Category: Iceland

Posted on

Overview of earthquake activity in Iceland past few weeks

During the past few weeks it has been quiet in Iceland. With few earthquakes. March for instance was rather quiet month. In Week 17 there was more activity in Katla volcano, then the weeks before.

There have been several small earthquake swarms taking place in Iceland during past few weeks. Most noticeable was off the coast of Flatey. That is on TFZ earthquake zone. Also there was a noticeable earthquake swarm in Hengill volcano due to water pumping activity. There has also been earthquake activity on the Reykjanes ridge. Where the largest earthquake had the size of ML3.3.

Other then this minor earthquake activity. It is has been rather quiet in Iceland for several weeks now. This does happen in Iceland. But even so, there is always something interesting going on when it comes to earthquake activity in Iceland.

Posted on

Scary news about eruptions in Iceland in The Telegraph

The newspaper The Telegraph has scary news about volcanism in Iceland. They have scary claims like this one here.

[…]

Katla’s eruption in 1918 produced five times as much ash as the 2010 Eyjafjallajökull one. A major eruption could result in large parts of Iceland being flooded as snow and ice melted; significant poisoning of Icelandic agriculture; destruction of property; and, of course, the grounding of aircraft across Europe.

[…]

Well, the Katla volcano has many different types of eruption. For instance, the July 2011 eruption in Katla volcano was small. There is no way to know what happens until a eruption starts in Katla volcano. When ever that might. As for “large part of Iceland being flooded”, this is just rubbish and bad reporting. Less then 1% of Iceland would get flooded in the case of eruption in Katla volcano. What area exactly depends on where the eruption takes place under the glacier. The largest area that can get flooded if the glacier if the flood goes down Þórsmörk and close to the area east of the village of Hvolsvöllur. Eruption in Katla volcano is going to destroy roads, bridges and other things in its path. But that is to be expected. In fact, Icelanders living in the area well aware of what a eruption in Katla volcano means to them.

[…]

If enough material is ejected it could even have a cooling effect on the global climate for a few years. A precedent for that would be the 1783-84 eruption from the fissure of Laki, which is part of the same volcanic system, Grímsvötn, that erupted last year. This was a very large eruption of 15 cubic kilometres (3.6 cubic miles), compared to the fraction of a cubic kilometre ejected in 2010, and had a huge impact on the northern hemisphere, reducing temperatures by up to 3 C.

[…]

Well, no. The reason is that Katla volcano is unable to make that large eruptions most of the time. The largest eruption that is known is the Eldgjá fissure eruption in Katla volcano that took place sometimes around the year 934. As for cooling it is worth noticing that Mount Tambora eruption that was VEI=7 in the year 1815. But it only did drop the temperature around 0.4 to 0.7C (called Year Without Summer). A temperature drop of 3C would create glaciers in Europe all year round. Even Laki eruption in the year in 1783 did not cool the northern hemisphere down to 3C. That amount of drop in temperature would equal a new ice-age in Iceland, Europe and North-America.

The last eruption in Grímsfjall volcano (May, year 2011) did not have this effects. But was at least VEI=4 in size. But that eruption was many times larger then the eruption in Eyjafjallajökull volcano in the year 2010. So facts do not support the claim this news from The Telegraph is making.

This claims, among others in this types of news is nothing but fear mongering news. It is meant to scare people. Why, it is my guess that it about news paper sales.

Scary News from The Telegraph

Iceland volcano: and you thought the last eruption was bad…

Posted on

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.

Iceland

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.

Other

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.

Posted on

Minor earthquake activity in Iceland

There isn’t a lot taking place in Iceland at the moment. This is somewhat down to stormy weather in Iceland during the past few days and weeks. As strong storms reduce the sensitive of the Iceland Meteorological Office SIL network.


Quiet Iceland. Copyright of this picture belongs to Iceland Met Office.

Activity in Iceland happens in jumps. Between high activity episodes there are long episodes of low to none activity at all in Iceland. This period of low activity are different in length. Some can last for few weeks. While others can last for many years and up to thousands of years.

Global activity

Global earthquake activity is slow this days. Few earthquakes over Mw6.0 in size. The activity for earthquakes smaller then Mw6.0 in size is about the same as normally. Volcano activity seems to be about normal. But it is hard to know that for sure as reports appear late on global volcano activity.

Posted on

More earthquakes should be expected on the Reykjanes

The earthquake swarm on the Reykjanes has slowed down considerable since it did start yesterday. But it is still ongoing in my opinion. Even if there are no earthquakes currently taking place at the moment. There are several reasons for this. The biggest one is that this area seems to be getting more active now then it has been for many decades now. The fissure that is currently moving is connected to Krýsuvík volcano, but this was reported in the news. I do not know every fault line in this area and how they are connected (plus, my volcano map is in an box until I move back to Denmark) together. But I do know that

During the past 2 to 3 years the volcano Krísuvík has been showing more activity. With inflation and deflation episodes that lasts from few days to weeks at the time. Followed by an earthquake swarms both before and after each episode of activity. This activity seems to be increasing, at least that is my opinion on what is happening at the moment.

While this earthquake swarm is still ongoing. It might have long periods of no activity at all. This is common for faults that have not moved in an long time. As seems to be the case in Helgafell mountain and nearby area. But the fault lies close to that mountain or under it (I am not sure). But this started this year with an magnitude ML3.2 earthquake in this area earlier this year.

It is hard to know exactly when next episode of this activity is going to continue. But I am sure that it is going to be soon.

Posted on

Earthquakes in north and south Iceland [Updated]

This evening has been busy in Iceland. There was an ML3.5 earthquake just outside an area called Gjögurtá (part of TFZ). Followed by an ML3.2 aftershock. Earthquake activity seems to have stopped there for the moment. This took place at 22:06 UTC on 29.02.2012. The largest earthquake was felt over an large area that was closest to its location.


