Magma detected deep under Reykjanes peninsula

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.

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Increase in earthquake activity in Reykjanes and Fagradalsfjall volcano

During the night of 3. June 2023 an earthquake swarm took place in Reykjanes volcano, at location called Reykjanestá. Largest earthquake in that swarm had a magnitude of Mw3,0. Other earthquakes where smaller. This earthquake swarm suggests a magma movement, but it is difficult to be sure if that is what happened now.

Earthquake swarm out in the ocean next to Reykjanestá and there's also an earthquake activity in Fagradalsfjall volcano. Time on map is 03. june. 23 12:35 (Iceland time)
Earthquake activity in Reykjanes volcano and Fagradalsfjall volcano. Copyright of this image belongs to Icelandic Met Office.

Its been ten months since last eruption took place in Fagradalsfjall volcano. It is likely that a new eruption is going to happen soon, but it is impossible to know when. In last few weeks earthquake activity has been increasing in Fagradalsfjall volcano and that suggests that magma pressure inside the volcano is increasing. It just has not reached the levels to start a new eruption.

Early signs of next eruption phase in Fagradalsfjall volcano

Since end of February 2023 there have been slowly growing signs in form of a small earthquake activity in Fagradalsfjall volcano and nearby area. It is impossible to know when next eruption starts in Fagradalsfjall volcano, but last time the quiet time was around 10 months. If it is going to be shorter or longer now is impossible to know.

Red dots and orange dots, not many of them in Fagradalsfjall volcano, in Krýsuvík-Trölladyngja volcano east of Fagradalsfjall and orange and blue dots west of Fagradalsfjall volcano in the volcano Reykjanes.
Earthquake activity in Fagradalsfjall volcano. Copyright of this image belongs to Icelandic Met Office.

Currently the earthquake activity is minor, but that can change quickly and without much warning. At the writing of this article, its been 6 months and 24 days since the eruption in Meradalir valley ended. I don’t know if this is going to happen the same was as it did before last eruption. Since there’s a lot of magma at depth of 5 to 10 km now and that changes how everything functions and behaves in the crust.

Eruption expected in Fagradalsfjall volcano this year (2023) or next year (2024)

It was reported in Rúv News that eruption is expected to happen in Fagradalsfjall volcano this year (2023) or next year (2024). When those eruptions happen is impossible to know. But before any eruption there’s going to be a large earthquake swarm as happened before the eruption in March 2021 and in August 2022. Fagradalsfjall volcano before the eruption in March 2021 had not erupted for 6000 to 8000 years. That means it unclear how the volcano is going to behave and its going to take a while until that is figured out, but for now it is probable that Fagradalsfjall volcano is going to work in similar way how Krafla volcano erupted between the year 1975 and 1984. With the difference that eruptions in Fagradalsfjall volcano are possibly going to last longer, based on data from other volcanoes on Reykjanes peninsula. This might go on for the next 10 to 20 years, with eruptions and quiet time period between them. Currently Fagradalsfjall volcano is in a quiet time.

This does not rule out eruptions in Reykjanes volcano (west of Fagradalsfjall volcano) and Krýsuvík-Trölladyngja volcano (east of Fagradalsfjall volcano) in next few years. Neither of those volcanoes have erupted in 700 to 900 years and at the writing of this article, don’t show any clear signs that they are about to erupt. Reykjanes volcano has had a lot of dyke intrusion activity since 2019, but no eruptions so far. Krýsuvík-Trölladyngja volcano has not had any dyke intrusion activity. Volcanoes east of Krýsuvík-Trölladyngja volcano, Brennisteinsfjöll volcano and Hengill volcano are currently quiet, but that might change without warning if magma starts to find path up those volcanoes.

Earthquake swarm in Krýsuvík-Trölladyngja volcano

Today (21. December 2022) an earthquake with magnitude of Mw3,4 took place in Krýsuvík-Trölladyngja volcano. This earthquake is because of inflation in Fagradalsfjall volcano. This possibly means that the inflation in Fagradalsfjall volcano is reaching critical point and might result in a eruption soon, when that point is reached is difficult to know.
Continue reading “Earthquake swarm in Krýsuvík-Trölladyngja volcano”

Possible dyke intrusion in Fagradalsfjall volcano

Early morning today (10-November-2022) an swarm of earthquakes took place slightly north of the place where the eruption in August 2022 took place in Fagradalsfjall volcano. This possible dyke intrusion was small and only lasted for about 1 hour before it stopped. Depth of the earthquakes was from 5 km to 7 km.

High resolution image of the earthquakes in Skjálfta-Lísa interactive earthquake map from Icelandic Met Office. It shows the dots line up in a fissure like location.
Skjálfta-lísa high resolution map of the earthquake activity. From Icelandic Met Office website.

This activity might give a clue on in what area next eruption is going to take place in Fagradalsfjall mountain. Based on earlier eruption there won’t be any warning before an eruption earthquake swarm starts. In August that eruption started with a minor earthquake swarm, created from a dyke intrusion that was happening. In the hours before an eruption starts there’s going to be a strong earthquake swarm, based on what happened just before the eruption in August. It is interesting if the eruption activity moves north-east, rather than south-west. Why that happens, if it does so, is not something I am clear on why happens.

Earthquake swarm in west part of Fagradalsfjall volcano

This morning on 23-October-2022 an earthquake swarm took place in west part of Fagradalsfjall volcano. Largest earthquake in this swarm so far had a magnitude of Mw3,0.

Green star just west of main Fagradalsfjall volcano. Few blue, yellow and red dots on the map showing earthquakes in other nearby volcanoes
Earthquake activity west of Fagradalsfjall volcano. Picture from Icelandic Met Office.

This earthquake activity is the result of magma pushing up into the crust at around 5 km depth. This is not a large dyke intrusion and possibly won’t result in a eruption, unless there’s a sharp increase in earthquake activity and that has happened (the August 2022 eruption started this way). This is currently a situation that requires monitoring for changes. If anything is going to happen is impossible to know.

Magnitude Mw3,5 earthquake in Krýsuvík-Trölladyngja volcano

Today (12-October-2022) at 14:18 UTC an earthquake with magnitude of Mw3,5 took place in Krýsuvík-Trölladyngja volcano. This earthquake was followed by few smaller aftershocks. This earthquake seems to be happening because of a inflation that is taking place in Fagradalsfjall volcano and this strongly suggests that inflation in Fagradalsfjall volcano is slowly reaching critical levels. There is no eruption expected from Krýsuvík-Trölladyngja volcano as is.

Green star with few red dots just west of Kleifarvatn lake, showing increase in activity in Krýsuvík-Trölladyngja volcano
Earthquake activity in Krýsuvík-Trölladyngja volcano. Copyright of this image belongs to Icelandic Met Office.

This earthquake activity suggests that more stronger earthquake activity is possibly on the way. When it might start is difficult to know for sure. This has been the pattern in recent months. Earthquake activity starts to appears like this and then one day a major earthquake swarm starts. What happens now is a wait and see as before.