In Icelandic volcanoes deep in the highlands, lava is rarely a major threat. The serious threats we face from volcanoes in the currently active system, as mentioned previously, are:
1) Jökulhlaup - catastrophic glacial outburst floods which can reach biblical proportions. This is a local catastrophe.
2) Pumice / ash falls - some of the volcanoes in the current system have had tremendous explosive eruptions of a scale that caused widespread abandonment of farms and towns over a hundred miles away. This is a local catastrophe.
3) Ash clouds - eruptions from this system before airplanes were invented have caused orders of magnitude worse ash problems than Eyjafjallajökull. This is both a local and international disaster.
4) Gas emissions - eruptions from the broader system have at times released enough climate-altering, poisonous gases to kill millions of people worldwide.
Those who remember my first article in this series will recall the consequences of the last time, a couple hundred years ago, that #4 led to a catastrophe. Well, finally we have meters on site measuring sulfur dioxide emissions from the first sizeable eruption of the current event.
And the results are not good.
More Eldfjallavakt after the fold.
(Sorry for the delay this evening, I accidentally hit "home" right after finishing the article and lost everything :( )
Don't let the distance of the photos fool you - you're looking at a row of lava fountains 1 1/2 kilometers long that have unleashed in a day and a half 20-30 million cubic meters of lava spread out over 4 square kilometers.
That's no little plume. And along with it? Sulfur dioxide and other gases.
Sulur dioxide is a colorless, foul-smelling toxic gas. When it encounters water, it dissolves into it and forms sulfuric acid, and it can be lethal in high quantities. Even inhalation of low levels is associated with respiratory illness, premature birth, and reduced lifespan. Children and the elderly are at particular risk. Think "living right next door to a coal power plant with broken pollution controls".
There's always some degree of sulfur dioxide with volcanic eruptions, so it's important to measure. Today, the scientific team, as part of the FutureVolc project, got their first measurements of its levels in the air. And their conclusion?
The gas measurements make it clear that there is a large quantity of sulfur compounds in the the eruptive plume. Consequently there can be a great deal of danger approaching the region. It is important that those who go near the eruptive site are with gas masks and meters.One article which I ran into but can no longer locate said that the danger area is said to extend out to 10 kilometers from the fissure. Note that these meters have been measuring gases during a windstorm, which would be expected to significantly dilute and disperse them.
This shouldn't be surprising. Scientists have been remarking about the gas - for example, in a recent interview (below) one warned an interviewer that they shouldn't hang out too long where they were standing or they'll start getting irritation from the sulfuric acid forming in their eyes. But now there are meters. And the results are leaving transportation service operators that service the area investing in meters and masks. It's not that briefly doing a news report or whatnot without a mask on site will kill you... but it's definitely bad for your health to spend any significant time there without one.
What's the emission rate per second? That hasn't been estimated yet. But wow, is it ever leaving a sulfur plume detectable from space:
How does that compare? Here's how Europe looks.
Now, that doesnt mean there's no sulfur dioxide pollution in Europe - simply that at present it barely meets the satellite's minimum threshold for display in most parts. For a higher pollution area to compare to Iceland, here's China:
The press has been reporting on this NOAA data, but rather than just trust them blindly, I want to make doubly sure this isn't an error on the part of the NOAA satellite data, or that it's not being misinterpreted - so I sent an inquiry to NOAA, which they'll hopefully reply to soon. Because that's a really freaking big plume for a day and a half eruption.
Because we're not talking about an eruptive event that's going to be going on for one day.
As reported yesterday, some were saying that the eruption would be down to just a few short-lived craters come this morning. That did not happen - while activity declined significantly in the morning, it but then rose back up, nearly to the level of the previous day. The average flow rate today was around 100 cubic meters per second. Though that number is lower than what was reported yesterday, the comments from the scientists suggest that the difference in figures is more related to an overall degree of uncertainty on the figures than a major decline.
So... will this current eruption die off before too long? Possibly. Probably.
