Category: Breinnisteinsfjöll

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Earthquake swarms in Brennisteinsfjöll volcano and TFZ

Over the past few days there has been continued earthquake activity in Breinnisteinsfjöll volcano. The largest earthquake in this swarm had the magnitude of ML2.5. It is possible that this earthquake swarms have there orgin in SISZ. Rather then Breinnisteinsfjöll volcano. But at current time is hard to be sure on this detail.


Earthquake activity in Breinnisteinsfjöll volcano during the past few days. Copyright of this image belongs to Icelandic Meteorological Office.

Tjörnes Fracture Zone

Earthquake activity has also been taking place east of Grímsey Island. This earthquake activity has mostly been small. But this are earthquake swarm did not have any earthquake that was above 3.0 in magnitude.


Earthquake swarm on TFZ. Copyright of this image belongs to Icelandic Meteorological Office.

The largest earthquake in this swarm had the magnitude of ML2.8. More earthquake activity should be expected in this area. As this is one of most active areas in Iceland when it comes to earthquake swarm.

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Magnitude 3.8 earthquake in Breinnisteinsfjöll volcano

Earthquake with the magnitude of 3.8 took place in Breinnisteinsfjöll volcano at 19:42 UTC. This earthquake was felt in Reykjavík and nearby area. Many aftershocks have followed this earthquake. Most of them are however below 2.0 in magnitude. There was also pre-earthquake activity before the magnitude 3.8 earthquake did take place. Most of those earthquakes where below 2.0 in magnitude. Last month an earthquake with the magnitude 4.3 took place in this same area. Earthquake activity is currently ongoing with smaller earthquakes for the time being.


Green star marks the place where the magnitude 3.8 earthquake took place. Copyright of this image belongs to Icelandic meteorological Office.

So far there is nothing to suggests that current earthquake activity is nothing but tectonic. But this area is a riftzone. So there are earthquake swarm often take place there without them being related to any volcano activity in this area. This earthquake swarm appears clearly on my geophone network in Iceland. I am going to continue to monitor this earthquake activity. As more strong earthquakes in this area can take place in the next few hours to days.

Icelandic news about this earthquake activity

Jarðskjálfti upp á 3,8 í Bláfjöllum (Rúv.is)
Jarðskjálftar við Bláfjöll (mbl.is)
Jarðskjálfti í Bláfjöllum (Vísir.is)
Skjálftinn var 3,8 stig (mbl.is)

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Ongoing earthquake swarm in Breinnisteinsfjöll volcano / SISZ

Since yesterday (02.09.2012) there has been ongoing earthquake swarm in Breinnisteinsfjöll volcano / SISZ (south iceland seismic zone). It is impossible to know how this earthquake swarm is going to proceed. But from what I can tell. It does not seem like it is going to be over any time soon. It is also an possibility that current earthquake swarm is part of an larger stress change in the area. But for now it is too early to know for sure what it means in the long term. Current earthquake activity is ongoing. With almost no breaks or stops. Most earthquakes have the magnitude of 0.1 and up to 2.0. But no larger earthquakes have been detected so far. The first earthquake in this earthquake swarm had the magnitude of ML4.4. Depth of this earthquakes is from 3 to 7 km (in that range).


The earthquake activity in Breinnisteinsfjöll volcano. The earthquakes align them self on an fault line that almost directly north-south direction. Copyright of this image belongs to Icelandic Meteorological Office.

It is impossible to know what is going to happen next in this earthquake swarm. But strong earthquake should not be ruled out for now. This might also activate nearby fault lines if the activity intensifies. As that sometimes happens in Iceland. Whatever happens next in this area. It is worth keeping an eye on the progress of this earthquake swarm.

Icelandic news about this earthquake swarm

Enn skelfur undir Bláfjöllum (mbl.is)
Enn skelfur í Bláfjöllum (Rúv.is)

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Earthquake in Brennisteinsfjöll volcano / SISZ earthquake zone

Today (30.08.2012) at 11:59 UTC there was an earthquake with the magnitude of ML3.8 (4.2Mw) in Brennisteinsfjöll volcano / SISZ. But SISZ overlaps this area to some extend. So large earthquakes do happen in this area of Iceland on regular basis. This earthquake was felt in Reykjavík area, south Iceland and some part of western Iceland.


The earthquake location and the following aftershocks. Copyright of this image belongs to Icelandic Meteorological Office.

In around 30 aftershocks have been detected in the area. More aftershock activity in this area cannot be ruled out. This earthquake did appear clearly on my geophones all over Iceland.


The earthquake at Eyrarbakki geophone station. This geophone is the closest to the earthquake. The most movement in this earthquake was on an N-S and E-W fault according to my geophones. This picture is released under CC Licence. See licence page for more details.


This is the earthquake as it was recorded on Heklubyggð geophone. It is the second closest geophone station to this earthquake. This picture is released under CC Licence. See licence page for more details.


Here is the earthquake as it did appear on Skeiðflöt geophone. This picture is released under CC Licence. See licence page for more details.


Here is the earthquake as it did appear on Hvammstangi geophone. This picture is released under CC Licence. See licence page for more details.

It is impossible to know for sure what this earthquake activity means. But earthquake activity in this area of Brennisteinsfjöll volcano did stop around 15:49 UTC. No aftershocks did go above 2.0 in magnitude. More earthquakes in this area should not be ruled out in the next few days to weeks.

Icelandic News about this earthquake

Alltaf von á eftirskjálftum (Rúv.is)
Skjálftinn á enda stórs misgengis (Rúv.is)
Verra ef safnið hefði skemmst (Rúv.is)
Skjálftinn hápunktur – ekki fyrirboði (Rúv.is)
Jörð skalf í dag (Rúv.is. Afternoon radio show about this earthquake in Icelandic)
Jarðskjálftasvæðið undir smásjá sérfræðinga (Vísir.is)
Má búast við nokkrum eftirskjálftum (Vísir.is)
Fólk hljóp á dyr í Litlu Kaffistofunni (Vísir.is)
Jarðskjálftinn var 4,6 stig (Vísir.is)
Á þriðja tug eftirskjálfta hefur mælst (mbl.is)
Jarðskjálfti upp á 4,6 stig (mbl.is)
Snarpur jarðskjálfti á höfuðborgarsvæðinu – Stærsti skjálftinn í 3 ár (Pressan.is)
Jarðskjálftafræðingur: Ekki búið að losa um neina spennu að ráði (Pressan.is)

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Minor earthquake swarm in Brennisteinsfjöll volcano system

When I was moving there was an small earthquake in Brennisteinsfjöll volcano. Because I was moving I was unable to track this earthquake swarm properly. But the largest earthquake was around ML1.5 from what I can remember. The earthquakes had the depth of at least 2 km. But I am not sure what the exact depth is. But I have not yet looked at the reviewed data on this earthquake swarm.


The earthquake swarm in south-west part of Brennisteinsfjöll volcano. Copyright of this picture belongs to Iceland Meteorological Office.

There has not been a lot of activity in Iceland during all summer. So I have not had lot to write about. But that might change without any warning. As is common in Iceland.

I did also move on 7th of August to a new town in Denmark. That means I am out of ADSL connection until 24th of August. So this blog is going to suffer from lack of updates until I am properly connected to the internet.