Category: TFZ

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Large amount of stress in Tjörnes fracture zone

According to a news by Icelandic Meteorological Office. There is enough stress in the Tjörnes Fracture Zone for magnitude 6.8 earthquake. This is based on a study (Metzger o.fl., 2011). When and where this stress, or if it is going to be released in one 6.8 magnitude earthquake is impossible to know for sure. As it is impossible to predict behavior of this type of earthquake activity.


The circle shows the odd earthquake swarm on 22.10.2012 that where more east then the main earthquake swarm in TFZ. Copyright of this image belongs to Icelandic Meteorological Office.

For the time being, at least while the earthquake swarm is currently ongoing. It is best to keep an eye out for it and any sudden changes in it. But as I sad before. It is impossible to predict this events. All that can be done is to wait and hope for the best when this earthquake activity do starts to happen.

Current earthquake swarm in TFZ is still ongoing. But earthquake activity so far continues to drop at the same rate as before.

Icelandic Meteorological Office news

Earthquake activity offshore North Iceland continues (en.vedur.is)

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Earthquake swarm update for TFZ and Kverkfjöll volcano at 12:55 UTC

Earthquake swarm in TFZ continues. But earthquake activity continues to drop at fast rate. The largest earthquake so far from midnight has the magnitude of 4.0 (reviewed magnitude). Several smaller earthquakes have taken place during the night in TFZ. But no larger earthquakes have so far taken since midnight. Current earthquake activity has moved little bit east since it started on 21.10.2012.


Current earthquake activity in TFZ for the past few months. Copyright of this image belongs to Icelandic Meteorological Office.

Kverkfjöll volcano

Earthquake activity has continues since it started again in Kverkfjöll volcano. The strongest earthquake so far had the magnitude 3.3. This earthquake activity in Kverkfjöll volcano has it source in magma movements inside Kverkfjöll volcano. This is most likely not going to start an eruption. But it is worth keeping an eye on.


Earthquake activity in Kverkfjöll volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Earthquake activity has been slow in Kverkfjöll volcano. This is normal. As this is not tectonic movements, as in TFZ. But magma often moves slower and makes fewer earthquakes then just pure tectonic movements.

Blog post updated at 14:06 UTC on 23.10.2012
Blog post updated at 14:14 UTC on 23.10.2012

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TFZ earthquake swarm update at 11:03 UTC on 22.10.2012

The earthquake swarm in TFZ continues at slowed rate then before. But number of earthquakes has dropped more then half since yesterday. During the night the strongest earthquake was ML4.1. With several earthquakes with the magnitude of 3.0 to 3.9. Many smaller earthquakes have taken place. Most of them with the magnitude around 2.0.


The area of earthquake activity in TFZ. The green stars mark earthquakes that where larger then ML3.0. Copyright of this image belongs to Icelandic Meteorological Office.


Trace showing the earthquake activity in TFZ during past 48 hours. Copyright of this image belongs to Icelandic Meteorological Office.


Tremor plot showing the earthquake activity. This is Hraun á Skaga SIL station. Copyright of this image belongs to Icelandic Meteorological Office.


Tremor plot showing the earthquake activity. This is Siglufjörður SIL station. Copyright of this image belongs to Icelandic Meteorological Office.

Earthquake activity is currently ongoing and is not expected to stop any time soon. But it might slowly decrease if there are no large earthquakes in this area in next few hours to days. But there is always more earthquake activity following stronger earthquakes in this area. The largest earthquakes in this earthquake swarm have been felt in the town of Siglufjörður and at times in other nearby towns in the area.

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Earthquake traces of the magnitude Mw5.6 earthquake

Here are the earthquake traces of the magnitude Mw5.6 earthquake that took place in TFZ on 21.10.2012 at 01:24 UTC. I did detect this earthquake in all of my geophone stations in Iceland.


The Mw5.6 earthquake in TFZ. This is the Z trace. This image is released under Creative Commons licence. See licence page for more details.


The Mw5.6 earthquake in TFZ. This is the E-W trace. This image is released under Creative Commons licence. See licence page for more details.


The Mw5.6 earthquake in TFZ. This is the N-S trace. This image is released under Creative Commons licence. See licence page for more details.

The interesting thing about this earthquake is how stronger the N-S,E-W trace is compared to the Z (vertical). This shows that this earthquake movement was strongest on E-W and N-S then vertical (Z).


The Mw5.6 earthquake in TFZ. This is Heklubyggð geophone station. This image is released under Creative Commons licence. See licence page for more details.


The Mw5.6 earthquake in TFZ. This is Eyrarbakki geophone station. This image is released under Creative Commons licence. See licence page for more details.


The Mw5.6 earthquake in TFZ. This is Skeiðflöt geohone station. This image is released under Creative Commons licence. See licence page for more details.

Earthquake activity is currently ongoing in TFZ. With earthquakes often reaching magnitude 3.0 in size. But many smaller earthquakes have taken place in the past 10 hours in TFZ. But overall the earthquake activity has slowly been dropping down since the large Mw5.6 took place at 01:24 UTC. If the earthquake activity is going to increase again is impossible to know for sure at current time.

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New earthquake magnitude information

According to news announcement (Icelandic) from Iceland Meteorological Office the largest earthquake in the ongoing earthquake swarm at TFZ had the magnitude of Mb5.6. Currently the earthquake swarm in TFZ is ongoing. This is the largest earthquake in TFZ since the year 1976, when a magnitude 6.2 earthquake did take place not far from Kópasker village.


