This is a short update on the eruption in Fagradalsfjall mountain in Krýsuvík-Trölladyngja volcano system.
There has not been any major change since last update. In this week four new craters started erupting and I write an article about that earlier in this week for more details.
It was reported today (16-April-2021) that lava has now started to flow outside of Geldingadalir and to the east. This lava is now flowing over a walking path that people used to get close to the eruption. Getting close to the eruption might not be possible any more. There is also a chance that lava is going to is going to flow to the south of the craters more than it already has done.
Swarm of small earthquakes took place north-east in Fagradalsfjall mountain early morning around 06:00 UTC. Largest of those earthquakes had a magnitude of Mw2,8.
There is no sign of the eruption ending.
There continues to be a high risk of new vents opening up and start erupting without warning.
There are no more reports this week outside of what I did write about what was happening earlier in the week. If anything major happens I am going to post an update soon as possible.
Yesterday (15-April-2021) it was reported (late) that harmonic tremor seems to have been increasing in the eruption since midnight. This normally happens if new craters have opened up. The weather is really bad at the eruption site currently so viewing the eruption with any web camera is difficult if not impossible. Rúv web cameras failed last night because of the weather that has been seeing wind peaks up to 41 meter/second with heavy rain. Current weather forecast is that the weather is not going to start improving until late today (Friday 16-April-2021). The increased tremor might be weather but weather is in general easy to filter out and doesn’t affect the lower bands (0.5 – 1Hz) that much as it does higher bands (2 – 4hz). What is happening won’t be clear until the weather starts getting better.
This is a short article about the eruption in Fagradalsfjall mountain that is part of Krýsuvík-Trölladyngja volcano system.
This week has been busy and please read the older articles about what happened earlier in this week.
Lava output is now 50% more according to University of Iceland measurements compared to start of the eruption (19-March-2021). Gas output is also more then in start of the eruption. It has resulted in problems depending on wind direction.
There is a high risk that an eruption might start south of Geldingadalir valley eruption. There is also a high risk that new eruption is going to start north of the 5-April-2021 eruption.
There is no change in inflation in the area. It has slowed down but remains the same.
There continues to be low level earthquake activity along the dyke from Keili to Fagradalsfjall mountain.
Any change that is going to happen without warning and might not happen without any earthquake or little earthquake activity.
Next update is going to be on 16-April-2021 unless something major happens. This eruption is always changing and this weekend and next week might get interesting. If anything happens I am going to write new article soon as possible.
Update at 22:43 UTC
Icelandic Met Office released this map and press release (in Icelandic only) about the risk new fissures can open up both north and south the the current craters that are erupting. This page is updated regularly so if you are looking at this later than 9 to 10 April 2021 you might have to look for this information.
The map shows the area that is now at risk of new fissures opening up without warning.
Update 10-April-2021 at 15:20 UTC
Around 03:14 UTC on 10-April-2021 fissure number 4 did open up between fissure number 2 (5-April-2021) and fissure number 3. The eruption from this crater doesn’t seem to be large but it did happen under a new lava that had flowed over that same area few days before from fissure 2. In fissure/crater 1 the amount of erupting lava did drop a little just before the new eruption.
I am noticing that it seems new fissures are opening up more frequently then before. This seems to have changed after opening up of fissure 3.
Timeline of fissure openings so far.
1st fissure 19-March-2021
2nd fissure opened 5-April-2021
3rd fissure opened 7-April-2021
4th fissure opened 10-April-2021
Time period between new fissures opening up currently seems to be 3 to 4 days. I suspect that this is going to change soon and it is possible that new fissure that opens up might get larger as the eruption goes on. There seems to be phase in this eruption that is happening in Fagradalsfjall mountain. I am not perfectly sure what that phase is now since I’ve never seen this before and I don’t have any data on this type of eruption behaviour from other volcanoes outside of Iceland. That I know of.
This is a short update on the eruption in Fagradalsfjall mountain as it is part of Krýsuvík-Trölladyngja volcano.
There has been a slight increase in micro-earthquake activity along the dyke after the new fissures opened up in Fagradalsfjall mountain. Most of them are interestingly forced on a area close to Keilir mountain.
