Iceland's Fagradalsfjall Fires

[bjdeming]

Afar TV is on it, apparently -- no, that's the work building up defenses on the power pylons in another area (mbl.is and others have reported on that):

 

[bjdeming]

Here we go: mbl.is view of the power plant somewhere. That's Reykjavik in the background.

 

[bjdeming]

RUV has gone live (autotranslated).

 

[bjdeming]

Here's a 360° view of things, taken yesterday around noon local time.

By all accounts, the situation is under control, though lava is still up to the top of the ramparts in several places and water cooling continues (as I understand it, to raise the rampart, they must widen it first and they intend to do so over cooled lava; my speculation is that this also might help by performing the "squeeze" technique that stopped a flow overflow from the lava pond earlier this year).

What makes me take back my earlier "matter of fact" statement is knowing, from this chapter, that the scientists' role is advice; instead, they broke the news about the Svartsengi crisis -- when the PM and the media were not mentioning the threat, though they, too, must have seen the rising lava level -- and only afterwards did public statements come out, including the not unimportant one that everyone in the district might lose their heat again.

It is probably relevant that Iceland's parliamentary elections are next week.

So Icelanders are human after all. But I now know not to trust media reports there for all the reliable news -- just some of it, when it suits major players' convenience and/or affects immediate public safety.

You know -- like here, and everywhere else.

 

[bjdeming]

Wow.



If they can successfully use the lava itself to build the berm outward and upward -- reportedly, they're going for 3-4 meters gain in height -- then they might be able to handle future eruptions, too.

This is so far out there on the tech curve, I think I just met myself coming from the opposite direction.

 

[bjdeming]

The former president of Iceland tweeted this amazing image of the barrier work. That's the new lava flow in the foreground -- per IMO today, this western flow is glowing hot a few meters down and is still oozing along, but the main action right now is in the northernmost crater and that lava is heading east into the boonies.

Basically, the workers have made a partial lava tube, I guess.

 

[bjdeming]

Yesterday marked the one-year mark for these Fires, and in today's update, IMO (the Icelandic Met Office) issued a summary and look forward.

Via GT:

Updated December 19 at 11:50

• The total area of the latest lava flow is 9 km 2 and the volume is about 49 million m 3
• Continued magma accumulation under Svartsengi
• The likelihood of a magma eruption will increase in a few weeks if magma accumulation continues at a similar rate.
• Risk assessment updated , valid until January 2, 2025, everything unchanged
• Risk assessed as significant at Sundhnúk crater series

The imaging team of the Natural History Institute and the National Land Survey of Iceland flew over the eruption sites on December 13. Measurement data from the flight show that the lava flow that formed during the last eruption from November 20 to December 9 was 49.3 million m 3 and 9.0 km 2 in area. The thickest part of the lava flow was measured at the crater and the dykes at the Blue Lagoon, but the average thickness of the lava flow was 5.5 meters.



Map showing the extent and thickness of the lava flow that formed during the last eruption (November 20 - December 9). The map is based on data from a flight by the Icelandic Institute of Natural History and the National Land Survey of Iceland on December 13. The yellow color shows the most recent lava flow, while the purple areas show lava that has flowed in the area since December 2023.

Compared to previous eruptions at the Sundhnúk crater series, the eruption, which lasted for eighteen days, was the second largest in volume since December 2023. The largest eruption (August 22 - September 5) was 61.2 million m 3 and 15.8 km 2 in area (see graph).



The graph shows a comparison of the length (blue) and volume (orange) of volcanic eruptions that have occurred at the Sundhnúk crater series since December 2023. Volume calculations are the product of collaboration between many parties and are based on data from the Civil Protection Agency, the Institute of Natural History, Efla, Verkís, Svarmi and the Icelandic Meteorological Office.

Yesterday, December 18, marked one year since the first eruption in this series of events at the Sundhnúk crater series began. Since then, there have been a total of seven eruptions lasting a total of 114 days and producing about 216 million m3 of lava flows.



Lava waterfall that formed during the eruption that began on December 18, 2023. Photo: Halldór Björnsson/Icelandic Meteorological Institute.

