Volcano and earthquake activity in Iceland
It currently is quiet in Iceland, both in volcano and earthquakes. But it is not all without earthquakes. Few earthquakes have taken place in Krísuvík volcano, the largest being ML2.6 and in Kverkfjöll volcano. Few earthquakes have also appeared in TFZ, but all of them where small.
Besides this small activity. Everything remains quiet.
Since Week 52 in the year 2010 there have been strange earthquakes between Bárðarbunga volcano and Grímsfjall volcano. It is hard to know exactly what this means. But it is clear that tension is rising fast in Grímsfjall volcano, as is evidence by the ML4.2 and ML3.5 earthquakes in Grímsfjall volcano few days ago. But this might be something, or this might simply be nothing at all. Only time is going to tell us what this means.
Far as I know, nothing like this was recorded before the Gjálp eruption (SIL earthquake data from 1996) between Grímsfjall volcano and Bárðarbunga volcano in the year 1996. But it is a important factor that the SIL network was a lot smaller back in those days.
Krísuvík volcano
This morning there has been a micro-earthquake swarm in Krísuvík volcano. The largest earthquakes have gone up to ML2.0 (automatic SIL data), with the focal depth of ~4 km. So far around 20 earthquakes have been recorded by the SIL system that Icelandic Met Office runs. This morning the earthquake swarm has quieted down a bit. But it is hard to know if it is over or not. But this area of Krísuvík volcano has been having a lot of micro-earthquakes swarms over the past few weeks. This has been followed by a uplift in the volcano (inflation). But that did start early last year after a short period of deflation.
Other then this, it remains quiet in Iceland volcano and earthquake wise.
A new earthquake swarm appears to have started yesterday in the Krísuvík volcano. This earthquake swarm is a small one, in the number of earthquakes and the size of them. The largest earthquakes according to the automatic SIL system are around ML1.8 in size. The depth is constant around 2 to 5 km or so. This earthquake swarm is just the latest of earthquake swarm that have been taking place in Krísuvík volcano over the past few weeks. As the earthquake activity has been more or less continues for the past few months in Krísuvík volcano.
The current GPS plot shows some inflation taking place at Krísuvík volcano. But so far it is small and does not indicate that a eruption is immanent in Krísuvík volcano. But if the inflow of magma changes suddenly this might change when Krísuvík volcano might start erupting.
Thanks to Carl le Strange on müsli for the tip on the GPS plot.
Here is a short update on what did go on in Iceland over the Christmas. In all there where few earthquakes in Iceland during Christmas. The main reason for this was a major storm that started in south Iceland on the 25th of December, it lasted until 27th of December in some parts of Iceland. The wind was topping 47m/s in strong winds. But the average wind speed was about 32m/s I think.
Around 17:02 UTC on the 25th of December there was a ML2.77 earthquake in Krísuvík volcano. Far as I can tell by the wave form this earthquake was mostly tectonic in nature. But it is impossible to know if the main source of this earthquake was the magma that is collecting in Krísuvík volcano or not. But activity continues in Krísuvík volcano as it has been doing in the last few weeks before. This earthquake was followed by 20 or so smaller earthquakes in the same area.
Due to the strong storm there where few to no earthquakes recorded on the late 25th to 27th of December. But the storm did simply hide all the minor earthquake that might have been taking place.
The ML2.77 earthquake in Krísuvík at 17:02 UTC at Heklubyggð geophone station. The storm noise almost drowns out the earthquake signal. This plot is filtered at 4Hz as a cut off frequency.
The ML2.77 earthquake in Krísuvík at 17:02 UTC at Hvammstangi geophone station. A normal level of noise can be seen both sides of the earthquake. No storm noise is presented in this plot, as it had not started in north of Iceland at this time.
A few deep earthquakes where seen in Eyjafjallajökull volcano over the same period. At current it is hard to know what they mean in the long term. But it is clear that Eyjafjallajökull volcano continues to make a little rumble and has not quieted down at current time.
Here is the last activity update before Christmas starts. As I did expect a deep earthquakes have started again under Eyjafjallajökull volcano. So far the main depth is about 10 to 15 km. So far nothing indicates a immanent eruption in Eyjafjallajökull volcano. But it is wise to keep watch on the deep earthquakes that have started to re-appear under Eyjafjallajökull volcano.
But Eyjafjallajökull volcano is not the only volcano making earthquakes. There are also earthquakes taking place in Grímsfjall volcano and in Esjufjöll volcano. The continues earthquake swarm in Krísuvík volcano. But this is the same that has been going on in previous weeks in that area.
There has also been some minor earthquake activity in Grímsfjall volcano. A signal that Grímsfjall volcano is getting ready for a eruption in the year 2011 maybe.
