Category: Monitoring

Posted on

Few words on my geophone network

I run a small geophone network in Iceland. This geophone network won’t be getting any bigger any time soon. I have two reasons for that statement. I cannot get hardware that I need to build my geophone network. The main part remains out of stock, the geophone. I have also come to releases that after about 10 years time I won’t be able to run the geophone network anyway. But my plan is that in about 10 years time I am going to move to the Falklands Islands. Based on distance, cost and such factors. It is going to make it impossible for me to run an geophone network at that distance. It is going to take me 10 years to assemble my plan and get the funds before I can move to Falklands Islands. During that time I am going to be living in Denmark.

I have been running the current geophone network, in one or other form since the year 2006. So that is already 6 years. This has not been easy task. With hardware failures, software failures, internet failures and other issues that I have had to deal with during this time. But I have managed to keep the system running during that time, with help of the people how are hosting it for me at location. I am always thankful for that help.

I am however just going to close the geophone network in Iceland after 10 years. Closing at one place means that I can open up at new place. That place is going to be in Falklands Islands with time. As I need time to set-up new geophone network. Along with solving connection issues and such things. Setting up new geophone network in Falklands Islands might take up to 5 years for me. Depending on connections and such. As I might have to set-up my own radio links (I just expand my lan into such radio links on 2.4Ghz). Since ADSL speeds are expensive and have limited data quota are included with the subscription (the largest is just 3,3GB for 1 month), along with limited mobile coverage in Falklands Islands. But this is just really early planning. The details are going to get shorted out when I move there after 10 years or so.

I however think it is good to run my own geophone network for more then 10 years (oldest parts of the geophone network have then been running for up to 16 years in the year 2022) on my own. I am not sure. But I do not think many people in the world are doing this as I am. But I might be wrong on this.

Hardware that I can buy in the future

With the future lack of geophone for me to buy. I have several options on what hardware to buy so I can record earthquakes. First of is the cheap SEP seismometer. But that is a long period seismometer with period up to 20 seconds. Good for detecting earthquakes more then 2000 km away. My second option is to by a digital seismometer that is called VolksMeter. But that is also a tiltmeter. But VolksMeter seismometer is expensive (while I am broke at least). They cost $1245 single channel and $1795 dual channel. This is without GPS, power supply and such things. Based on this prices. I am not going to buy VolksMeter seismometer any time soon.

Blog post updated on 28.09.2012 at 04:45 UTC.

Posted on

Minor earthquake swarm in Katla volcano

Normal autumn activity appears to be starting in Katla volcano. This earthquake activity is not something to be alarmed about. But worth keeping an eye on anyway.


The earthquake activity in Katla volcano during the past 48 hour period. Copyright of this image belongs to Icelandic Meteorological Office.

This is just normal autumn activity. As such it is not dangerous and does not mean anything. More earthquakes might happen in next few days to weeks.

Posted on

Earthquake activity drops in TFZ

During the past few hours earthquake activity in TFZ has dropped. This is not unusual. As earthquake activity in this area happens in swarms. Last earthquake swarm in this area where in the years 1996 and 2004. Those earthquake swarm lasted for several days and made several earthquakes with the magnitude 4. It is impossible to know how long activity is going last in this area. But since it has been ongoing for better part of current week (week 38). It might well be this activity is already over. But only time is going to tell what happens next. In current earthquake swarm. More then 500 earthquakes have been recorded so far.


The area of activity in TFZ. Stars mark earthquakes that are larger then magnitude 4 in size. But red dots show other earthquakes. The arrows show the fault movements in this area. It is from this news here on IMO web page. Copyright of this image belongs to Icelandic Meteorological Office.


The earthquake swarm as it looks during the past 48 hours. Copyright of this image belongs to Icelandic Meteorological Office.


The earthquakes on IMO tracker. It shows the magnitude of most of the earthquakes that have taken place during past 48 hours. Copyright of this image belongs to Icelandic Meteorological Office.

