Analysis of the earthquake pattern in El Hierro volcan

Please note that this is not a professional analysis of the recent earthquakes in El Hierro volcano. So it might be wrong. It also might not hold any science value at all.

During the eruption of El Hierro volcano a earthquakes activity has been in the north part of El Hierro volcano. This earthquake activity is most likely created by dike intrusions into the bed rock. At this moment it is unclear if any of them are going to reach the surface. There also seems to be some minor connection between the earthquake swarms and how active the eruption is in the south part of El Hierro volcano is. But what and how that connection is and works is unknown to me at present time. The strongest earthquakes that have happened so far are up to Mb4.6 in size (I do not think that this earthquake size has been downgraded. But I might be wrong).

The current location of the earthquake swarm has not changed a lot during the past few weeks. So it is more or less in the same place. There are however reports that the earthquakes are getting shallower. But it is currently unknown if that is because of magma movements or because the crust is releasing stress because of the dike intrusions in El Hierro volcano. A full list of earthquakes larger then ML2.5 can be found here (EMSC).

The results of this dike intrusions are going to that in some areas of El Hierro Island a hot springs and other types of hydrothermal activity might show it self. Without warning. But that can result in this type of hot springs.

Picture is from Hveragerði, Iceland. Picture taken by me (Jón Frímann Jónsson). This picture is released under Creative Commons Licence. See Creative Commons Licence web page for more details (link in top bar).

This is also going to be the result for El Hierro volcano after the eruption end, if any magma remains shallow in the crust to cool down.

A 48 hour map of the earthquake activity in El Hierro volcano. Copyright of this picture belongs to IGN (Instituto Geográfico Nacional).

The earthquake are in almost N-S line, that is most likely the fault line that might erupt if it opens up. But as it stands now. Most of it would be out to the sea. But the exact length of a fissure is impossible to predict. What happens is only clear when it starts erupting.

The 4 day amount of earthquakes in El Hierro volcano. There are some earthquakes in south El Hierro volcano. But those earthquakes are fewer and smaller in size. Copyright of this picture belongs to IGN (Instituto Geográfico Nacional).

The total number of earthquakes in El Hierro volcano since the magma intrusion started in July 2011. As clearly can be seen on this picture, the new area with earthquakes makes a clear signal that it a magma injection into the rock. Rather then result of tectonic movements in the area due to the eruptions. Copyright of this picture belongs to IGN (Instituto Geográfico Nacional).

Update on the eruption it self: Explosions appears to be taking place in El Hierro volcano again. That suggests that the eruption is once again more powerful, after a few hours of lowered activity. It is not yet confirmed if any new vents have opened up closer to the shoreline. There are pictures that suggest it. But nothing is confirmed at this moment. But it cannot be ruled out that new fissure is going to open up closer to the coast. If that happens, it is going to be noticed if the depth is shallow enough.

As for the eruption in El Hierro volcano. I now classify it as long term eruption, as it has lasted for longer then 1 month. So rather then sharp blog posts about what is going on. I am going to post regular updates on what is happening in El Hierro volcano eruption. If there are any major changes. I am also going to cover that soon as possible. But I am not always in front of the computer, and El Hierro volcano is far away. But I am doing my best regarding this eruption.

Blog post updated at 12:25 UTC on 16 November, 2011

138 Replies to “Analysis of the earthquake pattern in El Hierro volcan”

  1. Thank you for the summary.

    In your photo, is the hot red stuff cooling lava? Clearly look where you are putting your feet should be added to the list of advice for tourists.

    1. The red stones are old lava. I am not sure why it is red in color. This is a hot spring, that appeared on the pave-walk it seems. In Hveragerði town I think that this happens sometimes.

      1. Red stones probably from oxidation of iron minerals in the lava if one thinks of the red inter-flow soil developments

        Bed-time now nighty-night folk!!

