla GPS stations are also shown …

    http://twitpic.com/5w42j2/full

    26.07.2011 06:04:39 64.017 -19.586 19.6 km 1.2 99.0 4.9 km NE of Hekla

  20. Small swarm?

    Tuesday
    26.07.2011 14:39:08 63.609 -19.118 2.3 km 1.3 74.83 3.3 km NNW of Hábunga
    Tuesday
    26.07.2011 14:37:51 63.608 -19.133 2.2 km 1.1 90.01 3.5 km NNW of Hábunga
    Tuesday
    26.07.2011 14:36:31 63.590 -19.174 2.2 km 1.2 90.01 3.8 km WNW of Hábunga
    Tuesday
    26.07.2011 14:36:23 63.613 -19.127 3.7 km 1.1 54.61 3.9 km NNW of Hábunga
    Tuesday
    26.07.2011 14:36:21 63.536 -19.356 30.9 km -0.3 31.77 6.9 km E of Skógar

      1. The earthquake swarm is one more sign that magma is moving inside Katla’s magmatic chamber (located at about 3km deep). The tremor is due to weather: has been very rainy this afternoon here.

      2. Wouldn’t it be nice if engineers would design tremor detectors which could subtract out weather-related noise?

        I’m thinking of, for instance, having a duplicate tremor detector at a distance of a meter or so away, but having it mechanically isolated from ground vibrations. And then simply electronically subtract that detector’s signal from the first detector’s signal! Voila! … A tremor plot with the weather noise and other noise cancelled out!

        That will actually be easy to do, and would be be very useful. Note: it would also cancel out other auditory noise which travels primaily in the air, such as noise from planes, cars, lightning etc.

  21. I have never liked the idea of matle plumes being bundled into one catergory. Hawaii is very diffrent from Iceland but Iceland does share some similarity with the Ethiopian Rift Valley. Flood basalts (Trap events) are again completley problematic when trying to create a model. There are many papers on both subject`s but the only thing that is agreed on is it is caused by convection currents in the mantle. The rest is just speculation. All is still beyound our total understanding there is not much in the way of funding for these things but each year new ideas rise and maybe all have some correct context.

  22. I’ve often wondered if there ever was/ or potentially in the future could be a volcano in Iceland capable of VE7’s and VE8.

    1. Recalling older discussions on this matter, consensus was no – not possible, but huge fissure eruptions generating lava flows, even larger than past ones, could be possible. The VEI scale mostly accounts for volcano explosivity (ash immediately erupted or erupted in the short term in the atmosphere), not SO2 emissions or lava flow size (which can potentially be long lasting).

      1. so say if Baroarbunga was to have a full scale eruption with fissures and a partial or complete collapse of the volcanoe like Mount St Helens did. With all the glacier sat on top of Baroarbunga would the ruption still only be a VE6??

      2. If you have an initial big boom – not cataclismic – then a moltitude of fissure eruptions taking place in months or years of time, culminating after a few decades in a slowly progressing caldera collapse and melting of all the glacier, yes, it’s possible (though improbable). As I said, the VEI scale only accounts for the ash, not lava or other long lasting effects or events.

  23. VEI 6 is the largest eruption in Iceland. 7 and 8 are truely massive and beyound anyones true comprehention. These occure around subduction zones

    1. There have been multiple vei7+ eruptions in earth’s past not localized immediately adjacent to subduction zones. In example Valles Caldera is in new mexico in america, La Garita Caldera in colorado, Bursum—Bloodgood Canyon in new mexico again, and Yellowstone of course is another example. But there are even more mind numbingly large eruptions from flood basalts. I.E. the Deccan traps, Paraná and Etendeka traps While non explosive, a flood basalt eruption can put out even more material then most more explosive eruptions. I think most if not all flood basalts (including Laki and Eldgja) are fueled by mantle plumes rather then subduction zones. I am not claiming we will ever see a VEI 7 eruption anytime in our lifetimes let alone iceland as there is no reason to ever expect an eruption of that level in iceland. I am merely attempting to state that truly mind numbingly large eruptions are not confined to subduction zones.

