3.9 magnitude earthquake strikes north of El Hierro as quake swarm total exceeds 10,600

October 30, 2011CANARY ISLANDSThe National Geographic Institute has confirmed this morning at the direction of the Civil Protection Plan for Volcanic Risk (Pevolca) a magnitude 3.9 earthquake struck northwest of Frontera, located in the sea at a depth of 22 miles deep. The earthquake was followed by a 3.2 magnitude aftershock which struck at a depth of 19 km. The quake, which was felt by the population, occurred at 07.46 hours and is the largest earthquake recorded in the island after the onset of the eruption south of La Restinga. The Emergency Coordination Center and Security (CECOES) received 1-1-2 calls from the towns of Isora, Guarazoca, Mocanal (Valverde) and Tigaday (Border). The evolution of seismicity in the north of the island has increased in recent days and scientists, who are monitoring constantly all possible scenarios, still cannot ascertain what this new activity means. In this sense, they are inclined to believe that this new activity could be producing a seamount. Moreover, those responsible for the IGN have confirmed that yesterday, 62 earthquakes were reported along this region with two of them being felt by the population. The earthquake of greatest magnitude in yesterday’s swarm reached a magnitude of 3.6 on the Richter scale. This movement has been located at sea in the Gulf area about 4 miles from the coast at a depth of 23 kilometers. It has been felt by the population with maximum intensity IV in the town of Valverde. The depths vary between 15 km and 25 km. In total, since the day July 17, 2011, the island of El Hierro has been shaken by more than 10, 615 earthquakes. According to reports from scientists at the University of Cadiz, and with reference to the deformation of the ground, this continues in two separate scenarios. The south of the island shows a remission in increasing deformation, clearly marked by the eruption process and that is evident in the data recorded in the GPS station of La Restinga. However, in the north of the island, there is an increased component of deformation component to the North and the East. –Europa Press translated
Volcano forming on the sea-floor south of La Restinga
contribution Luisport
This entry was posted in Earth Changes, Earth Watch, High-risk potential hazard zone, Lithosphere collapse & fisssure, Potential Earthchange hotspot, Seismic tremors, Volcanic Eruption, Volcano Watch. Bookmark the permalink.

36 Responses to 3.9 magnitude earthquake strikes north of El Hierro as quake swarm total exceeds 10,600

  1. c/o Luisport

    According to reports from scientists at the University of Cadiz, and with reference to the deformation of the ground, continue two separate scenarios. The south of the island shows a remission in increasing deformation, clearly marked by the eruption process and that is evident in the data recorded in the GPS station of La Restinga.
    In the north of the island, seen in the deformation component increased to a lesser extent North and the East”””


  2. c/o Luisport

    Special report: New eruption vent (or vents) might have opened up in El Hierro volcano eruption
    Posted on October 30, 2011 by Jón Frímann

    The current tremor data now suggests that a new vent or vents have opened or are about to open up just outside north-west coast of El Hierro volcano. The depth where the main earthquakes have been taking place is about 100 to 300 meters (but might be more). So far the largest earthquakes to take place in this area was a ML3.9 with the depth of 22 km. What is important in this is not the fact that the earthquakes are at great depth. But also the fact that a more shallow might not take place. As that was not the case when the eruption started in El Hierro on 10 October, 2011. It is unlikely that there is going to be any shallow earthquake activity before a new eruption vents opens up. As that was not the case on the 10 October, 2011 from what I can remember.
    I am not sure how strong earthquake this area can make. But I am guessing that it might well be in the upper Mb5.5+ range. The earthquakes that are now taking place are due to magma injection. Not a tectonic one. There is a difference between the two. But this rifting in El Hierro might trigger a earthquake close to El Hierro Island in near future, that earthquake would be a tectonic one. Not a earthquake created by magma movements.

    So far the new vents are still unconfirmed. But there are signs in the harmonic tremor data that new eruption vents might be opening up or have already opened up. But at this moment I am waiting for a confirmation on this actually taking place. That is going to take a few hours, given the experience so far.


  3. c/o Luisport

    Important Update 30/10 – 07:53 UTC
    – Based on all what follows Earthquake-Report.com predicts that PEVOLCA will meet very soon. Main reason : The increasing strength of the earthquakes.