      2. I remember seeing a small geysir erupt alongside the end of a row of houses in Hveragerdi. It was about 4m from the end wall of the house and erupted twice a day to roof top height.

        And there’s the story of a bigger geysir in the town that stopped erupting, leaving a useful deep hole. Useful for tipping rubbish for a year or so – until the geysir started erupting again.

      3. I could do with a little underfloor heating here at the moment and my boiler is playing up. One good thing about Iceland is maybe the cost of heating houses is far less than here.
        However I would like to be able to control just how hot it gets 🙂


      ‘Huge deposits of hematite are found in banded iron formations. Grey hematite is typically found in places where there has been standing water or mineral hot springs, such as those in Yellowstone National Park in the United States. The mineral can precipitate out of water and collect in layers at the bottom of a lake, spring, or other standing water. Hematite can also occur without water, however, usually as the result of volcanic activity.’

      That might answer your question KarenZ (and fill a gap in Jons extensive knowledge!) I recognized the colour having lived in the lake district in England near an iron ore mine!

  2. From old thread…

    ian says:

    November 15, 2011 at 20:43

    Well Katla just had a fresh injection of magma from the deep. I suspect it will be working its way up now and the effect should shown over the comming week. This from observations normally seems to be the case.

    The last one that lead to the recent clusters orginated near to Habunga, this new one from Goabunga at a depth of 28.6km – but still within the caldera.


    Newby says:

    November 15, 2011 at 21:15

    Sorry Ian but how do you know about the fresh injection of magma? Do you mean the recent quakes or is it something else I missed?


    Shallower earthquake swarms always seem to follow isolated deep 18km+ quakes under the Katla caldera… im assuming this is because of fresh magma being pushed upwards from the Mantle which would be located at this depth. The swarms result as the magma makes pathways up.

    The people in El Hierro are having a horrible time with all the tremors. They are making them feel sick and dizzy.
    The above is an idea for making your own seismaphone. It makes a noise when an earthquake happens.
    From reading AVCAN’s facebook pageit would seem that not only are there constant vibrations but also sounds below their houses.

    1. I can imagine how insecure the constant tremors would make you. Not to be able to trust the ground under your feet is one of the most basic terrors. My partner gets something similar during high winds (we get a lot of those) as we live beside our little 56 million year old volcano.
      My recaptcha this time includes an illuminated initial character. Classy eh!

    2. It can’t be very nice and must be made worse by anxiety.

      Diana, are you feeling better after your accident a couple of weeks ago?

      1. Hi Karen, Thank you for asking . I am much better 🙂 Nearly ready to get back to digging the Vegetable patch over 🙂

  4. Don’t know what it means but since about 8am the spectrograms for all the islands near El Hierro have developed greater high frequency content especially La Gomera (provided you expand the areas of the data unaffected by that big transient). Normally I’d associate high frequencies with gas escape but as we are talking here about frequencies in the range 4-14Hz I don’t know.

    1. I was wondering about the same thing a couple of weeks back.

      The higher frequency component is especially visible on the CFue and EHig daily frequency spectral displays. Then I noticed a recurring daily pattern – the higher frequency ‘signal’ seems to begin each day around 5-6 am and then tapers off after 10-11pm. It also is less prominent on weekends than weekdays.

      My theory – it’s probably road noise .

  5. A new image form rapideye:

    Afte read the IEO paper of 13-nov i found:

    -Las calmas submarine volcano is 160m underwater.
    – Had a new vent, It was active nov, 13th.
    Old and new vent where active this morning.

    Old vent:
    data from here:

    New vent:
    comparation of IEO maps of 24-10 and 13-11:

    Al data compared with new rapid eye image:

    What do you think happens in the new north lava flow?
    A submarine landslide?
    A new fisure open?


    1. Good luck and have fun. I thought about it but I would guess that it is hard work maintaining a blog.

      Keep in touch.

