Volcano and earthquake activity in Iceland
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.
Few days ago an large landslide did happen in north Iceland. This landslide did come from the mountain Móafellshyrna. It has been estimated that this landslide is about 300 meters wide and is about 1 km long. Rocks continue to fall from the mountain. Some are large as houses in some areas. So going up close to this landslide is not save for the moment.
It is believed that mixture of earthquake activity in Tjörnes Fracture Zone along with rain and melting snow is the reason for this landslide.
Icelandic news about this
Drunur í björgum við Þrasastaði (Rúv.is, Icelandic, Pictures)
Gríðarstór skriða (Rúv.is, Icelandic, video)
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)
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.
This morning (19.09.2012) at 04:53 UTC the earthquake swarm that has been ongoing in TFZ (Tjörnes Fracture Zone) started to intensify. But it was not until 07:55 UTC the first strong earthquake did happen. But then a magnitude 3.0 earthquake did take place about 20 km north-east of an town named Siglufjörður. The largest earthquakes have been felt in Siglufjörður, Ólafsfjörður and Sauðárkrókur and possibly more towns close to this area of activity on TFZ. The largest earthquake so far had the magnitude of ML4.3, other earthquakes had the magnitude 3.0, 3.4, 4.0 and 3.2. The depth of this earthquake swarm is from 17 km and up to 2 km or so. This area does not have any active volcanoes. But it highly active when it comes to earthquakes. But spreading in this area of Iceland is up to 50mm/year.
This image shows part of the Tjörnes Fracture Zone. It is from this science paper here. Copyright of this image belongs to Icelandic Meteorological Office/Hjorleifur Sveinbjornsson
Earthquake swarm at 15:10 UTC. As can be seen here on this image where the earthquake swarm is taking place. Copyright of this image belongs to Icelandic Meteorological Office.
The earthquake swarm at 16:15 UTC. This image has few new earthquakes that have taken place in this earthquake swarm since the picture from 15:10 UTC. Copyright of this image belongs to Icelandic Meteorological Office.
The earthquakes as they did appear on my Hvammstangi geophone. This image is released under Creative Commons Licence. Please see CC page fore more details.
The earthquakes as they did appear on my Heklubyggð geophone. This image is released under Creative Commons Licence. Please see CC page fore more details.
The magnitude ML3.0 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.
The magnitude ML3.0 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.
The magnitude ML4.3 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.
The magnitude ML4.3 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.
The magnitude ML4.3 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.
The magnitude ML4.0 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.
The magnitude ML4.0 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.
The magnitude ML4.0 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.
The last earthquake was at 16:52 UTC. That was magnitude 2.0 earthquake. But it is hard to know if this earthquake swarm is over or not. I am going update this blog post or make a new one if any new major development take place in TFZ. Larger earthquakes in this area cannot be ruled out at this time.
Icelandic news about this earthquake
Harðir jarðskjálftar fyrir norðan (mbl.is)
Skjálftahrina fyrir norðan (Vísir.is)
Jarðskjálfti 4,3 í Eyjafjarðarál (Rúv.is)
Enn skelfur undan Tröllaskaga (Rúv.is)
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.
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.
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.
Yesterday (16.09.2012) an earthquake swarm did start in TFZ (Tjörnes Fracture Zone). The largest earthquakes in this swarm so far got the magnitude of 3.1 that took place at 11:07. The second earthquake took place at 14:13 UTC and had the magnitude of 3.4. This earthquake activity is located in an non-volcanic area. So this is nothing but tectonic activity. It is difficult to know for how long this activity is going to last. But it can be anything from two days and up to several days.
Current earthquake activity in TFZ. Copyright of this image belongs to Icelandic Meteorological Office.
This area might have more earthquakes that are above 3.0 in magnitude. But that is in no way certain that is going to happen. The largest earthquakes appear on my geophone network. Not all the stations. Just the one located in Hvammstangi.
Icelandic news about this activity
Skjálftar norður af Eyjafirði (Rúv.is, Icelandic)
Jarðskjálfti í Eyjafjarðarál (Rúv.is, Icelandic)
Skjálftahrina við Siglufjörð (Vísir.is, Icelandic)
Jarðskjálftar í Eyjafjarðarál (mbl.is, Icelandic)
Blog post updated at 16:58 UTC on 17.09.2012
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.