Category: Monitoring

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Ongoing earthquake activity in Katla volcano

For the past few days there has been a earthquake activity in Katla volcano. This is in two forms, as earthquake swarm that are taking place and earthquakes that spread around the caldera and the volcano.


The earthquake activity in Katla volcano over the past 48 hours. Copyright of this image belongs to Icelandic Met Office.

All clues suggest that an eruption is going to happen soon in Katla volcano, as it currently stands. The problem is that Katla volcano might cool down and not erupt at all, what makes this period different is the fact this earthquake activity has been ongoing since end of August-2016. At the moment the earthquake activity is just a minor activity, with most earthquakes have less magnitude of 3,0. There are no signs that suggest that this activity is slowing or stopping.

Technical problems (Iceland geology)

Yesterday I was having technical problems with Iceland geology. Turns out the source of this issue is that my server is getting too small. I started using the current dedicated server in 2015 and then it was enough (page view count for 1 day ~1100, today that is ~2100 for 1 day). Today, Iceland Geology has traffic that is too much for my current server. This means that I need to do an upgrade when I can afford it. That won’t be this month as it currently stands, moving to a new server costs $219/month, at the moment I’m paying $140/month for dedicated hosting. The new server is going to be 3,60Ghz with 16GB ram. Current server has 4GB ram and just 1,66Ghz CPU. Making this upgrade a urgent one due to the increase in traffic that Iceland geology is currently seeing.

At the moment I’m hoping that I’ll be able to move to a new server in May or June at the latest. I just hope that Katla doesn’t erupt before that, since it would result in a server issues due to lack of capability to handle all the traffic.

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Earthquake swarm not far from Skjaldbreið (Presthnjúkur area)

Yesterday (22.02.2017) there was an earthquake swarm in the Presthnjúkur area, in a area not far from Skjaldbreið volcano.


Earthquake activity yesterday close to Skjaldbreið. Copyright of this image belongs to Icelandic Met Office.

This was a minor earthquake swarm, with the largest earthquake only having a magnitude of 2,2. Depth was from 18,3 km and up to 1,1 km. This earthquake swarm appears to be over.

Article updated at 12:08 UTC on 24.02.2017. Title error fixed.

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Continued and strong earthquake activity north of Kolbeinsey Island

For the past few weeks something has been going on in the deep ocean far north of Kolbeinsey Island. The area north of Kolbeinsey Island has been having strong earthquake swarms for several weeks now, what is creating them is less clear.


The earthquake activity north of Kolbeinsey Island (blue dots). Copyright of this image belongs to Icelandic Met Office.

All magnitudes are under-estimated at this location. I managed to record the last earthquake swarm (largest earthquakes) and it was clear by this activity that something was going on. Five earthquakes that where at least magnitude 3,2 (estimate) took place in the space of 4 – 8 minutes. This where only the earthquakes that I was able to record, distance from my geophone to this area is ~230 km at shortest distance. Making it difficult for me to record earthquakes on my simple geophone. Icelandic Met Office SIL network is not having much better luck recording earthquakes at this location, due to distance the SIL network underestimates the magnitude and location of the earthquakes has higher than normal error margins (up to several dozen of km at most).

There is a possibility that an eruption is taking place at this location now. There was a possible eruption or dyke injection at this location in October of the year 1999, the Global Volcanism Program report on that activity can be found here.

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Earthquake activity increasing in Katla volcano again

For the last 24 hours (15 and 16.02.2017) earthquake activity has been increasing in Katla volcano. If it follows earlier pattern, a swarm of earthquakes with magnitude 3,0 or stronger might happen in Katla volcano in next few days or next week at the latests. Please note that there is no good way to say when this might happen and time estimates are just guesses (based on current best data).


Earthquake activity in Katla volcano. Copyright of this image belongs to Icelandic Met Office.

Current earthquake activity was not strong, the largest earthquake that happened had a magnitude of 2,0. All other earthquakes had smaller magnitude (at the moment). Earlier pattern have been that small earthquake swarm starts, a break happens for several hours for up to several days and then a swarm of activity happens with one or more earthquake with magnitude above 3,0. I’m expecting this pattern to repeat it self now, but what actually happens remains to be seen.