    1. Uh… that’s on the north of the island. (page 5)


      “Systematic recognition using multi-beam probe and EK-60 from the north,
      especially the area of greatest concentration of earthquake epicenters.
      During the study on the evening of day 25 and the morning of 26 are located in the multifrequency probe areas of light leaks gas (Figure 3).”

      Caption of Figure 3 (also giggletrans)

      “Screen is shown above the EM-710 echo sounder recording the gas in the column water and very close to the seabed (white line).

      Bottom: single beam echosounder profile 120 kHz and often. Be seen to the right of registration fluid emission minor.
      Right: MDT on which are placed the two areas where exhaust was seen the night of 25 October. Data pre-processed onboard and ArcInfo GIS represented by the geology team IEO-Madrid.”

      Emisiones de fluidos => Fluid Emissions.

      1. So we have more de-gassing, now to the north.

        Do we know what measuring of temperature is being done on the island, and what the results are?

      2. It shows that we were right when we observed the discoloration to the north and wondered if it was a new source or just the current taking it round to the north, as well as away to the south from Bob.

        Thanks very much for the link. Interesting that the points of ‘exhalation’ are just off the ends of the promonteries.

  6. Ya know, MRK has some valid concerns about the swiss cheese island of El Hierro.

    Does anyone know if any monitoring of the different cave/tunnel systems has been done?

    Hell, even someone from the local fire department could go do a test on one or two caves, while they may not have the full ensemble of probes for the different gases, I know they at least have equipment for CO detection. We always had to test the air from our cascade system before filling air bottles.

      1. The place is riddled with them. I only thought it was a few.

        Let me dig around and see if I can find the pdf. or at least a plot of the entrances to the ones I know of. It will be a few minutes.

      2. I thoroughly enjoyed reading about these caves, Lurking. I also see that one of them translates as Mother of the Crater, which is situated at La Restinga, and although I know there’s probably nothing in it, it made me go Oooooh! all the same 🙂

      3. Cuerva de Don Justo is supposed to be mapped out to 6.3 km in length, but I haven’t found a map of it yet.

      4. Heh… I backtracked on that link to look for descriptive info, using Google translate.

        My guess is that either Google has sort of a one track “mind” or that El Hierro is looking to set up archival storage facilities using the caves.

    1. I don’t know that I would call El Hierro a Swiss cheese island in same manner as we think of a karst region being Swiss cheesy. Lava tubes are almost always surface features (or very near to it), and I’d be surprised if any of the tubes on El Hierro were very much more than 40-50 meters below the surface. I’ve done my fair share of caving, and there is a huge difference between lava tubes and karst features. Tubes don’t branch much, it’s essentially just a long “hallway”.

      1. Interesting – I’ve not done much caving, but it doesn’t look like the green lines (that map out the cave) in xeno’s link for cuevo del viente (above) fit with your ‘not branching much’ ?

        Though that might just be my definition of ‘not branching much’ being different, as ‘not much’ is ‘quite’ subjective. 🙂

      2. Cueva del Viento (which is on Tenerife not El Hierro) is one of the world’s longest tubes, and is somewhat of an anomaly, with a coalescence of tubes forming a cave system. Don Justo on El Hierro also has many passageways, but all the other El Hierro caves are less than 500 meters long, and pretty much single passageway. Lava tubes are very different than the limestone caves that are better known, and often Swiss cheesy.

