Strong earthquake in Japan, small earthquake swarm on Reykjanes Ridge in Iceland and more

Yesterday (14.03.2012) at 09:08 UTC there was an strong earthquake in Japan. The size of this earthquake was Mw6.9 and it had the depth of 10 km. Local tsunami warning was given out for the area closest to the epicenter of the earthquake. Aftershock activity has been ongoing after the main earthquake. The largest aftershock so far had the size Mw6.0. More details on the earthquake in Japan can be found here at EMSC web page.

Regional view of the earthquake in Japan yesterday morning. Copyright of this image belongs to EMSC.

Local view of this earthquake. It appears to have been in an subduction mountain, or close to it. Copyright of this image belongs to EMSC.


Currently there is an earthquake swarm ongoing on the Reykjanes Ridge off the coast of Iceland. So far the strongest earthquake has reached the size of ML2.7. The depth is about 7 – 16 km. There is an slight chance that his might be an dike intrusion taking place on the Reykjanes Ridge. But this also might just be normal fault movement in the area. For the moment. There is no way to know for sure exactly why this earthquake swarm is taking place.

Reykjanes Ridge earthquake swarm as it is at 00:35 UTC. Copyright of this image belongs to Iceland Met Office.

South Norway

An minor earthquake took place in south Norway at 19:22 UTC. The size of this earthquake was ML3.5 according to EMSC. With the depth of 10 km. This earthquake was clearly felt in Norway according to EMSC and news reports of this earthquake. More details on this earthquake can be found here, on EMSC web page.

The regional view of the earthquake in south Norway. Copyright of this image belongs to EMSC.

Local view of the earthquake. It can clearly be seen here how close it was to several towns in south Norway. Copyright of this image belongs to EMSC.

This earthquake was clearly felt in Norway due the old crust that it took place it. But older crust conducts earthquakes better then new crust. Like the one that can be found in Iceland. That is due to lack of faults in it and the fact it is more dense with sediments then new crust. Earthquake in this area should be expected every 5 to 20 years or so. As there are old fault lines in this area, they sometimes break and create a earthquake.

Norwegian news about this earthquake.

Kanskje noen glass har falt ned fra bordet
Jordskjelv i Rogaland i kveld

New Britain region

Today at 21:13 UTC there was an Mw6.4 earthquake in New Britain region. The depth of this earthquake was 80 km according to EMSC. I do not know if this earthquake was felt or not. It at least has not been reported yet.

Regional view of the earthquake from EMSC. Copyright of this image belongs to EMSC.

Local view of the earthquake from ESMC. Copyright of this image belongs to EMSC.

More information about this earthquake can be found here, on EMSC web page.


I am sorry for late post. I was flying back to Iceland today. It took awhile. I also had to do other things this evening before I could write about the most recent activity yesterday. This is going also going to happen later when I move back to Denmark. But I am going to post more details on that later.

Blog post updated at 12:11 UTC on 15.03.2012. Location of the earthquake in Norway was fixed.

Earthquake activity in France and Iceland

This is an collection post of events that I have been taking place while I was travelling to Denmark. This is just an short update. Not going into great details on what has been happening.


On 26. February 2012 at 22:37 UTC there was an earthquake with the size of ML4.8 in south France. This earthquake had the depth of 2 km. This earthquake was widely felt in France, Monaco and in nearby Italy according to EMSC reports. More details on this earthquake can be found here, on EMSC web page. Several aftershock have taken place since this earthquake and earthquake activity is still ongoing it seems. But it is mostly small earthquakes that are now taking place so far.


There has been some earthquake activity in Katla volcano. This activity is not outside the normal range of what has been going on in past few weeks. Some activity has also been continued in Hengill volcano. But that is due to water pumping down, as has been the story since this activity started last year. Other then this activity, it has been generally quiet in Iceland.

I am most likely missing some activity. But reports of activity that I am missing can be reported in the comments section. This is just an short update. I am hoping for an better update tomorrow on what is going on in terms of activity.


Good news on the glasses. I can pay them little by over period of months. But that might be an good way (even if I do not like it) to buy the glasses. As the cost is going to be around 4000 DKK for the whole thing. But that is the glasses frame and the glass in them. I do not have the money to pay for them all at once at current time. But glasses are an high priority for me, as I need them to see the world around me.