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Earthquake swarm on the Reykjanes Ridge

Yesterday (12.02.2017) and today (13.02.2017) there has been a earthquake swarm on the Reykjanes ridge. For this area of the Reykjanes ridge, this earthquake swarm is normal. It doesn’t appear that it was due to magma movement and only tectonic in nature. The area in question is a fault valley according to ship survives (I think).


The earthquake swarm on the Reykjanes ridge. Copyright of this image belongs to Icelandic Met Office.

Largest earthquakes in this swarm had the magnitude of 3,1 and 3,2. Depth in this earthquakes swarm was from 17 km and up to 2,4 km (there is some error margin). It appears that this earthquake swarm is over for now. It might restart again with double or triple amount of earthquakes happening, there is also a equal good chance of that not happening. All that can be done is to wait and see.

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Deep earthquake activity in Öræfajökull volcano

I haven’t written many articles about Öræfajökull volcano, since most of the time nothing happens in it. Öræfajökull volcano is located outside the main activity area in Iceland, like Esjufjöll and Snæfell (east Iceland). This three volcanoes form a volcano “arch” in south to east Iceland. Research suggests that old continental crust is possibly melting under Öræfajökull volcano and maybe Esjufjöll volcano (unclear). Research into that can be found here. This research shows a possible volcano directly east of Esjufjöll, I don’t have it on my maps so I don’t have a name for it (it might be unconfirmed volcano in that area, some maps show it, other don’t. I don’t know why).


Earthquake activity in Öræfajökull volcano. Öræfajökull volcano is in the right-south corner. Copyright of this image belongs to Icelandic Met Office.

The magnitude of the earthquakes in question is only 1,1 and up to 1,8. What makes them interesting and might be a signal about something is about to happen in Öræfajökull volcano is the depth of earthquakes in question. The earthquake (magnitude 1,1) with the most depth has the depth of 21,2 km. The rest of the earthquakes has the depth of 19,0 to 20,7 km. View on the tremor plot suggest that this earthquake activity is magma related, rather than being driven by tectonic forces.

This activity started in the year 2011 with few earthquakes, no earthquakes happened in 2012 according to my data. Since then few earthquakes have been happening each year. How long the process is from just minor earthquake activity until an eruption starts in Öræfajökull volcano is something I don’t know and far as I know historical documents about the known eruptions are limited at best. Last known eruptions took place in the years 1362 June 5th until 1362 October 15 +-45 days, the other known eruption was in the year 1727 on August 3 and it lasted until May 1st 1728 +-30 days.

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Strong earthquake swarm in Bárðarbunga volcano

Yesterday (30.01.2017) there was exactly one week (article here) since last earthquake activity in Bárðarbunga volcano. In this weekly activity there is an emerging pattern, that pattern is that earthquake magnitude is growing. Number of earthquakes happening in each swarm has not increased that I have noted (at the moment at least). Magnitude 4,3 earthquake moves the fault few mm upward in this case. Those millimetres have now started to add up. I don’t know what the inflation currently is due to lack of GPS data at the moment.


The earthquake activity in Bárðarbunga volcano. Copyright of this image belongs to Icelandic Met Office.

Latest earthquake swarm had magnitude (in the order they happened), magnitude 4,3, magnitude 4,1, magnitude 3,4. Depth of this earthquake swarm was also slightly different, being from 9,4 – 8,3 km. It is difficult to know for sure what is going on at this depth, magma might be creating path for it in the crust on its way to the surface or this simply might just be the fault inside the caldera moving upward at slow phase. Earthquake activity happens when fresh magma is injected into Bárðarbunga volcano. This is going to continue to happen for a long time, maybe until next eruption.

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Strong earthquake activity on Kolbeinsey Ridge

Yesterday (27.01.2017) and today (28.01.2017) has seen some strong earthquake activity on Kolbeinsey Ridge. Largest earthquake in this swarm had the magnitude of Mb4,6 according to EMSC (information here). This area, or area close to it possibly had a dike injection or an eruption in the year 1999. That was however never confirmed.


The earthquake swarm on Kolbeinsey Ridge. Green stars show earthquakes with magnitude above 3,0. Copyright of this image belongs to Icelandic Met Office.


