Fewer earthquakes close to Keilir, no eruption in Fagradalsfjall mountain for almost one month

Earthquake activity continues close to Keilir mountain. But it remains at depth of 5 to 6 km and doesn’t show any sign that it is about to move to the surface. More than 10000 earthquakes have been recorded and 18 earthquakes have been recorded with magnitude above Mw3,0. This is according to Icelandic Met Office.

Earthquake activity close to mountain Keilir marked by a green star close to it of the map on Reykjanes peninsula
Earthquake activity close to Keilir mountain on Reykjanes peninsula. Copyright of this image belongs to Icelandic Met Office.

The eruption in Fagradalsfjall mountain (more information at Krýsuvík-Trölladyngja website at Global Volcanism Program) has not been active since 19-September-2021 and there are no signs that the eruption is about to restart soon. Global Volcanism Program no longer updates its information for this volcano as an active eruption. Icelandic scientists in eruptions have not declared the eruption over. It should be expected that the eruption in Fagradalsfjall mountain is over for now, but it can start again at the same location or at new location in few weeks time or maybe even few years from now.

Earthquake swarm in Reykjanes volcano

Yesterday (12-October-2021) an earthquake swarm took place in Reykjanes volcano. Largest earthquake in this swarm had a magnitude of Mw3,3 and the earthquake swarm was out in the ocean not far from the coastline.

Two green stars out in the ocean shows the location of the earthquake swarm that was happening on Reykjanes ridge in the volcano of Reykjanes. Green star is also close to Keilir volcano that had an activity yesterday also.
Earthquake activity out in the ocean on Reykjanes ridge. Copyright of this image belongs to Icelandic Met Office.

It is impossible to know for sure if this earthquake activity is directly connected to magma movements in this area. It is possible, but there have been some sign of magma moving in the crust in this area. The magma is moving but is not erupting or starting an eruption. Earthquake activity seems to be growing in this area of Reykjanes peninsula and Reykjanes ridge after the eruption in Fagradalsfjall mountain stopped.

Inflation and earthquake activity in Askja volcano

Inflation has been increasing in Askja volcano over the last few weeks. According to latest news that inflation is now at 14 cm, since the inflation was detected at the end of August. On Saturday 9-October-2021 an earthquake with magnitude of Mw3,2 was detected in Askja volcano (I’ll try and add the picture later if I remember). This is was the strongest earthquake in Askja volcano in the last 20 years according to the news.

Askja is remote and there are no or limited amounts of web cameras in the area. With winter arriving going there is impossible for most people. If an eruption happens this winter the best view is probably going to be harmonic tremor data until pictures appears from Icelandic Met Office or someone with an air plane (if the weather allows for that).

Ongoing earthquake swarm close to Keilir mountain

The earthquake swarm with Keilir mountain continues today (2-October-2021) and largest earthquake at the writing of this article had a magnitude of Mw4,2. This might change without warning.

Green stars on Reykjanes peninsula close to the mountain Keilir. Shows where the current activity is.
The earthquake activity close to Keilir mountain. Copyright of this image belongs to Icelandic Met Office.

Based on what I am seeing it is my view that magma is the reason why this earthquake activity is happening. The magma seems trapped, based on the earthquake activity and that is interesting. This suggest that the feeder channel, that possibly started at this location has closed up and that is the reason why the eruption in Fagradalsfjall mountain stopped. At least that is the working idea, if it is true I don’t know.

Department of Civil Protection and Emergency Management and Icelandic Met Office has warned people against going to Keilir mountain because of risk of volcano eruption or large earthquakes.

It is unclear at the writing of this article if there are changes to hydrothermal activity close to Keilir mountain. There have been reports about it, but they remain unconfirmed at the writing of this article.

There is now a risk of an earthquake with magnitude of Mw6,0 in the area of Keilir mountain. The earthquake activity shows a pattern of high and low activity every few hours. Why this happens is not well understood at the writing of this article.

Earthquake activity south of Keilir mountain

On Saturday 25-September-2021 an earthquake swarm started close to Keilir mountain, at the writing of this article this earthquake swarm is ongoing.

Red dots on Reykjanes peninsula show the location of an ongoing earthquake swarm that is now happening.
Earthquake swarm on the Reykjanes peninsula. Copyright of this image belongs to Icelandic Met Office.

The eruption in Fagradalsfjall mountain has been having its longest quiet period since 19-March-2021 and at the writing of this article that is ongoing situation.

This earthquake activity suggest that the eruption time period in this part of the Reykjanes peninsula is not over, even if nothing is happening at the moment.

Krýsuvík-Trölladyngja is a volcano system is currently erupting in this area.

Article updated on 29-September-2021 at 11:49 UTC. Correct date of the earthquake swarm start added to the article.

Massive lava cave opens up, results in lava flood down to Nátthagi

Yesterday (15-September-2021) around 11:10 UTC a large lava cave just south of the crater in Geldingadalir had a roof collapse in a small area or a lava breakup in the surface. This resulted in the lava flow down Geldingadalir into Nátthagi. The flow covered Geldingadalir in less than 20 minutes. After that it did reach the barrier that stops it from going into Nátthagakriki, if that happens both walking path A and B are going to get closed forever or having to be redrawn from their current locations. Lava down that path also allows the lava flow to go in the direction of Grindavík town and nearby roads.

The lava flow yesterday did go down into Nátthagi but didn’t get far into there compared with the older lava it was flowing on top of. This sudden lava flow did put people in danger and shows that the lava field is full of dangerous caves that can collapse or burst open at any time without any warning. The lava flow that started yesterday is ongoing best to my knowledge. But the view has been limited due to fog and bad weather in Fagradalsfjall mountain this evening.

