Dyke intrusions – Page 41 – Iceland geology

May 9, 2014May 9, 2014

Update on earthquake swarm in Herðubreiðartögl on 9-May-2014

This is a short update for the earthquake swarm in Herðubreiðartögl on the 9-May-2014.

For the past 24 hours there has been drop in activity and no earthquake has been over magnitude 2,0. Activity continues but a lot lower levels then before. It does not look like it is over at this point, but the end of this soon to be seven day earthquake swarm in this area.

The earthquake swarm in Herðubreiðartögl as it was today. It can be seen that earthquake activity was at lot lower levels today then yesterday (08-May-2014) or the days before that. Copyright of this image belongs to Icelandic Meteorological Office.

This can also be seen in the tracer on Icelandic Meteorological Office website. Copyright of this image belongs to Icelandic Meteorological Office.

This drop in activity can also be seen in drop in the harmonic tremor plots in Askja. Fewer earthquakes means less earthquake related noise on the harmonic tremor plot (2-4Hz blue line). Not all of the activity that appears here is from Herðubreiðartögl, some of it is from SISZ and Reykjanes ridge activity. Copyright of this image belongs to Icelandic Meteorological Office.

The drumplot from Icelandic Meteorological Office also show this drop in activity. Some of the activity that appears is from Reykjanes Ridge. Copyright of this image belongs to Icelandic Meteorological Office.

None of this earthquake activity is strong enough to appear on my geophones. Since earthquakes at Herðubreiðartögl need to be at least magnitude 3,0 or larger to appear clearly on my geophones. My webicorders website can be found here, it shows all earthquakes that are taking place in Iceland and are large enough to appear on it. Its mostly earthquakes larger then magnitude 3,0 that are currently taking place (when this written).

Donation notice: Please remember to donate to support my work. Otherwise I am going to be broke this month and that is not a good thing. Thanks for the support.

Updated at 20:11 UTC.

May 9, 2014

Earthquake swarm on the Reykjanes Ridge

The earthquake swarm that has been taking place on the Reykjanes Ridge for the past few days did increase today (09-May-2014). The largest earthquake had the magnitude of 3,6 with the depth of 15,6 km. So far around 70 earthquakes have been recorded in this area. The earthquake swarm is taking place in area considerable distance from land and next populated area, so it might not be felt at all.

The earthquake swarm on the Reykjanes Ridge. Green star marks the magnitude 3,6 earthquake. Copyright of this image belongs to Icelandic Meteorological Office.

The magnitude 3,6 earthquake on the Reykjanes Ridge as it did appear on my Heklubyggð geophone. This image is released under Creative Commons Licence. Please see CC Licence page for more details.

It is difficult to know for sure what is taking place on the Reykjanes Ridge. There are clues this might be due to magma movement at depth, possibly dike intrusion. So far there are no signs of eruption taking place at this location at current point in time. It is possible to see any earthquake that takes place (at least large one) here on my webicorder website. It is also possible to see earthquake activity in Iceland at Icelandic Meteorological Office website.

Donation notice: Please remember to donate to support my work. I have just social welfare income and it is quite low. More details can be found here. Thanks for the support.

May 6, 2014May 6, 2014

Herðubreiðartögl earthquake swarm update 6-May-2014

This is an update on the earthquake swarm in Herðubreiðartögl on 6-May-2014. This information might go outdated quickly if the activity in this earthquake swarm changes suddenly.

For the past 24 hours the earthquake activity in Herðubreiðartögl has been dropping. This means fewer earthquakes overall, the magnitude of earthquakes taking place has also been getting lower, with strongest earthquakes just in the magnitude 2,5 to 2,9 range. In the past 24 hours no magnitude 3,0 or larger earthquake has taken place.

The earthquake activity in Herðubreiðartögl on 6-May-2014. Copyright of this image belongs to Icelandic Meteorological Office.

The earthquake tracer at Icelandic Meteorological Office website clearly shows the drop in activity. Copyright of this image belongs to Icelandic Meteorological Office.