  24. Grimsv0tn this year was VEI4 ( more than 1 km³) A VEI7( more than 100 km³) and 8 is more than 1,000 km³ of Tephra ejected !

  25. What about Yellowstone, does this sit on a subduction zone?

    Another question if may…. If a supervolcano was to go of under deep ocean would it have the same effect gloabally as say one that went off on land.?

    2. I remember somebody did an animation of that chart for the period immediately prior to the 2010 Eyjafjallajökull eruption.

      2. Unfortunately I can’t find it.
        I remember it was made by a french guy.

      3. Thanks, maybe I can find it, it may have been on infoclimat, we followed the eruption on that forum.

  27. (apologies this is a bit off-topic but in partial answer to the question…)

    A theory I’ve seen re Yellowstone is it’s the last bubbling remnant of the lava field that caused the Columbia River flood basalts. The continent has moved West over the hotspot since then and the reason it erupts so explosively when it does is it has to punch through that thick ancient continental bedrock. In the theory the lava was caused by antipodal resonance about 17 or 18 million years ago, when an asteroid hit the south Indian ocean, and the shock wave went around the Earth to converge again in North America. Supposedly the same thing happened with the rock that killed the dinosaurs, opening up the Deccan Traps in India, and the big one that hit the Antarctic 250 million years ago, causing the Siberian Traps, which caused climate conditions similar to those towards which we are heading now, melting the frozen ocean floor methane which was a runaway positive feedback loop, killing 95% of all life.

    Re ocean floor calderas, there’s also a theory one of the calderas between Java and Sumatra caused nuclear-winter-like conditions for 18 months after it erupted in 536 AD, separating the two islands. It was well-chronicled at the time — the Chinese even claimed they heard thunder-like sound coming from the south west. Some think that might have been a meteor too though.

    1. (meant to be a reply to Ian — failed on recaptcha the first time which might have thrown the comment section logic off).

      1. Oh and forgot to add — as the theory goes, the antipodal resonance happens when the asteroids hit water, because that drives the shock wave deep enough into the crust it rings the Earth like a bell.

        Just another controversial theory, although evidence for the same thing is discernible on Mars and Venus — e.g. the Hellas basin on Mars caused by a big impact, and the giant volcanoes on the other side.

    2. I think Iceland has little potential for an explosive sudden VEI7, because volcanism is so frequent. I think the most likely volcano for this is Bardarbunga, for several reasons: it is fed by the iceland plume, has to break through a thick 45km deep crust (which can led to a big explosive event like in Yellowstone), has a big caldera (as big as Katla, about 12km wide), is under a huge load of ice (ash eruption), which is even thicker than in Katla, and the volcano has been sleeping for long. Bardarbunga has the record lava eruption in the Holocene, but that was a lateral fissure in a ice-free zone. It all this material would be released in the caldera, in a single explosion, after a long sleeping repose, I think this could mean the release of about 50 cu Km. If it reaches VEI7 (100 cu Km) that would be quite difficult. The biggest recorded eruption from Bardarbunga released up to 20 cu Km material.

      About the 536 event, it caused a huge and long climatic disruption, longer and bigger than Laki, it was almost for sure caused by a volcanic VEI7 winter but the volcano is unknown. There are sulfate deposits in Antarctica.

      Another event happened in 1314, but it is unknown whether is was caused by a volcanic eruption or a rare climatic disturbance.

      1. thanks irpsit for yet another very informative post 🙂

        Perhaps the 536 event might have been located in antartica itself?? Or some other desolate area such as the sahara.

    3. No, the Columbia River hotspot was rhyolitic in it’s early stages. This was caused by the basaltic magma penetrating a continental shield which slowly turned basalt into rhyolite. After a while there was no more rhyolite and all that was left was plain basalt. The hotspot still exists today and renewed tremors have identified hot bodies beneath Canadian soil.

