Volcano and earthquake activity in Iceland
Yesterday (29. August 2023) at 23:49 an earthquake with magnitude of Mw3,7 took place in Katla volcano. This earthquake was felt on nearby camping sites and farms according to a news report. Few smaller earthquakes took place following the largest earthquake.
Nothing more happened following this earthquake, as has been the case for the last few earthquake swarms in Katla volcano. More earthquake activity can start in Katla volcano without warning.
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.
This is a short article about Askja volcano. Because I am getting information that are in my view slightly conflicting with each other.
It seems that an there has been a increase in gas and hydrothermal activity in Askja volcano and in nearby area because of inflation that is currently taking place. At the writing of this article the inflation in Askja volcano seems to have reached between 80mm to 100mm. The reports have been slightly difficult to place in a good picture of what is happening. That’s why I am limiting coverage about this until it becomes more clear to me what is going on.
The general advice from Icelandic Met Office is that people should not hike around Askja volcano or nearby area because of risk of gas and sudden eruption. There is no special earthquake activity at the moment and that makes it difficult to know what is going on. This might change without warning, as is sometimes the case with volcanoes.
Yesterday (12. August 2023) an small earthquake swarm took place in Hofsjökull volcano. Largest earthquake had a magnitude of Mw3,0 and the second largest earthquake had a magnitude of Mw2,5. The area is remote and there are no reports of this earthquakes being felt.
According to Morgunblaðið news there where report of smelling gas after this earthquake activity. There is a risk of gas pockets around Hofsjökull volcano, probably mostly to the north in the area closest to the earthquake area.
I don’t have any other information about Hofsjökull volcano. Because it last erupted more than 12.000 years ago. At most there might have been smaller eruptions that resulted in lava flows sometimes in the last 12.000 years. I don’t expect an eruption now, this earthquake activity might signal a long term change in Hofsjökull volcano. How long that is going to be is anyone guess. It might be in the next 100 to 500 years or maybe never. Hofsjökull volcano is on its own rift zone that is slowly dying off. Along with Kerlingafjöll volcano to the south of Hofsjökull volcano. This are the only two (?) active volcanoes on this old dying rift zone (its around 5 to 10 million years old).