Iceland's Fagradalsfjall Fires

[bjdeming]

Pretty amazing couple of updates at RUV at the moment (particularly with something like the opening scene of Dante's Peak in mind for the more typical way we respond to eruptions!):

Still some time for lava to reach Suðurstrandarvégur​

The main task of civil defense tonight is to monitor the infrastructure in the vicinity of Grindavík, says Víðir Reynisson, director of civil defense. Two lava streams that run from the crater should be carefully observed. On the one hand, the one who crossed Grindavíkurveg tonight, and on the other hand, the one who is now lining up against the defenses at Svartsengi.
Víðir says that the lava flow that lies southeast still has a long way to go to Suðurstrandarvégur. Lava flowing along bulwark L12 has not reached its end.

Víðir says that ramparts are being added to the town of Hraun because lava flows towards it.
Electricity was cut off in Grindavík for a while. Víðir says that this was done to ensure safety in the power plant at Svartsengi if it were necessary to interrupt the current through the Svartsengi line. Electricity has been restored in parts of Grindavík.

16 minutes ago – updated

"The lava is now just under our paws"​

Reporter Benedikt Sigurðsson was on a fortification east of Grindavík when he was interviewed on RÚV news at 2 o'clock.

"And the lava is now just right below our feet, so to speak, and it naturally gives off a lot of heat, apparently, 1,200 degrees hot lava. It just slowly slides down the park and approaches Suðurstrandarveðin, but it goes very slowly. It's kind of hopeless to say if and when it will reach down there."
"In the short time I've been here, it's moved maybe 50 meters. It is amazing to see how it lays along the rampart that has been made here. The road yard is working right up to ten."

...

 

[bjdeming]

Grindavik's barriers are still holding, per this story (autotranslated). Other reports say that lava is approaching the power plant barriers.

Varnargards proved their worth tonight​

Lava from the northern tongue flows over Grindavíkurveg. In the background, Svartsengi can be seen behind the fortifications that were built around the power plant and the Blue Lagoon. Photo/Hörður Kristleifsson​

...

If it weren't for the dikes that were built, the lava in tonight's eruption would probably have flowed south, over the settlement in Grindavík, and into the harbor there....

 

[bjdeming]

From Magnus Tumi (to RUV live) a little good news, especially for those trying to defend Hraun -- not so good in the short term on the western flow:

The eruption has subsided a little​

Magnús Tumi Guðmundsson, a geophysicist, was on the second helicopter flight of scientists over the eruption centers since the eruption began. The Coast Guard helicopter landed in Reykjavík just before two. Magnús says the eruption was still very powerful and little if anything has slowed it down.

"The speed of progress is significant. You have crossed the Grindavíkurveðin road. That current is still very powerful and is moving several hundred meters per hour. On the south side, it has slowed down significantly. There, lava is flowing along the rampart in the east, but there it has slowed down significantly compared to what it was at the beginning."

Magnús Tumi says that the crack seems almost as long as it was in the previous helicopter flight that landed between 10 and 11 this evening, about 3.5 kilometers. "It hasn't changed, but it's actually starting to get a little shorter at both ends and breaking apart." The activity has started to shrink."

He says that although the eruption has started to subside, it is still quite powerful. "This appears to be somewhat more powerful than the last eruption and probably the most powerful so far in this series of eruptions in the Sundhnúkasprungun."

After this long time - did the other eruptions start to subside?

"Yes, it was starting to reduce them a bit more. But I don't think it pays to draw too many conclusions from this. This is now in a similar rhythm as them and now we just see what the wind will bring. It is now likely that it won't be much bigger in the end than the others. But we just have to wait and see."

 

[bjdeming]

From the Litli Hrutur cam near Reykjavik just now, light reflections make this look like a nuclear explosion:

 

[bjdeming]

"You shall not pass."



That's the Visir power plant cam. They also have a Grindavik cam now, with a similar Gandalf-Balrog vibe, but there it looks like weather conditions are deteriorating (or maybe a camera issue, if the one above, just 7 or 8 km inland from town, stays clear).

