Month: June 2012

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Minor earthquake swarms in Iceland

It has been quiet in Iceland during the past few weeks. Besides activity in Katla volcano and Kolbeinsey ridge. Nothing of interest has been going on in Iceland. Here is however the overview of activity in Iceland during the past few hours.

Kolbeinsey Ridge

Some minor earthquake activity has been taking place in Kolbeinsey Ridge during the past few hours. This earthquake swarm is small in nature, with largest earthquakes reaching the magnitude 2.4. Otherwise it remains quiet in this area.


Earthquake activity in Kolbeinsey Ridge. Just north of Grímsey Island. Copyright of this image belongs to Iceland Meteorological Office.

Kolbeinsey ridge has seen some activity during past few weeks. But it might just be normal tectonic earthquakes taking place. So far nothing suggest any volcanism nature of this earthquake activity.

Krýsuvík volcano

During the past few hours. Krýsuvík volcano did see some earthquake activity. This activity is most likely to be tectonic in nature. As Reykjanes peninsula has frequent earthquake swarm that are tectonic in nature.


Earthquake swarm on Reykjanes. It is located within Krýsuvík volcano. This was small earthquake swarm. Copyright of this image belongs to Iceland Meteorological Office.

It remains rather quiet on Reykjanes besides this minor earthquake swarm today.

Katla volcano

After rather interesting activity during the past few weeks. It seems that Katla volcano is slowing down in earthquake activity. For now at least. But it is impossible to know for sure if current quiet sense is going to continue in Katla volcano.


Earthquake activity in Katla volcano during past few days. The activity is mostly concentrated into Katla volcano caldera. Copyright of this image belongs to Iceland Meteorological Office.

Besides this top of the activity. All is quiet in Iceland. Both in volcanoes and earthquakes. That might however change at any time without warning. It happens often in Iceland. I also want to remind people of my geophone web page. Where earthquakes can sometimes be seen soon after they have taken place.

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Update on El Hierro volcano activity

This is a short update on the activity in El Hierro volcano.

In the last 24 hours there have been no major changes in the activity of El Hierro volcano. No eruption has started yet. But earthquake activity continues with the same rate as in past few days. Magnitude of the earthquakes that are currently taking place is around ML1.5 to ML3.5, with the focal depth of around 20 km. But deepest earthquakes have the depth of around 28 km. While the shallowest earthquakes have the depth around 15 to 12 km. No harmonic tremor is currently taking place in El Hierro volcano. According to GPS data from El Hierro volcano. There is inflation taking place at the current moment. That means magma is injecting it self into the volcano at the depth of 20 km. There is already older magma from last year magma injection. Some of that magma erupted last year, but not nearly all of it. I do not know what happens if the new magma gets into contact with older magma that is in El Hierro volcano. There is also possibility that older magma from eruptions that took place thousands years ago is still in El Hierro volcano. That magma might be andesitic to rhyolitic in nature. If that is the case is impossible to know for sure. But this is always an risk with any volcano, regardless where they are located in the world.


Earthquake activity in El Hierro volcano during last four days. Copyright of this image belongs to IGN.


Earthquake activity during one week in El Hierro volcano. This map clearly shows the extent of the magma during this past week. Copyright of this image belongs to IGN.


Earthquake activity since 1. January 2012 in El Hierro volcano. Copyright of this image belongs to IGN.


Total amount of earthquakes in El Hierro volcano since activity started last year. Copyright of this image belongs to IGN.


Current earthquake activity in El Hierro volcano. No harmonic tremor is currently being detected in El Hierro volcano. Copyright of this image belongs to IGN.

It is difficult to day what happens next in El Hierro volcano. But I do believe that current earthquake activity is going to continue for the next few days to weeks. That activity depends on how much magma flows into El Hierro volcano. That flow might not be constant all the time. So there is going to be period of time with low activity during current events. When this is written, total of around 130 earthquakes have taken place in El Hierro volcano today (29. June 2012) so far.

Known eruptions in El Hierro volcano

Year 4790 BC (Radiocarbon)
Year 950 BC (+- 150 years)
Year 550 BC (+- 75 years)
Year 1677 (Uncertain eruption. Not confirmed.)
Year 1692 (Uncertain eruption. Not confirmed.)
Year 1793 May to 1793 June. Erupted on NW rift, GVP says that the eruption may have taken place at Volcán de Lomo Negro (?). But that is not confirmed or established at current time.
Year 2011 September to December, off the coast. Not on GVP web page.