It has been reported that lava flow from the new and old eruption site is now more than what was most at the old eruption site (Geldingadalir valley). It is now estimated to be total 10m3/second.
Craters are building up at the new eruption site. That might change the lava flow long term and there is a risk that it is going to flow towards Geldingadalir valley when that change in lava flow happens.
There is a high risk of new fissures opening up both north and south of Geldingadalir valley (1st eruption) and north of Fagradalsfjall mountain eruption (2nd eruption).
Lava is now flowing into Meradalir valley. That valley is far larger then Geldingadalir valley and won’t be filled up easily. There seems to be more water in this valley and that might result in lava explosions if the lava gets that far down into the valley.
Currently there are no other new information that I can find. Next update should be on Friday 9th April 2021 unless something major happens.
This is a short article about the eruption in Geldingadalur. The volcano that is erupting continues to be Krýsuvík-Trölladyngja volcano system. This might change at later date. This article is written on 22-March-2021 at 17:30 UTC.
The eruption is now mostly just in one crater. There is some activity in two other craters but it seems to be getting smaller as the eruption goes on.
This eruption is tiny and one of the smallest eruption observed in Iceland.
There is risk of new eruption opening up once this eruption ends or starts to get close to ending.
There is a fissure in the ground on the right side of the main crater (as seen on the web camera). A lot of volcanic gas comes from that fissure but no eruption has taken place so far.
There has not been any noticeable deflation according to GPS data from today (22-March-2021).
The main crater is now estimated to be 30 meters high but it is unstable and collapses often.
The lava is estimated going to fill Geldingadalur valley in 10 to 14 days if the eruption continues this long.
Earthquake activity has almost stopped on Reykjanes peninsula after the eruption started. Once the eruption stops earthquake activity might increase again.
The last eruption period on Reykjanes peninsula lasted from the ~700 to the year ~1400. It can be estimated that current eruption period that has now started on Reykjanes peninsula is going to last until the year ~2400 to the year ~2600. During this time shortest time between eruptions is 1 year but the longest time between eruptions might be up to 10 years. How this going to be exactly is a big question but this estimate of mine is based on the limited historical data that I have read somewhere (I no longer remember where that was).
According to the evening news on Rúv the lava and magma that is now flowing into the valley of Geldingadalur is around 1200C and is a primitive magma of Tholeiitic magma series (Wikipedia). The source of this eruption is a magma chamber with the depths of 17 km to 20 km and the origins of the magma it self is far deeper into the hotspot below Iceland. This magma has a lot of CO and CO2 gases that are highly dangerous. There is also a lot of SO2 gas in the eruption and that is dangerous gas.
News in Icelandic about this
Since the eruption is now in stable activity I am going to limit update to if anything major happens. Next update about the eruption should be on Friday 26-March-2021. Other activity in Iceland is going to be reported as normal if anything happens.
Please remember to support my work with donations. Google Adsense remains limited on my website and I don’t know when it might get back to normal. Thanks for the support. 🙂
Article updated at 18:32 UTC. New web camera added. Article updated at 20:50 UTC. Web camera information updated. Article updated at 23:57 UTC. Information added about the eruption.
This is a short overview of the eruption that is now ongoing in Geldingadalur in Fagradalsfjall mountain area. This is part of Krýsuvík-Trölladyngja volcano system according to latest information. This information might change as the time and more information is collected. This article is written on 20-March-2021 at 02:58 UTC.
The eruption started at 20:45 UTC according to Icelandic Met Office. The harmonic tremor from the eruption is almost invisible.
The fissure is at the writing of this article estimated about to be 1 km long with the direction south-west and north-east.
Currently the eruption is small and there is no risk of damage to any infrastructure. Next road (currently closed because of earthquake damage) that might get damaged is 2,5 km distance from the eruption site.
This eruption suggests that more eruption might start in different fissures once this eruption is over.
The valley that the lava is flowing into might get filled with lava if the eruption lasts long enough. The valley next to it is equally deep so there is no danger of this lava flow.
The eruption is in a area that is difficult to access even by a car.
