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Earthquake activity in Herðubreið is not volcanic in nature

The earthquake activity in Herðubreið during past few days is not volcanic in nature, or magnetic in nature. It is purely tectonic in nature. But the faults that have been moving are vertical, not horizontal as so many earthquake faults. Earthquakes are common in this area, as it on the eastern rift zone. The fault lines in this area of Iceland are highly active at times. Iceland Metorlogical Office has released this interesting information about the earthquake activity in this area during the past few years.


The first fault plane in Herðubreið. This one has the direction of N41°A. Copyright of this image belongs to Iceland Meteorological Office.


The second fault plane in Herðubreið. This second fault has the direction of N221°A (49°). Copyright of this image belongs to Iceland Meteorological Office.

Most of the earthquakes are on the depth of 5 to 6 km according to IMO.


The earthquake activity in Herðubreið the days 14 to 17 of May 2012. Copyright of this image belongs to Iceland Meteorological Office.


Earthquake activity in Herðubreið during the years 2005 to 2006. Copyright of this image belongs to Iceland Meteorological Office.


Total amount of earthquakes in Herðubreið from the years 2005 to 2012. This clearly shows that activity in this area has been rather constant during this period. Copyright of this image belongs to Iceland Meteorological Office.

The area in question is outside Askja volcano main fissure swarm. It is also outside Kverkjföll volcano main fissure swarm. So this earthquakes are tectonic in nature. But even so this area has erupted in the past. But for now. It is just earthquakes and not magma on the move, or breaking its path up to the surface as was case in Upptyppingar tuff mountain. The images are from Week 20 overview (what is up about it) at IMO web site.

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Special report: Magnitude Mw6.1 earthquake hit northern Italy, many aftershocks recorded

At 04:03 CEST (02:03 UTC) an earthquake with the magnitude of Mw6.1 did happen in north Italy. This earthquake was in an area that has seen a lot of earthquake activity during past several months now. But earthquake activity did start in this area late last year (2011). This earthquake did create a lot of damage in north Italy according to news reports. At least seven people have died from this earthquakes and well over 50 people have been injured because of this earthquake. Many historical sites have been damaged or completely ruined in this earthquake. I do not know what type of fault that did break. But data suggest that it was a slip fault that did break. I am unsure on directions of the fault that did break.


The earthquake in Italy as I did record it in Aabenraa, Denmark. There was a lot of surface waves following this earthquake. But those waves can be seen after the S-wave of the earthquake. This image is released under Creative Commons Licence. See CC Licence page for more details. Owner of this image is Jón Frímann Jónsson. Software used is WinQuake.


Local map of the Mw6.1 earthquake in North Italy. Copyright of this image belongs to EMSC.


The magnitude Mb5.2 earthquake in Northern Italy. I did not record this earthquake as clearly as the strongest one. This image is released under Creative Commons Licence. See CC Licence page for more details. Owner of this image is Jón Frímann Jónsson. Software used is WinQuake.


Local map of the Mb5.2 aftershock in North Italy. Copyright of this image belongs to EMSC.

What is most interesting about this earthquake is that it was had a pre-earthquake with the magnitude of ML4.2 about an hour to two hours before the main earthquake did happen. Web page of EMSC is not working properly at the moment. So I can’t check the time of the pre-earthquake at the moment. There have been more then dozen aftershocks less then Mb4.0 in size. But there have also been several earthquakes with the magnitude of Mb4.5. This aftershock activity continues at the moment.

Update 1: According to EMSC the pre-earthquake took place at 23:13 UTC on 19.05.2012.


Local map of the ML4.0 earthquake that took place at 23:13 UTC on 19.05.2012 in North Italy. This appears to be clearly pre-earthquake to the larger one. Copyright of this image belongs to EMSC.

I am going to update this blog post as more information are published.

English news about this earthquake.

At least 7 dead after quake rocks northern Italy (CNN.com)
Deadly northern Italy earthquake hits heritage sites (BBC News)
In pictures: Italy earthquake (BBC News)

Blog post updated at 15:44 UTC (17:44 CEST) on 20.05.2012.

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Earthquake swarm continues close to Herðubreið. Earthquake activity in Katla volcano

The earthquake swarm that started in Herðubreið two days ago continues. So far over 100 earthquakes have been recorded. Most of them are less then ML2.0 in magnitude. But this earthquake swarm continues at slow rate. This is not a big earthquake swarm. Based on number (in my system) of earthquakes pr hour. But in my system, a large earthquake swarm has tens to hundreds of earthquakes pr hour.


The earthquake swarm in Herðubreið. Copyright of this image belongs to Iceland Meteorological Office.


A bit higher resolution of the earthquake swarm in Herðubreið. Copyright of this image belongs to Iceland Meteorological Office.

Katla volcano

There is some earthquake activity in Katla volcano. But it is not high. There was one small earthquake this evening (it did appear on my Skeiðflöt geophone). But it has not been reviewed. So both size and depth are going to change.


Earthquake activity in Katla volcano during the past few days and until today. Copyright of this image belongs to Iceland Meteorological Office.