  7. There seems to be new quake swarm going on at Katla. There also seems to be tremor rise on Godabunga sil

    1. Wednesday
      16.11.2011 07:09:58 63.673 -19.187 6.7 km -0.1 33.97 4.8 km NE of Goðabunga
      16.11.2011 07:08:20 63.611 -19.118 1.1 km 2.8 81.21 3.6 km NNW of Hábunga
      16.11.2011 06:56:09 63.667 -19.124 0.7 km 0.0 79.77 6.9 km ENE of Goðabunga
      16.11.2011 06:33:58 63.599 -19.189 1.8 km 1.1 90.02 4.9 km WNW of Hábunga
      16.11.2011 06:18:58 63.593 -19.198 2.8 km 1.2 90.03 5.1 km WNW of Hábunga
      16.11.2011 06:18:55 63.600 -19.187 1.4 km 0.3 90.01 4.8 km WNW of Hábunga
      16.11.2011 05:22:38 63.661 -19.173 3.5 km 1.1 90.02 4.5 km ENE of Goðabunga
      16.11.2011 05:22:30 63.668 -19.145 1.1 km 0.3 71.56 6.0 km ENE of Goðabunga
      16.11.2011 04:14:06 63.610 -19.118 1.7 km 0.0 47.54 3.4 km NNW of Hábunga
      16.11.2011 03:22:26 63.608 -19.122 5.1 km -0.3 74.67 3.3 km NNW of Hábunga
      16.11.2011 03:15:57 63.610 -19.117 0.2 km 1.8 38.3 3.4 km NNW of Hábunga
      16.11.2011 03:14:50 63.609 -19.128 1.0 km 1.2 90.03 3.5 km NNW of Hábunga
      16.11.2011 03:00:20 66.305 -18.562 4.3 km 0.7 30.17 19.8 km NW of Gjögurtá
      16.11.2011 02:02:05 63.611 -19.128 1.7 km -0.0 64.91 3.7 km NNW of Hábunga

      1. There are a couple of more now. Interesting is the one at 08.17h which is listed as a 0.5 but clearly appears on Jóns helicorder. So I guess its stronger.

  8. A bit ot maybe, but the shaking and blurrines of El Hierro webcams are most likely due to three things:
    1. wind; causes camera to swing so image moves and seems a bit out of focus due to heavy image compression.
    2. Tremoring/ quakes; causes the sharp horizontal distortion lines(same effect is seen when drilling a hole to concrete wall where a camera is installed, with a hammerdrill)
    3. Cheap optics circuitry; propably a Basic ccd sensor in day/night camera board/software, causes image to go out of focus when there is enough change in light condition.

    These assumptions are only based on my 7 year experience on designing, installing and maintaining security camerasystems.

    1. Thank you for this Stoneyard.
      I have noticed the different movements on the La Restinga Cam. Two days ago the tremoring was noticeable and very distinct from wind movements. As you say it was a definite sideways movement, starting slowly, getting a little more rapid then ceasing.
      Wind is less patterned if that is the right term.

      1. Good morning!
        Time for coffee and the round of volcanoes.
        Yes, Diana, you mentioned that camera vibration. I was able to check it myself. Doesn’t look like wind.

  9. Off-Topic: Tanks Guys for the compressed winter iceland advices. Just a suggestion, jon if you put these advices together plus I will provide some fotos after the trip wouldn’t it be a nice to have this availabe on your website? “Short report on winter travel in iceland”

  10. Arrrgggghhh! Posted on the wrong page!
    Diana Barnes says:
    November 16, 2011 at 07:47
    Good morning Jon et Al and as Ian( ian says:
    November 15, 2011 at 20:43)
    has predicted in his post, here are Katla’s resulting quakes after the intrusion yesterday.
    For new readers to find details of these quakes click on the tab that says “Table” above the map.
    I haven’t visited Bob yet as I am only on coffee # 1

  11. Comment from Avcan FB page regarding the signal on La Palma

    It seems a sign of tremor but I am not able to relaccionarla with nothing outside of La Palma. Seeing out there in other pages do not see any nearby earthquake or lajano that can justify it. Besides, for me is as a sign of tremor with three episodes, and a Hz signal is very high, as if it were produced by an outflow of gases by a small fissure. Or not. !

    1. The signal on La Palma looks like it is from a car of shorts. At least I do think that I found La Palma seismometer to look at the signal that you speak about.

