Posted on by Jón Frímann

A magma related earthquake at Hamarinn volcano

The earthquake that happened this morning at Hamarinn volcano appears to have magma signature in it based on what I see in my own wave data. The size of this earthquake was ML3.5 according to automatic SIL data. The automatic depth of this earthquake is 1.1 km. This data is a subject to a review by Icelandic Met Office.

So far this has been a single event and no aftershocks or other earthquakes have happened in Hamarinn volcano. That might however change. But sometimes large earthquake swarms take place in Hamarinn volcano. But this volcano is known for a lot of earthquake activity at times.

There are no indications of a eruption starting in Hamarinn volcano.

Other earthquake activity

The earthquake at Hamarinn volcano appears to have started a earthquake swarm in Herðurbreiðartögl. But the area must have been at breaking point anyway and the earthquake that happened in Hamarinn volcano might have just acted as a trigger.

There have been earthquake not far from Kolbeinsey island volcano. The strongest earthquake got ML3.3 by the automatic data by the SIL system. But due to the distance this is a underestimate in size of the earthquakes taken place at Kolbeinsey island volcano. I am not sure if the earthquake swarm that was taking place there has stopped or not, as small earthquakes are not detected by the IMO SIL Network.

41 Replies to “A magma related earthquake at Hamarinn volcano”

    1. Just reading your comments and not posting because I’ve been too busy reading up on things I’ve never heard of like pseudo craters, smoking cones (sounds like incense) and volcanoes on Mars. Figured it’s best to leave the comments to those who know what they’re talking about in this seismic saloon.

  3. Remember that it is Thanksgiving in the US… that might affect what people are looking at. (football/food/obnoxious but you have to be nice to them relatives etc…)

    The larger quake near Hamarinn was northeast of the volcano as it is outlined on many charts. The actual region is on that deviation in the Bouger anomaly that leads from midpoint of the Bárðarbunga – Hamarin line in a gentle arc over to Grímsvötn. Dunno if that has any significance. You can see the deviation in the anomaly on Gudmundsson’s Bouger anomaly Figure 3.

    Here is a cropped and zoomed in image of it.

    http://i52.tinypic.com/10wi3qv.png

    While looking at Figure 4 of that same document, I noticed that that area is labeled “skaftar-katlar” (????? butt boilers ?????) Looking into that I found a nice article describing the 1996 event there.

    http://www.mbl.is/mm/gagnasafn/grein.html?grein_id=290032

    Google translate doesn’t do as weird a job on that one.

    2. Yeah.. all the government stuff is shut down until next week, and if they don’t break anything I don’t have anything to do… so I get a holiday by proxy.

      Yesterday was a hoot, it seems that every year I wind up with a long distance service call on the heaviest traffic day of the year. Outbound was nasty, mostly rude people. Find a transport truck and duck in behind him and let the impatient travelers go off and do their thing. Only saw one traffic accident on the way back, though the FHP site listed quite a few of them along my trip route.

      I think I will go bake a pie… if I can shoo the wife out of the kitchen.

    3. Bad move on my part. Got sent to the store.

      I think I will flank the ham operation and attack the kitchen later today… feigning retreat in the meantime.

  4. Kolbeinsey:
    Could that be the island actually falling down below the sea-level? I know that it has been loosing large chunks the last few years and that it is considered to unstable to land on with a boat.

    Hamarinn:
    It is very odd that we all of a sudden have that large expected quake between our 3 favourite volcanos Bardarbunga, Grimsvötn and Hamarinn and nothing at all happens at any tremor-chart except the quake-spike… The only activity I see anywhere is on Jóns helicorder. And some of that is probably the heavy micro-quakes that still are going on under Godabunga.
    I am really psyked at what we will see on the GPS during the next few days. If we do not get a heavy uplift I will be surprised.
    Something “just” have to have gotten shaken around by that quake. But there doesn’t even seem to be tremor from even moderate gas-release taking place. So weird. But perhap’s it was to small, or it will pick up speed later on…

    *Serious scratching of the Noggin'”

    Happy Thanksgiving Lurking and all else from the US!

    1. Kolbeinsey island is actually a peak of a volcano that formed during the 18th century. It is falling a part and there is little left of it last time I did check for information on it.

  5. Looks like there was an encore.

    Friday
    26.11.2010 04:36:56 64.505 -17.539 1.1 km 2.8 90.09 13.1 km E of Hamarinn
    Friday
    26.11.2010 04:17:34 64.491 -17.489 1.1 km 2.3 90.04 14.1 km NW of Grímsfjall
    Friday
    26.11.2010 04:17:33 64.436 -17.394 1.1 km 2.2 90.03 6.8 km WNW of Grímsfjall

    1. It is a bit odd that they are all at the same deapth, 1,1 kilmetres, even the one that is a bit off-centre at Tröllardungja. The one at Tröllardungja is withing Bardarbunga volcanis system, and that says a bit about how large it is.
      And still no tremors at all. It is weird, there should be.
      Jón, do you know what the chemical/magmatic properties are off the Bardarbunga magmas? There should be gas-realease tremors in there. Second question, do you know the deapth of the magma reservoir at Bardarbunga since the quakes are so shallow?

