Category: Earthquakes

Posted on

Low earthquake activity in Iceland

This is not going to surprise anyone how read this blog on regular basis. But earthquake activity and volcano activity in Iceland is minimal those past days. As it has now been for past several weeks. This has sadly lead to less blog post then I like. But I have also been busy. So it has helped in that sense for me. At current rate, the year 2012 is so far the most quiet year that I remember in an long time. I have been monitoring earthquake activity in Iceland more or less since the year 1996.


Current earthquake activity in Iceland on 29. August 2012. As can be seen. Activity is rather slow today. Copyright of this image belongs to Icelandic Meteorological Office.

While it is quiet in Iceland. I am going to work on other articles about other interesting features in Icelandic geology. They won’t be long. But short and as informal as I can make them. This quiet time might last a bit longer then it already has. I would not expect anything else.

Posted on

New earthquake swarm in Katla volcano

This morning at 07:03 UTC on 21. August 2012 an earthquake swarm started in Katla volcano. This earthquake swarm lasted for few minutes with the last earthquake taking place at 07:50 UTC. No harmonic tremor was detected following this earthquake swarm in Katla volcano. Update 1: The largest earthquake in this earthquake swarm had the magnitude of 2.6 at the depth of 0.1 km.


Earthquake activity in Katla volcano this morning. Copyright of this image belongs to Icelandic Meteorological Office.

It is impossible to know for sure what this activity means. But this might just be normal autumn activity in Katla volcano. I am expecting more earthquake activity in Katla volcano in next few days to weeks.

Icelandic news about this earthquake activity

Skjálfti í Mýrdalsjökli (Rúv.is, Icelandic)
Jarðskjálfti upp á 3,1 stig í Mýrdalsjökli (Vísir.is, Icelandic)
3,1 stigs skjálfti í Mýrdalsjökli (mbl.is, Icelandic)

Blog post updated at 15:18 UTC on 21.08.2012. I have not yet fully recovered from the heat wave. I forgot the important information about this swarm. They have now been added.

Posted on

Earthquake swarm in progress in Krýsuvík volcano

Today (18.08.2012) at 15:52 UTC an earthquake swarm did start in Krýsuvík volcano. So far this swarm is not big. With the largest earthquake having magnitude 1.8 according to automatic size. It is impossible to know at this point if this earthquake swarm is going to be strong, or has just ended. So far earthquake activity continues with minor earthquakes.


The earthquake swarm in Krýsuvík volcano. Copyright of this image belongs to Icelandic Meteorological Office.

If the earthquake activity picks up. I am going to do my best to update this blog. But I am on limited 3G internet connection. So it might be a while until update takes place.

Posted on

Earthquake in Katla volcano today (17.08.2012)

Today at 15:48 UTC there was an magnitude 3.8, at the depth of 0.1 km in Katla volcano. This earthquake took place on the caldera rim in Katla volcano. No major harmonic tremor was detected following this earthquake. However some harmonic tremor was detected. But it was minor. This might have been hydro-thermal-activity or magma on the move. It is impossible to know for sure what is the case now. This earthquake did appear clearly on my geophone network. Mostly on the geophone station at Skeiðflöt and Heklubyggð.


The location of the earthquake in Katla volcano. It was located on the edge of Katla volcano caldera. Copyright of this image belongs to Iceland Meteorological Office.


Influence map of todays ML3.8 earthquake. This suggests that it was not felt in nearby populated areas. Copyright of this image belongs to Iceland Meteorological Office.


Tremor plot that clearly shows the earthquake of today. The spikes are the earthquakes that have been taking place in Katla volcano or close by areas. This is Alftagrof SIL station. Copyright of this image belongs to Iceland Meteorological Office.


This tremor plot shows some minor harmonic tremor following the earthquake in Katla volcano. The spikes show the earthquake from Katla volcano and areas close by. This is Austmannsbunga SIL station. Copyright of this image belongs to Iceland Meteorological Office.

It is impossible to know what this means exactly. But Katla volcano has been quiet since around middle of July. It remains to be seen if earthquake activity is picking up again or if this was just an single event.

Icelandic news about this earthquake

Jarðskjálfti í Mýrdalsjökli (Rúv.is, Icelandic)
Jarðskjálfti í Mýrdalsjökli (Vísir.is, Icelandic)
Jörð skalf við Austmannsbungu (mbl.is, Icelandic)

Blog post updated at 18.08.2012 at 11:51 UTC. Blog post title fixed for the future.

Posted on

Magnitude 3.7 earthquake in Netherlands [Updated]

At 20:30 UTC on 16. August 2012 there was an magnitude 3.7 earthquake in Netherlands according to EMSC web site.


The earthquake in Netherlands at 20:30 UTC (22:30 local time). This earthquake was mostly felt in the area where it did happen. This picture is released under Creative Commons licence. Please see CC page for more details.


Regional view of the area where the earthquake did happen. Copyright of this image belongs to EMSC.


Local view of the area where the earthquake did happen. Copyright of this image belongs to EMSC.

Some have already been speculating this earthquake might be due to gas extraction in this area. That might be. But there is also an chance that might have just been intraplate earthquake that sometimes happens. There might be other factors at work here that I do not know about. But I am not well into local geology of this area at current time.