Will another one start up at some point as part of this series? Highly likely. And likely again, and again. Researchers have been talking about how it's quite a realistic probability that this will go on for weeks, months or years, as has happened many times in the past. And it could possibly - if we're very unlucky, but hopefully not - come with a big Bárðarbunga or Askja eruption mixed in.
But let's not get too ahead of ourselves. We don't know what will happen with those two (more on them in a minute). But on the dike, there are no signs that the rate of spreading and the flow rate of magma is on the decline.. And so long as that is the case, this activity will keep going in one form or another, with any respites just being an opportunity for another buildup of pressure.
Is the pressure even dropping from the current eruption? It doesn't look so at this point in time, but they'll analyze the GPS data in more detail tomorrow. Lava fountains are still reaching 60-70 meters high at times.
Meanwhile, Bárðarbunga keeps quaking up a storm:
What else can I say? Either these completely unprecidented quakes that keep breaking records will stop, or... something will happen. Most likely something "not nice". I'm obviously rooting for the "stop" option. As with previously, the operating theory is that these are not due to a "roof collapse" from underpressure, rather due to the pushing down of a conical plug making up the "floor" of the magma chamber due to overpressure.
Quake activity is, as with yesterday but moreso, way down in the dike. For the obvious reason that the magma has a place to go and doesn't need to break rock at present. This is a good thing. What's not a good thing? That which is going on in Herðubreiðartögl:
Since we're going to cover it a bit, let's go back to pronunciation.
Bárðarbunga: BOWR-dthar-Boon-ka (r=alveolar tap)
Dyngjujökull: DINK-yih-YUH-kih-tl (tl=tongue click)
Holuhraun: HAW-lih-Hroyn (n=devoiced)
Sorry that this is where the activity is... I imagine this is probably the hardest place to pronounce yet. ;) It means Herðubreið's Tails (tails as in horse tails - there's about 10 different words for different types of tails in Icelandic). Herðubreið ("Broad Shouldered") is sometimes called "Drottning íslenskra fjalla" (Queen of the Icelandic Mountains) for her well-formed shape of steep, highly difficult to climb sides and a flat top (typical of volcanoes that formed underneath a thick ice sheet). The "tails" are a chain of volcanic vents built up around... you guessed it... an active rift.
A rift that is now quaking in a manner making up over 30% of the activity in this current earthquake swarm. Beyond Askja.
Since even the Icelandic news has given this concerning fact basically no coverage, I got in touch with Ágúst Guðmundsson, a professor of earth sciences who has been involved in researching what's going on here. You may remember him from earlier in this series from his hypothesis that the dike is being fed not from Bárðarbunga, but from the far larger deep magma reservoirs. Well, he responded while I was writing this article with an excellent summary. I'll translate:
This is a primary dike or "regional dike". Such dikes connect sometimes with shallow magma chambers under large volcanoes, but much more often come from large magma reservoirs which underlie most or all of the major volcanic systems in Iceland (see Figure 10 in "How local stresses control magma-chamber ruptures, dyke injections, and eruptions in composite volcanoes" / Guðmundsson 2006). The dike in the Bárðarbunga system now is primarily or completely from such a reservoir. It has long been considered a possibility that a dike could connect between eruptive belts and volcanic systems (see "Volcanoes as elastic inclusions: Their effects on the propagation of dykes, volcanic fissures, and volcanic zones in Iceland" / Andrew and Guðmundsson, 2008), but this is the first well documented occurance with modern technology (the system of the Met Office, which has been first class in this event). These articles give you a good bit of background.Put simply? The dike is stretching everything in the area. Herðubreiðartögl is one area that's already highly stressed, so the extra pressure is causing it to break, and could possibly lead to an eruption. Other things in the area (such as Askja herself) are stressed but not quite as much, so they're not breaking as readily - but if the dike moves further north, they could start undergoing quake storms and potential eruptions as well.
