Category: Earthquakes

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Update on Tjörnes Fracture Zone earthquake swarm

It has been almost a week since the earthquake swarm started in Tjörnes Fracture Zone. Today (30-September-2013) this activity continues. Since this earthquake swarm just around 1000 earthquakes (according to news) have so far been recorded by Icelandic Meteorological Office (when this words are written). The largest earthquakes have had the magnitude of 2.8, but no earthquake so far has reached the magnitude above 3.0.

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The earthquake swarm in Tjörnes Fracture Zone. Copyright of this image belongs to Icelandic Meteorological Office.

Currently there is no sign of this earthquake swarm ending. So far it has not been felt by anyone and so far. I do not know how this earthquake swarm is going to develop. It’s however important to keep an eye on this earthquake swarm, since it’s impossible to know what happens next in this area.

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Earthquake south of Hekla volcano

Tonight (28-September-2013) at 21:47 UTC an magnitude 2.0 earthquake took place south of Hekla volcano. Depth of this earthquake was 2.9 km according to automatic results from Icelandic Meteorological Office. So far no future earthquakes have been detected and there are no signs of eruption starting in Hekla volcano.

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The earthquake south of Hekla volcano. Copyright of this image belongs to Icelandic Meteorological Office.

This is the second earthquake that takes place inside Hekla volcano system this month. Last earthquake that took place in Hekla volcano was in the main volcano in the start of September. I wrote about it here. I am not expecting any more activity, but I might be wrong since it is difficult at best to know how Hekla volcano is going to behave before an eruption. Earthquake activity at Hekla volcano appears clearly on my geophone at Heklubyggð, it can be viewed here (updated every 5 min.).

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Earthquake activity continues on Tjörnes Fracture Zone

The earthquake swarm that started two days ago (wrote about it here) in Tjörnes Fracture Zone continues and appears to be growing in the past few hours. So far the largest earthquakes have not been stronger then magnitude 2.6 or 2.7 (automatic and reviewed results).

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The earthquake swarm in Tjörnes Fracture Zone. Copyright of this image belongs to Icelandic Meteorological Office.

None of this earthquakes have been felt that I know. Since they are good distance (~20 km) from populated areas and are small at the moment. That might change if larger earthquakes start to happen in Tjörnes Fracture Zone. Currently this earthquake swarm activity is mostly continuous with just few stops in it, no stop has so far not lasted more than 1 to 3 hours so far. Currently this earthquake swarm activity is ongoing and I do not expect it to stop at the moment.

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Magnitude 5.5 earthquake deep on the Reykjanes Ridge

Last night (26-September-2013) an earthquake took place deep on the Reykjanes Ridge. This earthquake had the magnitude of 5.5 according to reviewed results from EMSC. This earthquake was close to 1000 km from the south coast of Iceland so it was not felt by any human. Fish and crabs might have been disturbed however at that location. More information about this earthquake can be found here on EMSC website.

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The earthquake location on the Reykjanes Ridge. Copyright of this image belongs to EMSC.

An aftershock with the magnitude of 4.6 was recorded on the same location. Information about that earthquake can be found here on EMSC website. It is possible that more smaller earthquakes took place in this location, but due to distance from any seismometer network any smaller earthquakes then this are not detected at all.

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Earthquake swarm in Tjörnes Fracture Zone

Today (25-September-2013) an earthquake swarm started in Tjörnes Fracture Zone. This earthquake swarm started slowly and was mostly making small earthquakes early on. The largest earthquake today had the magnitude of 2.8 according to automatic results from Icelandic Meteorological Office. Currently the earthquake swarm is ongoing.

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Earthquake swarm in Tjörnes Fracture Zone. Copyright of this image belongs to Icelandic Meteorological Office.

I am expecting this earthquake swarm to continue for the next hours at least. TFZ is highly active when it comes to earthquake activity so this earthquake swarm is no surprise. If any major earthquake take place in TFZ it’s possible to see them here on my webicorder website.

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Minor earthquake swarm in Öræfajökull volcano

An minor earthquake swarm took place in Öræfajökull volcano today (09-September-2013). This was just minor earthquake activity and it was at shallow depth, just around 2.6 to 4.8 km. Largest earthquake in this swarm had the magnitude of 2.0.