The location of the earthquake in the TFZ. Copyright of this picture belongs to IMO.

At 00:29 UTC on 01.03.2012 there was an earthquake on the Reykjanes. It happened in an mountain called Helgafell. Early results suggest that this earthquake had the size of ML3.2. It was felt over an wide area in south Iceland. Aftershocks are currently taking place, and more large earthquakes in this area cannot be ruled out at the moment.


The earthquake location on the Reykjanes. Copyright of this picture belongs to IMO.

There is an chance for more earthquakes in Reykjanes. As earthquake swarms in this area of Iceland can often be tense and make many earthquakes that have magnitude 3.0 and stronger.

This earthquake activity appears clearly on my geophones in Iceland. They can be viewed here and are updated every 5 min.

Update 1: More strong earthquake activity is taking place on the Reykjanes at this moment. The largest earthquake so far is ML3.9 according to the automatic data from IMO.

Update 2: Here is the image from Iceland Met Office of the area where this earthquake activity is taking place.


The current earthquake activity on the Reykjanes. Copyright of this picture belongs to IMO.

Update 3: The size of the second earthquake has been upgraded to ML4.2. Some minor damage has already been reported according to new from Rúv.

Blog post updated at 01:14 UTC on 01.03.2012.
Blog post updated at 01:39 UTC on 01.03.2012.
Blog post updated at 01:52 UTC on 01.03.2012.

Icelandi News about the earthquake in north Iceland. All news are in Icelandic.

Jarðskjálfti upp á 3,5 út af Gjögurtá (mbl.is)
Snarpir skjálftar fyrir norðan (Vísir.is)
Skjálfti út af Eyjafirði (Rúv.is)

News about the earthquake on the Reykjanes. All news are in Icelandic.

Skjálftakippur á höfuðborgarsvæðinu (Rúv.is)
Jarðskjálfti fannst vel á höfuðborgarsvæðinu (Vísir.is)
Jarðskjálfti við Helgafell (mbl.is)

Posted on

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.

France

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.

Iceland

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.

Other

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.

Posted on

Two minor earthquake swarms in Hengill volcano

Yesterday, last night and this morning there has been minor earthquake swarm in Hengill volcano. This earthquake swarm is more or less over for now. But it might pick up at any time. This time around only around 140 earthquakes where detected in this two earthquake swarms.


The earthquake swarm in Hengill volcano. The location of this earthquake swarm is quite common. Copyright of this picture belongs to IMO.


The earthquake swarms in terms of each earthquake being marked. This clearly shows the two earthquake swarm pattern. Copyright of this picture belongs to IMO.

More earthquake swarms should be expected in this area. As Orkuveita Reykjavíkur (OR) continues to pump down water in this area. But that is creating this earthquakes it seems. This earthquake activity takes place at random times.

Posted on

Minor earthquake cluster in Katla volcano caldera

There seems to be forming of minor earthquake clusters in Katla volcano caldera. But this has been following growing number earthquakes in Katla volcano caldera during past few weeks. This is most likely an signal of increased activity in next few weeks to months. But the increase does not have to been slowly up. It can be sudden as did happen in July 2011 in Katla volcano caldera when earthquake activity did increase suddenly and there was an small eruption without an warning.


Current earthquake activity in Katla volcano. Note the small cluster of earthquakes close the area where an small eruption took place in the year 1999. Copyright of this image belongs to IMO.

There has been some small cluster of earthquakes taking place in Katla volcano caldera. I am not yet sure what that means at the moment. However this might be clues to minor dike intrusions into Katla volcano caldera. But without more data, it is impossible to be sure on this detail at current time.

Last night there was an change in harmonic tremor on two SIL stations around Katla volcano. But due to high wind noise I am unsure what was going on. But it is possible that this was an small dike intrusion taking place close to Goðabunga part of Katla volcano, or this was an minor glacier flood that was taking place under the glacier. At current time I have no good idea what was going on.


The harmonic tremor on Smjörgil SIL station. The signal is unclear due to high wind noise. Copyright of this picture belongs to IMO.


The harmonic tremor signal on the Goðabunga SIL station. Due to high wind the signal is unclear and hard to see. Copyright of this picture belongs to IMO.

It is hard to know for sure what happens next in Katla volcano. But important signs can be found in earthquake patterns. But it is also important not to overlay broad interpret the data in the favor of an eruption taking place. As it is impossible to know for sure when Katla volcano erupts, and then how big. All we might get is an new small eruption like in July 2011. As Katla volcano can also have small eruptions like big ones.

Posted on

Old rift zone in Iceland

Here are two pictures of an old rift zone in Iceland. This rift zone was active until about 7 million years ago or so. This cliffs that I show here on this picture are from this old rift zone. It was volcanic long time ago. But not any more. This area however holds an good amount of unknown fissures and fault lines that might become active one day and create earthquakes in this area. But the years that I have been in this area I have never felt an earthquake. But I have recorded earthquake somewhere in this area. But it was an minor one. Less then ML1.5 in size. This area also used to be under ocean for several million years before it became dry land.


This is the old rift zone that was active until 7 million years ago. Click on the picture for full size. This picture is released under Creative Commons Licence. See the licence page for more details.

There is still an chance of this area to get new volcanoes in far future. Like did happen on Snæfellsnes. But this rift zone did pass trough there also. In this old rift zones there are several old volcanoes. I have covered them before on this blog. But that blog post can be found here.

More articles on this area

The Iceland Hotspot (academic.emporia.edu)
Iceland 2003 Keck Junior Research Project Geology of an Abandoned Oceanic Rift: The Skagi Area, North-Central Iceland (people.usd.edu)