My earthquake counter clearly shows this drop in earthquake activity. It is for all of Iceland, but majority of earthquakes over the past days are from Herðubreiðartögl. This image is released under Creative Commons Licence. Please see CC Licence page for more details.

I did discover today that Icelandic Meteorological Office has updated its drumplot website. So its now possible to see the earthquakes directly. The drumplot here above is from Askja SIL station, it clearly shows the earthquake activity in Herðubreiðartögl. The website with the drumplots can be found here (I have just found this website in Icelandic, there does not appear to be English version available). Copyright of this image belongs to Icelandic Meteorological Office.

It remains difficult to know for sure what is the source of this earthquake swarm. There is a slight chance it might be due to magma injection at depth, but that remains unproven as is. My geophone stations (I only got two running now) are going to show the largest earthquakes and they are going appear clearly. It can be viewed here.

Donations: Please remember to support my work. Otherwise I am going to have a rather poor month of May. Thanks for the support!

Article updated at 21:22 UTC on 6-May-2014.
Article updated at 21:37 UTC on 6-May-2014.

May 4, 2014May 4, 2014

Update on ongoing earthquake swarm in Herðubreiðartögl

The earthquake swarm that started yesterday (03-May-2014) in Herðubreiðartöl continues. Information about this earthquake swarm changes quickly so this article about it is going to get obsoleted quickly. The largest earthquake in past 24 hours had the magnitude 3,9. Since around midnight over 370 earthquakes have been recorded. This means the earthquake swarm is more powerful in terms of earthquakes today than it was at the same time yesterday.

The earthquake swarm in Herðubreiðdartögl today. Copyright of this image belongs to Icelandic Meteorological Office.

The evolution of the earthquake swarm in Herðubreiðartögl today. As be seen here this earthquake swarm is heavy in number of earthquakes being detected. Copyright of this image belongs to Icelandic Meteorological Office.

The earthquake swarm in Herðubreiðartöl at Askja SIL station. As can be seen here this earthquake swarm is close to continuous. There is some minor drop in activity few hours ago before the earthquake activity picks up again. Copyright of this image belongs to Icelandic Meteorological Office.

The earthquake swarm seen on the SIL station at Mókollar. It is close to what is seen on Askja SIL stations and other SIL stations around this area. Copyright of this image belongs to Icelandic Meteorological Office.

My earthquake counter today showing all the activity. This gives me good comparison to how many earthquakes where recorded yesterday. This image is released under Creative Commons Licence. See CC Licence page for more details.

I am expecting more earthquake activity in Herðubreiðartögl next hours and even days. Since currently there are no signs of this earthquake swarm slowing down. The largest earthquakes (above magnitude 3,0) appear clearly on my geophone network website.

May 3, 2014May 3, 2014

Ongoing earthquake swarm north of Herðubreiðartögl

Today (03-May-2014) around midnight (00:02 UTC) a earthquake swarm started north of Herðubreiðartöglum (Global Volcanism Program link on Askja volcano can be found here), this area is an small mountain ridge that has built up with regular eruptions over some period of time. The largest earthquake in this swarm took place this morning at 05:49 UTC and had the magnitude of 3,5 with the depth of 7,6 km. After this earthquake took place the swarm increased with many minor earthquakes. So far over 265 earthquakes have been recorded today, this number gets obsoleted quickly since new earthquakes happens ever 1 to 3 minute when I am writing this text.

Tremor plot on nearby SIL stations show that a lot more earthquake activity is taking place than appears on IMO earthquake website. Reason for this is simple, the earthquakes cannot be located since they are only detected at one or two SIL stations, a minimal of three or four SIL station are required for location of each earthquake. The tremor plot in the area also show that no magma is erupting, but that does exclude the possibly that magma injection is responsible for this earthquake swarm. It has not reached the surface and currently there is no eruption taking place at this location. If an eruption takes place in this location, it is going to be Hawaiian eruption with large lava flows.

