Monitoring – Page 120 – Iceland geology

October 13, 2013October 13, 2013

Earthquake swarm on the Reykjanes peninsula

Today at 01:11 UTC (13-October-2013) an earthquake swarm started on the Reykjanes peninsula. Early in this earthquake it was just minor earthquakes until 07:34 UTC an earthquake with magnitude 4,8 took place on the Reykjanes peninsula. Before the strongest earthquake took place, an magnitude 3,4 and 3,5 took place. Several earthquakes with magnitude above 3,0 took place following the main earthquake. The strongest earthquake was felt over an wide area, from Vík í Mýrdal to Hólmavík in north-west Iceland. Far as I know no damage did take place following this earthquake.

The earthquake swarm on the Reykjanes peninsula. Green stars mark earthquakes with magnitude above 3,0. Copyright of this image belongs to Icelandic Meteorological Office.

This earthquake did appear clearly on all of my geophone stations in Iceland. They can be viewed here.

The magnitude 4,8 earthquake on the Eyrarbakki geophone station. The earthquake signal is strongest on this geophone station and clearly tops the sensor it self, it can be seen how the signal goes above the maximum line on the geophone image. This image is released under Creative Commons licence. Please see CC Licence page for more details on this licence.

The magnitude 4,8 earthquake at Heklubyggð geophone station. This image is released under Creative Commons licence. Please see CC Licence page for more details on this licence.

The magnitude 4,8 earthquake at Böðvarshólar geophone station. This image is released under Creative Commons licence. Please see CC Licence page for more details on this licence.

The magnitude 4,8 earthquake at Skeiðflöt geophone station. The earthquake did appear clearly even if the noise level is high on that station. This image is released under Creative Commons licence. Please see CC Licence page for more details on this licence.

It is impossible to know for sure if this earthquake swarm is going to increase again. For the past few hours activity has been dropping, there is however nothing that says activity is not going to increase again. Such activity is common in this area, but it’s impossible to know for sure what happens next. At the moment there is nothing to suggest that volcano activity is the source of this activity. That might change but I think it is unlikely to be the case at the moment, regardless of what the future has in store.

October 11, 2013October 12, 2013

Source of the glacier flood in Hofsjökull volcano found

In August-2013 there was an glacier flood from Hofsjökull volcano, this glacier flood was minor and did not cause any damage. The source of this glacier flood has now been found according to Icelandic Meteorological Office. A new glacier cauldron has been found in Hofsjökull glacier, where none was before. The cauldron is around 700 meters long and about 30 – 50 meters deep. The glacier is cracked a lot around the cauldron and it’s dangerous to travel to this area because of that. The hight of this cauldron is around 1700 meters above sea level.

Hofsjökull volcano and glacier. The new glacier cauldron is located at ~64°49,5‘N; 18°52‘W. Click on the image for full resolution. Image from NASA/USGS/Icelandic Meteorological Office/Geological Department of University of Iceland (Jarðvísindastofnun Háskólans).

According to Icelandic Meteorological Office this part of the glacier has not had any glacier cauldrons before that they know of. This cauldron has the volume of 1 million cubic meters (10⁶ m³) according to Icelandic Meteorological Office. This area now has highly active hydro-thermal area and hot-springs. What formed this glacier cauldron is unclear at the moment, it was not an eruption since no such signals have been recorded from Hofsjökull volcano before or after the glacier flood in August-2013. It is also unclear if this glacier cauldron is going to create new glacier flood in the future.

Icelandic Meteorological Office announcement

Hlaup úr Hofsjökli í ágúst 2013 (vedur.is, in Icelandic)

Icelandic News

Fundu sigketil á Hofsjökli (mbl.is, Icelandic)

Blog post updated at 21:02 UTC on 11-October-2013.
Blog post updated at 01:45 UTC on 12-October-2013.