Source: GVP web page, Hierro

Blog post updated at 20:16 UTC on 29.06.2012.

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Analyze on events in El Hierro volcano

This is a short analyze of what is happening in El Hierro volcano. What is taking place in El Hierro volcano has an simple explanation. What is taking place in El Hierro volcano is an dike intrusion. This creates earthquakes as new magma is injected into the crust. This is also creating inflation on the surface. It has been reported so far the inflation is 20mm up, 20mm east, 20mm north. This can clearly be seen on GPS data that was released today.


The inflation according to IGN. This is recent GPS data. Copyright of this image belongs to ING/AVCAN

The dike intrusion into El Hierro volcano is creating sill in it. While new magma is being injected into the volcano. It is going to mean earthquake activity and a lot of it. Currently there are three older sill that have formed in El Hierro volcano. This sill clearly appear on images that show the earthquake pattern over the past one year in El Hierro volcano.


Earthquake activity marks the sill and older magma injection areas in El Hierro volcano. Copyright of this image belongs to ING/AVCAN


Earthquake activity in El Hierro volcano as it is today. This is accumulated earthquake activity sine current earthquake swarm started. Copyright of this image belongs to ING/AVCAN

What happens if the new injection gets into contact with the old inection is anyone guess. But new magma, if it gets in contact with an older magma might mobilize it. It might not mean an eruption. But earthquake activity might get really intense for a while. A lot more intense then it already is today. With earthquake well above magnitude ML3.0 and up to ML5.0 (depending on the stress of the crust in the area).


Earthquake activity in El Hierro volcano today. So far no harmonic tremors have been detected. But that might change without warning if the magma finds a path to the surface. Copyright of this image belongs to ING/AVCAN

When I write this I see that El Hierro volcano has had it first ML4.0 earthquake as I did fear yesterday might happen. But I made a comment on that on AVCAN Facebook page yesterday (Somewhere, I have no idea where it is located).

References:

Dike (geology) (Wiki)
Sill (geology)
Intrusion triggering of the 2010 Eyjafjallajökull explosive eruption (http://geoscience.wisc.edu/)

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New activity in El Hierro volcano, Canary Islands

While this blog now covers mostly Icelandic volcanoes. I am going to cover other volcanoes from time to time.

New earthquake activity started around 21:26 UTC in El Hierro volcano with an earthquake that had magnitude ML3.1 with the depth of 20 km. Largest earthquake so far had the magnitude of ML3.8 and the depth of 19 km. Depth of this earthquake swarms is mostly around 20 km. At current time nothing suggests that new eruption is about to start in El Hierro volcano. But that might change without any warning if the magma finds an clear path to the surface. But that would be detected by seismometers on El Hierro Island. So the risk of such events taking people by surprise is minimal. My automatic earthquake counter for El Hierro volcano shows that at least 143 earthquakes have taken place today so far. For the moment the earthquake swarm seems to have stopped. But I expect it to resume at any time and without any warning at all.


Earthquake activity today at El Hierro volcano. This picture is from 18:08 UTC. Copyright of this picture belongs to IGN.


Location of the earthquakes, with depth in El Hierro volcano. This image is from 25. June at 18:09 UTC. Copyright of this picture belongs to IGN.

I do not know what is going to happen next in El Hierro volcano. But current status of the volcano is clearly something that needs to be and is monitored today. It is impossible to know for sure what is going to happen next in El Hierro volcano. But I am not going to rule out an eruption at this point.

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Earthquake swarm in Katla volcano today (24.06.2012)

Earthquake swarm started in Katla volcano at 13:33 UTC. This earthquake swarm lasted until 14:26 UTC (24 June, 2012). Most of the earthquakes in this swarm where small. Less them magnitude ML1.0 in size. The largest earthquakes did have magnitude of ML1.3 and ML2.0. No harmonic tremor did take place during this earthquake swarm. However, harmonic tremor data from IMO suggests a lot of hydro-thermal activity under Mýrdalsjökull glacier. This might result in small glacier floods coming from Mýrdalsjökull glacier in hours to days time. There is also a good chance that new earthquake swarm starts in Katla volcano at any time. Since there has been pattern of repeated earthquakes swarms in Katla volcano for several weeks now.


Earthquake activity in Katla volcano today. The newest earthquake also appears on this image. Copyright of this image belongs to Iceland Meteorological Office.