 

[bjdeming]

The problem at the power plant, as one of the scientists on that 2 a.m. run noted to a news questioner, is that much of that is coming in on top of the February lava, which puts it closer to the barrier top. Only a little, though, I think.

 

[bjdeming]

At last report the lava was about 300 meters from the shielded geothermal pipes. Magnus Tumi was quoted as saying that this western flow is moving at hundreds of meters an hour, so we should find out soon if the shielding can withstand initial contact.

 

[bjdeming]

Okay, watching lava move, at a distance, is more like waiting for a pot to boil than like having a hurricane or severe storm system barreling at you, but the stakes here are so high, I can't stop watching.

I assume that if the shielding fails there will be a steam explosion, as in February. The rain and fog might obscure it, but there are those distant background lights.

Latest news is from Morning Paper a little while ago -- the lava front hadn't reached the pipe yet. Down at Grindavik, the eastern flow is slowing anf lava is pooling along the barriers there.

Also, the fissure vents might be consolidating. That's good news for it to be happening so soon. This could turn out to be similar to the last two eruptions, not an extended run as in Fagradalsfjall. Fingers crossed...

 

[bjdeming]

Meanwhile, as the lava flows... Iceland does not mess around with road closings:

Southshore road closed​

Suðurstrandarveð has been closed to ensure that the lava flow does not follow it if it reaches it all the way. According to the latest information from the Swedish Meteorological Agency, the edge of the lava is about 900 meters away from Suðurstrandavegur.

That reminded me of something I've read a few times: our infrastructure can channel lava and other volcanic hazards.

It's not something we laypeople would realize.

Probably the worst-case scenario I've come across while reading is at Campi Flegrei (of course). The caldera rim forms a hill that separates communities along Pozzuoli Bay from Naples. As the area urbanized, they built a highway tunnel through the hill, which saves everybody time now but which will definitely channel pyroclastic flows into Naples, per some boffins, if Campi Flegrei has a strong enough eruption in the right wrong place (the Solfatara thermal field, which close to the tunnel).

Back to watching the Icelandic pot boil...

 

[bjdeming]

I'm falling asleep here, so will take a break and rewind the cam when I get up.

Besides the geothermal pipes on Svartsengi, it's worth noting that it was after the February opening fissure eruptions waned that one opened in Grindavik back in February.

That and the earlier note from IMO about the increased quake activity recently being from cracks widening in that general area and west of town show that this is not yet over.

 

[bjdeming]

There was no disastrous news when I checked this morning, and last night it wasn't me: the lava did slow down to a crawl and, incredibly, as of now has not reached the pipes!

It is about to cut the other main road into Grindavik, though. There reportedly is a third road, which will become the only way in or out. It's not in great shape and is subsiding, although they aren't sure whether that's geology or just a result of way more traffic than usual.

That possibility of subsidence tones down the other super good news: IMO's latest update reports that seismicity is almost nonexistent.

If the eruption fissure (now down to three active vents, though it looks like a few more than that just now) -- if things weren"t stable, the ground would be shaking as the crack tried to extend further or, I suppose, if lava were trying to force its way up at some other point.

Morning Paper included a map of the flow thus far in an article (autotranslated) about the overall situation:

"I think this eruption will be something similar to what we've seen before." It may well be finished today, tomorrow or in the next few days. I think it is unlikely that the eruption will last a week or longer than that," says Kristín to mbl.is.




Map/mbl.is

No one was surprised​

She says that the eruption did not surprise anyone. "We're seeing this critical volume of something around 10 million cubic meters that needs to build up before there's a magma flow." In the last spurt that came on March 2, there was not enough magma volume that went into that magma run, and we don't know why that happened."

It's in Icelandic, but if you've been following this closely, you'll recognize the main landmarks ("Bláa" is Icelandic for "blue," as in Blue Lagoon).

RUV's report on Kristin's press conference included her saying that this eruption fissure extended farther south than the one in February.

Kind of makes you wonder about next time. Iceland has done what many considered to be impossible, but they can't erect barriers underground.