  12. They are saying though its not related to anything on El Hierro that it is independent to La Palma.

    1. Judith, I just ask, don’t somehow get me wrong – you’re not Una Canaria, are you?

  13. @Jon one minor grammar thing 🙂
    In both places (in the title and the first sentence) where you’ve written ‘analyse’ in the blog post above it should be ‘analysis’.

  14. Forgot to ask whether the line of earthquakes in the Tjörnes fracture zone map are anything significant – or is that just tectonic ?

  15. Looks like you may start getting some more seasonal weather up there in Iceland, Jon. From about next Thursday (24th) you should start seeing some low temp upper air which should see the temperature drop rapidly. Nothing better than a volcano on Snow white background. Does snow or severe weather effect the analysis of inpending eruption, due to access limitations, or make no difference at all?

    1. What do you mean with access limitations? The instruments which are recording quakes and tremor work autonomously and transmit their data to Reykjavik. There is usually no need to look after them (and the batteries have been replaced in the fall).

      1. Perhaps a message saying look at your website would have been a better answer, i can see now you have photos of special vehicles with large wide wheels and experienced drivers to get them to the areas required in adverse conditions and terrain

      2. Ahh, sorry. Yes, there are vehicles available to go on the glacier literally everytime. But the conditions in winter are harsher than in the summer (no surprise I would guess). The geolocical department of the University of Iceland owns such cars as well.

  16. Well, if a power failure, correction or replacement needed you get to need to get there to do it, Sometimes for instance a camera goes down, happened many times.
    What do they have, and what kind of priority is given if a failure takes place during a period of adverse weather. High wind also hides some information, do humans ever need to use on site observation at all? I would be surprised if no human on location observation takes place to gather further information.
    Not sure if seismic recording information does fail, but as its electrical i would think like everything else its prone to faults and poer outages that needs human intervention.

    1. They can go to the sites if necessary. But usually this is done in the summer when the conditions are better. A lot of these place are quite remote anyway.

  17. I think that it should move a series of concrete questions to the IEO and IGN, for a clear response: 1. To that distance of land find the emission/s in The Restinga. 2. All the eruptive mouths have been located. 3. That depth they find in these moments. 4.Some emission of gases exists in the marine zone of the Gulf… I do not deal since they do not give this information like that of white of egg at this point of the operation Bimbache. They us represent the bathymetric one but they do not give us the resultant information. It does not seem to me likely.

  18. Re: Cave systems of El Hierro. What we have seen from the posts is various discovered caves but for me it never was able to explain the sulfur smells in the face of the high winds they have been seeing.

    So, lets play devils advocate. I counted like 23 caves in the vicinity of El Golfo and thats the ones I could find, and 10 or 11 down in La Calmas and a few to the north. The ones to the north are very obscured, collapsed mostly and likely old lava tube ends.

    We also have the nicest lava tube for hundreds of miles around and its the tunnel from one side of the island to the other. Very cool and also at a depth that if this thing gets magma into the center via a tube or another vent will pour this stuff out into the population centers and well, make a new volcano that shouldnt be there. But we also have to consider the old tubes in the volcano to be there even though they arent seen. They are likely loaded with water, possibly sealed and they are steam bombs waiting for the burner to be lit.

    My first clue about this was that Jon was talking above about steamers popping up in Iceland. That tells me that there isnt any magma yet into the main island because there isnt any steam and frankly I couldnt find anything that indicated that heat was rising in the internals of the island. But, they could save a box load of people if they instrumented the things now just in case. If the temp starts to rise even slightly and approaching 110 F then it will steam regardless as heat will interact with the air and make condensation. Lower than that if the air is cold.

    The islanders need to be made aware also that the gases could build up in that tube system and their vaunted tunnel and emerge without warning. Flammable gas, poisonous gas, and it could come creeping out in the middle of the night (most likely at that time because the winds are calm) and roll into one of the population centers.

    “Smelling” a gas of any kind or seeing steam is bad, bad ju-ju because its a warning sign, possibly a sign of impending death. It doesnt matter which gas gets you, you are just as dead. Co2, HSo2, So2 or a six pack of Bud Lite to the head and all will take you out.