The harmonic tremor level at Álftagrof SIL station. This is normal background movement. There are however clues that hydro-thermal activity might have increased under Mýrdalsjökull glacier following this earthquake swarms. Copyright of this image belongs to Iceland Meteorological Office.


Harmonic tremor at Slysaalda SIL station. This is normal background noise. Spikes are earthquakes in Katla volcano. In this image there are also minor clues about increased hydro-thermal activity in Katla volcano. Copyright of this image belongs to Iceland Meteorological Office.


The earthquake at 13:45 UTC on Skeiðflöt geophone. This trace is filtered at 1Hz. This image is released under Creative Common Licence. See CC Licence page for more details.


The earthquake at 13:45 UTC on Heklubyggð geophone. This is filtered at 1Hz. This image is released under Creative Common Licence. See CC Licence page for more details.

It is hard to know for sure what happens next in Katla volcano. But I am sure this activity is currently taking place is going to continue. This does however not say anything about possibility of an eruption in Katla volcano. That possibility remains unclear, as earthquake activity does not mean that an eruption is imminent. For the moment, there are just earthquake swarms taking place in Katla volcano. But that can change without warning. Until then less speculation on what is taking place in Katla volcano is best (in the news media anyway).

Blog post updated at 08:34 UTC on 25.06.2012.

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Earthquake swarm in Katla volcano, Kolbeinsey ridge, Hveravellir geothermal area

It has been a bit busy day earthquake wise in Iceland. But there has been more activity today then in past few weeks in Iceland. But it has been really quiet for a long time now in Iceland. But let’s start with the largest earthquake of the day.

Kolbeinsey Ridge

Today at 11:11 UTC there was an earthquake with the magnitude of ML3.65. This earthquake was not felt since it was more then 100 km away from nearest human population in Iceland. The earthquake took place on Kolbeinsey Ridge. It last erupted in the year 1755. No known eruption is known in this area since then. My geophone network did record this earthquake properly. The signal was strongest at my Hvammstangi geophone station. But it was also recorded on my Heklubyggð geophone station. On other geophone stations. The signal was too weak to be properly detected by my geophone.


The ML3.65 magnitude earthquake as it was recorded on my Hvammstangi geophone. This image is released under Creative Commons licence. Please see the CC Licence page for more details.


The ML3.65 magnitude earthquake as it was recorded on my Heklubyggð geophone. It is filtered at 1Hz. This image is released under Creative Commons licence. Please see the CC Licence page for more details.


The location of the earthquake. Copyright of this picture belongs to Iceland Meteorological Office.

Hveravellir geothermal area

There is an earthquake swarm ongoing (or it might be over. I have no good way to know that currently) at Hveravellir geothermal area. I only know there is an earthquake swarm there because of the tremor recording on Hveravellir geothermal area. But only two earthquakes have been large enough to appear on earthquake map on IMO web page.


The two earthquakes that did appear on IMO earthquake map. Copyright of this picture belongs to Iceland Meteorological Office.


However, Hveravellir SIL station did show that more was going on then did appear on the earthquake map. Most of this earthquakes are too small to appear automatic on the earthquake list. Some might even be too weak to be properly located by the SIL network. Copyright of this picture belongs to Iceland Meteorological Office.


Some of this activity did also appear on Skrokkalda SIL station I think. Copyright of this picture belongs to Iceland Meteorological Office.

Katla volcano

Katla volcano did have an new earthquake swarm during the night. This earthquake swarm had around 30 or so earthquakes. Most of them where located almost in the central caldrea. This type of swarm activity has now been ongoing since end of April, when it started rather sharply with an earthquake swarm. Since then it has had many earthquake swarm. But the current rate of earthquake swarm is around 1 to 3 earthquake swarm pr. Week. Normally they are in an new area inside the Katla volcano caldera.

My geophone station at Skeiðflöt records most of the earthquakes if the background noise is not too high during that time.


The earthquake activity in Katla volcano last night. Copyright of this picture belongs to Iceland Meteorological Office.

So far. This is just normal earthquake activity. It does not signal any chance of eruption activity so far. But this earthquake pattern is interesting. What it means is a different matter. So far, nobody knows for sure at this point in time. This activity seems to change hydrothermal activity inside Katla volcano caldera. This has also created minor glacier floods from Katla volcano caldera. But the flood have been seen on instruments that record water conditions in Múlakvíls glacier river. Glacier floods are marked by higher conductivity of the water, darker color and stronger sulfur smell (rotten egg smell). What happens next in Katla volcano is anyone guess. As Katla volcano has proven to be unpredictable volcano.