Data from GPS meters show that the land rise in Svartsengi has been at a steady rate. This indicates that magma accumulation under the Svartsengi area is continuing. While magma accumulation continues, new magma flow and even an eruption at the Sundhnúk crater series can be expected. In light of the data currently available, it can be assumed that magma accumulation will need to continue at a similar rate for at least several weeks before the likelihood of a magma flow begins to increase. If there are changes in the rate of magma accumulation, this assessment will change. The Icelandic Meteorological Office continues to closely monitor activity in the area and if there are significant changes in magma accumulation or seismic activity, new information will be released.

From my reading on other volcanoes over the past year for the blog, I've learned that there are at least two ways to start an eruption.

IMO appears to be going with the first: magmatic inflow builds up pressure in a reservoir until part of the wall cracks and the resulting dike reaches the surface.

Call that internal. Another way to trigger an eruption, as this layperson understands things thus far, is from the outside -- in many cases, including this one, regional tectonics can play a role.

I wonder if changes in the stress field are why that lavafall happened, why the summer eruption whiffed out so suddenly, why the next to last one moved north, and why the last one started unexpectedly.

This ridge-hotspot situation in Iceland complicates the attempt to try finding answers to all that -- a complication that only indirectly affects public safety and so isn't necessary in public statements because it would only worry many people.

But the boffins must know it and also know that the next eruption will happen whenever and wherever Earth wants it to.

In other news, the government has approved (autotranslated) a major raise of the power plant barriers. And the Blue Lagoon is open: the world's most hardcore thermal spa.

 

[bjdeming]

The UI's Southern Volcanoes group reports that a change has occurred. (Facebook will translate the post, but if you can copy and paste, I’ve found that Google Translate is better with Icelandic.)

No landrise has been recorded recently. They are still expecting an eruption/dike intrusion around the end of the month to early February, per this post and online media articles, but it is always notable when significant changes happen during active volcanism, especially when that activity is underground and can’t be directly observed.

Time will tell how significant this change might be.

Meanwhile, I've seen news reports that they are raising the power plant barriers by something like 9 meters. If lava is going to come their way soon, I hope that work is well underway -- this is no time of year for another geothermal heating failure.

 

[bjdeming]

Iceland is having some really bad weather, and also IMO has expressed concern about a possible start with very little warning, given how the last eruption began.

 

[bjdeming]

Weather is still in the news. Round one is over, but now powerful winds are forecast and the country's power supplier says outages are possible.

Per RUV today (Icelandic), via browser translator (copy and paste included a link to another article, but the headline is so amazing that I left it in, though you'll need your translator to read it):

...The Icelandic Meteorological Office announced over the weekend that bad weather forecast for the weekend and beyond could affect the meters, extending response times. Kristín Elísa Guðmundsdóttir, a natural hazard specialist at the Icelandic Meteorological Office, says that now that the weather has calmed down, it is better to monitor the situation. Bad weather can have a significant impact on the sensitivity of meters. “The smallest earthquakes are drowned out by the biggest weather events,” she says. “But we can still see the biggest ones.”

However, she notes that inclement weather is forecast this week, so measurements may be disrupted again.

Grindavik Town

The Vikings of Grindavík build fortifications on land and sea.​

While the worst of the weather was over, the Icelandic Meteorological Office monitored earthquakes on the Reykjanes Peninsula using other means, such as using a fiber optic cable that acts as a seismometer. It is buried in the ground and is therefore not affected by weather. “It has been a very good tool for monitoring when magma flows start,” says Kristín Elísa.

Bad weather can delay response​

However, bad weather does not just affect meters, as extreme weather conditions affect the entire civil protection system and its ability to respond to a volcanic eruption. For example, bad weather can make it difficult to keep escape routes open out of Grindavík.

"Given how the eruptions have behaved, Grindavíkurvegur has been covered in lava several times, and if it is difficult to keep Suðurstrandavegur open, it affects people's ability to escape from both the town and the Blue Lagoon," she says.

I think they also monitor pressure changes in one of the geothermal plant's boreholes, though AFAIK there isn't much warning time once a change is noted.

 

[bjdeming]

A couple of interesting images in today's IMO weather update (autotranslated) -- oops. They're in the second post.