As sad before. It is impossible to know what happens next in this earthquake swarm. But it might well be that it is over by now. Only time is going to tell us what happens next in this. Chance of an larger earthquake taking place in this area remains high.

Almannavarnir announcement (Icelandic Civil Protection System)

Jarðskjálftahrina úti fyrir Norðurlandi (Almannavarnir.is, Icelandic)

Icelandic news about this earthquake swarm

Jarðskjálftar í Eyjafjarðarál (Icelandic, vedur.is)
Talsverð jarðskjálftavirkni á Norðurlandi (Icelandic, Vísir.is)
Fjórir skjálftar yfir 4 að stærð (Icelandic, mbl.is)
Íbúar geri ráðstafanir til að draga úr tjóni (Icelandic, mbl.is)

Posted on

TFZ earthquake swarm update at 20:50 UTC

This is a short update for the earthquake swarm in TFZ at 20:50 UTC.

At 19:42 UTC on 20.09.2012 an earthquake with the magnitude of ML4.2 took place on TFZ. This earthquake swarm was most likely felt in Siglufjöður town, Dalvík town and possibly more places around the epicenter of this earthquake. This earthquake did also appear clearly on my geophone network in Iceland. Swarm of smaller earthquakes did follow this larger earthquake as before.


The epicenter of the latest magnitude ML4.2 earthquake in TFZ. Copyright of this image belongs to Icelandic Meteorological Office.


The progress of the earthquake swarm during the past 48 hour period. This earthquake swarm happens in swarm, with drop in activity between them. Copyright of this image belongs to Icelandic Meteorological Office.


The earthquake swarm as it did appear on my Hvammstangi geophone station. This image is released under Creative Commons licence. Please see CC licence page for more details.


The earthquake swarm as it did appear on my Heklubyggð geophone station. This image is released under Creative Commons licence. Please see CC licence page for more details.

It is impossible to predict the progress and development of this earthquake swarm. But I expect this earthquake swarm to continue for the next few hours to days. It might last longer then few days. But only time is going to tell us what is going to happen next in this earthquake swarm. I am going to post new update on this earthquake swarm once I have had the time to check some of this data. But that might take few hours until I can do so. At the longest, not until tomorrow. Depending on IMO work on this earthquake swarm data. I am going to post new updates on this earthquake swarm soon as possible if anything major happens.

Posted on

Earthquake activity drops in El Hierro volcano

Earthquake activity in El Hierro volcano has started to drop off again. During the last 24 hour period there have only been something around 28 earthquakes. But earthquake activity did peak with 182 earthquakes during 24 hour period on Sunday 16. September 2012.


The earthquake activity in El Hierro volcano at 19:22 UTC. As can be seen here. Everything is quiet for now.Copyright of this image belongs to IGN.

It is hard to say what happens next in El Hierro volcano. But magma is still getting injected into El Hierro volcano at depth. Eruption is still an possibility while inflation continues at the rate it is going. There is always the chance that deflation is going to start in El Hierro volcano. Chance of an eruption in El Hierro volcano remains high. But when it might start it impossible to say at this point.

Posted on

Earthquake swarm between in Denmark and Sweden

Today (18.09.2012) at small earthquake swarm started in northern Denanmark, with the fault line extending upwards Sweden. The reason for earthquakes in this area is old fault lines. Along with the fact the Alps pressure the crust in Denmark (from what I did read long time ago). There is also glacier rebound taking place in Denmark and Sweden, along with Norway and Finland. The largest earthquakes in this swarm have had magnitude of ML2.4 and ML2.3. Both with depth of 1 km. But that might also be subject to change.


The area of the earthquake swarm. Some earthquakes might not have correct location. Copyright of this image belongs to EMSC.


The ML2.4 earthquake that took place at 16:30 UTC. Copyright of this image belongs to EMSC.