The earthquake activity in Katla volcano is also showing interesting pattern during this week (Week 20). It seems that earthquake activity is focusing on one point inside the caldera. It is hard to know for sure what this means at current time. But it is my opinion that it is not a good sign. But so far, nothing major has been happening inside Katla volcano caldera at this time. Until that happens, it is just best to keep watch and keep speculations within the amount of what is going on.


Earthquake activity in Katla volcano during Week 20 (current week). Copyright of this image belongs to Iceland Meteorological Office.

Beside this activity. It has been quiet in Iceland now for several weeks now. That is not un-common to happen during some years. While other years are often more active, some years are quiet. It is not clear yet if the year 2012 is going to be quiet year in Iceland or not.

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Earthquakes in Katla volcano. Earthquake swarm continues close to Herðubreið. Other earthquake activity

This morning there was a short earthquake swarm in Katla volcano caldera. This earthquake looks like a minor dike intrusion did take place this morning. Current series of events did start on 28. April 2012. With a small earthquake event and a small glacier flood that did follow it. Along with harmonic tremors coming from the glacier flood and possibly Katla volcano caldera (hydro-thermal activity boiling or something of that nature). I do not yet know if there was any glacier flood following the event this morning. But so far there is nothing that suggests a small glacier flood did take place following the earthquake swarm this morning.

The earthquake swarm this morning took place on an location that did erupt on 8 and 9th of July 2011. So it is clear the area that erupted last year is picking up activity again. But there was an drop in activity from end of November 2011 until end of April 2012.


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

This earthquake activity did appear well on my geophone at Skeiðflöt farm.


Earthquake activity in Katla volcano caldera this morning on my Skeiðflöt geophone. There is a lot of noise on this geophone. But earthquake activity can still be seen on this. The earthquakes are marked by red (some noise is also marked by red). This picture is released under Creative Commons Licence. See CC Licence page for more details.

It is clear that Katla volcano seems to be warming up to an eruption. But it is impossible to know when such eruption might happen, or how big it is going to be.

Herðubreið

Earthquake activity continues south-west of Herðubreið. But almost all of the earthquakes have been less then ML2.0 in magnitude. Earthquake activity has been slowing down all day. At the moment, it appears this earthquake swarm is close to being over.


The earthquake activity close to Herðubreið mountain. Copyright of this picture belongs to Icelandic Meteorological Office.

This area is well known for for earthquake activity. So this is not something that is new in this area.

Reykjanes Ridge

According to EMSC and USGS there have been several earthquakes with the magnitude of Mb4.5 to Mb4.8 on the Reykjanes Ridge. Earthquake activity is common on the Reykjanes Ridge. But because of the location and depth (around 2km) it is impossible to know if there any volcano eruption taking place at this location. It might well be, or not.

Kolbeinsey Island

Over the past weeks there has been some earthquake activity close to or in Kolbeinsey Island. The largest earthquakes have had the magnitude around ML3.0, with some underestimates due to distance from the SIL network. At this moment it is impossible to know if this earthquake activity is related to possible eruption activity. But it believed that an eruption (or dike intrusion) took place on Kolbeinsey Ridge in the year 1999. It started off with a large earthquake swarm.

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Minor earthquake swarm close to Herðubreið

Today a small earthquake swarm started just south-west of Herðubreið. But Herðubreið is a volcano cone formation that erupted during last ice-age. But that eruption did break up trough the glacier. Explaining its shape.


The earthquake swarm off Herðubreið. Copyright of this picture belongs to Iceland Meteorological Office.

Largest earthquake so far had the size around ML3.1. But aftershocks have reached the size of ML2.5 according to IMO automatic magnitude estimate. This earthquake swarm is currently ongoing.

Icelandic news about this.

Grunnur skjálfti við Herðubreið (Vísir.is)
Jarðskjálfti nærri Herðubreið (Rúv.is)

Plus. Here are pictures from The Telegraph of Iceland volcanic nature.

Iceland from the air: aerial pictures of the country’s dramatic volcanic landscapes

Other: Donations help me running this blog (they also help me paying the bills, buy food and what comes with being a human being). Plus it appears that I need go the dentist. But as it is now. I can’t afford it properly. Thankfully this is not an emergency that I am dealing with in one of my tooth. But I need to get it fixed one way or the other soon. Thanks for the support! 🙂

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Katla volcano warming up for an eruption. Small glacier flood continues

This is going to be a short blog post. As I am going to be short of table and a cheer for few more days.

It seems that Katla volcano is warming up for a eruption. As I did mention in last blog post. But there is more to this. As the glacier flood that started on the 28. April 2012 continues according to a email that I got from an geologist working at Iceland Meteorological Office. But that suggests two things. That there is currently an ongoing melting of glacier taking place in Katla volcano, or there is a slow drainage taking place from some area in Mýrdalsjökull glacier. But given increased conductivity following this it is clear that this water has been in contact with magma. But that can be seen with the increased conductivity in the water.