    2. You want to see weird? A plot of everything in that area from 4/17 shows a very clear diagonal wedge .. provided you can spin the plot and watch the dots move.

      Very difficult to represent as a static image, but the path of this diagonal wedge follows that deviation in the Bourger anomaly image that I keep harping about. It arcs up through that path, then back down into the depths of Hamarinn.

      This is the best I can show… perspective view SE, NE and plan view.

      The recent quakes are in that arc. I didn’t use separate symbols, so your gonna have to eyeball it.

      Plan View
      http://i54.tinypic.com/2uot0s7.png

      View NE
      http://i51.tinypic.com/b49qwh.png

      View SE
      http://i53.tinypic.com/2jfg4yh.png

      NOTE: Only quakes referenced by SIL to Hamarinn or Grímsfjall are in this plot.

      1. Nice one… Kind of implies a connection between Hamarinn and Grimsvötn, and that would in a way make the entire Grimsvötn and Bardarbunga into one huge in some way interconnecting volcanic system.

  6. Jón said that 1.1 km was the default depth assigned until reviewed by a seismologist. Since many quakes over at Eyjafjallajökull during the past year seem to remain at that depth even after being reviewed (i.e. being assigned 99.0% quality), either a lot of quakes do occur at 1.1 km, or the depth is not deemed important enough to review.

    But I do agree that the location of the recent – very few – quakes is intriguing. Could they be the result of uplift at Bardarbunga, Hammarinn and Grímsfjall collectively (i.e. response to a depression created when this location has not moved) or is the uplift centered here?

    1. Yes, and that is a very interesting question that we will not have an easy answer to. The hyper-inflation a few days ago at GFUM could be either of the alternatives.
      Problem is just that we wont know that due to there just being one GPS-station there. But there is no way to place more since it’s all covered in deap ice.
      I would though wish they had a high-def stereographic geophone ontop of Grimsfjall working in the 0,01 to 20 hertz span. Then we would see the direction of the tremors, and we would also see the various frequencies as a “water-fall” representation. With the correct softweare you can then sweap around 360 degrees and “see” everything that is going on in glorious 3D. But it doesn’t come cheap. You can even see independent structures when you use time-line trace-plotting.
      Sadly this says something about our world, only time you see things like that being used is when it is a commersial operation, pretty much no scientists get their hands on it. But Iceland should have 2 at least, one at Katla and one at Grimsjöll since they have the worst potential.

      1. Shame that no Soviet boomers ever navigated Vatnajökull or we’d have all those sensors in place, eh?

      2. Ah, but that would not really help, a geophone is a totally different beast of technology than a hydrophone.
        But the analysiz algorithms are pretty much the same though.
        But it was not adapted from geo-science to sub-hunting as in “Red October”, it was the other way around. And the adaption was made quite recently.

      3. 😉 You miss the point – had boomers patrolled Vatnajökull, technology would have been developed to identify man-made noise amidst the background, geological noise. Jests aside, surely this problem; submarines hiding in geologically active areas, would have been thoroughly investigated by now?

      4. Yes, you are correct in that if there had been military need in a volcano for sensors, there would have been a lot of those sensors and we would have better data.
        In a way it is the same now. The equipment has been developed, but it is only used by oil, mining and geothermalenergy-companies. As far as I know, no “private” scientists have access to this kind of equipment since the starting price for a system is 1M€. And then we havent even started with the active systems.

        Sad that the hacking order is military, company and then far down pure science.
        And from companies scientific material rarely surfaces. The two volcanos where most money have been put in for equipment are Krafla and Mt Fako. and pretty much nothing have come out of it as papers. At Krafla they have a drill-hole down into the rhyolite in the magma-chamber (but no rhyolite has been given to researchers) and at Mt Fako there exists a 1-metreresolution 3D geomap of the entire system resulting in the only accurate map of the “tubinged magma-reservoir” of any volcano.

        So cash is king concerning volcanos too.

  7. @ Henrick and Carl

    I have a post in the moderate que that you might want to check back in on later. It has 3 plots of the Hamarinn / Grímsvötn area that may or may not be of interest to you.

    1. Ah… My daily fix of Lurkings plots is comming up 🙂
      Hope that they clear before I go to work, otherwise I will look tomorrow. Company christmas party tonight. It seems like hollidays start earlier and earlier every year 🙁

      1. yes it is indeed something like a daily fix of visualised seismic data. i really apprechiate this!

        interesting to me is, that the quake pattern seems to be similiar to the gjalp eruption of 1996.

        i think that this might actually be a magmatic sill intrusion from barbadunga towards grimsfjall. the same pattern as in the 1996 eruption.

