November 26, 2021: This quieted down some in September, but there has been more seismicity recently.
Note the “archived footage” sign.
On the 16th of November volcanologists reportedly said that no magma had been seen for three months. There is some ground inflation and increased seismicity going on just now, but no sign of imminent eruption restart, apparently. Meanwhile, PRETTY!
October 25, 2021, 12:06 p.m., Pacific: On the 18th, they lowered the Aviation Code to Yellow, however noting:
The Fagradalsfjall eruption will not be declared over until much later in the future, as the distinction between a break and a true ending is only apparent in retrospect. Activity might resume again in the near or distant future, either in the same place or at a new opening.
October 4, 2021, 9:04 a.m., Pacific:
There has been a lot of speculation regarding Fagradalsfjall. Truth be told, it is still uncertain what is going on. But we have been experiencing a seismic swarm. We had an 3.9M earthquake today at 15:32h felt widely in Reykjavík, that we saw in near real time at #LavaCentre pic.twitter.com/LUdHOqLZej
— Lava Centre (@LavaCentre) October 2, 2021
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More than a thousand quakes reported (Icelandic) in the last 24 hours.
Per the Icelandic Met Office (Icelandic), October 1st, via Google Translate:
The quake [swarm] began on 27 September SW of Keilir. The earthquakes in the cluster are located at the northern end of the magma tunnel that formed earlier in the year led to an eruption at Fagradalsfjall. Today, about 2,000 earthquakes have been detected in the cluster so far, 6 of them have been over 3 in magnitude. No eruption is observed, but the seismic activity in this eruption is similar to what was seen at Fagradalsfjall in the run-up to the eruption there. At this stage, however, it can not be ruled out that the earthquakes may be due to voltage fluctuations in the area, but not due to magma movement.
The latest measurements of crustal movements show no clear signs that magma is making its way to the surface of the earthquake’s trajectories. However, this does not preclude magma from moving at great depths that are not visible in the measurement data, and it is therefore necessary to further monitor the development of the activity at Keilir.
We really need more data”, says Sara Barsotti, director of volcanic eruptions at the Icelandic Meteorological Office. “There is hope for new satellite images next week that will hopefully shed a clearer light on the development of things at Keilir and whether there is magma moving near the surface,” says Sara.
Not recommended to be on the move in the vicinity of Keilir
Little activity has been visible from the main crater at Fagradalsfjall since 18 September and less eruption has been observed. “The eruption’s behavior so far has been characterized by such breaks,” says Sara. “A change in the eruption’s behavior in conjunction with increased seismic activity near Keilir could mean that magma seeks something else, but the source of the seismic activity at Keilir is in an area connected to the magma tunnel that formed this spring. So we continue to follow developments closely and scientists and response parties are prepared if magma reaches the surface at Keilir “, Sara concludes.
If there were an eruption at Keilir, it would be similar to the eruption at Fagradalsfjall. The area is well guarded and is off the beaten track but a popular outdoor recreation area. At this stage, people are advised not to be on the move in the vicinity of Keilir.
It is also recommended that people consider earthquake prevention in their homes during the eruption.
September 13, 2021: The eruption is now coming in cycles. Here’s the GVP weekly report page.
When it’s on, there is LOTS of lava.
Also, the Icelandic Met Office reports (Icelandic) that new cracks have opened up on a hill nearby. They aren’t sure what will happen next but do warn people and helicopters to avoid that site.

Look at all that lava! How fortunate that no human settlements are close by. This was taken during one of the quiet spells. The new cracks are outlined in red. (Image: Icelandic Met Office)
Here is a satellite view of the flow field yesterday. Yes, it seems that yet another valley has been filled up!
#volcan #volcano #Krysuvik Certaines coulées ont pu sortir de la vallée Meradalir par le nord-nord-est/Some lava flows found a way to exit of the Meradalir valley by the north-north-east, via @sentinel_hub @esa @CopernicusEU pic.twitter.com/tllO2Q1E5M
— CultureVolcan (@CultureVolcan) August 9, 2021
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June 12, 2021, 2:03 p.m., Pacific: Here are three streaming cams from mbl.is:
Crater close-up:
In the Natthagi valley (which the unsuccessful diverting dams mentioned below were constructed to protect):
Overview:
It’s not very fiery at the moment. You want fiery?
Okay (a retweet, so you might have to click again to see the lava-fall, but the thoughts on magma quality are interesting):
A similar event from a different angle. #Lava viscosity seems very low; reminds me a bit of thin carbonatite flows at #OldoinyoLengai. 3 ways to ⬇️ lava viscosity: raise temperature, lower silica (SiO₂) content, or increase volatile (esp. H₂O) content. https://t.co/49XKt220Eg
— Simon Carn (@simoncarn) June 11, 2021
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Per Jon Frimann on the 11th of June, “The main crater is slowly closing and lava fountain activity has almost or has ended at the writing of this article…There are overflows happening in the crater but according to the news the main lava flow happens underground in large dykes that go from the main crater into the lava field. Creating lava ponds [sic] that regularly break and expand the lava field at random.”
He also mentions an ongoing change in harmonic tremor, but this is vague and not yet followed up on.