The star marks the location of the magnitude 5.6 earthquake. The red dots show the current earthquake swarm, the white dots show the earthquake swarm that took place in early September. Copyright of this image belongs to Icelandic Meteorological Office.

The earthquake swarm in this area of TFZ is currently ongoing and does not show any signs for now that it is stopping. But earthquakes with magnitude 3.0 and stronger are still taking place and might still take place in the next few hours tod days. Any strong earthquake is going to appear clearly on my geophone network in Iceland. If anything major happens. I am going to post new blog post about it soon as possible. I update my twitter and Google+ when needed.

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TFZ earthquake swarm update at 11:54 UTC

This is short TFZ earthquake swarm update at 11:36 UTC. The strongest earthquake so far was a magnitude Mb5.2. It has been followed by many earthquakes that are 3.0 to 4.8 in magnitude. Number of earthquakes that are below that magnitude is around 300 to 350. But this number is updating constantly so it is going to be outdated once this blog post is up.


The earthquake area today at 11:25 UTC. The green stars show earthquakes that are above ML3.0 in magnitude. Copyright of this image belongs to Icelandic Meteorological Office.


The tracker showing how dense this earthquake swarm was at times. Copyright of this image belongs to Icelandic Meteorological Office.


The earthquake swarm on Hvammstangi geophone station. This image is released under Creative Commons licence. See licence page for more details.


The earthquake swarm on Heklubyggð geophone station. This image is released under Creative Commons licence. See licence page for more details.


The tremor plot at Hraun á Skaga showing this earthquake swarm clearly. Copyright of this image belongs to Icelandic Meteorological Office.


The tremor plot at Siglufjöður. This SIL station is closest to the earthquake swarm. Copyright of this image belongs to Icelandic Meteorological Office.


The tremor plot in Grímsey Island. This tremor plot is showing the earthquake swarm clearly. Copyright of this image belongs to Icelandic Meteorological Office.

This earthquake swarm is not over at current time. But earthquake activity has dropped something for the moment.That might change at any time. Since this earthquake swarm does not show any signs of being over at the moment. There is no risk of volcano activity in this area following this earthquake swarm. Since there are no volcanoes in this area of Iceland. This earthquakes are strike-fault earthquakes. I am going to post more updates on this earthquake activity during the day, or when something major happens in this area.

This earthquake swarm has been felt in Siglufjöður town. The largest earthquake was felt over most of north Iceland. Some minor damage has been reported following that earthquake.

Blog post updated at 11:54 UTC on 21.10.2012. Added images that I forgot to add the first time around.

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Heavy earthquake activity in TFZ

At the moment there is heavy earthquake activity taking place in TFZ. With earthquakes taking place every second. Strong earthquakes taking place every 2 to 10 minutes. One earthquake has at least reached the magnitude 5.0 and more earthquake with that magnitude is currently taking place on TFZ.

This earthquake activity can be monitored live (5. min, delay) on my geophone network web page here. I am going to post more information when I have more details.

Update 1: According to USGS the largest earthquake had the magnitude of M4.8. I do not know if this is reviewed data or not. USGS data can be viewed here.

Blog post updated at 01:02 UTC on 21.10.2012.

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Earthquake activity update on 20.10.2012 at 14:51 UTC

Today (20.10.2012) has been busy in terms of earthquake activity in Iceland. So I am expecting to write a second update later today on this activity.

Hekla volcano

At 05:28 UTC there was an earthquake in Hekla volcano. This earthquake had the magnitude of ML1.1 with the depth of 0.6 km. No other earthquakes have followed this single earthquake. What this means is impossible to know at this time. But so far everything remains quiet in Hekla volcano.


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

Kverkfjöll volcano

Earthquake activity continues in Kverkfjöll volcano. This earthquake activity is the result of dike intrusion into Kverkfjöll volcano. So far this earthquake activity is taking place in short burst of earthquake swarm.


Earthquake activity in Kverkfjöll volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Tjörnes Fracture Zone

At 02:07 UTC earthquake activity did start in TFZ. Just off the coast of Iceland. This earthquake activity is taking place in area that last had earthquake swarm in September. I did cover that earthquake activity in details on this blog. So far the largest earthquakes in this area of TFZ have had the magnitude of ML2.9. This is purely tectonic earthquake activity.

Earthquake activity in TFZ. Copyright of this image belongs to Icelandic Meteorological Office.

It is difficult to know what happens next in TFZ earthquake activity. But it likely going to continue for the next few hours to days like earlier. It is best to keep an eye on this earthquake activity. This earthquake activity also sometimes stops for few hours before it continues again. Most of this earthquake activity can be seen on my geophone network web page.

If anything major happens in this earthquake activity. I am going to post new blog post with updated information on that activity.

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New earthquake swarm east of Grímsey Island

This night there where two minor earthquakes on TFZ (according to the Richter scale). According to automatic results from Iceland Meteorological Office. The first earthquake had the magnitude of ML3.7 and the second earthquake had the magnitude of ML3.5. Many smaller earthquakes took place between this earthquakes. Most of them with the magnitude of 1.0 to 2.5. Earthquake activity is currently ongoing in this area at the moment. Earthquake activity started east of Grímsey Island around 00:04 UTC, 13.10.2012. The first earthquakes where smaller then 2.0 in magnitude.


The earthquake swarm on TFZ during the night. Copyright of this image belongs to Icelandic Meteorological Office.

This area of TFZ is well known for earthquake activity. During past few weeks it had several earthquake swarms around this location. More earthquakes should be expected in this area in next few hours to days. I do not know if any of this earthquake activity has been felt in Grímsey Island.

Blog post updated at 08:05 UTC.

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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.