October 10, 2013October 11, 2013

Earthquake swarm in Eyjafjallajökull volcano

Today (10-October-2013) an minor earthquake swarm took place in Eyjafjallajökull volcano. This is the first earthquake swarm in Eyjafjallajökull volcano since the eruption stopped in May-2010 [link, Wikipedia]. This just appears to be an earthquake swarm, currently there are no signs of new magma getting into Eyjafjallajökull volcano. I am uncertain on what is creating this earthquake activity, but this might be old magma starting to move again or just stress changes in the volcano, the reason remains unclear as is. It is also important that this earthquake activity is minor, none of the earthquakes so far has reached the magnitude 2,0. The largest earthquake recorded had the magnitude 1,0 at 4,3 km depth.

Earthquake swarm in Eyjafjallajökull volcano today (10-October-2013). Copyright of this image belongs to Icelandic Meteorological Office.

There are no signs that any volcano activity is about to take place in Eyjafjallajökull volcano. So far it’s just earthquakes and nothing else. If this is old magma on the move there is a slight chance it might reach the surface via old transport tubes , such events would never be anything more than just minor explosion. It would not be anything like what happened in the year 2010. The only reason why this earthquakes are being detected today is because there is now a dense SIL network around Eyjafjallajökull volcano that measure it’s every earthquake and change that takes place. At the moment I doubt this is going to be anything like what happened in the 19th century eruption of Eyjafjallajökull volcano [link, wikipedia]. Currently there are no signs of such event is about to take place at current time. There are also no signs that show an imminent or possible eruption in Eyjafjallajökull volcano.

I do not expect anything more to happen in Eyjafjallajökull volcano. It might, but I am not expecting anything at this time of writing.

Blog post updated at 23:12 UTC on 10-October-2013.

October 8, 2013

Earthquake south of Hekla volcano

Today (08-October-2013) at 04:48 UTC an earthquake with the magnitude of 1,9 took place south of Hekla volcano, it’s depth was 7,3 km. A second earthquake took place at 04:59 UTC and had the magnitude of 0,8, it’s depth was 5,8 km. This earthquakes where not felt. It is also unclear what is creating this activity, the most likely reason is change is magma pressure inside Hekla volcano plumbing system. This does not mean an eruption is about to take place in Hekla volcano.

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

Earthquake activity in Hekla volcano has been unusually high for the past few months. Improvements have also been made on the SIL network close to Hekla volcano, this means that more smaller earthquakes have been recorded now then in the past. So far there are no signs of this connecting to an imminent eruption in Hekla volcano, the volcano has remained quiet so far and it’s unlikely to change at the moment.

October 3, 2013

Fewer earthquakes taking place on Tjörnes Fracture Zone at the moment

Donation note: I still need donations for October. I currently have no money for anything and that is rather bad. This bad situation that I am having is going to last for several months according to an excel document that I have set-up to figure out my total debt repayment. I can repay my debt (or buy replacement hardware if anything fails), but not buy food at the same time. The exchange rate of ISK to DKK is also bad at the moment. I hope for improvement but that won’t happen for next several months at least.

Activity in Tjörnes Fracture Zone continues as it has been doing for the past week. There is not a lot of other activity taking place in Iceland at the moment. The largest earthquake today (03-October-2013) had the magnitude of 3.5, a second earthquake with the magnitude of 3.1 also took place in TFZ today. Depth of this earthquake swarm remains the same, around 5 to 15 km at current time.

The largest earthquakes in this earthquake swarm in TFZ. Image in original context can be found here (Icelandic). Copyright of this image belongs to Icelandic Meteorological Office.

Today (03-October-2013) there were fewer earthquakes in this swarm than yesterday. The drop is currently around half of less activity than yesterday. I am not sure why this is as currently the earthquake swarm is ongoing. Even if there are fewer earthquakes taking place. This might just be a short time drop in earthquake activity, or this might signal an end of this earthquake swarm. Currently it’s too early to know for sure. The only thing that can be done is to wait and see what happens next in this earthquake swarm.

