Monitoring – Page 114 – Iceland geology

August 17, 2014

Update on activity in Bárðarbunga at 18:13 UTC

This is a update on the activity in Bárðarbunga volcano. This information might get outdated quickly as things change.

Earthquake activity continues in Bárðarbunga volcano with no signs of stopping. Since midnight the total earthquake count for Iceland has now reached 578 (at 18:14 UTC) this number gets outdated quickly due the continuous earthquake activity in Bárðarbunga volcano. The total amount of earthquakes recorded yesterday was around 480 for the whole day, so it seems that earthquake activity has increased today from what it was yesterday. It is possible to see the largest earthquakes on my geophone website here. I want to note that my geophones are both more then 100 km away from Bárðarbunga volcano, so only the largest earthquakes appear on my geophones.

The earthquake activity in Bárðarbunga volcano. It has now moved into two groups of activity. Copyright of this image belongs to Icelandic Met Office.

The earthquakes are forming an line south-south-east in Bárðarbungu volcano. I don’t know why that is, but this might be a feature of the SIL network, rather then actual alignment of the earthquakes. There also chance that the earthquakes really are aligning them self into a line like this.

Earthquake activity continues to be dense. A minor drop in activity was seen around 12:00 UTC, but it increased again around 13:00 UTC. Copyright of this image belongs to Icelandic Met Office.

There has been little drop in activity, besides the drop in activity seen around 12:00 UTC, that drop in activity however only lasted for about one hour, maybe less. There has overall not been much change in activity during the past 24 hours. I don’t know if that is going to change, but for the moment there are no signs of the activity slowing down.

Harmonic tremor at Dyngjuhálsi SIL station. It moves up and down with the earthquake activity. Copyright of this image belongs to Icelandic Met Office.

Harmonic tremor at Vonaskarð SIL station. It shows the changes in activity as other SIL stations around Bárðarbunga volcano. Copyright of this image belongs to Icelandic Met Office.

There are interesting theories on why the harmonic tremor is as it is. Currently there is nothing to suggest that an large eruption has taken place, there is a chance that a small eruption started all this, but I expect by now that it is over if it took place. It has not been confirmed. There is also a chance that earthquake activity is so high in Bárðarbunga volcano that it is registering as continuous harmonic tremor. It does not happen often, but it can happen. There is also chance that the harmonic tremor is due to boiling of hydrothermal systems in Bárðarbunga volcano, or something other related to magma under heavy pressure. Whatever the reason for this tremor, it’s there and an eruption does not seems to be the reason behind it.

Visual observations have now been made of Bárðarbunga volcano and nothing has been seen on the surface of the glacier. Scientists are also installing new monitoring hardware and a web-camera on Bárðarbunga volcano in order to get proper visual observations of the volcano when something happens. I don’t expect the web-camera to be a public at the moment.

August 17, 2014August 17, 2014

Short update on Bárðarbunga volcano at 02:12 UTC

This is a short update on Bárðarbunga volcano activity.

Earthquake activity continues in Bárðarbunga volcano and shows no signs of slowing down. Two swarms have appeared in Bárðarbunga volcano system. One is at location called Kistufell, while the second one is at the south-east part of the Bárðarbunga volcano. Increase in earthquake activity in south-east part of Bárðarbunga volcano seems to increase harmonic tremor. I am not sure why that is. As of now (when this is written) no eruption has been confirmed in Bárðarbunga volcano, the volcano is under glacier so confirmation is difficult at best.

Earthquake activity in Bárðarbunga volcano. The two groups of earthquake swarms are visible on this map. Copyright of this image belongs to Icelandic Met Office.

Earthquake activity has been dense as can be seen here. Copyright of this image belongs to Icelandic Met Office.

Harmonic tremor remains high on the Dyngjuháls SIL station. Why that is not clear at the moment. Copyright of this image belongs to Icelandic Met Office.

Harmonic tremor remains high at Vonarskarð SIL station. It has dropped little during the day, but it remains constant at current time. Copyright of this image belongs to Icelandic Met Office.

So far no major eruption has started in Bárðarbunga volcano. That might change without warning as this activity continues. There is a risk of large earthquakes taking place before such eruption. Since the crust in this part of Iceland is thick (up to 40 km thick) and last eruption in Bárðarbunga volcano took place in the year 1794. The eruption in the year 1910 took place in a volcano named Hamarinn and is south-west of Bárðarbunga volcano. Fissure eruptions are also a feature that Bárðarbunga volcano has, if this activity is going to result in such eruption is something that is impossible to know at current time.

Current status changes fast. I post new information on this activity as needed and as things get more clearer on what is happening.

August 16, 2014August 17, 2014

Short update Bárðarbunga volcano at 17:52 UTC

This is a short update on current status on Bárðarbunga volcano.

Uncertainty level has been declared on Bárðarbunga volcano and it status has been raised to yellow. There are fluxuation in earthquake activity, this is normal since earthquake activity in volcanoes is never close to constant in this type of situations. There is also a storm taking place in the area at the moment, that is lowering what is detected by the SIL stations that are close to Bárðarbunga volcano.