The earthquake swarm north of Herðubreiðartögl as they appear on Icelandic Meteorological Office maps. Copyright of this image belongs to Icelandic Meteorological Office.

The earthquake rate during this earthquake swarm. Copyright of this image belongs to Icelandic Meteorological Office.

The SIL station in Askja volcano. As can be seen the earthquake swarm is dense and highly active. Copyright of this image belongs to Icelandic Meteorological Office.

The SIL station south of Herðubreiðartögl, this SIL station is called Mókollar and the earthquake swarm appears clearly on it. Copyright of this image belongs to Icelandic Meteorological Office.

Earthquake swarms are common in this area and have been for a long time. Most of that earthquake activity has been contributed to normal tectonic activity in this region (plate tectonic movements). This area also has erupted in the past (last 12,000 years). I don’t think there have been any eruptions in this area in the past 1000 years, at least there are no such signs on the surface (crates, lavas). It is difficult to know what happens in this area for the next few hours to days, all that can be done is to continue monitor the activity that is now taking place. The largest earthquakes appears clearly on my Böðvarshólar geophone (link here), even if the distance is up to 200 km.

Donation note: Please remember to donate. Otherwise I am going to have a rather bad month of May in terms of being broke. Thanks for the support.

April 27, 2014May 3, 2014

Minor earthquake swarm in Bárðarbunga volcano

Yesterday (26-April-2014) and today (27-April-2014) an minor earthquake swarm took place in Bárðarbunga volcano. I am not sure if this earthquake activity is due to dike intrusion or normal tectonic activity.

Minor earthquake swarm in Bárðarbunga volcano. Copyright of this belongs to Icelandic Meteorological Office.

This area of Bárðarbunga volcano is well known for high earthquake activity. If this is an dike intrusion as is an possibility, it does not increase the risk of an eruption, since dike intrusion without starting an eruptions are a common feature in Icelandic volcanoes.

April 4, 2014

Earthquake swarm on Reykjanes ridge

During the night (4-April-2014) an earthquake swarm took place on the Reykjanes Ridge. Largest earthquake in this swarm had the magnitude of 3,5 and was felt on land according to information from Icelandic Meteorological Office. This earthquake swarm might still be ongoing, but it only lasted for about 1 hour last night. That is not really long period of activity for an earthquake swarm in this area. It is possible to monitor the earthquake here on my webicorder website. I am going to remove the test card images once I have my Gentoo Linux up and running in few days time.

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

Unconfirmed information in news on Rúv.is suggest that this earthquake swarm might have its origin in magma movement at this location. Rather than tectonic activity at the same area. This area often has powerful earthquake swarms. Earthquake swarms in this area often drop in activity for few to several days at the time, before they resume at even more powerful then before. I don’t know if that is going to happen now, there is an good chance that is going to happen now or this might just be it. All that can is possible to do at the moment is to wait and see what happens next.

Update on the hard drive saga: So I did buy a new hard drive. When I did try to use it I found out that the drive I had bought was faulty from the factory. The store has already ordered an replacement hard drive and I should get it on Monday. I hope this issue is resolved by then. I have already received donations to support buying this new hard drive. But that does not mean my financial status is good this month. But it is far better now than in April or the months before it. Thankfully. Thanks for the support. I am currently using my Windows XP (normally just used to play games) hard drive to write this while my Gentoo Linux is out of commission due the hard drive failure.

March 28, 2014March 28, 2014

Earthquake swarm in Grímsfjall volcano

Today (27-March-2014) an earthquake swarm took place in Grímsfjall volcano. This activity is connected to current minor glacier flood from Grímsvötn glacier lake that is now taking place. The glacier flood it self is an minor and is about the same size as an glacier flood from Grímsvötn glacier lake in November-2012.

Earthquake activity in Grímsfjall volcano today (27-March-2014). Copyright of this image belongs to Icelandic Meteorological Office.

Harmonic tremor has been increasing in Grímsfjall volcano following this glacier flood. The leading idea is that the glacier flood is creating this high frequency harmonic tremors. This idea however remains unconfirmed at current time.