The ML2.3 earthquake that took place at 17:04 UTC. Copyright of this image belongs to EMSC.

The last earthquake that took place in this area was at 17:04 UTC. Since then no new earthquake have taken place. There might be some earthquakes later. But I find it unlikely to happen. But it hard to know for sure. But this is continental crust. So it moves slowly, when it moves at all in when it comes to earthquakes or other such changes. More earthquakes from this earthquake swarm can be found on EMSC web site.

Posted on

Earthquakes in Tindafjallajökull volcano

One of the most quiet volcanoes in Iceland had earthquake swarm today (17.09.2012). I am not aware of any major earthquake activity in Tindafjallajökull volcano during the past 20 years. I am not sure that if there has been any earthquake activity in Tindafjallajökull volcano during this time. One off-earthquake might have happened once in a while. As they do with every volcano in Iceland from time to time. It is unclear why this earthquake swarm took place. But this might be due to stress changes in the area. Rather then anything volcanic taking place in Tindafjallajökull volcano.


Activity in Tindafjallajökull volcano. Copyright of this image belongs to Icelandic Meteorological Office.

The largest earthquake in this swarm had the magnitude of 1.1. The depth of this earthquake swarm was from 10.7 km and up to 3.1 km. This earthquake swarm appears to be over by now.

Katla volcano

The image above also shows earthquake activity in Katla volcano. This earthquake activity is well below what did happen in May to end of July this summer (2012) in Katla volcano. Currently the activity in Katla volcano is low and has been so for many weeks now. I am not expecting that change without some increase in smaller earthquakes first. For the moment, everything is quiet in Katla volcano.

Posted on

Constant earthquake activity in El Hierro voclano

On the 14. September 2012 an earthquake swarm started in El Hierro volcano, Canary Islands, Spain. The earthquake swarm is currently ongoing and there have been more then 300 earthquakes already. The earthquake activity is more or less constant at the moment. Since yesterday (16.09.2012) had around 182 earthquakes have taken place during the past 24 hour period (when this is written). The depth of this earthquakes is around 18 to 28 km. But this suggests an new magma intrusion into El Hierro volcano, or at least that magma is on the move inside El Hierro volcano from older sill inside it.


Start of the earthquake activity in El Hierro volcano. Copyright of this image belongs to IGN.


The earthquake activity on 15.09.2012. There is also an harmonic tremor pulse in this image. The first harmonic tremor pulse starts at 09:00 and lasts until 09:25 UTC. The second harmonic tremor pulse starts at 18:50 and lasts until 19:25 UTC. Copyright of this image belongs to IGN.


The earthquake activity yesterday (16.09.2012) until 21:14 UTC when this image was saved. No harmonic tremor pulses can be seen on this image. But earthquakes appear clearly on this image. Copyright of this image belongs to IGN.

This magma that is being injected into El Hierro volcano now is unlikely to erupted. But there is an pocket of magma located North of the El Hierro Island that might erupt. That magma pocket is only located about 10 km from the top of crust. In the start of the current that area was making earthquakes. But it soon did go silent. Why that I do not know.


The current area of activity in El Hierro volcano. As can be seen it is mostly located at great depth. But the pocket of magma that is located at 10 km depth north in El Hierro volcano might be reason to worry about. This image shows the activity over the past 4 days. Copyright of this image belongs to IGN.

The area that I worry about is marked by blue dots in the image above.


The current activity over the past 36 hours in El Hierro volcano. This image clearly shows where most of the activity has been taking place during this time period. Copyright of this image belongs to IGN.


Earthquake data for the past 1 year in El Hierro volcano. Copyright of this image belongs to IGN.

It is only when we get the earthquake data for past 1 year when things get really interesting. Based on this data. Magma is now already at the depth of around 10 km in El Hierro volcano. Why it has not erupted is hard to answer (the answer might come after an eruption takes place. But no sooner). There are even clues in this image that some of the magma might be as shallow as 5 km. But it is hard to see it for sure. This image also suggest that amount of magma in El Hierro volcano, in the forms of magma sill is a lot more then what did erupt last year in El Hierro volcano. The tube that is feeding this magma into El Hierro volcano appears to be located at 18.05 longitude. That tube is marked by earthquakes going down well below 28 km depth.