    – The strongest earthquake since October 8 (a M 4.4 quake at the time), now a Magnitude 3.9 quake, occurred at 07:46 this morning in the El Golfo bay. Its epicenter was close to the Frontera coast line. The 4.4 earthquake on October 8 was the start of a number of events like the beginning of harmonic tremor and the start of the green stain (eruption) soon after. The depth is still a secure 22 km. Some scientists are linking however the magma area below the El Golfo to the still continuing eruption to the south of La Restinga. These are however speculations who cannot be proofed.
    – At earthquake-report.com we do not consider quakes up to Magnitude 5 as dangerous for houses, although indirect damage can be triggered by rockfall and landslides in mountainous areas like El Hierro. Authorities will certainly follow up the El Hierro landscape scars when the quakes get again to Magnitudes 4 to 5. This will be a major concern for the El Hierro authorities from now on.
    – Harmonic tremor remains the same as during recent days. This may change fundamentally if the quakes continue and are getting more powerful.
    – Since midnight UTC IGN listed 11 earthquakes and only 2 of them were lower then 2! The last 3 quakes had values of 3.2, 3.9 and 3.0.
    – Authorities have closed the Los Roquillos tunnel out of fear of Rockfall for the 3 to 4 magnitude quakes in the beginning of the month and have reopened him last week due to the pressure of the population. Will authorities close the tunnel again ? We do not think that they will take such a decision very soon as technicians have improved some parts of the tunnel. The concern among scientists and PEVOLCA must grow though.
    – Joke reported yesterday that the Frontera population reacted completely different to the earthquakes than the El Pinar and La Restinga people. More indifferently and certainly not as alerted as them.
    – Those people wanting to follow the discussions among specialized volcano amateur followers can click on this link. We can warmly advise it. A lot of scenarios are being discussed.

    2011-10-30 02:20:36.3 27.79 N 18.05 W 20 ML 2.6 CANARY ISLANDS
    2011-10-30 08:15:43.4 27.79 N 18.04 W 22 ML 3.0 CANARY ISLANDS
    2011-10-30 07:46:35.8 27.79 N 18.04 W 22 ML 3.9 CANARY ISLANDS
    2011-10-30 07:13:42.1 27.78 N 18.05 W 22 ML 3.2 CANARY ISLANDS


  4. luisport says:

    Minor earthquake activity continues at the impressive Lagoa do Fogo/Agua de Pau volcano in the Azores.
    3/4 earthquakes of M2.0 today.


  5. RainMan says:

    Greetings Alvin,
    thanking you and all concerned for the great work and info, always muchly appreciated, but there doesn’t seem to be a link I can find regarding volcanic discussions, hope it’s just my antiquated PC connection.
    Regards and well wishes.


  6. Tim says:

    Why does USGS not include quakes from areas like El Hierro?


  7. Thank you for keeping us updated on El Hierro. Much appreciated.



  8. luisport says:

    Jón Frímann says:
    October 30, 2011 at 22:14
    The harmonic tremor that can be seen on other stations close to El Hierro suggests that the new vent that is about to open is bigger. That means a larger eruptions on a longer fissure. But it might well happen that this fissure goes up to dry and out to the sea. I am not going to rule that out. As the earthquake data suggests that to be a real possibility.

    In my view they should evacuate this whole area right now. Before the magma reaches the surface. Better save then sorry in the matters of volcanoes.


  9. luisport says:

    According to Takeshi Sagiya, Professor at the University of Nagoya, scientific collaborator of the INVOLCAN and scientific resposnable of the permanent GPS network of the INVOLCAN volcanic Canary surveillance, no significant shifts in the permanent instrumental GPS stations are observed during the last few weeks. On the other hand, data from seismic activity reflected a reactivation of the same under the North coast of El Hierro which may indicate a second magma ascent process. There are two possibilities to explain the changes observed in the GPS stations. One of them is Let’s see again signs of inflation (shifts eastward in FRON and westward in SABI). Probably the current seismic activity is deep and the deformation of the ground will gradually intensify as it occurred during the months of July – August… but we must also think about another possibility. Given that a fracturing has been created that already he has promoted magma as a result of the activity of July-August, the magma can be climbed without registering additional inflation. So far we have not seen signs of significant deflation, so that the amount of magma at depth can be large enough to continue to provide magma to positions more shallow under El Hierro. If so, the activity can continue.