The earthquake activity in Bárðarbunga volcano. Green stars show earthquake larger than magnitude 3,0. Copyright of this image belongs to Icelandic Meteorological Office.

Largest earthquakes recorded so far have the magnitude of 3,1 and 3,5. There is a chance that more magnitude 3,0 have taken place but have not been reviewed yet by geologist at Icelandic Meteorological Office due the amount of earthquakes taking place at the moment.

As can be seen here the earthquake swarm is dense. Copyright of this image belongs to Icelandic Meteorological Office.

Harmonic tremor in Dyngjuháls SIL station. It has been dropping in the past few hours. Copyright of this image belongs to Icelandic Meteorological Office.

Harmonic tremor in Vonarskarð SIL station. The drop in harmonic tremor also appears clearly here. Copyright of this image belongs to Icelandic Meteorological Office.

Harmonic tremor in Húsbóndi SIL station. The drop in harmonic tremor also appears here clearly. Copyright of this image belongs to Icelandic Meteorological Office.

In the past few hours the harmonic tremors around Bárðarbunga volcano have been dropping slowly. The drop in harmonic tremor has not been followed by drop in earthquake activity. At least that is not the case when this is written. This means that the magma that is on the move there still has not yet found a pathway to the surface, even if some small part of it has done so in possibly in one or two eruptions vents under the thick glacier. If the harmonic tremor stops completely without the earthquake activity stopping it means that magma is still on the move there and it might look for a new pathway to the surface. When and where that might happen is impossible to know at current time, but once the magma has clear path to the surface, even if it is under a glacier all earthquake activity is going to stop (for most part).

I am going to post more information when more details are available.

August 16, 2014August 17, 2014

Unconfirmed eruption in Bárðarbunga volcano

This information is going to get outdated quickly as more information is collected on this activity.

During all last week (Week 33) there has been a minor earthquake swarm in Bárðarbunga volcano. No other activity followed this minor earthquake activity during the week until last night (16-August-2014). During the night (around 02:20 UTC) a harmonic tremor started to appear on SIL stations around Bárðarbunga volcano. Following the appearance of the harmonic tremor earthquake activity started around 03:30 UTC. Largest earthquakes in this swarm have magnitude around 3,0 so far. Depth is around 5 to 10 km. During the night the earthquake swarm moved around in the volcano and is now more east then it first started. According to Rúv news the glacier around this part of Vatnajökull glacier is around 700 meters thick, so it going to take a major eruption to break the ice. This however also means that when a glacier flood starts in this area there is a high risk that is going to be large.

The largest earthquake that I did record during the night. This image is released under CC Licence. Please see CC Licence page for more details.

The earthquake swarm in Bárðarbunga volcano at 11:45 UTC. Copyright of this image belongs to Icelandic Meteorological Office.

Harmonic tremor on Dyngjuháls SIL station. This SIL stations is closest to the area of activity in Bárðarbunga volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Harmonic tremor on Vonaskarð SIL station. This is one of the SIL station that is closest to the area of activity in Bárðarbunga volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Currently the activity in Bárðabunga volcano is not stable, it does fluctuate a little. Besides this minor fluctuation it seems stable. Based on harmonic tremor signal and its range this does not appear to be a large eruption so far. That might change without warning. I do however expect larger earthquakes before any major volcano eruption in Bárðarbunga volcano. What seems to have happened is that a dike intrusion got to the surface and started this eruption, even if it is just small one at current time.

I am going to post update soon as more information gets available. This situation is going to change quickly and without much warning.

August 15, 2014

Earthquake swarm in Hveravellir

Two days ago (13-August-2014) an minor earthquake swarm took place in Hvervellir (volcano). Largest earthquake in this swarm had the magnitude of 2,5. All the earthquakes that happened had depth less then of 10 km.

Earthquake swarm in Hveravellir (blue dots). Copyright of this image belongs to Icelandic Meteorological Office.

Earthquake activity is fairly common in this area. It however works in a short activity periods with long quiet period between them. So far nothing suggest that major earthquake activity is going to take place there, as has happened in the past. If that happens, the largest earthquakes can go up to magnitude 5,0.

August 12, 2014

Minor earthquake swarm in Krísuvík volcano

Yesterday (11-August-2014) a minor earthquake swarm took place in Krísuvík volcano. The largest earthquake in this minor earthquake swarm had the magnitude of 3,4 with the depth of 4,4 km. Only few minor earthquakes took place after the largest earthquake.

The earthquake swarm in Krísuvík volcano, the green star shows the location of the magnitude 3,4 earthquake. Copyright of this image belongs to Icelandic Meteorological Office.

There is a risk of more earthquake activity in this area. Since earthquake swarms are known to start with minor activity that slowly grows until it tops and then slowly drops over a period of days or weeks. It might not happen now, but this is a common pattern on the Reykjanes.