    Its an observation that I am making here. I have no knowledge that this is where the gases are coming from especially around El Golfo, but the fact that they can smell it means its rising from the ground somewhere. It would be a real kick in the butt if they found they were parked on top of an old lava tube filled with gas today, and magma tomorrow.

    1. I agree that there is evidence of previous volcanic activity all over the island, and the cones and empty tubes suggest that gases are the main event, otherwise surely the tubes would remain full?

      The breaks are also areas of concern, as it is not immediately evident what might precipitate a collapse or shear in a particular location. Lurking’s magnificent graphs show La Restinga was raised before Bob, and lowered after, while El Golfo, and west, now shows raised areas.

      It is also worth recalling that before the quakes moved north and deeper, they were centred under the island. I haven’t got my head round what the connection might be. The concept of crystallised magma remaining from previous eruptions seems somehow unevidenced. The wetness of the interior of Bob’s floaters suggests several different areas of the island and the crust below, consist of different chemical mixes.

      The missing El Golfo section and the long period of time since the last major eruption also leave many unanswered questions as to how to predict the risk accurately and safely.

      1. Also a vent to the north-east of El Golfo was unexpected to my mind. If the 2 vents to east and west in El Golfo indicate the diameter of a hot spot plume then it is very large potentially.

      2. Again we have to llok in the macro rather than the micro. The island is shot through with volcanic vents, but there is little if any evidence that I have found of thermal springs or anything like that. its GOOD that we havent gotten that yet.

        But what is Bob Maximus at Restinga? Think about Old Faithful at Yellowstone. Submerge it to 330 feet and give it a little more juice in the form of magma. Water heats in the vent while its trying to form magma dome on a small scale. It builds pressure and like cooking pieces of rock it clears it into pure gas which makes the magma load up with it and then boom the top blows off and we get a geyser like shot around Restinga.

        So move back up onto the island. I am trying to find the PDF that shows the total number of vents but its in the thousands. They are surely loaded with water and if the quakes start rising into the island its due to magma and gas breaking rock. When it gets to the point that it starts to heat trapped water, it may be too late. Or it will be recognized too late. We are all focused on the focus…Bob Maximus at Restinga and Bob Minimus in El Golfo. I am betting now looking at those quakes that there is a terrible possibility emerging that its cracking the island slowly and its starting to invade the layers of ash that has been compressed into really crappy rock. Magma could cut through an ash layer if it gets high in the hill and be out and on top within hours because its really not rock, its layer(s) of ash that never compressed or was done so imperfectly. Steam could blow it out, magma could melt it out. Think of it like a layer cake that you squirt frosting into the middle of. Its going to pour out the weak sides.

        Its not so hard to imagine and its not the scare factor. We have seen it on the sides of many volcanoes, vents popping up. Eyjaf started in a vent hundreds of yards from the main show. We have at least 1000 other possibilities on this island for this to come and visit through.

        Hell, I WANT it to erupt at sea because the effects of it erupting on land might just be mind boggling.

        Has a volcano ever eaten a 80 mile long island whole before? Look at the size of those crater rims that are left and start thinking scope. Just cause its 2011 doesnt mean it cant do it again.

      3. I am not an expert. But I would be very surprised if the volcano swallowed the entire island – there are no craters that would indicate that this is likely. But the volcano could have a large impact on the island whereever it erupted, depending on the nature of the eruption.

        I agree that there is a risk that a vent could open in the bay or on land anywhere along the NNW-SSE ridge. Magma may be rising under SW Frontera, W Frontera and NW Frontera – where it finds a route to escape is anyone’s guess, as is how much warning it gives.

        Given that Bob seeems to be mainly de-gassing so far, we probably also need to factor in the impact on the magma reservoirs of the loss of gas at its top.

        Unfortunately the eruption history of Hierro is not clear. An evacuation plan that can be executed in 4 hours, while impressive, may be cutting it very fine.