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Donations and advertisements

As many have seen during past few weeks. I have been cutting down advertisements on this blog. The reason is simple. The ads that I am cutting down do not work. I get little pay from them. For that reason I have removed them. The only one left to remove is infolinks. But I am going to remove them soon as I get there payment threshold. But that is $50. At current time I only lack around $5 until I reach that threshold. It should be in the next few days to weeks I hope.

Donations

I do not know at current time if I keep the donations open up longer. As I do not get so much donations at current time. I wold like to hear from people on that before I remove that options completely. But at any rate. I am planning on changing the money aspect of this blog. Since current trial and error approach is not something that I want to continue in the long term.

For those how have been donating directly via bank it is important that you update your information. As I have moved to a new bank in Denmark, called Sydbank from Nordea. The new IBAN and SWIFT code can be found here, on the donation web page.

If I stop accepting donations. I am going to remove all the links. For those how I have promised a ebook for a donation. Don’t worry. I still remember my promise in that regard.

Future direction

As I say here above. I am planning a change on this blog. Not on what I cover. I have already tested that, and failed. I am rather changing how this blog can help me make a slightly better living then I am currently having. But I not expect this blog to become super-popular any time soon. So I do not know how that is going to work out in the long term. But one thing is clear. I am going to keep covering volcanoes and earthquakes in Iceland for many years to come.

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Possible glacier flood from Grímsfjall/Grímsvötn glacier lake (Unconfirmed)

There seems to be a glacier flood did start this morning in Grímsfjall glacier lake. Based on the tremor, the glacier flood is already subsiding or something of that nature. So far this glacier flood has not yet been confirmed by monitoring scientists. So I am unsure what exactly what is going on. But current activity seems to have started around 13. June 2012, when the tremor changed from normal background noise to higher frequency noise. This can be seen on the SIL station from Grímsfjall volcano.


Grímsfjall SIL station tremor reading. The spike marks what seems to be a glacier quake taking place. Copyright of this image belongs to Iceland Meteorological Office.

This harmonic tremor started early this morning. But it can be up to 12 to 24 hours before the glacier flood is visible in the rivers that flow from Grímsfjall volcano.


The second SIL station that tremor appears on from Grímsfjall volcano. Copyright of this image belongs to Iceland Meteorological Office.

Until there is official conformation what is exactly going on in Grímsfjall volcano. It is bit hard to know exactly what is going on there at the moment. But I hope that it is going to be cleared up in the next few hours or tomorrow. There are no signs that an eruption has started in Grímsfjall volcano at current time. It is impossible to know if that is going to change following this events that are taking place in Grímsfjall volcano.

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How to spot an earthquake on my geophone helicorders web site

I run today 5 geophones. Four of them are located in Iceland. I have one geophone in Denmark where I am living. My helicorder web site can be found here. This blog post is meant to help people on reading what takes place on this geophones. What is earthquake and what is noise. As on my geophones there is a lot of noise taking place. I have put in markers on this images for easy reading. It is my first attempt on doing that. I hope it looks decent.

This is Hvammstangi geophone station earlier today. The green line, marked as note 1 means that I lost the connection with Hvammstangi geophone station during the night. Note 2 shows a typical noise on that geophone.

The red circle on shows a small earthquake that took place during the night close to Hekla volcano. The rest appears to be just a noise from nature, wind etc. Heklubyggð is often a quiet station.

Red circle around the earthquake that took place in Katla volcano during the night. The rest is just noise, cars, human walking around, wind etc.

This is the geophone station at Eyrarbakki. It doesn’t have any earthquake that I can see. But it has plenty of noise from all types of sources. Mostly washing machines of all types, human waking around, cars, wind etc.

I hope this rather short guide helps people finding earthquakes among the noise on my geophones. It is easier to find larger earthquake then smaller on my helicorders that I have online.

Update 1: Here is a picture of a larger earthquake taking place in SISZ in the year 2011.

The earthquake is the line that crosses above the helicorder image. This earthquake however only the magnitude of ML2.0 or around that. But it was close to my geophone at Heklubyggð.

Blog post updated at 01:14 CEST on 15.06.2012.