Magma – Page 81 – Iceland geology

April 27, 2013June 17, 2013

Earthquake activity in Hekla, Katla, Krísuvík and Bárðarbunga volcanoes

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Hekla and Katla volcanoes

I am going to write about both this volcanoes here. Since I am going to be using the same image anyway for both volcanoes.

Yesterday (26.04.2013) there was a magnitude 1.1 earthquake in Hekla voclano. This earthquake was in the same area that triggered uncertainty level to be declared just before Easters in March. It was later cancelled when nothing more happened.

Earthquake in Hekla volcano. Also on this picture earthquake activity in Katla volcano (read more below). Copyright of this picture belongs to Icelandic Meteorological Office.

Katla volcano has been having some earthquake activity in past days. So far it has just been minor earthquakes and nothing more. But it has been taking place where a minor eruption took place in Katla volcano during the summer of 2011. That minor eruption created a minor glacier flood. But it did destroy a bridge and closed down the ring road (road 1) in this part of Iceland.

While this activity is currently nothing to worry about. It is worth keeping a eye on it. Just in case it increases, or if some other changes start to take place in Katla volcano.

Krísuvík volcano

A minor earthquake swarm took place in Krísuvík volcano today (27.04.2013). The largest earthquake had the magnitude of 1.9. The depth of this earthquakes was around 8.6 km. Activity in this area is normal and there does not seem anything strange about it. But Krísuvík volcano has been having periods of inflation and deflation for the past three years. Earthquake activity increases when Krísuvík volcano is in period of inflation. If that is the case now I do not know.

Earthquake activity in Krísuvík volcano. Copyright of this picture belongs to Icelandic Meteorological Office.

Bárðarbunga volcano

A minor earthquake swarm took place in Bárðarbunga volcano today. Largest earthquake in this swarm had the magnitude of 1.3. Depth range was from 18.8 km and up to 11.1 km. This earthquake swarm is important. Since it appears that this is a dike intrusion in Bárðarbunga volcano. But a minor dike intrusion also took place in this area few weeks ago. That also resulted in a minor earthquake swarm in this same area.

Earthquake activity in Bárðarbunga volcano. Most likely due to minor dike intrusion into the volcano. Copyright of this picture belongs to Icelandic Meteorological Office.

A minor dike intrusions into a volcano does not mean a eruption is going to take place. In many Icelandic volcanoes (and around the world also) dike intrusions into the volcanoes are common event and in most cases do not result in any eruptions. But it is worth keep a watch out for this type of eruptions. Since it might signal a more active period ahead in Bárðarbunga volcano. But it might also just equally don’t mean anything. There is no way to know for sure.

Other then this activity. It has been rather quiet in Iceland at the moment. No larger earthquakes have been taking place in the past two weeks since activity slowed down in Tjörnes Fracture Zone.

Blog post updated at 22:32 UTC on 27.04.2013.
Blog post updated at 22:53 UTC on 27.04.2013.

April 6, 2013April 6, 2013

Minor dike intrusion in Bárðarbunga volcano

Today (05.04.2013) a minor earthquake swarm took place in Bárðarbunga volcano. The depth of this earthquakes was around 18 – 26 km. Meaning this is magma, rather then tectonic creating this earthquakes. None of this earthquakes had magnitude above 1.0.

Earthquakes in Bárðarbunga volcano. They are the orange dots. Copyright of this image belongs to Icelandic Meteorological Office.

Dike intrusions happens sometimes in Bárðarbunga volcano without it meaning there is a eruption going to take place soon it. This appears to be one of those cases.

April 6, 2013April 6, 2013

Magnitude 3.6 earthquake in Hamarinn volcano

Last night (05.04.2013) at 01:50 UTC a magnitude 3.6 earthquake took place in Hamarinn volcano (no GVP profile yet!). This earthquake had the depth of 2.1 km. This seems to be a dike intrusion taking place in Hamarinn volcano. No clear signs of harmonic tremor have been detected based on tremor data from Icelandic Meteorological Office.