August 7, 2014

Strange sounds heard from Herðubreið

Yesterday (6-August-2014) strange sounds were heard from Herðubreið (Wikpedia link). It is unclear what is creating this sounds, it was first thought that a avalanche had taken place, that however doesn’t seems to be the case. Some have suggested a land-slide or rock-slide might have taken place. That has not been confirmed at the time of writing of this article. What might have happened, if anything did happen in Herðubreið is currently unknown and might remains so for a while longer.

Icelandic news about this

Snjóflóð féll í Herðubreið í gær (Vísir.is)
Óútskýrðar drunur frá Herðubreið (Vísir.is)

July 31, 2014

Minor earthquake swarm in Torfajökull volcano

Today (31-July-2014) a minor earthquake swarm took place in Torfajökull volcano. This was a minor earthquake swarm and no earthquake did go above magnitude 3,0. Strongest magnitude of this earthquake swarm had the magnitude of 2,3. Depth of this earthquake swarm was from 15,1 km to around 1,0 km.

The earthquake swarm in Torfajökull volcano. Copyright of this image belongs to Icelandic Meteorological Office.

This earthquake swarm appears to be over, at least at the moment. It might start again at later time. Earthquake activity is common in Torfajökull volcano and there are no signs of any other activity from Torfajökull volcano at the moment.

July 26, 2014July 26, 2014

More details on the landslide in Askja volcano

Over the past few days scientists from Icelandic Meteorological Office and University of Iceland, geology department have been studying the massive landslide in Askja volcano. The area is considered unstable as is and might remain unstable for the next year and even longer. Risk of new landslide in Askja is not higher now than normal, but even so the walking paths around Askja lake are going to remain closed due to changes that took place when the flood wave hit the volcanic crater coastline following the landslide.

It remains unclear why this landslide took place. It does not seem that wet soil is the reason for this, as was originally thought. Some speculation have been that this might be due to increased hydrothermal (hot springs) activity in Askja volcano. Nothing has yet been proven on what did cause this large landslide. There have also been news items that a earlier landslide around the same size might have taken place in Askja volcano in the years 1902 to 1960 (exact date is not known). Current size estimates are that the landslide is around 50 million cubic meters in size and around 700 meters wide at the top. More research is going to give more details on this landslide in the future. The seismic signal and following harmonic tremor that was detected following this landslide has a detailed analyse here on Icelandic Meteorological Office website.

If more landslides do happen in Askja volcano I am going to publish that information soon as possible. If more information is going to be published I am going to post them soon as possible.

Donations: Please remember to donate to support my work. Due to my move to Iceland in December I have updated the information here. Please take a note of the changes that are going to take place in January 2015. Thanks for the support.

Article updated at 00:10 UTC on 26-July-2014.

July 23, 2014July 24, 2014

Updated information on Askja volcano landslide

This is a short update on Askja volcano landslide.

Travel ban is still in effect to Askja volcano. Parts of it are going to be lifted later today or tomorrow, but access to Askja lake is going to remain forbidden at least until Friday, after estimates on risk of new landslides have been performed by Icelandic Meteorological Office and Civil Protection in Iceland (Almannavarnir). Risk of new landslides taking place in this area remains and might remain for many months to come. It is now estimated that 50 to 60 million cubic meters of material did collapse down into Askja lake, but with only part of the material ending up into the lake it self. New estimates on the flood waves that where created now put them around 50 meters high, there was also not one wave that took place, but it is now estimated that four waves took place once the landslide hit the water.

Hiking paths to Askja volcano and Víti have been closed due landslide risk in the area around Askja lake. Please respect this closure since this area is now highly unstable and more landslides might fall without warning.

Update 1: The landslide (or rock slide as IMO calls this) is now estimated to be around 1 km wide. The tsunami waves that followed this landslide in Askja lake are now estimated to have been around 73 meters high (around Hallgrímskirkja church high). The area remains closed and is now regarded as highly unstable. Risk of new landslides in this area remains high at current time. The amount of soil that did just go into Askja lake is estimated to have been around 24 million cubic meters, with the total amount much higher (this is unconfirmed number).

I will post more information as more is known what happened.

Icelandic news of this

„Bráðabani“ að fara niður að vatninu (mbl.is)
Vígalegur mökkur steig til himins (mbl.is, pictures)
Lukka að þetta gerist um miðnætti (Rúv.is)
Svona lítur Askja út í dag – Myndband (Rúv.is, video of Askja today)
Askja – fyrir og eftir berghlaupið (Rúv.is, this are before and after images of Askja)
Berghlaupið í Öskju eitt það stærsta (Rúv.is, new video of Askja area)

Donations: Please remember to donate to support my work (and keep me away from starving). I will move back to Iceland in December (see here). Thanks for the support.

Article updated at 13:55 UTC.
Article updated at 16:01 UTC.
Article updated at 22:16 UTC.
Article updated at 22:18 UTC.

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