Non-volcanic earthquakes
There has been a lot of earthquakes in the Tjörnes Fracture Zone (TFZ). But the largest earthquakes in the last 24 hours did get the size ML3,0 according to the automatic SIL system that Icelandic Met Office runs. The size might be subject to a review later on.
But other then this it has been quiet in Iceland earthquake wise and volcano wise. But when the most frost was going on over Iceland there was a lot frost earthquakes taking place. But those events are false earthquakes and are due the fact that freezing water appears to crack the ground, sometimes with considerable force. The frost needed for this to happen has to be below -10C far as I understand.
Christmas stuff
I am going to take my Christmas break from 12:00 UTC on the 24th of December (2010) until the 27th of December (2010). While this break is on comments might be held longer in the moderation queue then normally. If anything major happens, I am going to post information about it when I can in this time. But unlike us humans nature doesn’t care about our days off. But I am hoping for a quiet Christmas in Iceland like everywhere else.
There is going to be special Christmas blog post tomorrow for all those Christmas greetings.
Here is a image from Icelandic Met Office about the earthquakes that have been taking place in Krísuvík volcano over the past few weeks. This plot shows the latest 15 days.
This image is from Icelandic Met Office. Copyright belongs to them. The original copy can be found here. Click on the image for full resolution.
I have been viewing data on Krísuvík volcano and what has been happening recently. Out of this checking I have come to a conclusion that a eruption in Krísuvík volcano is going to place in immanent future. When that might happen is impossible to know for sure.
Far as I know there is no written history on the last eruption at Krísuvík volcano that took place in 14th century. Because of this lack of historic witness of the last eruption in Krísuvík volcano it is impossible to know how the Krísuvík volcano is going to behave before it starts erupting.
It is my un-professional opinion that when a eruption starts in Krísuvík volcano we are going to see something like that took place in Krafla volcano when it erupts. Not exactly like Krafla volcano but something along those lines in eruption style. But Krísuvík volcano is going to have Hawaiian type eruption style when it starts erupting. Unless the eruption takes place under water. Then a Surtseyjan style eruption takes place while a water can get into the crater.
Please note that this is a theory that I am working on. It might work out in part or in full. But then again it might be completely wrong and not work at all. If the second option is true, then I am going to start again and make a new idea on what is going on at Krísuvík volcano.
I got this pictures in a email from a person how wants to remain nameless. Don’t ask me why, it is just a request that I got with the email and I see no reason not to grand it.
The hot springs at the south end of Kleifarvatn lake hot springs. The hot springs there are not new. But they do get lost when the water level rises in Kleifarvatn lake. When the water level dropped after the year 2000 years in the area this hot springs where for the first time visible to humans.
Click on all the pictures to get a full resolution.
The earthquakes swarm at Krísuvík (close to this area) continues with few breaks it seems.
I don’t have a lot to write about the earthquake swarm in Krísuvík volcano that took place there yesterday. But according to IMO the largest earthquake was felt in Hafnafjöður and in Reykjavík.
Here are the wave form data of the largest and the second largest earthquakes. There are no location data in this image. As I have not had time to put them into the wave form data.
From Hekubyggð. This is the ML2.8 earthquake.
From Hvammstangi. This is the ML2.8 earthquake. This one is low-pass filtered at 4Hz.
From Hekubyggð. This is the ML2.5 earthquake.
All pictures can be clicked to see the higher resolution of them.
At current time there are two main earthquake swarms taking place in Iceland. The first one is at Krísuvík volcano and has been going on since early this week. Currently there is nothing to suggest that it going to end any time soon. This earthquake swarm however sometimes stops for several hours and up to one to two days at the longest. Most of the earthquakes taking place are less then mag 2.5 in size. It is not clear why this earthquakes are taking place. This might be tectonic process or something to do with the magma intrusion that is taking place in Krísuvík volcano.
The second earthquake swarm is taking place at Herðubreiðartögl with earthquake taking place at Herðubreið at it’s north limits. Several mag 3.0+ earthquakes have taken place. This earthquakes appears to be due to tectonic process in the area. But I have heard theories that this process might have started due to influx of magma into the Askja volcano that is close to earthquake swarms in Herðubreiðartögl. At current time I cannot confirm that this ideas are correct or not. This earthquake swarm is ongoing and does not appear to be ending. But there are breaks in it that last from few hours and up to one day at the longest. Please note that Herðubreiðarfjöll is a central volcano that is active. It is not on the GVP volcano list for the area. This volcano is located inside Askja fissure swarm and has many active fault lines that cross it from north-south.
The newest earthquake swarm that appears to be at slow start is taking place in Esjufjöll volcano. But since activity started there in early October 2010 earthquakes appears to be on the rise in Esjufjöll volcano. It is worth noticing that earthquake swarms in Esjufjöll appear to start slowly but they due appear to peak after 20 to 180 hours after they starts. This earthquake activity is due to new flow of magma into Esjufjöll volcano.
