Category: Earthquakes

Posted on

Two earthquakes in Grímsfjall volcano

Earlier this morning there where two earthquakes in Grímsfjall volcano. There size was ML3.5 at 09:06 UTC and ML4.2 at 09:22 UTC. I am currently unsure about the depth of this earthquakes. This earthquakes take place in a area north-east in the Grímsfjall volcano system. But according to news this area has been seeing a increased earthquake activity in recent weeks.

No aftershocks have been detected since this earthquakes took place. But currently the weather is rather bad in this area, so that might be the explanation for the absence of earthquakes that should have followed this two earthquakes. According to the news the Icelandic Met Office is monitoring the area for more earthquakes or signs that a eruption might be starting. So far nothing indicates that a eruption is about to start in Grímsfjall volcano.

The area that was active today (13th of January 2011) in Grímsfjall volcano.

Icelandic News about this. Use Google Translate at own risk.

2 jarðskjálftar við Grímsvötn (Rúv.is)
Snarpur jarðskjálfti við Grímsfjall (Vísir.is)
Fylgjast náið með Grímsfjalli (mbl.is)
Jarðskjálfti við Grímsfjall (mbl.is)


Blog post updated at 13. January 2011 at 22:51 UTC. Picture has been added to the blog post.

Posted on

A magnitude ML3.5 and ML4.2 (IMO) and ML4.0 (EMSC) earthquake hits Grímsfjall volcano

A magnitude ML3.8 earthquake has hit Kverkfjöll volcano. This earthquake had the depth of 14,4 km according to the automatic SIL system.

This earthquake appears to have triggered earthquakes in Grímsfjall volcano. But two earthquakes appeared imminently after the ML3.8 earthquake in Kverkfjöll volcano. – This is not the case, the earthquakes happened before (09:06 UTC) the ML3.8 earthquake in Kverkfjöll volcano.

I have been going over the reviewed data on this earthquake. The web site EMSC is reporting this to be a ML4.0 earthquake that took place at 09:22 UTC, with the depth of 10 km. While IMO is reporting this earthquake to have the size ML4.2 (depth unkown). There was a earlier earthquake that took place at 09:06 UTC, it has has the size of ML3.5 (depth unkown). Both of this earthquakes took place in Grímsfjall volcano. There is a good chance that Icelandic Met Office is underestimating the size of this earthquake, given the data from EMSC and the fact that this earthquake was recorded on remote seismometer networks in Europe.

I am going to post updates on this if anything more happens.

Text updated at 09:49 UTC on 13th January 2011.
Text updated at 10:21 UTC on 13th of January 2011.
Text updated at 12:55 UTC on 13th of January 2011.

Posted on

A string of small earthquake swarms

A string of small earthquake swarms took place yesterday. It started with a small earthquake swarm at Geysir volcano. The a small earthquake swarm took place at Hengill volcano few hours later. This string of earthquake swarm ended with a earthquake swarms did end with a short but powerful earthquake swarm out on Reykjanes Ridge. Where the largest earthquake was ML4.1 in size (depth 10,4 km) according to the automatic SIL system. All of this swarms lasted from 1 hour and up to 3 hours and the total number of earthquakes was something less then few dozens of earthquakes.

Besides this it remains rather quiet earthquake wise in Iceland. But that can change without any warning at any time.

Posted on

Earthquake swarm at Geysir volcano

Tonight at 01:34 UTC (9th of January 2011) a earthquake swarm started at Geysir volcano. So far this earthquake swarm is slow moving, but with the largest earthquake reaching the size ML2.7 at 4.2 km depth according to automatic earthquake detection system that Icelandic Met Office has (SIL system).

So far it is hard to know how this earthquake swarm is going to develop. As this area normally does not have a lot of earthquakes.

I am going to post more updates of there are any major developments in regards to this earthquake swarm at Geysir volcano. I do expect the largest earthquake to have been felt in nearby farms in this area.

Posted on

Earthquake detection and winter storms

In the last two days there have been a strong winter storm going over Iceland. The wind has been coming from the north with snow and cold weather. But this has also been followed by a strong wind all over Iceland and this strong wind has been preventing the SIL network from detecting micro-earthquakes in Iceland. Because of that it appears that Iceland has been unusually quiet on Iceland Met Office maps. This might not necessary be the case in reality. But due to a lot of wind noise the SIL network is unable to detect the smallest earthquakes that happen in Iceland. Some stronger earthquakes might appear on the SIL network if they take place.

So the quiet time in Iceland is down to weather, not something else. As the weather improves we should start to see micro-earthquakes again on Icelandic Met Office maps. It is always a good idea to check the weather forecast in Iceland if there is a sudden drop in earthquakes in Iceland.

Note 1: There are sometimes times however in Iceland when there is nothing wrong with the weather and yet still no earthquakes. What is going on there is simple, there are no earthquakes taking place in Iceland. This happens sometimes. But this is a rare, but it does sometime happen.

Posted on

The earthquakes in Eyjafjallajökull volcano

The night of the 6th of January 2011 had few earthquakes in the Eyjafjallajökull volcano. This minor earthquake activity has been reported by the Icelandic media this morning. The news on this is not a long one. But confirms that some of the earthquakes in Eyjafjallajökull volcano are real (but might be wrongly located by the automatic SIL system). In the same news it is claimed that icelandic geologist are not concerned about this minor earthquake activity in Eyjafjallajökli volcano. But none of the earthquakes that did happen tonight (on the 6th of January 2011) did get over the size of ML2.0.

The news on the earthquake activity in Eyjafjallajökli volcano. Use Google translate at own risk.

Nokkrir jarðskjálftar í Eyjafjalla- og Mýrdalsjökli (Vísir.is)

Posted on

A new deep earthquake in Esjufjöll volcano

A new deep earthquake did just happen earlier tonight. The SIL system at IMO did give the earthquake the size ML1.7 with the depth of 22,5 km. In my experience this normally means that a earthquake swarm is about to start in Esjufjöll volcano. But this is not always the case, so we just have to wait and see what happens. But since earthquakes did start in Esjufjöll volcano last autumn (2010) with a earthquake swarm of about 70 earthquakes.

The activity has continues since then. But the earthquakes have completely stopped in-between earthquake swarms. This behaviour appears to be not uncommon in volcanoes in Iceland and elsewhere around the world. The earthquake yesterday in Esjufjöll volcano was size ML1.9 with the depth of 5.4 km. It is clear that a magma is creating this earthquakes, but there are few tectonics earthquakes in this area (but they do happen).

Posted on

Update on new years activity and Eyjafjallajökull volcano

Here is the update for the new years activity in Iceland. During the new year there was a ML3.0 earthquake in Bárðarbunga volcano system (local name is Kistufell). Where location of the earthquake swarm took place is known for a high level of earthquake activity in the past. So a earthquake swarm in that area is not a surprise and doesn’t mean anything special.

There has not been any more news on the rumble or the explosions in Eyjafjallajökull volcano since yesterday. It might well be that the event that was creating this noise is over. But I am far from sure on that due to lack of information. Due to cloud cover I am unable to see what is going at the top of the Eyjafjallajökull volcano with a web camera. What ever was going on in Eyjafjallajökull volcano it is clear that it was a powerful blast. One idea that I have had that this where a gas explosions of some type. But yesterday there where no reports of ash clouds or anything like that in the news. The weather forecast for the Eyjafjallajökull volcano area is not good for the next day or two. But currently the wind forecast is for a storm in the area of Eyjafjallajökull volcano and other mountains in south-east of Iceland.

Posted on

Update on the activity over the Christmas

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.

Posted on

Last activity update before Christmas and Christmas stuff

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.