    2. I went looking around to try and find the tunnel. The only one I could locate was on the far North end going from the Frontera area on the El Golfo side apparently bypassing a sheer cliff by going into the island to get to the north coast.

      Are there any other tunnels through the bulk of the island? I seem to recall one oddly looking straight, near horizontal line through one of Carracedo’s graphics.

      1. There is a (the) tunnel from Las Puntas via Moracanal to valverde. I think this is the tunnel they closed sometimes.

      2. There is another tunnel on the south-east coast on the road from Puerta to Las Playas, close to Parador and CHIE.(Roque de la Bonanza)
        Probably out of EQ and Gas zones.
        Don’t recall others but those two after a week spent there in february,

      3. I think the risk is, that a small landslide at the entrance of the tunnel could close it up and then is only a road over the mountains left. And there could be a eruption or the road is full of people running away. So the people in the golfo area are trapped. The tunnel has been discussed in connection to the rescue ways.

  19. things seem to heating up again at El Heirro: I suspect we will have another blow in the south to center-south in less than a day or so .. Maybe even some Geysering again ? It seem to somewhat cyclic with a period of 7-8 days

    1. Possibly but there has been very little EQ activity south of SW Frontera; most has been NW and W Frontera.

    1. I posted it yeasterday. I don’t think that there is an active vulcano. It’s the rifting zone. Someone comments in a forum the new webcam: “It’s about time. Now you can finally watch the live plate tectonics” 🙂
      They say also that there will come more cams.

    2. This is the Allmannagjá in Thingvellir, where the old parliament took place (this dates back to 930). In the left part of the image you see a flagpole, that Lögberg (the hill of the law) where the speaker of the thing (the old parliament) acclaimed the laws against the wall of the canyon so everybody could hear it. The building at the right belongs to the iclandic state and is guest house of the government. The church a little bit left of it is part of Halldor Laxness famous novel “Iceland’s Bell”.
      Any further questions? 🙂

  20. Hi all first ever post here been following this blog a good while now from the UK

    Its where Icelands first parliment was formed can’t recall dates google-eye it.
    Also you can walk the fault line there.
    Go to Iceland every year 🙂 Was there this year sat in hot-tub with a bit of Ash falling on me from Grims lol

  21. It’s over now, but it was right in the middle of the picture. Over the end of the quay wall.

  22. The La Gomera and Tenerife seismic spectrographs, but most strongly on the La Palma station, have slowly developed a 1 Hz monotone in their ‘voice’. This is new and because of the slow onset I believe it is not man made. Looks like a new magma induced harmonic tremor placed in such a way that it is best heard at La Palma.

    1. notice how notchy it is getting if you click on the one hour only PSD at end of regular PSD (24 hours PSD)

    1. Hey, you created a new name for bob or who is waldo?
      Perhaps he is at carls new resting room…

      1. Nah… waldo in the Waldo series.

        Bob remains bob. I don’t think Bob is gonna don glasses and a gaudy red and white shirt to go lurk behind the waves, daring you to find him.

    2. Maybe another source of harmonc tremor than Bob?
      IGN should know, now they have a network of sensors.

      1. I think the tremor source is deep… and always has been.

        The question is where. IGN seems to enjoy keeping mum about what is actually down there and releases only ephemeral data.

        How long did it take for the presence of hydrothermal fluid percolation on the North coast to make it out?

      2. Yes, deep. The high silica content of the Restingas indicates a deep sandstone source – and the sedimentary layer is at 6-8km. That’s a long vent to Bob. So why not further long vents opening in El Golfo? – and why no further announcements of sonar exploration of venting there since October?
        Maybe IGN dont want frighten the horses

    3. When AVCAN released the names of the stations, CHIE (the site of the largest tremors) was Las Playas; Restinga had a much smaller tremor (sorry can’t remember the station initials). This implies that Las Playas is closer to where the magma is currently moving than Restinga.