Under Upptyppingar (Ed: Another volcano in the area) and Herðubreiðartögl there was a quake storm in 2007. It began at around 20 kilometers underground but was primarily at 12 to 17 kilometers deep. Such quakes have also occurred at about 15 to 25 kilometers deep under Askja, Vaðalda, Kollóttadyngja, and others. Most are connected with magma intrusions from these deep-set reservoirs which I mentioned. Reservoirs and magma chambers are cavities in the crust and accumulate tension which changes occur in the tension field in the vicinity. The same applies to active faults - they accumulate tension. This is called in physics tensioning and applies to all solids with gaps or cavities under pressure. This is what is going on now in Herðubreiðartögl and also Askja. This large dike has a tremendous magma pressure and has applied tension across a large region. Whereas magma chambers or reservoirs are in the vicinity, or large faults, they accumulate tension and can, if it becomes suficiently high, cause intrusions out of the chambers or reservoirs, and/or quakes in faults. This is what we've been seeing as a consequence of the dike and it's for the first time with modern technology and devices in the country. And among other things it's why this is such an incredible geological event for everyone.
The eruption is now so small that it changes little to nothing for the dike which can still spread further to the north. There its tension effect would be even stronger, in Herðubreiðartögl and Askja, and could lead to an eruption. But whether the dike (or its siblings, many dikes are composite and created in many magma intrusions side by side) keeps going or stops we don't know, but it will be determinate in the coming days, weeks or months.
Meh. Let's change subject. Time for some pretty pictures of hot things coming out of the ground!
... and a few of Icelanders performing their national duty of standing in front of a volcano to take pictures of themselves looking all töff to use as facebook profile pics. ;)
... and maybe a few videos while we're at it. :)
Lastly, another not-so-grim note: the debate over what the new lava field should be called. :) It's never too early to start! The leading candidate right now is "Flæðahraun" (flæða = flow), because it's been flowing over a region called Flæður. Other suggestions have been to name it after the Apollo astronauts who trained in the area, while another is to name it after its appearance as a glowing dragon (Drekahraun). Bárðarhraun is an obvious suggestion as well. Tons have been suggested, but my so far is Þorbjargarhraun, in honor of Þorbjörg Ágústdóttir who is doing her Ph.D thesis on the scene researching the flows.
Update, 3:00 2 september: The Mila cams sure are pretty tonight. Lots of activity going on there.
Good night, everyone.
Update, 10:00 2 september: Early reports are that activity is roughly the same as yesterday. Quake activity in the dike continues to be (proportionally) low but steady. Scientists are now heading out to the site with gas meters to decide whether they think it's safe enough to work there today or not.
Update, 13:00 2 september: Finally got a good NESDIS SO2 satellite pass, at least for the northeast side of the country (the 11:07 pass here). Not pretty. :Þ It's halfway to Svalbard and Northern Norway.
New Met Office update. GPS meters suggest that outflow is nearly matching inflow. Of course, that doesn't suggest how long inflow will continue, but at least it limits it's potential to expand to the south (jökulhlaups) or north (potentially triggering Askja). This the current status is thus, obviously, a good thing, one that we hope will hold. Flow rates are said to be similar to yesterday. SO2 emissions are reportedly up, but still no estimates on the total emission rate. I should send an inquiry.
Heavy seismic activity continues in Herðarbreiðartögl and the Bárðarbunga caldera.
Update, 16:00 2 september: People have asked me whether it's a good thing that the fountains have been getting taller (by some reports up to 200 meters, the height of a 60 story skyscraper) and the magma viscosity has increased. I said no, that would be a bad thing, anything that hinders flow or represents higher pressures increase the risk of the eruption transitioning to an explosive phase. Explosive phases mean pumice and ash. Which means spreading the damage beyond Holuhraun and hindering access to the site. And the more the eruption turns into rises in pressure with sudden bursts letting it out, the liklier the dike becomes to resume expansion.
Well, now we've got just what I didn't want to see. Three explosive eruptions have been reported on the site. No news as to the scale of the explosions, although I would assume nothing too huge at this point. A black cloud rose up, but Þorbjörg (the scientist being interviewed) said she was far enough away that she's not sure in what direction it went. It's not known yet whether any scientists were nearby when the explosions occurred.
More on this when it comes.