The Hamarinn volcano is where the green star is. But that is the location of the magnitude 3.6 earthquake that took place last night. Copyright of this image belongs to Icelandic Meteorological Office.

Harmonic tremor plot do not show any harmonic tremor pulse. The signal on this harmonic tremor plot is the earthquake swarm in TFZ for most parts. Copyright of this image belongs to Icelandic Meteorological Office.

This earthquake activity is due to minor dike intrusion. Rather then something else. It is not clear if this activity is just normal activity for Hamarinn volcano or signal about something else is about take place. But as before. Hamarinn volcano remains mostly quiet for the moment.

March 31, 2013

Deep earthquakes in Askja and Kverkfjöll volcanoes

This is a update for both Askja and Kverkfjöll volcanoes. Since they both had deep earthquakes today. None of this earthquakes where larger then magnitude 1.0. There depth was around 22 to 24 km inside the volcanoes them self.

Earthquakes in Kverkfjöll and Askja volcanoes. There depth was around 22 to 25 km. Copyright of this image belongs to Icelandic Meteorological Office.

GVP Kverkfjöll volcano profile. GVP Askja volcano profile.

It is impossible to know for sure what this means in terms of future activity. But this are both active volcanoes and should be treated as such.

March 29, 2013March 29, 2013

Magnitude 4.4 earthquake north of Kolbeinsey Island

Today at 17:32 UTC there was a magnitude 4.4 earthquake north of Kolbeinsey Island. I do not know if this earthquake was tectonic or volcanic in nature. I do know that there where several aftershocks following this earthquake. Since I did register them on my geophone in north Iceland. The geophone web site can be viewed here. More information about the earthquake can be found here, on EMSC web page.

Regional view of the area where the earthquake took place. Copyright of this image belongs to EMSC.

Icelandic Meteorological Office did also detected many of this earthquakes that took place there. But detection from this location is difficult due to distance from the SIL network.

The earthquake swarm location according to Icelandic Meteorological Office. Copyright of this image belongs to Icelandic Meteorological Office.

For now this is just a earthquake swarm and nothing else. Regardless of what happens later. Earthquake activity has been common in this area of the rift zone for several months now. I do not know why that is. The ocean depth in this area is around 3 to 4 km where it is the deepest. So if an eruption takes place there it is not going to be noticed due to the depth of the ocean.

March 26, 2013March 26, 2013

Deep earthquakes in Askja volcano

Today (26.03.2013) at 08:09 UTC there where three deep earthquakes in Askja volcano. The most depth of this earthquake swarm was 25.5 km. None of the earthquake had the magnitude above 2.5. The strongest earthquake had the magnitude 2.1 with the depth of 20.4 km

Earthquakes in Askja volcano. Askja is located to the north of Vatnajökull glacier and the lake is round in shape on this map. Marked by the orange dots on it. Copyright of this image belongs to Icelandic Meteorological Office.

This activity is part of an progress that started in Askja volcano back in the year 2010. So far this has not lead to any eruption. But it has created some odd changes. Along one was that Askja lake was ice free last year (winter 2012). The reasons for that are still not known to me.

Blog post updated at 16:32 UTC on 26.03.2013.

March 26, 2013March 26, 2013

Uncertainty level declared on Hekla volcano

Uncertainty level has been declared on Hekla volcano due to strange earthquake activity in it for the past week or so. But in total of seven earthquakes where recorded in Hekla volcano at the depth of 11 to 12 km. This is highly unusual for Hekla volcano. People are advised against going up to Hekla volcano while uncertainty level is in force. It is also dangerous to be too close to Hekla volcano. Since if an eruption starts, it is going to start without any warning at all.

I am going to post updates on Hekla volcano as needed if anything happens. It is possible to watch activity live from Hekla volcano on my geophone page here. But I have a geophone located about 16 km away from Hekla volcano. List of web cameras that I know of are online and focused on Hekla volcano can be found here. Update 1: Web camera that is showing Hekla volcano (pictures) can also be found here.