The Mb4,6 earthquake as it appeared on my geophone in Böðvarshólar. This image is under Creative Commons Licence, please see CC licence website for more information.

There have been around 5 earthquakes with magnitude above 3,0, I don’t know exact numbers of earthquakes with magnitude around and above 3,0. Due the distance of this earthquake swarm from the SIL network it is difficult for Icelandic Met Office to estimate the numbers and magnitudes of the earthquakes that happen. The distance was around 85 km from Kolbeinsey Island and around 160 km from Kolbeinsey Island. It does appear that two earthquake swarm took place in this area for the last 24 hours, but not much else is known at the moment. This activity is currently ongoing at the moment (I think).

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Katla volcano has magnitude 4,3 earthquake

Today (26.01.2017) at 15:14 UTC a magnitude 4,3 earthquake took place in Katla volcano. This earthquake was felt in Vík í Mýrdal (village) and nearby area. A second earthquake with the magnitude of 3,0 took place few moments after the largest earthquake, a magnitude 2,9 earthquake (3rd largest) took place soon after the magnitude 3,0 earthquake. Other earthquakes have been smaller in magnitude (at the moment).


The earthquake in Katla volcano, green star is the magnitude 4,3 earthquake. Copyright of this image belongs to Icelandic Met Office.


The magnitude 4,3 earthquake in Katla volcano as it appeared on my geophone in Heklubyggð (distance ~53 km). This image is under Creative Commons licence, please see CC Licence website for more details.

No major change has happened in tremor plots around Katla volcano following this earthquake. Unclear signals on one SIL stations suggest that hydrothermal areas might have gotten exited just before the main earthquake, but that is unconfirmed and unclear if it can be confirmed at all.

This article is going to be updated as new activity happens (if there is a reason to do so).

Update 27.01.2017

Science council of the Civil protection agency in Iceland (Almannavarnir) has issued the following statement. This is a rude translation of that statement since none has been issued in English yet.

Increased risk of eruption in Katla

Earthquake activity in Katla has been unusually high since August 2016, with three earthquakes larger than magnitude 4,0 and many more earthquakes with magnitude 3,0. Earthquake activity is shallow and spread around the caldera. No harmonic tremor has been detected following this earthquake activity. Following this increase in activity small increase in geothermal heat has been observed. GPS station show that small inflation has been taking place since 2010 in the top kilometres of the crust. When activity increases in Katla, as has been the case now, the risk of eruption grows and that has to be considered by the emergency response teams.

(The rest is about Bárðarbunga, just the basic translation of it.)

Since September 2015 Bárðarbunga has been inflating slowly under the caldera. It might be many years until the next eruption, until magma pressure is at the same levels before the eruption started in 2014. It is impossible to exclude new eruptions in next few years. Limited measurements are on geothermal activity in Bárðarbunga, to the best knowledge little has changed in last few months. It is important to monitor geothermal activity due to risk of water collection in the caldera.

My note: Water collection increases the risk of sudden glacier flood from Bárðarbunga.

The news announcement in Icelandic

Fundur í Vísindaráði almannavarna
Auknar líkur á eldgosi í Kötlu (Rúv News)

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Article updated on 27.01.2017 at 18:53 UTC.

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Earthquake swarm under Grímsey island (Tjörnes Fracture Zone)

Yesterday (25.01.2016) there was an earthquake activity directly under Grímsey island (Wikipedia information). Earthquake swarms directly under Grímsey islands are uncommon, but they do happen from time to time. Current earthquake swarm is getting close to a mid-range scale (as I count them) in number of earthquakes, with around 36 earthquakes recorded so far. Some of this earthquake activity must have been felt in Grímsey island, even if it has not been reported anywhere (that I know of). This earthquakes are not large enough to create any damage, just a little rattle of glasses and dishes in cabins and such items.


The earthquake activity directly under Grímsey island. Copyright of this image belongs to Icelandic Met Office.

Largest earthquakes in this swarm had the magnitude of 2,8 and 2,7. Other earthquakes have been smaller in magnitude so far. I don’t think this earthquake swarm is over at the moment, even if the earthquake activity has dropped at the moment.

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Article updated at 02:23 UTC.