  10. kay says:

    Thank you for translating!


  11. I.R.I.S. is a good site for general world wide earthquakes, but it is not showing anything for the El Heirro area that I can find….Thanks to you guys on here, I am finding the info on this site very enlightening…MAB


  12. Tcrale says:

    The sad part to say about this whole ordeal is that they probably won’t evacuate these people until it’s already too late; assuming something is to happen of course. They told the people there probably wouldn’t be an eruption, it erupted; they say it’s all okay now, theres still a red alert and on top of that the green stain is supposedly heavily acidic. I guess all one can do is wait; but that won’t replace my worry for those of el hierro.


  13. Tcrale says:

    Side note the heavily acidicness of the water is killing the fish; I read it from that earthquake report website; sorry forgot to include that with the main comment. I’ve said it before this volcano doesn’t give me a good feeling; maybe my intuition means nothing, maybe it doesnt. I had a bad feeling ever since it erupted.


  14. luisport says:

    The PEVOLCA confirms a change in the seismicity being valued in terms of a new eruption

    31.10.2011 … 15:43 – Ministry of Economy, Finance and Security working group of the scientific committee states that without an acceleration of deformation can not talk of an imminent eruption committee director of Civil Protection Plan for Volcanic Risk (PEVOLCA), meeting this morning in El Hierro has confirmed a seismic shift in the north of the island that is being evaluated to “determine whether or not there is a possibility of an eruption in that area.” Thus, the working group of the Scientific Committee meeting this morning, and involving representatives of non-tip, IGN, CSIC and IEO, have referred to “a seismicity occurs at 20-26 km depth , associated with a possible feedback mechanism magmatic eruption process in progress. ” also establish another scenario “to 10-15 km, which itself could be valued as a precursor to an eruption . ” Anyway it is still early to forecast, since the acceleration of seismicity at that depth, shallower, it is not producing an increase in deformation. The deformation would have to provide evidence in the coming days designed to ensure that there would be a new source of emission in the north. For his part, hoped that the results of the analysis of helium , performed by the non-tip, to give more information. Recall that a month before the eruption of La Restinga there was a significant increase in the gas. La Restinga south eruptive process, continues to develop normally, as indicated by the tremor signal recorded, and data collected by the Ramon Margalef ship, the IEO, which is believed to have seen a collapse of the volcano, with the data obtained with the echo sounder. Given the murky water, it is unlikely that the ship can take video images of the underwater eruption. http://www.gobcan.es/noticias/index.jsp?module=1&page=nota.htm&id=144294


  15. luisport says:

    yesterday there were 93 earthquakes, 6 of them greater than / equal to 3 degrees.
    Today and about 113 earthquakes There are currently 5 of them greater than / equal to 3 degrees.


  16. luisport says:

    Images of the volcanic cone formed south of La Restinga obtained by the ship ‘Ramon Margalef’ http://www.flickr.com/photos/presican/ Images formed volcanic cone south of La Restinga obtained by the ship of the Spanish Institute Oceanography ‘Ramon Margalef’. Date: October 31, 2011 Location: La Restinga (El Hierro)


  17. luisport says:

    Magnitude ML 3.3
    Region ICELAND
    Date time 2011-10-31 19:58:27.6 UTC
    Location 63.63 N ; 19.18 W
    Depth 2 km


    • luisport says:

      Magnitude ML 4.8
      Date time 2011-10-31 21:44:45.1 UTC
      Location 66.32 N ; 20.04 W
      Depth 12 km
      Distances 258 km N Reykjavík (pop 113,906 ; local time 21:44:45.1 2011-10-31)
      112 km NW Akureyri (pop 16,563 ; local time 21:44:45.1 2011-10-31)
      53 km W Siglufjörður (pop 1,391 ; local time 21:44:45.1 2011-10-31)

      Probably an error


      • luisport says:

        Jón Frímann says:
        October 31, 2011 at 21:58
        A SIL seismometer did go loose in the storm or something. A string of “earthquakes” is registered. But they are all errors.