As for the concerns I expressed below about haze, IMO reported on May 21st via Google Translate:
Yesterday and today, gray-blue fog has covered many parts of the south and west of the country. This is an eruption fog from the eruption on the Reykjanes peninsula. The eruption fog is composed of sulfur particles (SO 4 ) that have formed as a result of the eruption’s reaction to the oxygen in the atmosphere. These sulfur particles are not measured on SO 2 gas meters, but are seen as gray-blue mist when a certain concentration is reached. Elevation of microfine particulate matter (PM1) may be an indication that SO 4 is present. Measuring stations that measure very fine particulate matter (PM1) are at Vesturbæjarlaug, at Bústaðavegur in Reykjavík, at Dalsmári in Kópavogur and at Keflavík Airport…
Haze does sometimes affect Reykjavik and other population centers, but that is reportedly sand.
Thus far, I haven’t read of any major problems outside the country from this after the reports (below) from northeastern Canada.
In Iceland:
Along with the TV weather forecasts, Icelanders get volcanic gas (SO2) forecasts. @RUVSjonvarp. @Vedurstofan #volcanomonitoring #Geldingadalir pic.twitter.com/Vx5kK8n4As
— Kristín Jónsdóttir (@krjonsdottir) June 12, 2021
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Here is an air quality map for Europe, including Iceland.
Original post
Whether you call it Geldingadalir, Fagradalsfjall, Krisuvik, or something else, this is the gloriously fiery eruption on the Reykjanes Peninsula that has gotten so much media coverage since it started earlier this year.
Icelanders hope to reroute some of the lava flow to protect a road and some infrastructure, including fiber optic lines.
The hill-and-valley topography is helpful for dam building (those brown areas at the two lava lobes above are lava dam construction sites), and lava has been redirected before, for instance, in Italy and elsewhere in Iceland.
But they’re not facing a mere volcano this time (though we call it that for convenience). This is activity on a spreading center, possibly complicated by the presence of a hot spot. (PDF download)
Amazing footage of the active vent at the current eruption at the #Reykjanes Peninsula in #Iceland.
Would make a fun exam question: “In 1,000 words, plus diagrams, describe what the hell is going on here.”
#volcano #eruption #Fagradalsfjallhttps://t.co/YYfDfGRFqO
— Dave McGarvie (@subglacial) May 18, 2021
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What a fiendish test question! 😲
While I admire their spirit and foresight, Icelanders are fighting the planet here, not just a single mountain.
The mantle has indeed come up for a visit. Everybody is agreed on that.
Now I’m going to get speculative, so watch out!
A layperson’s speculations, no matter how clearly she expresses them, aren’t worth much. Real scientists know everything I’m now going to mention, but they also have tons of data and a firm grip on the general big picture. I have not read any authoritative backup for what follows — it’s merely my opinion.
The haze
This past week, some residents of eastern Newfoundland noticed a high-altitude haze that is probably from the eruption. Ground-level haze was also reported in St. Johns.
On May 17th, that volcano had blasted out over 3 ktons of sulfur dioxide — the largest I’ve seen while watching this casually (remember, I’m a layperson).

That bothered me, because the words “haze,” “fissure eruption,” and “Iceland” make me think of Laki’s 1783 eruption (brief summary). The Laki fissure system, in southern Iceland, is farther east and closer to Eurasia.
That eruption messed up Europe and other parts of the world, and ultimately killed off an estimated 20% of Icelanders.
And, per Oppenheimer, whose book contains a chapter devoted to this 1783 disaster, no one completely understands how Laki’s long-distance killer effects happened, since it was just lava fountains and flows, which don’t transmit much sulfur volatiles up into the stratosphere, where they can interfere with climate.
NOT Laki 2.0
Don’t get me wrong. I am not saying this will be Laki all over again. I saw those words; they reminded me of a deadly Icelandic eruption, on another and separate part of the island two and a half centuries ago; and I decided to do this post.
Experts who are on top of the ongoing activity express no concern, neither the Icelandic Met Office, which monitors gases (Icelandic) along with everything else, nor Montreal VAAC, which refers to this volcano of many names as Krisuvik. (It isn’t producing ash — though that will happen if lava reaches the sea in the future; Montreal VAAC has other responsibilities, too.)
I just want to focus on what might possibly become news later on — not necessarily catastrophic, either. Scientists are observing something that hasn’t happened in eight centuries. Many ground-breaking discoveries are possible here.
These peninsula eruptions go on, usually intermittently, for hundreds of years, so don’t hold your breath! Please don’t change your travel plans, either, if you can get up or over there to watch this spectacle, but do keep a weather eye on it, especially if you’re in northeastern North America and downwind.
The earlier Iceland updates are here.
Update on lava dam, May 22, 2021: Volcano 1, humans 0 (but lessons learned).
Closer up views of the lava breaching the wall. This wall was mostly designed as a means of testing out possible methods of management. If this eruption is the start of a new phase in Reykjanes, in future infrastructure might be threatened, requiring mitigations. #Geldingadalur pic.twitter.com/a5uI5exAvm
— Alistair Hamill (@lcgeography) May 22, 2021
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Featured image: FragenuberFragen
Sources:
Oppenheimer, C. 2011. Eruptions That Shook the World. Cambridge: Cambridge University Press. Retrieved from https://play.google.com/store/books/details?id=qW1UNwhuhnUC