Deep earthquakes in Askja volcano. Data on how Japan Mw9.0 earthquake was recored in Iceland

I see that in last week (week 10) that there was a deep earthquake swarm that took place under Askja volcano. This time around the earthquake swarm lasted for about 75 seconds and the depth of this earthquake swarm was about 20 km. The location of the earthquakes was north-east of the main Askja caldera, but within the Askja volcano system it self. The largest earthquake last week in Askja volcano was ML2.2 in size. Last year there was also a deep earthquake swarm in Askja. But that time around it lasted for few hours, not second. That activity took place in Week 09 of the year 2010. Here is a map of that weeks activity. But this deep earthquake swarm suggests that magma is on the move under Askja volcano, as was the case in the year 2010 when a similar event did happen.

Above: Picture of the Vatnajökull glacier area. The deep earthquakes north-east of Askja volcano can be seen here.

Above: The 75 second earthquake swarm north-east of Askja volcano.

Japan Mw9.0 earthquake

Strong earthquakes like the Mw9.0 earthquake in Japan appear all over the world on seismometers. In fact the effect from this earthquake could be seen up to five days at least on long period seismometers. Icelandic Met Office did release in last week overview.

Above: How the earthquake did appear on the IRIS seismometer in Iceland.

Above: This is how the earthquake did appear on the SIL network. Aftershocks can also been seen in this plot.

Copyright of this pictures in this blog post belong to Icelandic Met Office or other parties unless I notice otherwise.

Blog post updated at 21:57 CET on 16.02.2011.

Special report: Part of Japan moved 4 meters due to the Mw9.0 earthquake

According to BBC News it seems that that part of Japan moved up to 4 meters in the Mw9.0 earthquake. Closest to the epicentre of the earthquake the movement is possibly up to 20 meters, but the movement might have not been all the same within the fault line (100 wide and 500 km long). This earthquake might also have shifted the Earth axis about 16.5 cm. But this earthquake has also changed the sea bead in such way that it needs to be remapped for ships.

Two videos of the earthquake.

BBC News on this.

How the quake has moved Japan (BBC News)
Pictures of the damage from the earthquake (BBC News)

Support Japan and it’s population with donations.

2011 Japanese Earthquake and Tsunami
(Google Information web page)

Special report: Pre-earthquakes to the Mw8.9 earthquake in Japan

It appears that before the large earthquake that did happen today (11th March 2011) there was a sequence of a pre-earthquakes. The pre-earthquake to the large Mw8.9 earthquake was a Mw7.2 (EMSC data) that took place on the 9th March 2011 at 02:45 UTC. This pre-earthquake was followed by about dozen or so aftershocks, the largest one being Mb6.2 (EMSC data).

The problem with this type of pre-earthquakes is that you cannot know that they are pre-earthquakes until after the large earthquake takes place. Because of that fact, it is only now known that the Mw7.2 was a pre-earthquake to the Mw8.9 earthquake that did hit Japan today (11th March 2011).

Please see BBC News or CNN for more news about this earthquake.

For webicorders that show the earthquake can be found here. USGS webicorders can be found here.

Special report: A Magnitude Mw8.9 earthquake struck Japan

At 05:46 UTC (14:46 local time) there was a Mw8.9 (or up to Mw9.1, it is hard to terminate the exact size of this large earthquakes right away) earthquake in Japan. The depth of this earthquake was registered 24 km depth. But that is the reason why this earthquake did create this big tsunami. According to news there has been great damage following this earthquake. Loss of human lives following this earthquakes is also feared. But already there have been found bodies of 300 people that died following this earthquake. After the earthquake a huge whirlpool was created according to BBC News, a video of it can be seen here.

The rupture zone is estimated to be about 500 km (EMSC). But that number might change on a later date. A lot of aftershocks have followed the main earthquake. The largest aftershock did reach Mw7.0 in size so far. But there have also been a lot of earthquakes that have magnitude Mb6.0 – Mb6.9. Many more aftershocks of size Mb5.0 – Mb5.9 have also happened. I have no information about smaller aftershocks. But I am going assume that the number of earthquakes in smaller range is in the number tens of thousands.

This earthquake was recored on all my geophones. Even the one that I have here in Denmark on the second floor where I live.

Above: The Mw8.9 earthquake in Japan on Heklubyggð (Iceland) geophone. This picture is under CC licence.

Above: The Mw8.9 earthquake in Japan on Hvammstangi (Iceland) geophone. This picture is under CC licence.

Above: The Mw8.9 earthquake in Japan on Sønderborg (Denmark) geophone. This picture is under CC licence.

I am going to post more information about this earthquake when I have them. I am also going to post more information about the aftershocks later on.

Please check all major news networks for news about this earthquake.