One or two idiots where seen walking on the crater rim yesterday and I think this are the same people that Icelandic coast guard had to transport from Gónhóll since they where unable to get back because of the new lava flow that had happened when they where there.

The crater is now ~334 meters above sea level high. Currently the crater is now growing in height but that can change without warning.

Pictures of this new lava flow are on social media. I can’t use them because of copyright but if searched they can be found and viewed. There are also some amount of videos of this lava flow on YouTube.

Fagradalsfjall mountain is part of Krýsuvík-Trölladyngja volcano system.

Update on the Fagradalsfjall mountain eruption on 12-September-2021

This is a late and short update on the eruption in Fagradalsfjall mountain on 12-September-2021. Fagradalsfjall mountain is part of Krýsuvík-Trölladyngja volcano system.

Yesterday (11-September-2021) at around 05:00 the harmonic tremor on SIL stations around Fagradalsfjall mountain started to show an increase in harmonic tremor after a break of 8 days. It took few hours for the magma to reach the crater and lava was visible in the crater around 12:00 UTC.

Harmonic tremor chart in purple (lowest frequency), green (mid range frequency) and blue (highest frequency) that shows in the increasing harmonic tremor by rising at the end of the link up to 6000 units (not defined) at 00:38 Icelandic time.
Increasing harmonic tremor at 00:38 UTC on Fagradalsfjall mountain SIL station. Copyright of this image belongs to Icelandic Met Office.

There have been possible new vents been opening up yesterday and today in the lava field. Icelandic Met Office says that this is a lava flow under the old colder lava and is now breaking up and looking like new vents. I don’t know yet if this is accurate, but it is my early assessment that this are new vents and are going to build new crater, at least there is a possibly of crater building if the new vents stay active long enough.

If this are new craters as I suspect, then they are going to change the lava flow quickly and increase the output of the lava flow from what it was. It might soon start to flow down into Nátthagi and other locations that are nearby.

It is a big question if the cycle eruption with no activity for hours has stopped for now. If this has turned back into an eruption that goes in 24 hours a day, that is going to allow the lava field to reach a lot more distance then before.

Askja volcano placed on uncertain level and yellow alert for flight

Because if Askja volcano quick inflation, that is now currently at 7 cm, Department of Civil Protection and Emergency Management has declared uncertain level and yellow alert for flight.

Green triangles shows most of the volcanoes in Iceland as green. Only Askja and Grímsfjall are yellow. Krýsuvík volcano is orange in colour.
Current status of volcanoes in Iceland as of 9-September-2021. Copyright of this image belongs to Icelandic Met Office.

Inflation is quick in Askja volcano and is now at 7 cm. When or if that is going to result in an eruption is impossible to know. Current Askja volcano is what remains of a mountain that blew up in an large eruption in the year 1875 century. Most eruptions are just lava flows, unless they happen to start in a water, then explosive activity happens while water remains.

Unconfirmed activity in the area of Keilir in Fagradalsfjall mountain eruption

This is unconfirmed so there might be number of other reasons why this is being observed. This also might be wrong reporting but based on web cameras that might not be the case. There has been some visual view of this on web cameras. Here are two pictures that I was able to screen grab from two of those cameras.

Thermal black and white image showing a bright spot on the centre of the image suggesting a strong heat source.
There is a heat source in this image. Where it is located is currently unclear. Copyright of this image belongs to Míla and Securitas.
Black image showing two light dots. With the dot on the left being a car or some human made noise. While the dot on the right might be a small eruption that is unconfirmed.
The light on the right of this image might be the an unconfirmed eruption. Copyright of this image belongs to Míla.

It is unclear what is going on and this might all be wrong. But I am also seeing this new light source on the web camera from mbl.is on YouTube as it peaks a little from behind the large crater in Fagradalsfjall mountain. That crater is not active at the moment.

I don’t know when confirmation is going to appear. If this is an eruption. If this is not an eruption, then there is going to be a confirmation of that too. I’ll post update here is I learn anything more in the next few hours.

Update 03:07 UTC 7-September-2021

The light on the second picture (on the right) is a human made light. I think it is the lighthouse. What is appearing on the thermal camera has not been identified.

Update 13:36 UTC 7-September-2021

This is wrong reporting that happened here. Nothing happened and what was seen on the thermal camera is most likely the heat from the crater. This type of wrong information happens every once in a while. Currently the main crater remains inactive and sulphur colours have started to appear on him from the sulphur outgassing that is now happening.

Article updated at 03:08 UTC on 7-September-2021

Article update at 13:39 UTC on 7-September-2021

Askja volcano started inflating in August 2021

Icelandic Met Office published the news today that Askja volcano has started to inflate.  This inflation started in August 2021 and has been measured at 5 cm a month. The inflation is happening just outside the Askja lake in area known as Ólafsgígar (Ólaf craters).

Inflation map of Askja volcano. Triangle in the centre of Askja volcano caldera show the location of the inflation in red to blue colour.
Inflation in Askja volcano. Copyright of this image belongs to Icelandic Met Office.

It is impossible to know if this is going to result in any eruption. This inflation however seems to have resulted in earthquake activity in Askja volcano. Most of the earthquakes so far have been minor in magnitude.

Inflation map of Askja volcano. It show displacements in north - south and east - west directions and up displacement of 5 cm
Inflation in Askja volcano. Copyright of this image belongs to Icelandic Met Office.

Icelandic Met Office announcement

Land rís við Öskju (Icelandic)

Uplift signal detected in Askja volcano

Icelandic News

Grannt fylgst með landrisi við Öskju (Rúv.is)

Landris við Öskju í fyrsta sinn í áratugi (mbl.is)

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