And with each eruption from now on, all things being equal, lava will climb higher and higher up the barrier.

Anyway, right now reportedly lava on both branches is ponding. Every now and then whatever has dammed the flow gives way, leading to a downstream surge.

Finally, for now, here are a couple of screenshots from the cams last night.

Somewhat weather-obscured face-off between Grindavik and Earth:

That incredible view from Litli Hrutur last night (the car lights probably belong to sightseers rather than scientists -- I've seen no reports of anything stirring there):

My screenshot of the power plant flow, creeping around the barrier, didn't come out as anything but red, black, and some gray steam.

 

[bjdeming]

It's fun to see science in action!



I recognize his name from a lot of the papers I'm reading on Iceland. Per that RUV article, the sample results will be reported here (autotranslated) when available.

It's the first sample possible since Thorbjorn shifted in February and a dike intrusion occurred just two weeks ago.

I probably won't be able to follow the findings but do know that this petrology, especially when combined with other data, might be very helpful.

Y'see, there are peculiarities galore here, including:

• The 2021 to early 2023 eruptions, while not destructive, were not typical rifting episodes (both per my reading and per Armann).
• The chemistry of that lava and this new round from December 18th on is the same, which shouldn't be, since Fagradalsfjall (? Krysuvik) and Svartsengi have been considered separate sysyems up til now -- and to add more complexity, this material coming up near the Sundukhnur craters does not match the old Sundukhnur lavas (all still basalt, of course, but a different batch).
• Per my current understanding of the reading, the vast majority of these rifting episodes involve dikes, NOT eruptions, let alone eruptions with a three- to four-week frequency.
• Nor do they shift mountains the size of Thorbjorn around, AFAIK. Krafla -- which has a central volcano as well as a fissure system -- sits on the divergent boundary, too, and yet AFAiK it didn't go skittering around during its fires in the 1970s and 1980s.

We shall see what the boffins find and how they interpret it.

 

[bjdeming]

This is one of those other sets of data (collected on the ground) that might answer such questions as "Why so powerful?" and "Is the sulfur content high because it's fresh from down below -- raising interesting possibilities to consider in future predictions?"

 

[bjdeming]

As for the lava, per Twitter translation of Birkir's two-part thread (note Alberto plugging away at it in the background ):



-- "In previous eruptions, both in December and January, there was an incredible variation in the composition of the lava. We were very surprised. Which meant that the magma wasn't very well mixed down before it came up...

It tells us something about the process underground, that is what we are writing about now and is a complete secret. On the other hand, in February, something else happened, and we have no idea what is happening now. That's why we're taking samples."

 

[bjdeming]

Oops! This is the one with Alberto at work. Twitter translation:
"..this is rapid cooling so that the liquid immediately forms a glass but does not crystallize, it is so easy to chemically analyze the glass by shooting with a micrometer, so we get results very quickly which are then published on our website https://jardvis.hi.is "*lava collapse in the background* "

 

[bjdeming]

They cut to a shot of Magnus Tumi being interviewed on one of those Twitter videos, although it was the field worker from the University of Iceland speaking.

Here is the RUV live update report on the studio interview (Google translation):

It's just as likely that the eruption will end soon, although nothing is certain​

Magnús Tumi Guðmundsson, professor of geophysics, says that the eruption will most likely end soon, just like the last eruptions. Nothing is certain in that respect.

"It is much more likely that this will just fade away and then we will repeat a similar process as has been the case in recent months," Magnús said on TV's evening news. Magnús says that everything happened much faster than in previous eruptions at Grindavík, which means that the lava flow was greater. The flow has since decreased a lot.
"Naturally, it is most likely that this will just fade away. It is not out of the question that it will continue for a while longer and it will reach some kind of permanent flow. There is a possibility that we cannot rule out, but then it will be a very slow flow."


It is most likely that landris will start again as soon as the eruption ends. There are no signs that magma accumulation is ending, but it can end very quickly. Magnús says that history teaches that only time will reveal how things develop in Reykjanes.

"Based on previous events, it can be expected that this will continue somewhat. Weeks, months, even years. Then there can be periods where everything is at a standstill for a short time," said Magnús.

