Earthquake swarm south-west of Langjökull glacier

Since December 2021 an earthquake swarm has been ongoing south-west of Langjökull glacier. This area is not part of any known fault zone or any volcano. This is just tectonic earthquakes and is outside of main earthquake areas. This intra-plate earthquakes happens sometimes in Iceland. Why that is remains unknown, but best idea is this happens because of stress changes because of tectonic movement. Earthquake magnitude can go up to Mw5,5 or larger. But such events are extremely rare, but do happen.

Earthquake swarm south-west of Langjökull glacier. Green star shows a magnitude Mw3,3 earthquake
Earthquake south-west of Langjökull glacier. Copyright of this image belongs to Icelandic Met Office.

This is the second earthquake with magnitude Mw3,3 in this area, with the earlier one happening on 18th January 2022. The hill this earthquake swarm is happening in is called Húsafell.

Magma on its way up the crust in Fagradalsfjall mountain, last measurements shows 1600 meters left (1,6km)

According to a news on Vísir.is (linked below) the magma has started to rise in Fagradalsfjall mountain. At the time of the measurement from a satellite the magma had around 1600 meters (1,6km) left until it reached the surface. At the speed the magma was travelling, around 130 meters a day an eruption was expected to happen around 11-January-2022. This is the current estimate, but that might change of the magma increases or slows down the speed it is going up in the crust.

It is unclear what area is going to erupt since the new dyke is more alongside the older eruption dyke. There is more chance than less that new craters are going to open up and start erupting, some of the area is under fresh lava from earlier eruption. Making the area look interesting when this eruption starts.

Icelandic News

Kvikan á uppleið en á enn 1.600 metra eftir (Vísir.is)

Felt earthquake on South Icelandic Seismic zone

During the night of 30-December-2021 at 04:16 UTC an earthquake with magnitude of Mw3,0 was felt in Selfoss town and Hveragerði town. This earthquake was part of a swarm in the area that is ongoing at the writing of this article.

Green star on the far right on the map with few red dots, showing the earthquake activity in SISZ
Earthquake activity in SISZ. Copyright of this image belongs to Icelandic Met Office.

There are no volcanoes in this area so this is only a tectonic activity. It is not possible to know when this earthquake swarm ends. This might be a aftershock activity after the Mw6,3 earthquake in SISZ that took place in this location in the year 2008. I expect this earthquake swarm to continue to few more days to weeks and then just end quietly.

Earthquake swarm in Bárðarbunga volcano

Today (29-December-2021) at 14:46 UTC an earthquake with magnitude of Mw3,6 (Icelandic Met Office) or magnitude of mb4,5 (EMSC website information here).

Green star in Vatnajökull galacier in Bárðarbunga volcano. Few red dots show smaller earthquakes that also happened in Bárðarbunga volcano
Earthquake activity in Bárðarbunga volcano. Copyright of this image belongs to Icelandic Met Office.

This earthquake activity is normal and is because of inflation that is now happening in Bárðarbunga volcano. Eruption is not going to happen now. It might be few more years or few more decades until that happens.

Strong earthquake activity in Fagradalsfjall mountain, Krýsuvík-Trölladyngja volcano

This information is going to get outdated quickly.

There is now a constant earthquake swarm activity in Fagradalsfjall mountain, part of the Krýsuvík-Trölladyngja volcano system. More than a dozen of earthquakes have been larger than magnitude 4,0 and it doesn’t look like this earthquake activity is doing to stop soon. Largest earthquakes in last few hours had a magnitude of Mw4,8 and Mw4,5. The earthquake north of Grindavík town appears to be a tension breaking earthquakes because of magma inflation in Fagradalsfjall mountain.

A lot of earthquakes on Reykjanes peninsula, more than a dozen green stars, hundres of red dots showing smaller earthquakes
The earthquake activity on Reykjanes peninsula. Copyright of this image belongs to Icelandic Met Office.
Heavy earthquake activity shown on Icelandic Met Office earthquake tracker. The density of earthquake activity has the image swamped with activity
Earthquake activity on Reykjanes peninsula in Fagradalsfjall mountain for the last 48 hours. Copyright of this image belongs to Icelandic Met Office.

