Volcano and earthquake activity in Iceland
Today (4. October 2023) at 16:11 UTC an earthquake with magnitude of Mw4,7 (Icelandic Met Office) or Mw5,0 (EMSC) took place in Bárðarbunga volcano.
This is normal inflation earthquake in Bárðarbunga volcano and large earthquakes like this happen every few months. This means that Bárðarbunga volcano continues to inflate after the eruption in 2014 to 2015. This earthquake activity is not going to result in a eruption and won’t result in a eruption for a long time.
Today (27. September 2023) an earthquake swarm took place in Reykjanes volcano on Reykjanes peninsula. This earthquake swarm is ongoing at the writing of this article. At the writing of this article, the largest earthquake had a magnitude of Mw3,3 and the second largest earthquake had a magnitude of Mw3,1.
The source of this earthquake swarm seems to be magma intrusion into this part of Reykjanes volcano. I don’t know if this is going to result in a eruption, this earthquake activity seems to be too low for that to happen. That might change without warning, as sometimes happens with volcanoes. This is at least highly active time period now and what is going to happen is unclear.
I am sorry that I am late on writing this article. I was moving from Denmark to Iceland and that was a lot of effort and I’ve been tired after this move.
On Sunday, 24 September 2023 an earthquake swarm took place in Brennisteinfjöll volcano, in a area called Geitarfell (Goat Mountain) in Brennisteinsfjöll volcano. Largest earthquakes had a magnitude of Mw3,0 to Mw3,2. A lot of smaller earthquakes took place at this same location.
This earthquake activity didn’t have any short term signs that an eruption is about to happen at this location. I don’t know when last eruption took in this location, but it was clearly more than 6000 years ago.
Earthquake webicoders
Since I have moved back to Iceland. I am now recording earthquakes again. The webicoders are going to go online tomorrow (if no delays). They can be found here once they are back online.
Today (18. September 2023) there was an earthquake swarm north of Grindavík town. Largest earthquake had a magnitude of Mw2,7 and was felt in Grindavík town according to Icelandic Met Office. This earthquake activity has the direction of SW to NE and is under the road to Grindavík town.
This is clearly a dyke intrusion taking place at this location. This location is bad, because this area has infrastructure that is important to Grindavík town. In this area both hot and cold water is transported along with electricity wires (I think, they might have a different path, but it is at most nearby). Eruption at this location would be a major hazard and a problem. Currently there are no signs that this magma is looking for a path to the surface.
Yesterday (15. September 2023) an earthquake swarm took place on Fagradalsfjall volcano. This earthquake swarm wasn’t in the news because it was only small earthquakes, that is earthquakes with magnitude less of Mw1,0. It was not even felt by the people standing on the volcano because of depth. If this earthquake swarm has stopped I don’t know. Since most of this earthquakes don’t show up in the automatic earthquake list at Icelandic Met Office website. They only appear after a manual review by Icelandic Met Office.
In my view, this means that next eruption might happen between November to February 2024 if this earthquake activity and dyke intrusion activity continues as it is currently doing. It has happened before earlier eruptions that a high period of activity is followed by a period of quiet until an eruption happens. Why that is I don’t know, that is a pattern I’ve observed. I don’t know if there has been change after last eruption in Fagradalsjall volcano. That is a possibility that should not be ruled out.
Today (7. September 2023) an tyke intrusion took place in Fagradalsfjall volcano. The main depth of the dyke intrusion is at around 7 km depth. All earthquakes following this dyke intrusion where small in magnitude, from Mw0,1 in magnitude and up to Mw1,0 in magnitude. This seems to be a rather large dyke intrusion, since part of it does not create any earthquake activity at all because of earlier dyke intrusions at this depth in this part of Fagradalsfjall mountain.
Morgunblaðið (link below) is reporting that inflation has now reached 15mm in this area. This is really soon after the end of the eruption, since in last three eruptions, dyke intrusions and other early signs of activity that an eruption is about to happen starts around three to six months earlier before an eruption happens at the ten month time, as has been the case in the last three eruptions. It is possible that next eruption is going to happen earlier than last three eruptions. It is possible to know when next eruption is going to happen.
Icelandic News about this
Skjálftavirkni og vísbending um kvikusöfnun (mbl.is, Icelandic)
Today (1. September 2023) at 17:55 UTC an earthquake with the magnitude of Mw3,1 took place in Reykjanes volcano. This earthquake was located out in the ocean and some distance from the coastline. I don’t think it was felt. Few other smaller earthquakes took place at the same location following the largest earthquake.
There is a storm now in this area of Iceland. That makes detection of smaller earthquakes impossible, along with distance from the coastline. If this earthquake swarm is going to be ongoing when the storm ends is impossible to know.
During the night of 26. August 2023 an dyke intrusion started in Brennisteinsfjöll volcano. This was in the form of many small earthquakes, most of them did not reach magnitude Mw1,0. What gives this away as an dyke intrusion is the fact the deepest earthquake in this swarm had a depth of 21,1 km. There was interestingly, a lot of surface earthquakes. I am not sure on why that is.
There’s no risk of eruption at the moment from Brennisteinsfjöll volcano. Earthquake activity is too low and this process is clearly not far along now for an eruption too happen. That might change without much warning at some point.
Icelandic Met Office reported that inflation has been detected in Torfajökull volcano. This inflation started around middle of June. The inflation has now reached around 40mm.
How fast this is going to evolve is difficult to know since last eruption took place in 1477 and that was probably an eruption as a result of magma injection from Bárðarbunga volcano. Last eruption in Torfajökull volcano it self might have happened last in the year 1170. Eruptions in Torfajökull volcano are almost always explosive eruptions with an dangerous ash cloud that drifts under the direction of wind.
Yesterday (13. August 2023) an large earthquake swarm took place close to Geirfugladrangur (small rock island, population birds) on the Reykjanes ridge. The largest earthquake had a magnitude of Mw4,5 and was felt to Akranes town and possibly in other nearby towns on Reykjanes peninsula. There where not many reports about this earthquake being felt. Something above 400 earthquakes took place during the most active phase of this earthquake swarm.
This earthquake swarm seems to be ongoing. It is at the moment, at much slower rate than before. There are clues that suggest this might have been a earthquake activity connected to magma movements in this area. Its difficult to be sure, because this area is under the ocean and measuring what is going on gets more difficult as future away from land activity happens. Eruption at this distance is going to appear on the Icelandic Met Office SIL network.