The current earthquake activity in El Hierro volcano is creating new magma sill inside the volcano. That is just storing magma for possible future eruptions. The activity so far has been bit stronger in terms of amount of earthquakes since last earthquake swarm in June and July 2012. But that earthquake swarm did top at around 172 earthquakes during 24 hour period. So the current earthquake swarm is larger in that regard. But so far no earthquake has been larger then magnitude 3.2. But that might change if any larger earthquake happens. As often is the case.

It is hard to say what happens next in El Hierro volcano. But I would guess that once eruption starts in El Hierro volcano it might last for months. Based on the amount of magma that seems to have build up inside the volcano during the past few months. That build-up phase however does not seems to be completed at the moment. How long it is going to last is impossible to say at current time. But this is something that is worth keeping an watch for. El Hierro volcano is going to erupt basalt if the eruption is on land. Older volcano cones are not going erupt again. At least that is my assessment of what I have seen with satellite pictures.

Posted on

Earthquake swarm on Reykjanes Ridge last night (16.09.2012)

Last night there was an earthquake swarm on Reykjanes Ridge. Possibly on one of the volcanoes that are in this area of Iceland. The earthquake swarm lasted for several hours. Strongest earthquakes in this swarm had the magnitude of 3.5. With the depth from 23 km and up to 0.3 km. Strongest earthquakes in this swarm where visible on my geophone network.


The earthquake swarm on the Reykjanes Ridge. Copyright of this image belongs to Icelandic Meteorological Office.

Last earthquake swarm in this area was on 8. February 2012. There was also earthquake activity deep on the Reykjanes Ridge. With two earthquakes that did get the magnitude 4.4 (EMSC) at 12:51 UTC. The second earthquake took place at 14:30 UTC and had the magnitude of 4.4 (EMSC). This earthquake activity is far enough from land that only the largest earthquakes are detected.

But there seems to be a lot of earthquake activity both south and north of Iceland (Jan Mayen earthquake activity). But this not connected activity as such. But it is known that activity on Reykjanes Ridge happens in jumps. It is an question if such time has come that an new activity episode is about to start on the Reykjanes Ridge. But last major episode in activity on the Reykjanes Ridge ended about 671 years ago. But there is one eruption documented off the coast in the year 1926 according to Global Volcanism Program. That activity did last for 4 days or so.

I am not sure what is going to happen next on the Reykjanes Ridge. But I am going to report it best to my ability. With the best information that I can get when the time comes.

Icelandic news about this earthquake activity

34 skjálftar frá miðnætti (mbl.is, Icelandic)

Blog post updated at 02:47 UTC on 17.09.2012

Posted on

Continued earthquake activity on Kolbeinsey Island ridge

In the past few days there has been considerable earthquake activity in Kolbeinsey Island ridge. Many of the earthquakes have been reaching the magnitude of at least 3.0. But some of it might be underestimation. As this earthquake activity is taking place far off Iceland coastline and far away from the SIL network. But that makes detection of earthquakes more difficult. Along with effects of weather and ocean waves that often prevent detection of smaller earthquakes in this area.


The location of the earthquake activity in Kolbeinsey Island ridge. Copyright of this image belongs to Icelandic Meteorological Office.

This is not the only activity in this area in the past few weeks. But the largest earthquake in this area was an magnitude 4.4 to 4.6 few weeks ago. So the activity in this area seems to be connected to something major. It is an question if this is due to volcano eruption currently taking place in this area now. But with depth of up to 4 km. It is impossible to know that for sure without actually going there on an ship. But given current weather. That is not going to happen any time soon. Maybe not for several years in fact.