      2. But, the Grimsvötn and Bardarbunga is two different volcanic systems?
        And Gjalp belongs to the Grimsvötn volcanic system and not Bardarbunga.

        But I believe that is magmatic intrusion into the magmatic reservoirs of Bardarbunga, but it is hard to see since it is magmatic intrusion going on at Grimsfjöll too.

      4. The Gravity Anomaly paper has this to say about the region where this handful of quakes are at:

        (note, some characters don’t cut and paste well)

        “The profile crosses the powerful geothermal area of Skaft´arkatlar 15 km to the nortwest of Gr´ımsv¨otn. Each of the
        two cauldrons (katlar) has created an independent ice drainage basin and water accumulates underneath both cauldrons,
        which drain every 2–3 years (e.g. Bj¨ornsson, 1988). The combined thermal power of these two areas is in the range
        of 1000MW (Bj¨ornsson, 1988). As suggested by the Bouguer anomaly map (Figs. 3 and 4) no high density upper
        crustal bodies can be associated with Skaft´arkatlar. As with other high temperature geothermal areas Skaft´arkatlar must
        derive their energy from hot rocks at shallow depth. The model indicates that dense intrusions have not accumulated
        in sufficient quantity to register in the gravity field. Some irregularities in the density of the uppermost kilometre of
        the crust apparently occur at and in the vicinity of Skaft´arkatlar, although the implication of this is unclear.”

        Gudmundsson et al 2006 Journal of Geodynamics 43 (2007) 153–169

      6. thanks for the quote ; )

        at least we can agree, that we don’t really have a clue, but that gives us room for speculation or discussion : )

    1. That actually happens quite often when the high tide is coming in. One day I caught seals riding merry-go-round on the ice; the pics are at Eruptions Blog Tuff Team’s Facebook site.

      1. And now it is gone with the outgoing tide.

        Yepp, it is a bit more common than people think. I just posted it for those who do not live in countries where they can observe things like this. You and me are a bit spoilt with the wonders of Ice, snow and northern lights 🙂
        Right now I am too spoilt with a snowstorm and minus 15C…

      2. Just caught a school of seals going out to sea in a long queue (towards the lower left corner). Amazing technology these days!

  9. To return to Skaftárkatlar – if there is a body of magma at shallow depth as the data suggests, is it too great a leap of imagination to consider the possibility of a tuya in the making?

    1. I would guess that all of the volcanos under Vatnajökull are at least in part Tuyas. But that we will see in a not to far future as the glaciers melts away.

      In this case I would guess it would be a fissure eruption since Bardarbunga really likes to produce those 🙂

      1. I doubt we will see any of the volcanoes under Vatnajokull in our life time or anyones lifetime that we know due to receding glaciers. That ice is thick and it is not going anywhere anytime soon. There is a better chance of Iceland falling into the sea then that glacier melting completely away.

      2. Sad for the Icelanders than that there island will fall into the sea.
        The glacier is in large parts sliding off into the ocean, henceforth the Jokulsarlon. And the melt rate is also large now.
        But that was not my point, I never said the entire glacier will melt, but enough of it will melt so that we will see the tops at least of the Tuyas if there are any there, and that will happen sometimes before 2050 if the more moderate climate projections is correct.
        Remember that the tops of the volcanos is much closer to the surface than the ice in the “cauldrons” of the calderas. The ice is only 700 metres deep in the caldera of Bardarbunga for instance, and Grimsfjöll is allready visible with 200 metres of ice remaining in the caldera.

  10. Lurking, thanks for the plots. From them it looks quite clear that we have earthquakes in two different systems, also, the Grímsfjall system is more clearly defined/evolved/delineated than Hammarin.

    1. Yepp, but it is still just condensation when the warm water evaporates into the sub-freezing temperature air. No activity at all there. The colder the more fog you get.
      Remember that the temperature is about the same as in your freezer up on the glacier.
      Here we’ve had half a meter of snow in the last couple of days and it is minus fifteen below freezing point. Do you guys have the real temperature.scale or do you use the american strange farenheit? I don’t know, so I used the freezing point reference (and that would be zero degrees Celcius).

      1. Cool experiment:)
        1. Boil some water.
        2. Place a newspaper in your freezer.
        3. Poor the boiling water into a plastic bowl.
        4. Place the plastic bowl ontop of the newspaper in the fridge.
        5. Close door.
        6. Wait a minute.
        7. Open door and look at the steam 🙂

        Compare the amount of steam from the freezer water the steam that was produced in the warm air of your apartment/house.

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