Harmonic tremor at 21:13 UTC on 27-March-2013 at Grímsfjall volcano. The harmonic tremor starts at the end of this plot. Copyright of this image belongs to Icelandic Meteorological Office.

Harmonic tremor at 22:55 UTC on 27-March-2014. As can be seen the high (blue line) harmonic tremor is increasing at the moment. Copyright of this image belongs to Icelandic Meteorological Office.

At present time there is nothing to suggest that an eruption has or is about to start in Grímsfjall volcano. However Grímsfjall volcano is unpredictable and highly active when it comes to eruptions. If an eruption starts in Grímsfjall volcano it might do so without an warning. Earthquake activity in Grímsfjall volcano would increase sharply just before the eruption would start as was the case before the eruption in 2011 (covered here). More detailed monitoring can of Grímsfjall volcano and other volcanoes in Vatnajökull glacier can be found here (Icelandic).

Advertisement: As I did say few days ago. I am adding advertisement back to my websites. Since I need to eat and pay the bills. There however has been a minor issue with my Google Adsense account. An issue that has so far not yet been resolved by Google. Once its resolved I am going to go trough the process of getting my account approved again. I was too detailed back in January when I closed down my Google Adsense account. I hope to have advertisements back before some volcano erupts in Iceland.

March 22, 2014March 22, 2014

Deep earthquake in Hamarinn volcano

Yesterday (21-March-2014) an extremly deep earthquake took place in Hamarinn volcano (part of Bárðarbunga volcano often called Loki-Fögrufjöll). The magnitude of this earthquake was just 1,4 but its depth was around 29,7 km. The location of this earthquake was just 10,4 km North-East of Hamarinn volcano (main). So it possibly was inside Hamarinn main volcano system, but I am not sure on that detail.

The earthquake activity in Hamarinn volcano and Öræfajökull volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Earthquakes that take place this depth happen due to magma movement or small dike intrusion at depth. I don’t know what is the actual case here, this might just be an earthquake at depth. The crust has the depth of 40 km at this location (study on this can be found here) due to hotspot [second link here] activity that has increased the thickness of the crust. Last eruption in Hamarinn volcano was in July 2011, it was an minor eruption that took place and lasted just for few hours and did not breach the glacier.

Post updated at 21:02 UTC.

November 27, 2013November 27, 2013

Harmonic tremor detected in Þórðarhyrna volcano

On the 21-November-2013 there was an earthquake swarm in Þórðarhyrna volcano (part of Grímsfjall volcano). This was not large earthquake swarm or a strong one. With the largest earthquake just having the magnitude of 1,9. While I did just suspect it I did not have it confirmed until today that following this earthquake swarm was an harmonic tremor pulse. This harmonic tremor lasted from 03:30 to 06:10 UTC. Based on nearby SIL station this was not a strong harmonic tremor, but this is important because it suggests that something is taking place in Þórðarhyrna volcano. If this is going to lead to an eruption is unknown at current time. This might be a dike intrusion into the volcano at depth, but that has not been confirmed.

The harmonic tremor pulse can be seen at 21-November date on this tremor plot from Icelandic Meteorological Office. Copyright of this image belongs to Icelandic Meteorological Office.

The harmonic tremor pulse as it did appear from Grímsfjall SIL station. Copyright of this image belongs to Icelandic Meteorological Office.

Harmonic tremor pulse as it did appear on Jökulsel SIL station. Copyright of this image belongs to Icelandic Meteorological Office.

This activity might not lead to an eruption, but given the past history of this area and the eruption in Grímsfjall volcano in the spring of 2011 I find it to be highly likely outcome that eruption is going to take place in Þórðarhyrna volcano in near future, it is not possible to know when such eruption might take place. Last eruption took place in Þórðarhyrna volcano in the year 1902, it is not known if any later eruptions have taken place in Þórðarhyrna volcano.

Blog post updated at 14:47 UTC.

Cookie acceptance