This earthquake swarm is close to Grindavík town, this is a similar situation that happened earlier in the year 2021. Just before the eruption in Fagradalsfjall mountain. This earthquake activity is going to continue to grow until an eruption starts. This earthquake activity also happens in a wave, resulting in it lower earthquake activity between powerful earthquake activity. I am expecting more strong earthquakes in next few days, unless an eruption starts in Fagradalsfjall mountain or nearby area.

Update on activity in Krýsuvík-Trölladyngja volcano in Fagradalsfjall mountain, eruption is going to happen soon

Information here are going to get outdated quickly.

The earthquake activity in Fagradalsfjall mountain continued on 22-December and on 23-December-2021. Largest earthquake in last few hours had a magnitude of Mw4,9 and was felt over a wide area. No property damage has yet happened because of this earthquake activity so far.
There are now three centres where the earthquake activity is happening. The first one is north of the large crater, the second one is under the main crater and the third one is in Nátthagakrika (about south-west of the large crater). This is the area where people used to walk up the eruption on walking paths A and B.

Dense earthquake activity on Reykjanes pensiula with lot of earthquakes and green stars and red dots
The heavy earthquake activity on Reykjanes peninsula. Copyright of this image belongs to Icelandic Met Office.
Plot showing the magnitudes of the earthquake and density. A lot of earthquake that go above 3 line and dense dots with smaller magnitudes
The density of the earthquake activity in the current earthquake swarm. Copyright of this image belongs to Icelandic Met Office.

This earthquake activity is not going to stop until an eruption starts. When that happens is not possible to know. If a new crater opens up that is going to result in ever growing and stronger earthquakes. If the crater that is already in place starts erupting again, that is going to result in some earthquake activity. What is known is that the magma is going to go the path of least resistance, whatever that path might be. At the writing of this article, over 6000 earthquakes have been recorded and around 50 to 100 of them have been larger than magnitude 3,0.

Earthquake swarm in Krýsuvík-Trölladyngja volcano, close to Fagradalsfjall mountain, eruption possible soon

This information is going to get outdated soon. Since the situation is changing quickly.

It is possible that a new eruption is about to start in Fagradalsfjall mountain in Krýsuvík-Trölladyngja volcano. This earthquake activity started around 17:00 UTC on 21-December-2021 and has been growing since then. At the writing of this article the largest earthquake had a magnitude of Mw3,3. Over 150 earthquakes have been recorded at the writing of this article. This earthquake activity doesn’t seems to be slowing down.

Earthquake activity in Fagradalsfjall, a lot of red dots, green star shows the largest earthquake
Earthquake activity in Fagradalsfjall mountain. Copyright of this image belongs to Icelandic Met Office.

The situation is changing quickly. As of writing this article a new eruption has not yet started but that might only be question of hours until an eruption starts. This might happen during the night or sometimes tomorrow during the day. There is not any way to know that for sure at the writing of this article.

I’ll post update late tomorrow if this changes and a eruption starts. Since I’ll be busy during the day the late article can’t be helped.

Continued aftershock activity south of Hekla volcano

Today (21-December-2021) at 09:37 UTC an earthquake with magnitude of Mw3,0 took place south of Hekla volcano.

Green star south of Hekla volcano showing the magnitdue 3,0 earthquake
Earthquake activity south of Hekla volcano. Copyright of this image belongs to Icelandic Met Office.

This earthquake activity is an aftershock activity of the Mw5,2 earthquake that happened about one month ago. This earthquake activity is possibly going to continue for months.

Earthquake swarm in Vatnafjöll mountain (south of Hekla volcano)

Today (13-December-2021) at 16:04 UTC an earthquake swarm started in Vatnafjöll mountains. This looks like a aftershock activity from the Mw5,2 earthquake in this area few weeks back. Three earthquakes with magnitude above Mw3,0 took place. The earthquake magnitudes where Mw3,0 (at 16:04), magnitude Mw3,2 (at 16:07) and magnitude Mw3,5 (at 16:08).

Græn stjarna suður af Heklu sýnir staðsetningu jarðskjálftanna í Vatnafjöllum mountains
Earthquake activity south of Hekla volcano in Vatnafjöll mountains. Copyright of this image belongs to Icelandic Met Office.

There continues to be a risk of more aftershocks in this area. It remains a question if there is going to be a stronger earthquake activity in this area in next few weeks.

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