There have not been many earthquakes following this events. But from the earthquakes that have happened. It seems that most likely source for current events is close to or the same area that erupted in July 2011. But at the moment this is just speculation based on limited data. It has not been confirmed so far.


The harmonic tremor that started on 28. April 2012. This is Lágu Hvolar SIL station. Copyright of this picture belongs to Iceland Meteorological Office. Used with written permission.

This plot shows clearly how the harmonic tremor starts and continues at same level for several days. I do not know if the harmonic tremor is ongoing. But I find it likely, if the small glacier flood is currently going on (that was my last information, but things might have changed during the day). But it is hard for me to know that for sure. But based on latest data from the water monitoring system around Katla volcano, the spike in this glacier flood is most likely over for now. But it impossible to know what happens next in Katla volcano. All that can be done is to wait and see what happens next.

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Small glacier flood from Mýrdalsjökull glacier on 28. April 2012 [Updated]

This has to be short. I do not have any table to cheer right now. I have already bought one (used and cheap). But I get it next week. I also do not yet have a ADSL connection so far. But this is what happens when one moves between countries.

On the 28. April 2012 there was a small glacier flood from Mýrdalsjökull glacier that on top of Katla volcano. This activity did start few days earlier according to Iceland Meteorological Office. But it did peak on the 28. April 2012. This was then followed by a small glacier flood in Múlakvísl river. The same river that had the glacer flood last summer, that did destroy a bridge in that same area.


The red line marks the harmonic tremor of Katla volcano. The blue line marks the conductivity in Múlakvísl glacier river. This is from Week 18 of the year 2012. Copyright of this picture belongs to Iceland Meteorological Office.

There was also a second event that took place in Katla volcano on 6 and 7. May 2012. But I do not know if there was any glacier flood in Múlakvísk glacier river following that event. Buit it is clear that Katla volcano is warming up again. This events are clearly something that I consider a warning on what is going on in Katla volcano. But it is a question if it continues or just stops, as so often does happen with volcanoes.

Update 1: According to a email answer that I got with a question of mine. This glacier flood is currently ongoing. It has not stopped so far. But this is a small glacier flood. But this is a interesting what is going on in Katla volcano at the moment.

Icelandic news about this.

Smáhlaup í Múlakvísl (mbl.is, Icelandic)

Blog post updated at 14:38 CEST on 11.05.2012.

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Iceland newest volcano (short of)

Iceland has many surprising things. Among those surprises is a volcano named Snæfell. I did mention it shortly yesterday. Now it is time for the long version of what this volcano is about. Snæfell volcano is a tall mountain, but it is 1883 meters above sea level. That makes it the highest mountain in Iceland outside of Vatnajökull glacier. Snæfell volcano has a small glaciers (more then one) on is top.

Snæfell volcano is the newest addition to Icelandic volcanoes. Little is currently known about Snæfell as a volcano. But it is now known that it has not erupted for at least 100.000 to 120.000 years. But it is debated among scientists if any eruptions have taken place after last ice-age. But that is around 12.000 years ago. The basic volcano system of Snæfell is in the direction of NNE, with eruption features going along those lines.

Origins of Snæfell volcano can be traced to several lava eruptions that started at least about 400.000 years ago. On top of that eruption even Snæfell volcano has been built by repeated eruptions in this area. Snæfell volcano belongs to the same volcano zone as Öræfajökull volcano and Esjufjöll volcano. In order with other volcanoes on this active volcano zone. It has little to no activity as I have

I do not know of any hydro-thermal areas close to Snæfell volcano. But that is not a surprise. Given how long it is since magma was on the move in this volcano. All the time that I have been watching for earthquakes in Iceland (well over 10 years now). I have never seen any earthquake activity in Snæfell volcano during that period.

South-east of Snæfell volcano is a extinct volcano. It has been weathered down by nature. I do not know how old it is. But that suggests that volcano activity in this area is not something new. Closest SIL station to Snæfell volcano is Vestari Sauðarhnjúkur.


Volcano and fault-line map of Iceland. Snæfell volcano can be seen on this map. Copyright of this picture belongs to Náttúrufræðistofnun Íslands. This picture is from this web site here.

Reference:

Eldvirkni Snæfells og Kárahnjúka tímasett (Morgunblaðið, 2005)
Snæfell og Nágrenni (OS.is, 2000)

Blog post updated at 22:43 CEST on 8 May 2012.

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Allt quiet in Iceland

It has been rather quiet in Iceland during the past several weeks. March for instance was unusually quiet. I suspect that April was also rather quiet earthquake wise in Iceland. With nothing special going on. I have currently limited to write about. But I am going to write about few volcanoes in Iceland and there history if there is any history to write about. But there is always some interesting information about volcanoes in Iceland.

Even the newest Icelandic volcano. Named Snæfell (no GVP website as of yet) and is located east of Vatnajökull glacier. It has not erupted for at least 12.000 years. But it is a part of the volcano arch that is made up of Öræfajökull, Esjufjöll volcanoes. Here are some information about in Icelandic. But I am going to write more on it later on. When I have my writer computer back up after I finish moving to Denmark properly.