Category: Earthquakes

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Earthquakes between Grímsfjall and Bárðarbunga volcano. Earthquake swarm in Krísuvík volcano

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.

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Minor earthquakes where seen after the large earthquakes in Grímsfjall volcano

Following the two large earthquakes (ML3.5 and ML4.2) there was a swarm of small earthquakes in that area. The earthquakes where seen on Grímsfjall SIL station, but do not appear to have been strong enough to be recorded on other SIL stations around Vatnajökull glacier. This appears to have lasted until around 13:00 UTC on 13th of January 2011. But after that it did quiet down.


Plot is from IMO web site.

Icelandic Met Office tremor plot that shows the two large earthquakes and following minor earthquakes. This area in Grímsfjall volcano has been quiet since the two earthquakes took place few days ago.

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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.

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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.

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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.

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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.

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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.

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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)

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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).

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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.