It is hard to know if any aftershocks are going to take place. But I find them unlikely at current moment. But that might change without warning.

Blog post has been updated. The earthquake size and location has been revised.

Posted on

Earthquakes deep south on the Reykjanes Ridge [Updated]

During last night there has been some earthquake activity deep south on Reykjanes Ridge. This earthquake activity is far from the south coast of Iceland so it has not been noticed by any people. It has only appeared on seismometers. The web page of EMSC has shows the current earthquake activity started at 00:21 UTC with two earthquakes. The largest earthquake recorded in following hours had the magnitude of Mb5.3 according to EMSC web page. But that is automatic size estimate and is subject to a change.


The location of the earthquake deep south on Reykjanes Ridge. Copyright of this image belongs to EMSC.

There most likely have been more earthquakes in this area then are registered by seismometer networks. It seems that earthquake activity in this area has quieted down again. For now at least. But this area is subject to strong earthquake swarms on regular basic.

Blog post updated at 21:33 UTC on 15.08.2012.

Posted on

Minor earthquake swarm in Brennisteinsfjöll volcano system

When I was moving there was an small earthquake in Brennisteinsfjöll volcano. Because I was moving I was unable to track this earthquake swarm properly. But the largest earthquake was around ML1.5 from what I can remember. The earthquakes had the depth of at least 2 km. But I am not sure what the exact depth is. But I have not yet looked at the reviewed data on this earthquake swarm.


The earthquake swarm in south-west part of Brennisteinsfjöll volcano. Copyright of this picture belongs to Iceland Meteorological Office.

There has not been a lot of activity in Iceland during all summer. So I have not had lot to write about. But that might change without any warning. As is common in Iceland.

I did also move on 7th of August to a new town in Denmark. That means I am out of ADSL connection until 24th of August. So this blog is going to suffer from lack of updates until I am properly connected to the internet.

Posted on

Magnitude 4.4 earthquake between Denmark and Sweden

This morning there was a magnitude 4.4 earthquake between Denmark and Sweden. This earthquake was felt in Denmark and Sweden. No damage did take place during this earthquake, best to my knowledge. I did not record this earthquake, as I am currently moving to a new place in Denmark. But based on static I should record next earthquake that happens in or close to Denmark in about 2 to 3 years time. More information about this earthquake can be found on EMSC web page here.


Earthquake regional location according to EMSC. Copyright of this picture belongs to EMSC.


Earthquake location at local level according to EMSC. Copyright of this picture belongs to EMSC.

It is hard to know for sure if there are going to be any aftershocks following this event. This might just be one-off earthquake. But I would not rule out aftershocks in next few days with the magnitude of ML2.0 – ML4.0. But this are intra-plate earthquake. They are not connected with any fault zone as such. But continental plates have fault zones on there own. This fault zones sometimes move and make a earthquake in the process.

Danish news about this.

Jordskælv i havet mellem Danmark og Sverige (DR.dk)
Jordskælv i Danmark: Krig, tog eller et bump på vejen? (DR.dk)

Update 1: More news on this from Danish media

Vores fundament er presset (b.dk)

Posted on

Earthquake swarm in SISZ this morning (31.07.2012)

This morning there was an earthquake swarm in SISZ. This earthquake swarm was located just south of Hveragerði and Selfoss town. The largest earthquake in this earthquake swarm had the magnitude of ML1.3. Most of the other earthquake where less the magnitude 1.0 in size. Focal depth for this earthquake swarm was 5 to 6 km. Total of 30 or so earthquakes where recorded in this earthquake swarm. This earthquake swarm is in continued activity in this area. But SISZ often has frequent smaller earthquake swarms.


The area of earthquake activity in SISZ this morning (31.07.2012). Copyright of this image belongs to Iceland Meteorological Office.

This doesn’t mean anything special. But SISZ (South Icelandic Seismic Zone) is always at risk having large earthquakes. But based on how short it was since last one took place (May 2008). It is unlikely that is going to happen now.

Posted on

Earthquake swarm on TFZ and in Þeistareykir volcano

This is going to be short blog post.

Earthquake east of Grímsey Island

Earthquake with the magnitude of ML3.5 (estimate) did take place at 19:48 UTC. This is normal tectonic activity for this area. But this area of Iceland has the most earthquake activity most of the year.


Earthquake activity in TFZ. Copyright of this picture belongs to Iceland Meteorological Office.

Þeistareykjabunga volcano

It was noticed by a reader of this blog that Þeistareykjabunga volcano was having few earthquakes. Þeistareykjabunga volcano last erupted in the year 900 BC (+- 100 years). This earthquake swarm was small. Mostly earthquakes with the magnitude of ML0.5 to ML1.0. The focal depth of this earthquake swarm was around 5 km. So this in all, is most likely an tectonic earthquake swarm. Rather then volcanic. Þeistareykjabunga volcano is an active volcano. But at current time I do not think anything has changed in that volcano at present time.


Þeistareykjabunga volcano is located north of Krafla volcano. Copyright of this picture belongs to Iceland Meteorological Office.

I do not expect anything more to happen in Þeistareykjarbunga volcano. But if there are changes, they won’t go unnoticed.

Thanks to Mafl for the tip on Þeistareykjabunga volcano.