Eartquake swarm in Hengill volcano

The Icelandic volcano known as Hengill did have a minor earthquake swarm of 20 something earthquakes today. This earthquake swarm might be related to geothermal power plant activity nearby (by pumping down or up water in the area). But at the moment I do not have it confirmed and this has also not been confirmed by the news.

This earthquake swarm in this area is normal and this volcano has several every year as it located on the main rift zone in Iceland. The last large earthquake swarm in this volcano took place during the year 1997 to 2000. Then many earthquake up to size Mb5.0 took place in Hengill volcano.

Icelandic news. Use Google translate at own risk.

Um 20 skjálftar hafa mælst (Vísir.is)

40 Replies to “Eartquake swarm in Hengill volcano”

  1. The activity is ongoing; rather more than 20 now. More fun than following sport on a Friday evening (though I am doing an exercise for a geology paper as well).

  2. A lot of tremors Hengill, 1:52 PM EST (USA East Coast)–68 temors today, most with a pretty good % of being valid. Is this all due to water being pumped up? All co-located, interesting activity.

  3. No… not due to water being pumped up. The area is very seismically active to begin with. (which is why it was chosen).

    A bit of perspective of where the quakes are in relation to the volcano and power station:


    A Time vs Depth vs Magnitude of the swarm (scarfed from my last post in the other thread)


    And… a bit about the geothermal field.

    Geologically speaking, the rock strata underlying Nesjavellir are relatively young as a result of intense volcanic activity. Palagonite turf predominates in the upper five hundred melees of rock, and there is basalt beneath them. Magmatic intrusions become more common at greater depths and become the predominant rock type at a depth of 1,400-1,600 meters and below.
    Reservoirs often occur at the peripheries of intrusions, especially from intermediate acid rock. There is a fault at the Kyrdalshryggur which is indiscernible at the surface, although the wells clearly show that the valley floor has subsided.
    The ambient rock temperature is highest at the Kyrdalshryggur, measuring around 100°C at sea level and increasing at greater depths, to reach a temperature in excess of 350°C below two kilometers.

    From this link:


  4. Eh.. I’m just waiting for the “Eartquake.” I didn’t even know that earts had a seismic problem up until today. It should be interesting. I’ve been watching my eart here in the backyard and it hasn’t moved yet.


    1. You mean the “Enhanced Aircraft Radar Test Stations”? or the “En Route Automated Radar Tracking Systems”? or “Earta Ale” volcano in Ethiopia?
      The latter has been experiencing such kind of problems, indeed.

  5. Lurking: I really love your plots!
    As I’m a visual person, they help me to better understand the dimensions and relations between the different “happenings”.
    The last one, with the MOHO also displayed, was very nice.
    Thanks for your work. ( and I hope you can move better and are healing from your fall!)

    1. I wonder . . . looks like fissure, why would just one “burb” on a Friday ?

      1. Well, the whole region is composed of old dikes and sprugur in waiting.

        Remember that this region is between Krísuvík where we had that interesting cone shaped swarm and Hekla, just on the other side of the more recent sprugur related quakes.

        The odd bend in the vertical alignment hint at one paper that I read… and can’t remember the title of, that examined if the cracks maintained their fault plane for any depth or if they took off on a different orientation with depth. (the implications were that they do)

      2. I’m thinking that they yanked that one. It would have shown up as a star.

        As for Hekla, I am connecting the events to it. Just not in the alarmist way. It all has to do with stresses along the MAR and the fact that the southern segment tracks that direction… past it and down to the Katla area.

        Magmatic? Nah, I’m not saying that. This thing has a fault plane that shows up in the plots and it seems to be more of a wide semi – flat sheet. If anything it’s a local dike, or is occurring along a previously implanted local dike. As the power station link stated (on that page), the valley floor shows evidence of previous subsidence. This is sort of what you would expect from a continental spreading area.

        As for being a new intrusion.. well, the time vs depth plot doesn’t really support that either. The swarm seems to have started at about 2 km depth and propagated deeper and up to the surface, sort of like the stress spreading out.

        Connected to Hekla? Most definately… in the same way that all the features along the MAR are connected. Nothing more.

        I would hint at a “stress wave” event like happened in the Gulf of California, but I don’t have anything to directly support that idea.

      3. This most likely was a ML4.? event far off Iceland. But the SIL network has issues locating those earthquakes properly and normally gives them low quality due to how few stations record it.

  6. Off-topic to this post.

    I was trying to re-apply to Google Adsense to increase my income from this web site. But they ask for root domain (www.jonfr.com) on there application form. My root blog is a mix of Icelandic and English blog. But the replay that I got from Google Adsense speaks of incompetence and stupidy on part of Google. If they cannot read the english part of my blog then it there own issue. They also did only offer english and not Icelandic in there drop down menu when I did apply at there web site.

    Here is the replay that I got from Google Adsense.

    —- in Danish, as I did apply from a danish IP —-


    Tak for din interesse i Google AdSense. Efter at have gennemgået din
    ansøgning kan vi desværre ikke give dig adgang til AdSense i øjeblikket.

    Din ansøgning blev afvist af nedenstående årsager.

    – Ikke-understøttet sprog
    — Translated in English with Google Translate —


    Thank you for your interest in Google AdSense. After reviewing your
    application, we unfortunately can not give you access to AdSense at the moment.

    Your application was rejected for the following reasons.

    – Unsupported language

    —- End —-

    What is really intresting is the fact that Google Adsense has and does carry Icelandic adsense advertisements.

    I hereby reject Google Adsense for the next 20 years or until there service support improves from there current brain dead levels that it is at.