News about this in English

Seismic activity in Mount Hekla (Rúv.is)

News about this in Icelandic

Ekki mikið um jarðskjálfta við Heklu (Rúv.is)
Óvenjuleg jarðskjálftahrina í Heklu (Rúv.is)
Engin bráðahætta á eldgosi (Rúv.is)
Jarðhræringar í Heklu: Óvissustig í gildi (Rúv.is)

Óvissustig vegna Heklu (mbl.is)
Engin sjáanleg merki um eldgos í aðsigi (mbl.is)
Hægt að fylgjast með Heklu (mbl.is)

Óvissustig vegna hugsanlegs goss í Heklu (Vísir.is)
Ferðamenn varaðir við að vera nærri Heklu (Vísir.is)
Fyrirvarinn yrði einn til tveir tímar (Vísir.is)

Óvissustig vegna óvenjulegra hræringa í Heklu (DV.is)
„Hekla gaus með litlum fyrirvara síðast“ (DV.is)
Eftirlitsstig vegna Heklu hækkað úr grænu í gult (DV.is)

Blog post updated at 17:26 UTC on 26.03.2013.

March 21, 2013

New earthquake in Hekla volcano

This morning there was an earthquake in Hekla volcano at 08:23 UTC. This earthquake had the magnitude of 1.4 according to the reviewed data from Icelandic Meteorological Office. The depth of this earthquake was 11,2 km. But that is considerable depth for this location. This is most likely not tectonic earthquakes. But it is hard to be sure on that detail as of this moment.

The earthquake in Hekla volcano is marked by an orange dot on this map. Copyright of this image belongs to Icelandic Meteorological Office.

I do not have a clue what Hekla volcano is up to at the moment. But this is highly unusual activity for this volcano. Since normally there are no earthquakes in Hekla volcano until just before an eruption takes place in it. For the moment. The only thing that can be done now is to monitor what is taking place in Hekla volcano.

March 17, 2013March 17, 2013

Three earthquakes in Hekla volcano

During the night there where three earthquakes in Hekla volcano. All of the earthquakes where small with the magnitude of 0.6 up to 0.9. Depth of this earthquakes was on the range of 10.7 and down to 11.8 km. No other activity has followed this earthquakes in Hekla volcano since this earthquakes took place.

The earthquakes in Hekla volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Currently there are no signs of volcano eruptions in Hekla volcano. If that changes I am going to write about it. But for now Hekla volcano is as quiet as it has been since the year 2000. When last eruption took place.

March 3, 2013

Deep earthquake swarm in Tungafellsjökull volcano

Today (03.03.2013) between 13:19 UTC and to 13:21 UTC a deep earthquake swarm took place in a volcano named Tungnafellsjökull. This was a minor earthquake swarm, with the largest earthquake having magnitude 1.4. But it is the depth that is important here. The depth was most at 28 km, with the shallowest earthquake having the depth 18.7 km. This suggest magma intrusion into the volcano at depth. A pattern that was seen during the Eyjafjallajökull volcano eruption as an example.

For the past few months. Tungnafellsjökull volcano has been having swarms of earthquakes. All of them small, but many of them above 2.0 in magnitude. But so far none above magnitude 3.0. While earthquake activity has remained low in Tungnafellsjökull volcano I find that events are speeding up there in the past few months. With the terms that more earthquakes are being detected in this volcano and now at more depth. I find this worrying and also interesting. This volcano is far from any populated area, so any damage resulting for an eruption in it should be minimal. It also has no glacier to speak of. There is going to be a bad weather in Iceland until Friday (according to the weather forecast at the moment), so detecting any small earthquakes in this area might be limited by it.

The red dots show the earthquake activity in Tungnafellsjökull volcano. Copyright of this image belongs to Icelandic Meteorological Office.

It is too early to know what happens in Tungafellsjökull volcano. It is also important to note that Tungnafelljökull volcano has never erupted in historical times. This makes figuring out what happens next in it more difficult then ever. This activity might not mean an eruption is imminent. But at the moment I cannot rule one out just yet. It is clear that more activity is going to be needed before the picture of what is taking place in Tungnafellsjökull volcano gets clearer.

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