Earthquake activity today on Tjörnes Fracture Zone. Copyright of this image belongs to Icelandic Meteorological Office.

So far there are no signs of any magma having reached the surface, if that is the reason for this earthquake swarm in this area of Tjörnes Fracture Zone.

October 3, 2013October 3, 2013

Update on Tjörnes Fracture Zone earthquake swarm

Donation note: I still need donations to survive this month as any other months while I am just on social welfare from Iceland as I have explained here. This month I just have around 24 DKK (3.21€) for food this month after paying all the bills and my debt. I have already got some donation, but they just allow me to buy food for about one and half week if I am smart. Thanks for the help.

The earthquake swarm on Tjörnes Fracture Zone continues. The earthquakes are getting stronger, with the largest one today having the magnitude 3.8 (automatic results) and five other earthquakes with the magnitude 3.0 to 3.2. Currently the depth is around the same, it remains at 5 to 15 km and at the moment it doesn’t seems to be changing. Rate of earthquakes is around the same today (02-October-2013) as it was yesterday (01-October-2013), with no major changes in earthquake rate from what I can see currently taken place.

Earthquake activity in Tjörnes Fracture Zone. Green star show earthquakes larger than magnitude 3.0. Copyright of this image belongs to Icelandic Meteorological Office.

All earthquakes above magnitude 3.0 have been felt in Siglufjöður and Ólafsfjörður towns and other populated areas that are close to this earthquake swarm. There are no signs of this earthquake swarm slowing down as is. It still has not been confirmed if this earthquake activity is connected to magma injection at depth, or if this is just normal tectonic earthquake activity in this area. It’s going to remain difficult to confirm this idea until an eruption starts in this area and that simply might just not happen at all. The largest earthquakes appear on my webicorders website here, on the geophone station named Böðvarshólar.

Blog post updated at 22:33 UTC on 02-October-2013.
Blog post updated at 22:39 UTC on 02-October-2013.

October 1, 2013October 2, 2013

More earthquake activity in Tjörnes Fracture Zone

Donation note: Please donate. This month as past several months before that are difficult for me. Due to poor exchange range from ISK to DKK and the fact that I generally have low income. This website and writing on it is my job, along with other writing jobs that I attend to. Older posts on donations can be found here.

Today (01-October-2013) there has been a lot of earthquake activity in Tjörnes Fracture Zone. Current area of activity is same as for the past week, what is now changing is the rate and magnitude of earthquakes. This morning an magnitude 3.2 earthquake took place in this area. That earthquake and at least two other smaller ones where felt in Ólafsfirði, the town closest to this earthquake swarm. Earthquake activity is currently ongoing and with no signs of stopping.

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

It has been reported by Rúv and other news media in Iceland that this might be an dike intrusion in this area. This is what geologist at Icelandic Meteorological Office are theorising at the moment. I do not know if this is true or not. What I do know is that at this location there is no known volcano and if there is an volcano at this location it is currently unknown and not documented at all (such things happen). If this is magma and if it finds an path to the surface we are going to see an eruption. I do not know if that would create an new island if that was the case, such speculations have to wait until an eruption started. If it ever gets that far. If this is magma then it is still at great depth, since the depth of this earthquake swarm is at the moment around 5 to 15 km and does not seem to change that much at the moment.

It is possible to watch this earthquake activity here on my webicorder website. The closest geophone station that I have to this earthquake swarm is the one named “Böðvarshólar”. It is already showing many of the strongest earthquakes in this swarm clearly. It is located in the country side far from any major traffic source.

I am going to post updates about this earthquake swarm when needed.

Blog post updated at 20:26 UTC on 01-October-2013.
Blog post updated at 23:53 UTC on 01-October-2013.

September 30, 2013September 30, 2013

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.

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.

September 27, 2013September 27, 2013

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).

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.

September 27, 2013

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.

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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