About that statement on future events happening more quickly, Pall Einarsson has some thoughts (autotranslated).

The only new information I've seen is that lava might not reach the sea, if it does at all, in less than 20 hours -- no word on the status of barrier work at Hraun.

 

[bjdeming]

He does smile sometimes!

"The whole system just has to work with the fact that we intend for Grindavík to become a good and prosperous town again, but we know it can take time."





-- Visir (autotranslated)

That's from the 19:51 update.

The "statistical games" remark in that linked article refers to this (autotranslated). A little layperson has no business monitoring a fight among giants (and everyone involved is at the top of their field), but just going by surface articles, it looked to me as though Haraldur was challenging IMO; RUV, by going with that article, was giving his fire oxygen; and then the eruption happened, with two heavyweights now (Pall Einarsson and Vidir) supporting IMO.

Take that for what it's worth, which isn't much from an outsider, a layperson, and someone with no horse in the race. I was just going to briefly mention it in a blog post I'm working on about that whole "vertical/horizontal" thing (or "spreading ridge/mantle plume"), but Vidir apparently prefers directness over subtlety -- who knows what, if anything, will come next.

 

[bjdeming]

Even though reportedly (autotranslated, current RUV live update quoting Bjarki Kardalons Friis) little to no lava flow movement is reported anywhere, the eruption is still energetic and lengthy along the fissure on cams.

The February eruption was much shorter.

Still hoping for a happy ending here, but maybe the Mid-Atlantic Ridge has other plans?

 

[bjdeming]

Hmmm -- this, from the current RUV updates page (autotranslated), about half an hour ago:

Evidence of continued landris in Svartsengi​

The first GPS measurements after the beginning of the eruption indicate that landris continues under Svartsengi.
This is reported on the Facebook page of the Southern Volcanoes and Natural Hazards Group
In the last 24 hours, a rise has been seen quite well on gauges in the immediate vicinity of Svartsengi. However, it should be kept in mind that these are unsurpassed results."

The translation probably should read "unreviewed" rather than "unsurpassed."

It should be deflating as magma leaves the reservoir.

This layperson doesn't see that inflation yet on the current GPS graphic. (Icelandic) But neither does there appear to be a break, as shown in January and February.

On the IMO site, there is no update about this yet. They do mention, as of around 7 a.m. local time, seeing one jet active, but I see several on cams (though viewing conditions are poor).

It's still early days, but this is something to keep an eye on, particularly given the recent change of magma-run pattern down to two weeks in between events, not the previous three to four weeks.

 

[bjdeming]

I'm not sure if what looks like decreased fountaining is real or, since the viewing is better, it looked more intense earlier.

Anyway, per Kristin to RUV live (emphasis added):

The activity is now confined to the southernmost part of this fissure, which opened late on Saturday. We can see from our turbulence measurements that it has just been fairly stable, although the activity has shrunk to this southernmost part, it seems to be fairly stable there."

There are no conclusive figures on the ongoing landrising in Svartsengi because it has been so short since the eruption. A lot of gas pollution was detected nearby this morning, and HS Orka decided to evacuate the power plant there.

In the lava bed next to Suðurstrandarveg there are lava ponds. "Even though the progress is so slow, it can break from the sides and something more can emerge. This is primarily for the people who are there in the area. We are not seeing any very large lava lakes or anything like that, but this is just one of the things that needs to be monitored," says Kristín.

Gas and the risk of sudden flooding if a lava pond wall fails are keeping Grindavik harbor closed (they still use it for business, though they're probably not processing cod full-scale yet).

The plume has been going mostly west out to sea, but in their update this morning IMO notes:

The weather forecast for the rest of the day is southeast and east 8-13 m/s at the eruption stations, but then slower south and southwest. Gas pollution then reaches the northwest and west, but the north in the afternoon. There is considerable uncertainty in the concentration of gas pollution. Southwest 10-18 tomorrow and the gas pollution will then go to the northeast. Gas pollution is unlikely to reach the Capital Region due to strong winds.