 

[bjdeming]

and lightning:

Magma thus far is still underground.

 

[bjdeming]

Eruption time might be approaching.
The Southern Volcanoes group reports on Facebook that (per Google Translate):

South Iceland Volcanology and Natural Hazards Group
Microseismic activity at Sundhnúkar now appears to be increasing. There has been very little activity in these areas since the end of the last eruption, but tiny earthquakes have been recorded from time to time. The accompanying picture shows the activity over the past week. The largest earthquakes are measuring between 1-1.5 in magnitude. Four of these earthquakes occurred last night, which can be said to be the greatest activity since the end of the last eruption in early December. The earthquakes last night occurred shallowly in the earth’s crust, from 1.5 km to 4 km. However, bad weather in recent days has affected the sensitivity of the measuring system, and it can therefore be assumed that more earthquakes have been recorded than those recorded.

 

[Anti Marine Layer]

Looks like this is about volcanoes, not wildfires. Need to keep watching for the eruption.

 

[bjdeming]

The lava barriers at the power plant are ready. Per browser translation:

Dikes around Svartsengi have been raised to a height of up to 17 meters to protect structures from a possible eighth eruption of the Sundhnúks crater series. Only the worst weather makes people stop working. Before noon there was hardly a place there...

-- Source (Icelandic, but check out the video to see the scale of this effort and, on a journalistic point, that it's possible to do an interview in wind that is rocking both interviewee and journalist! )

 

[bjdeming]

Well, the "get ready to jump" time is here.

Increased risk of volcanic eruption at Sundhnúk crater range​

A volcanic eruption must be expected at very short notice.​

21.2.2025

Updated February 21 at 11:50

• Updated model calculations show that magma accumulation under Svartsengi has reached the same volume as that which erupted during the last eruption
• It must be assumed that a volcanic eruption can begin at very short notice.
• The magma is most likely to first erupt in the area between Sundhnúkur and Stóra-Skógfell.
• The area affected by a volcanic eruption is governed by whether the fissures extend north or south.
• The risk assessment has been updated and the risk level increased in three areas.

That's just the headlines of today's IMO update (autotranslated). They say warning could be as little as 30 minutes, the area threatened will depend on where magma surfaces -- if it surfaces and doesn't do another underground dike intrusion -- and in which direction the fissures extend.

Policr reportedly are sending heads-up text messages in English to warn foreigners in the area.

 

[bjdeming]

Here's a look at a section of the lava barriers (sound alert, depending on your taste in music). For orientation, that steaming structure is the geothermal plant/Blue Lagoon complex and the highway is the north-south one running from Grindavik up to the Reykjavik area that gets lava-covered frequently.

 

[bjdeming]

Probably not Reykjanes relevant, but an amazing view anyway:

Askja, Katla, Bardarbunga, and other volcanoes are in there -- nothing really significantly changed from background restlessness, but they all happened to be restless this way at the same time.

One of those days when an Icelandic seismologist probably sighs and wonders why they didn't go into a relatively straightforward career path, like bullfighting.

 

[bjdeming]

This is the longest inter-eruption interval in the series. It doesn't seem to be over, though: the Southern Volcanoes group, a short while ago, noted microquakes at the Sundukhnur craters and there are now a few -- very few -- somewhat stronger quakes (up to 1-pointers) registering north of Grindavik in that area.

Which will be stronger: the pressures that whiffed out last year's eruption in that area (which, given the location, this layperson suspects of having the weight of the Reykjanes Ridge behind them as it meets and interacts with the hotspot), or the force of magma seeking a way out of its underground prison?

IMO and the Southern Volcanoes group both mentioned that last month there was a sudden low-level swarm at Sundukhnur that set off alarms, but nothing came of it.

"Sudden" is the keyword here, and if it's going to erupt again, the longer we wait, the more violent the initial fountaining will be and the faster eruptive fissures will open up as the eruption grows stronger.

 

[bjdeming]

Just in passing, on that vafri.is live earthquake graphic, sometimes (as now) there is a lot of activity north up the coast from Reykjavik -- that's another volcanic system waking up slowly, but it's worth mentioning for any Marvel fans here because sometimes (as now) a quake occurs near a real-world place called Bifrost.