  7. Magnitude ML 3.5
    Region ICELAND
    Date time 2011-02-12 10:05:42.5 UTC
    Location 64.56 N ; 20.64 W
    Depth 2 km
    Distances 77 km NE Reykjavík (pop 113,906 ; local time 10:05:42.5 2011-02-12)
    79 km NE Kópavogur (pop 26,157 ; local time 10:05:42.5 2011-02-12)
    63 km E Borgarnes (pop 1,783 ; local time 10:05:42.5 2011-02-12)

    Magnitude ML 3.3
    Region ICELAND
    Date time 2011-02-12 10:08:46.2 UTC
    Location 64.35 N ; 20.71 W
    Depth 1 km
    Distances 63 km E Reykjavík (pop 113,906 ; local time 10:08:46.2 2011-02-12)
    64 km NE Kópavogur (pop 26,157 ; local time 10:08:46.2 2011-02-12)
    45 km NE Hveragerði (pop 1,934 ; local time 10:08:46.2 2011-02-12)

  8. Swarm in this volcano? Magnitude ML 3.4
    Region ICELAND
    Date time 2011-02-12 10:11:51.0 UTC
    Location 64.56 N ; 20.64 W
    Depth 1 km
    Distances 77 km NE Reykjavík (pop 113,906 ; local time 10:11:51.2 2011-02-12)
    79 km NE Kópavogur (pop 26,157 ; local time 10:11:51.2 2011-02-12)
    63 km E Borgarnes (pop 1,783 ; local time 10:11:51.2 2011-02-12)

      1. It has not shown any signs of that in recent years. But there is always a possibility that volcano might erupt without warning. But thankfully the odds are normally small.

        So just watch this earthquake swarm while it lasts.

  9. One mighty swarm at Langjökull! It can be seen pretty clearly in nearly all of the tremor stations of Iceland.

  10. @Jón:
    I was looking at Etna’s seismographs and you can clearly see the two big jolts in Chile, arriving at about 1 hour of delay.
    Can’t you see them in your helicorders? How long later?

    1. Etna seismographs are long period as my geophone are short period. This is why you don’t see the Chile earthquake on my online plot. But often I see large earthquakes on my short period hardware.

  11. @Lurking:
    It would be nice to see a plot of the ongoing swarm… maybe later, when it’s over.

  12. Yesterday swarm at Hengill, this morning swarm at Langjokull.
    Probably it’s connected no? It’s along the same fault, just on the other side of the (Thingsvellir) lake.

  13. Langjokull is getting very interesting
    – 4 EQs today above M3 out of nowhere
    – very shallow quakes (mostly 1-4km)

  14. Could be tectonic origin. After all there are occurring along the rift. Recent quake activity has been centered over 3 spots: Reykjanes, Hengill and Langjokull.

  15. The USGS just sent me an notification email (see below) that they had deleted a 4.6 EQ in Yellowstone, Wyoming that occurred on UTC: 12 Feb 2011 02:36. I usually dont see this type of deletion.

    There was also two 3.5 quakes and a swarm of quakes near the 4.6 quake that you can see on the links below, HOWEVER, the USGS does not show any quakes at all in NW Wyoming except 1 very small quake which when you click on it, it redirects you to a page that indicates it was deleted. So, worrisome quake swarm near Yellowstone and the USGS show absolutely no quakes in that area going back to Feb 9?

    You can see the swarm here: http://quakes.globalincidentmap.com/ Just zoom in on Wyoming

    Sean Hannity (Fox News – major U.S. News site) has links showing increase in Harmonic tremors at Yellowstone and :

    Univ of Utah Seismographs showing quakes and harnonic tremors:

    Residents would have felt that so I queried Twitter. There are literally hundreds of tweets at this point so its hard to find any from local residents that say they are feeling these quakes. I will continue to look


    Residents would have felt that.


    DELETED: Event UU 00005729


    ***This event has been deleted after review by a seismologist.***

    Geographic coordinates: 44.270N, 110.973W
    Magnitude: 4.6
    Universal Time (UTC): 12 Feb 2011 02:36:09
    Time near the Epicenter: 11 Feb 2011 19:36:09

    Location with respect to nearby cities:
    32 km (20 miles) ENE (58 degrees) of Warm River, ID
    39 km (24 miles) SE (131 degrees) of Island Park, ID
    42 km (26 miles) NE (44 degrees) of Drummond, ID
    398 km (247 miles) N (11 degrees) of Salt Lake City, UT

    1. Now there is a rash of activity on all the social websites about this including many people who are getting delete notifications. The removal of literally all the quakes in this swarm is causing some paranoia so my question is, how likely is it that this could just be a glitch in hardware/software for both USGS and Univ Of Utah that is showing false quakes, especially given the quantity and quality of the seismic equipment up there around Yellowstone?

      1. Well… it is odd. But there is always a possibility that the seismo’s went off because of an avalanche. I saw one of the loon/conspiracy sites going nuts yesterday about a quake and I went and pulled the waveform data from IRIS Buds and didn’t see anything.

        Here is the link to the helicorders for Yellowstone.


  16. Sorry, my mistake. There is no swarms shown on the UofU site. Just read some false info and saw all the spikes on the webicorders and came to the wrong conclusion. I can only see the “supposed” swarm on the site below which states it gets its feeds from USGS.

    A lot of people from various web sources said they saw or received notice of the quakes on the USGS site ranging from 2’s to 4.6, but then they disppeared or were deleted like the deletion email I got on the 4.6 so I guess these are all false quakes…just strange though as they are spread over a large distance and in areas where there are not avalanches. Just another mystery.

    1. I would say that the mystary is all the conspiratists conspiring conspirations! 🙂

      I would hazard a guess that one of the more conspirational had the wrong mushrooms on his/her veggie pizza and saw quakes… This is more likely than the USGS pulling real quakes. After all, Yellowstone has a lot of real ones to begin with and those are never pulled.

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