The eruption might only last for two to three days as it currently looks but that might change without warning since it is impossible to know for sure what is going to happen next with this eruption.
There are no good web cameras of this eruption since it is remote and started late on Friday night and the weather on Reykjanes peninsula is not good for today (20-March) or tomorrow (21-March).
Updated at 04:49 UTC. Web cameras added to this article.
Fagradalsfjall volcano has no document eruption history over the last 10.000 years and the main volcano location is unknown if it exists.
Updates from the last few hours
Small rift valley has started to form between Keili mountain and Fagradalsfjall mountain. This is part of the rift zone that is Reykjanes peninsula.
Harmonic tremor stopped this morning and as Icelandic Met Office has been telling the news the origins of this harmonic tremor was earthquake activity that was so dense it created this harmonic activity. In the morning the activity dropped a little.
Magma continues to move in the Fagradalsfjall volcano system.
Earthquake activity is now between the volcanoes Reykjanes, Fagradalsfjalls and Krýsuvík. Why that is unclear but magma movement for now is only in Fagrdalsfjall volcano system.
Largest earthquake in last 24 hours had a magnitude of Mw4,5. Over the last 48 hours total of 72 earthquakes with magnitude over Mw3,0 have taken place. There is no sign of activity slowing down.
It is currently impossible to know for sure what happens next since this situation is extremely complicated because of all the volcanoes interactions and earthquake activity.
During the last few days there has been high conductivity in glacier rivers coming from Mýrdalsjökull glacier (Katla volcano). Due to how cold it is the glacier rivers are not getting any melt water or water from clear streams and that is making the hydrothermal water stronger than normal. Current conductivity is 567µS/cm in Múlakvísl in Mýrdalssandur sand area (not sure where the sensor is located). Some gas has also been detected and that gas is toxic and enough amount to result in breathing problems. Measured amount of H2S was 1ppm and this gas is toxic.
Some minor earthquake activity has been in Katla volcano during the last two days. That earthquake activity might be due to the emptying of the cauldrons in Mýrdalsjökull glacier. The magnitudes in this earthquake activity is minor and all below 2,0 at the moment.
Earthquake activity in Katla volcano. Copyright of this image belongs to Icelandic Met Office.
It is difficult to know if this means anything other than cauldrons in the glacier emptying them self in nearby glacier rivers.
According to news report on Vísir.is (Icelandic), it appears that Bárðarbunga volcano is continuing to inflate at the same rate as it has been doing since the eruption ended in Holuhraun in the end of February 2015. Gas measurements from cauldrons that formed on the caldera rim during the eruption in 2014 show that gas output from Bárðarbunga volcano have not dropped during the last year and continue to be high. The glacier drop that formed during the eruption is now almost full of new glacier and snow from last winter. Nothing suggest that water has been collecting at the caldera bottom during the last two years.
The research trip to Bárðarbunga volcano was taken during the days of 3 – 10th of June. A new seismometer was also installed on the caldera rim. I don’t know if it’s a SIL station or not. If it is, it is going to appear soon on Iceland Met Office website.
The eruption in Holuhraun ended yesterday (27-Februar-2015) it seems. Current status of Bárðarbunga volcano is now yellow. While the eruption is over the area continues to be closed for public due to danger of new eruptions in the area, both outside the glacier and inside it. It is unclear what is going to happen next in Bárðarbunga volcano. There is also a considerable gas emission from Holuhraun crater at the moment and that gas is toxic.
Current earthquake activity in Bárðarbunga volcano and for the past 48 hours. Copyright of this image belongs to Icelandic Met Office.
What happens next is not known. There is a high risk of new eruption taking place under the glacier. I don’t know if subsidence of the caldera is going on at the moment or has stopped. It might take days, weeks or months until inflation starts again in Bárðarbunga volcano. This is a rifting event and that means this is far from over. For the moment however it is going to be a little break (at least, it can be hope) in the activity in Holuhraun or Bárðarbunga volcano. The lava and the crater continue to be extremely hot (~800C) and are going to remain hot for many years (5 years?).
Since the eruption in Holuhraun is over I won’t post any update next Wednesday. Next update is going to be when something happens.
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.