      Waldo is probably trying to find route out, without checking the map or satnav.

  23. I wonder weather it is one of those large gas bubble rocks stuck in the vent again, remember it happened the other week in front of lots of people on the island a rock burst out of the jacuzzi…. perhaps it was one of those gassy pyroclasts, a larger one that caused a blockage, that is actually bifurcating the the jacuzzi. I am probably wrong but you never know.

  24. The hard drive in the main earthquake monitoring computer is getting bad due to old age (like every computer hardware that I own today..seesh). Does anyone know about good hard disk cloning software that I can use. As I want to clone the two partition into a new hard drive that I did just order.

    I want to limit the downtime on the earthquake computer into little as possible.

      1. From SourceForge

        “Manipulate file systems such as:

        ext2 / ext3 / ext4
        fat16 / fat32
        hfs / hfs+
        reiserfs / reiser4

      2. Thats just from the material on the website.

        Also note that they say “Manipulate file systems.”

        That might be an important piece of verbiage. It doesn’t say “clone,” it says “manipulate.”

      3. I have used it to clone XP systems to larger disks. As long as your original disk (which you clone) still works, you can test this by putting the newly cloned disk into the computer and boot from it. Worked for me without problems and I have a backup system in the drawer.

    1. The easiest to use and most reliable I have found is Paragon Hard Disk Manager. Of course there are plenty of utilities to do this of which the most popular is Acronis but I have had issues with the latest version. Norton Ghost also comes to mind but I researched it widely just recently and I would go with Paragon.

    2. Jon -clone or really good backup? I got both Carbonite and a plug in 1 TB backup drive called “Just plug me in”

      I did and it took it three hours to download the hard drive (80 Gig), then the second time it took an hour, then the third.. .only minutes.

      It makes a mirror image of the hard drive and then verifies the data as 100%. Its not on all the time but you can leave it plugged in without the power to it. Put the power to it and off it goes and makes it and takes it in DOS/Win98/XP/Vista and 7 formats so you can read it from just about anything other than a MAC. You can also use it to back up multiple computers. It only verifies the old data and saves the new so its literally on for maybe 5 minutes now. Portable, and you it saves everything in the format it was in. That is to say word goes to word, emails get saved as emails.

      Wikked little beastie IMO.

    1. I am surprised they haven’t resized it again, (not the best word but the best my mind will find when I am so tired) Someone suggested it could only be ‘resized’ a certain number of times. Is this true do you think and has it perhaps reached it’s maximum? Remember I am a total dimbo on this so be kind please with any answer. 🙂

  25. Katla related question – could the entire floor of the crater be moving up to relieve strain? I notice the earthquakes are mostly concentrated along the edge of the crater.

    This might explain the lack of gps movements as well. I just don’t know if it’s physically possible for the entire floor of the crater to move up and down fairly independently of the surrounding land without causing an eruption.

    Probably just a crackpot theory so feel free to ignore me 🙂

    1. No. The magma collects in pockets in the crust (via dike intrusions). So the earthquakes are areas where it is most likely that magma is now collecting.

  26. Acronis true image is what I use to clone drives for upgrading XP – it even clones the driveID so XP doesn’t think the drive has changed and need verification. Fast too.

    1. I’ve had problems with the latest version of Acronis, particularly the ‘non stop backup’ so I could no longer recommend it after years of use. I am now very happy with Paragon HD Manager Suite 2011. It’s also more intuitive to use.

  27. ====
    Jón Frímann says: November 16, 2011 at 21:09

    Can it clone ntfs ? If the cloning fails. I am just going to go trough the pain of setting Windows XP up again.

    If you have Seagate disks then Seagate diskwizard will do this really well. I have used it a couple of times. Best of all you can clone a smaller disk onto a bigger one!!

    I believe Western digital etc have similar utilities available.

    Oh, and did I mention, its FREEEEE!!

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