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Earthquake activity in Öræfajökull volcano. Öræfajökull volcano is located south-most part of Vatnajökull glacier (next to the km line on the map). Copyright of this image belongs to Icelandic Meteorological Office.

Earthquake activity is not common in Öræfajökull volcano and that makes this activity interesting. So far this is just earthquake activity and I am not expecting anything else to take place. More earthquakes might happen in next few days to weeks. Or nothing else might happen Öræfajökull volcano.

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Interesting earthquake activity in Hamarinn volcano

Over the past few days interesting earthquake activity has been taking place in Hamarinn volcano. The earthquakes have been aligning along two east-west lines. Possibly an fissure in the volcano. I am not sure why this is happening, but I did record one earthquake from Hamarinn volcano today (07-September-2013) and that trace suggests this earthquakes have there origin in magma movements in the Hamarinn volcano. That has not yet been confirmed and this might never be confirmed due to lack of data. Largest earthquake so far had the magnitude of 2.2 at the depth of 4.5 km.

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Hamarinn volcano earthquake activity. Copyright of this image belongs to Icelandic Meteorological Office.

Last eruption in Hamarinn volcano was on 11 – 12-July-2011. It was an minor eruption and I did cover it here and here. Small eruptions are common in Icelandic volcanoes just as the are in other volcanoes around the world. Before the minor eruption in the year 2011 there was several months of earthquake activity in Hamarinn volcano. The area that now has this earthquake activity is the same area that had this minor eruption in the year 2011. I do not know if current activity is an early indicator that it is going to happen again. It however cannot be ruled out currently. What can be done is to monitor current levels of activity and just wait and see what happens next.

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Minor earthquake swarm in Esjufjöll volcano

Today (05-September-2013) an minor earthquake swarm took place in Esjufjöll volcano. Largest earthquake in this swarm had the magnitude of 2.2 and the depth of 4.9 km.

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Earthquake swarm in Esjufjöll volcano. Esjufjöll volcano are located in south part of Vatnajökull glacier, just northeast of Öræfajökull volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Earthquakes in this area are because of magma movement it is believed. Now there are more SIL stations in the area, so more earthquakes are being recorded. Few years ago the lowest magnitude that Icelandic Meteorological Office was able to detect in Esjufjöll volcano was magnitude 1.5 and above.

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Earthquake activity in several volcanoes

Today (04-September-2013) had some minor earthquake activity in several volcanoes in Vatnajökull glacier. All of this earthquakes were small and less than magnitude 3.0 in size.

Kverkfjöll volcano

The deepest earthquake activity was in Kverkfjöll, with earthquakes at 31 km depth and 24 km depth. This deep earthquake activity is possible connected to magma movements since tectonic earthquakes are unlikely to take place this deep in the crust.

Grímsfjall volcano

One earthquake was recorded in Grímsfjall volcano, it was minor and shallow. This might even just be a glacier quake, rather than normal earthquake.

Öræfajökull volcano

Öræfajökull volcano did see two earthquake today, at the depth of 4 to 5 km. Both were small and tectonic in nature from the looks of it. Earthquakes are not common in Öræfajökull volcano so I am not sure why this increase has now taken place. It is worth noticing that sil network is now more sensitive in this area than before since new stations have been added in this area. This means that smaller earthquakes are now being detected than before.

Esjufjöll volcano

Esjufjöll volcano had two earthquake, the third earthquake might be a ice-quake. I am not sure if it was an real earthquake or not. Esjufjöll volcano normally do not have any earthquake activity, but few years ago an earthquake activity started with earthquakes that had magnitude of 2.5 to 3.0 so there is something going on in this volcano. What that might be I am not sure of yet.

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Earthquake activity in Kverkfjöll, Öræfajökull, Esjufjöll, Grímsfjall volcanoes. All small earthquakes. Copyright of this image belongs to Icelandic Meteorological Office.

I do not expect anything major to take place in Vatnajökull volcano. Since the current quiet period in Iceland just seems to be ongoing as is.

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Minor earthquake in Hekla volcano

Today (04-September-2013) a minor earthquake took place in Hekla volcano. The magnitude of this earthquake was just 0.4 and the depth was 0.1 km, so this earthquake was not connected to magma movements of any type.

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

Based on how shallow this earthquake was, it is unlikely that it means anything in terms of possible eruption in the volcano. At the moment there are same chances for Hekla volcano eruption as any other day of the week, that has not changed at all.