  18. luisport says:

    The volcanic monitoring surveillance network 24 hours of the National Geographic Institute (IGN) has confirmed, to the direction of the Plan of Civil protection by volcanic risk in the Canary Islands (Pevolca), the emergence of smoky pyroclastic of large size on the surface of the sea as advanced newspaper EL HIERRO.
    This afternoon, sources consulted by this newspaper confirmed the increase in the flow of magmatic material to the surface of the sea of La Restinga. La mancha has become dark and dense than other days and pyroclastic smoldering remains were in the area.
    On the other hand, during the October 30th is located 93 earthquakes, seven of which were felt by the population. Two of them were recorded with 3.9 magnitude on the Richter scale, the largest after the start of the eruption to the South of La Restinga.
    The majority of these movements were lined up in the NNW-SSE direction in the Gulf area, from the sea about 12 km from the coast, until the center of the island. The depth varies between 14 17 km and 20 25 km. In total, from July 17, have been localized 10,708 events.
    The amplitude of tremor stays stable, remains at levels similar to the previous day, and without significant episodes, advises the Pevolca.
    According to reports from scientists at the University of Cádiz, and in reference to the deformation of the ground, continue two distinct scenarios. South of the island shows a remission in the increase of deformation, clearly marked by the eruptive process and evidence in the data recorded in the GPS station of La Restinga.
    In the North of the island, deformations shows an increase in the North component and to a lesser extent in the East, directed by an acceleration recorded in the GPS station located in the NW of the Gulf.
    For its part, the situation of new seismicity that occurs in the North of the island does not rule out the scenario of a possible volcanic eruption…
    For this reason, from the direction of the Pevoloca, follow to the residents of El Hierro attentive to the advice and recommendations that are sent through the Civil protection authorities in the same way they have done throughout this eruptive process.


  19. luisport says:

    Data Update 31/10 – 20:20 UTC
    The mud stain that seems to be more active than ever. A satellite image shows a spot much larger than last week. The fact that the eruption at La Restinga increased again could be related to the strongest earthquakes in the area of the Gulf, one of the first scenarios discussed in jonfr.com, a dedicated follower volcano enthusiast discussion group was that the Restinga -. The Calm – Puerto Naos eruption was fed by the movement of magma in the depths of the Gulf. This scenario seems more realistic with current events. The image belongs to diarioelhierro.es and was taken by Gelmert Finol at 18:00 today!
    The research vessel, the Roman magmatic material Margalef detected with another composition that last week. Apparently, the material was red and totally different from the initial black stone with a white inner layer.


  20. luisport says:

    http://www.tvi24.iol.pt/sociedade/neiva-castelo-de-neiva-mau-tempo-viana-mar-tvi24/1294419-4071.html In the last days sea grows 5 meters and threatens houses… i don’t know if this is interesting to you Alvin.


  21. luisport says:

    Sinkhole Swallows Man, 80, As He Goes for Morning Newspaper in Long Island NY
    An 80-year-old man who went out to get his morning newspaper fell into an 8-foot sinkhole that opened up in his Long Island lawn.


    Thankfully he was not seriously injured.


  22. luisport says:

    Jón Frímann says:
    November 1, 2011 at 10:52
    The earthquakes have dropped off. So it is my guess that the magma has found a clear path to the surface somewhere. But where is a good question at this moment


  23. luisport says:

    From earthquake.report.com

    Important update 01/11 – 08:19 UTC
    – Scientists have found large smoking lava in the Las Calmas sea in front of La Restinga (earlier jacuzzi area).
    – It is hard to believe that we still do not have a webcam (and/or time lapse camera) directed on the stain. Such a camera would not only be great for us followers, but also for science. The Sakurajima volcano is a good example for the results.
    – The currently installed webcam @ Frontera should be directed towards the El Golfo Bay during the current events.
    – The University of Cadiz has said that the deformation is decreasing in the south because of the eruption and is gradually increasing in the El Golfo area (earthquake area). The university of Cadiz is cannot rule out a possible eruption in the Frontera bay area (ER: nobody can rule out anything at the moment. All instances are making their best guess, a volcano is unpredictable as where and when he/she will erupt. A major earthquake (M 4.5 to 5.5) may put events in a final direction or it may simple stop suddenly.)
    – Yesterday was the most seismic active since October 8 – 153 earthquakes were counted and 6 were greater than M 3
    – Today a new 3.9 magnitude quake was felt at 04:15 UTC. 2 quakes were greater or equal to M 3
    – a stronger harmonic tremor has been recorded since 07:00 this morning (see below at the end of the graphic).


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