Volcano and earthquake activity in Iceland
This is a short update on the activity in Fagradalsfjall mountain.
Currently there have been around 200 earthquakes that have happened at the writing of this article. The first magnitude Mw3,1 took place at 22:45 UTC. This magnitude is automatic and is going to change when the earthquake is reviewed.
There’s a lot going on at the writing of this article and the situation can change without warning. I’ll post updates as best I can.
Because of other activity in Iceland. This article is going to be short.
Two earthquakes took place in Bárðarbunga volcano at 19:59 UTC and 20:02 on 4. July 2023. The magnitudes was Mw3,3 and Mw3,9.
This is normal activity and happens because of inflation in Bárðarbunga volcano.
Today (4. July 2023) there has been a earthquake swarm in Fagradalsfjall mountain. Largest earthquake had a magnitude of Mw1,6 and at the writing of this article there have not been any earthquakes with magnitude above Mw2,0. This might change without warning.
Smaller earthquakes swarms sometimes seems to happen before an eruption in Fagradalsfjall mountain. The current earthquake swarm has all signs of dyke intrusion. If that is going to result in eruption now is impossible to know.
During the evening of 2. July 2023 at 22:57 UTC an earthquake with the magnitude of Mw3,1 took place in Katla volcano caldera. This was one of the few earthquakes that took place that evening and there has not been any more earthquake activity since then.
Since the last earthquake swarm in Katla volcano. Things have been rather quiet in Katla volcano.
This is an update on Katla volcano activity. The largest earthquakes in the earthquake swarm during the night had a magnitude of Mw4,4. There where total of eight earthquake with magnitude above Mw3,0 in this earthquake swarm and in total of 58 earthquakes in total according to Icelandic Met Office website. This earthquake activity is ongoing even if currently there are no earthquakes taking place (at the writing of this article).
This earthquake activity was clearly felt in Þórsmörk area and was resulting in people loosing sleep.
According to news reports on mbl.is there has now been increase in conductivity in Múlakvísl glacier river. This seems to be directly connected to the earthquake swarm activity that took place during the night. There is also more water in the Múlakvísl glacier river, if that is connected is unclear, because of rain in Iceland in recent days, there is general more water in rivers. Harmonic tremor has not started to change. That can happen without warning at any time.
Icelandic News
Rafleiðni fer stígandi í Múlakvísl eftir skjálfta (mbl.is)
Önnur skjálftahrina í Mýrdalsjökli (ruv.is)
During the night of 30. June 2023 an earthquake swarm started in Katla volcano. At the writing of this article the largest verified earthquake had a magnitude of Mw3,3.
This earthquake swarm is ongoing at the writing of this article. Currently an eruption has not started, if that is going to change is something that just has to show it self in next few hours if this earthquake activity continues to increase. All that can be done for now is to monitor this situation.
According to a news on Rúv News there has been detection of magma at considerable depth on Reykjanes peninsula. This magma is actively trying to reach the surface, but has not been successful for now. This has resulted in a lot of dyke intrusions on the Reykjanes peninsula in recent months. Earthquake activity seems to follow each inflation period on the Reykjanes peninsula according to the news.
The magma in the deep crust and in the mantle is going to increase in volume until it can break up the surface. How long that is going to take is something I don’t know. Next eruption cycle is going to start with a large earthquake, just like the last one. Based on all current data that I have.
Rúv news in Icelandic
Today (29. June 2023) at 07:48 UTC an earthquake with magnitude of Mw3,1 took place in Þórðarhyrna volcano. This was just one earthquake and a minor Mw1,3 earthquake happened at 08:17 UTC and since then its been quiet. Þórðarhyrna volcano is inside Grímsfjall volcano fissure swarm but is an independent volcano in this setting. Sometimes Þórðarhyrna and Grímsfjall erupt at the same time.
Last eruption in Þórðarhyrna volcano took place around late 1890 or early 1900. I am not sure what year exactly, because eruption often attributed to Þórðarhyrna volcano took place in Grímsfjall volcano and sometimes the reverse happened. Last eruption took place around 120 to 140-ish years ago.
Today (28. June 2023) an earthquake swarm took place in Krýsuvík-Trölladyngja volcano in Kleifarvatn lake. Largest earthquake had a magnitude of Mw3,2 at 09:21 UTC and was felt in Reykjavík area and other nearby towns.
Its unclear what is going on at this location. Most likely explanation for this activity is stress changes because of inflation in nearby Fagradalsfjall volcano. At the moment, I don’t think there is going to be an eruption in Krýsuvík-Trölladyngja volcano. This earthquake swarm looks like its ongoing at the writing of this article.
Today (28. June 2023) an earthquake swarm started in Hofsjökull volcano. At the writing of this article it seems to be over, but I am uncertain if that’s the case. This was not a large earthquake swarm, with just around eight earthquakes happening. All where below Mw3,0 magnitude in size.
Largest earthquake in this swarm had a magnitude of Mw2,6. While other earthquakes where smaller in magnitude. I am not sure what is happening in Hofsjökull volcano. There have not been any eruptions in Hofsjökull volcano in the last 8000 to 12000 years. There might not have been any eruption in Hofsjökull volcano for more than 12000 years, how much longer is information I do not have.