    1. 7 decades out of 21 did not have VEI 4 or higher eruptions.

      So, based on that, there’s a 33% chance we won’t have a VEI 4 or higher eruption this decade. Yikes, that would be boring!

    1. See my comment below. Katla chamber is about 3km deep, Hekla has a much deeper source.

    2. lol … the wording for that is tricky to interpret!

      To be clear, “a deep-seated magma chamber, which we model as a spherical source at 14–20 km depth”

      Not a 14-20 km spherical deep-magma chamber, as I first misread it from your post. 🙂

      The actual size of the magma chamber is quite small, it would seem from the article you site.

  33. Anyone noticed we had some deeper earthquakes in Katla past days? between 10 and 20km…

    Sander

  34. Spike at GOD was from the recent quake(s), it has since dropped down to normal levels which are rising due to the weather.

      1. The thing is that the blue line (mid frequencies) is still higher than the red line (low frequencies), and in general all three colors (including green for mid-low frequencies) are pretty close together. I thought that weather induced seismic signals involved mainly the red line for low frequency, as shown in past weeks on that chart.

        Maybe there really is more than meets the eye?

        Although to tell the truth, the RUV cam for Katla shows harsh weather with close to zero visiblility which might explain what we see in the charts:

        http://www.katla-volcano.co.uk/katla-webcam.php

  35. Four newish quakes at Katla, all at almost the same time, in a vertical line. Between 2.5 and 3.7 km deep. Significant? Tremor graphs acting up too, although could well be the weather as others have noted.

  36. Yes but the peak in the tremor graph has an update every 11 minutes si the peak it over an hour wide so it isnt just an earthquake and its not typical of weather

  37. Katla magma chamber is shallow located at about 3km deep. Krafla and Askja also have shallow chambers.

    Hekla has a much more deep source for magma (unknown but possibly around 10-15km deep). In Bardarbunga and Grimsvotn the magma also comes from deep sources. The crust thickness is about 45km deep under Vatnajokull (which is a well known anomaly, which led to the plume theory).

    The crust varies in other places, and the thinnest crust is in Reykjanes and Krafla, which is about 6km deep, similar to what is found under the oceanic floor.

  38. So those earthquakes were at approx magma chamber depth then. Magma is moving.

  40. For Frenchies: watch France 5 now, the doc about islandic volcanoes is beginning.

  41. I think we need Jon here to review this data on the harmonic tremors.
    Although the weather is bad at the moment, I think treacle could be right but im not sure.

  42. Katla it´s very moving.

    I supose that magma is moving… tremors and earthquakes are rising up at the same time.

    We need the expert´s opinion of, Jön Frimann,

    Thanks a lottttt ^^

  43. It always confuses me when there are more than one tremor at the same time in the same place. I was just wondering if there was a possibility it was one long tremor that chagned between the different mags and heights as it moves through the magma?

    1. Well tremors dont move through magma. Magma causes tremors. It can cause magmatic earthquakes when it pushes through rockformations and it can cause harmonic tremor much like the vibration you feel when holding a garden hose with water running through it. Very simplified of course as there are different types of volcanic earthquakes and tremors.

  46. I think that the current rise in tremor is due to weather!
    The weather here in South Iceland is quite stormy, really a lot of rain and some wind (gusts until 20 m/s). That is my opinion.

    1. I guess thats it then, I just thought it was a very sudden rise at ALF to be weather related, but I see there are no new earthquakes so I guess it must be the storm.

    2. Couldn’t there be some hidden quakes under this activity and even some harmonic too? I can see them on Jón’s helicorder.

  48. There is a harmonic tremor spike in Katla volcano at current time. It looks small. Why it is happening is unknown at the moment.

    A blog post about this in a moment.

    1. I thought that spike at ALF looked too sudden to be weather. 🙂
      Seems to have dropped back now again now though.

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