What a difference 15 kilometers can make.
For example, 15 kilometers once nearly led to war between Iceland and the United Kingdom. Known as the first "Cod War", it began with the UK's heavy deployment of large fishing trawlers across the Atlantic at the end of World War II. These heavily overfished Iceland's waters all the way up to 7 kilometers from the shore. Iceland's economy was almost completely dependent on fishing at the time, but there was apprehension about getting into a conflict with a nation hundreds of times its population and well over a thousand of times its GDP.
Eventually, the interests of fishing won, and Iceland extended its fisheries by 15 kilometers. Rather than leaving Icelandic waters alone, Britain responded by launching a naval fleet involving 37 warships and 7000 sailors, against Iceland's coastguard of seven patrol boats and 100 sailors. Live ammunition was fired. Iceland's most advanced patrol boat was rammed. Etc. But both sides ultimately managed to avoid escalation beyond any point of no return, and the UK ultimately accepted the new boundaries. It would take an additional two Cod Wars of increasing intensity before Iceland would gain control of its full modern EEZ - but it all began with that first 15 kilometers.
15 kilometers, too, is the reason that people in Ireland tomorrow will only be getting toxic-pretty-sunset-gas rather than being part of massive transatlantic air traffic jams.
It's time for Eldfjallavakt.
The winds are changing:
And with the changing winds, the volcano's plume has shifted directions. The old portion of the plume continues out into the arctic and northern Russia, spreading and diluting around. But the main current output? It's on the way to Ireland.
Which is where 15 kilometers comes in. Because if the current eruption had opened up at the southern end of its actively spreading zone - about 15 kilometers to the south, well underneath Dyngjujökull - the character of the eruption would have been very different. Obviously, there would have been flooding - jökulhlaup could easily take out all the bridges connecting northern and northeastern Iceland, threaten low-lying homes and towns, and change the landscape. But more than that, when these sort of subglacial eruptions break through, they tend to be ashy. Sulfur dioxide, which is easy to detect by satellite, can be used as a rough proxy for figuring out where ash has travelled.
Hence, had this eruption not opened up so far to the north, tomorrow an ash cloud would likely be arriving right into the middle of very busy transatlantic air corridors.
Okay, so that's all well and good... but what's this about a big cloud of poisonous gas moving over Ireland tomorrow?!?
Let's not freak out about it and overinterpret the satellite data. First off, this is SO2 that has been lofted into the upper atmosphere, not at the surface. Can it descend? Yes, that happened with Laki. But this volcano is still just in its early eruptive phases. While the gas emission rate isn't yet quantified, given the flow rates versus Laki, I doubt the emissions are anywhere approaching Laki's rate. I really wouldn't expect any surface-level problems outside of Iceland as things stand with this eruption.
That said, I'm still going to try to track down some Irish pollution meters in the coming days to see if I'm wrong.
One thing that's a lot more likely is optical effects. Even if this eruption doesn't accelerate, if it merely continues erupting for many months (something the researchers feel is likely), it's not unreasonable that this could yield Pinatubo or El Chichón-level climate alteration; it all depends on where things progress from here. When heavy SO2 concentrations are in the upper atmosphere overhead it seeds water droplets that reflect part of the sunlight away. In extreme cases, the sun can look like sunset at noon and be blood-red in the evenings. Furthermore, writers during earlier major SO2 events remarked about how the sun seemed to lose its force - how it didn't feel warm, how it became hard to start a fire with a magnifying glass, etc. While it's harder for a polar volcano to affect the climate than a tropical one, there's a long history of such climate affects nonetheless.
Whether we'll even get to the point of "pretty sunsets" is yet to be seen. I can only simply observe: there is a large plume of sulfur dioxide heading towards Ireland right now.
But back to Iceland.
The big news yesterday was the new fissure (or depending on how you define it, two fissures) that opened up in Holuhraun. And nothing about the new fissure, except for perhaps its present size, is good news.
The new fissure is notably smaller than the old one. But it's still quite active, and more to the point, it's doing nothing to decrease activity in the main fissure (if anything, that only seems to be rising).
It's also really darned close to the foot of the glacier.
Lava flows are getting quite close to the ice, if they haven't already reached it. The main fissure, by contrast, should be hitting the Jökulsár á Fjöllum tomorrow. Expect lots of steam and reduced flow rates over Dettifoss.
Now, having another fissure opening up on Holuhraun is indeed news. But unfortunately, it's increasingly looking like the news tomorrow or in coming days may be what we've been wanting to avoid for quite some time: a fissure opening up under Dyngjujökull. :(
That's one of two sigkatlar in Dyngjujökull over the rift, which has been growing and deepening. The ice there is 300-350 meters thick. Water flows have been slowly increasing in the Jökulsár á Fjöllum. Well, they've now taken on a clear sulfur smell, one of the key signs of melt driven by volcanism. If lava is not directly touching ice in there, it's at least getting very close. The whole situation is described as very unstable, says geophysicist Björn Oddsson. Geophysicist Magníºs Tíºmi says it's escalating.
The glow can be seen a hundred kilometers away in Mývatn:
The temptation of getting to see such an event is unsurprisingly drawing tourists to sneak in. A car was spotted today and its driver and passengers will be charged. But it's perfectly understandable that the region is closed, especially given the growing flood risk.
Will there be a big jökulhlaup? I have no clue. It all depends on precisely what happens, where, at what rate, what gives way, etc. But it absolutely is a possibility. The bridges absolutely are facing a real threat. People in at-risk areas to the north need to be ready to evacuate when the call goes out. And so forth.
Scientists are still keeping their distance and are watching from 20 kilometers away.
But that doesn't mean that we have no great pictures to see.
And some videos as well. The new eruption may not have the size or flow o the old one, but it has its own different beauty to it:
Plus, here's another excellent on-the-ground video of the main eruption to the north:
Lastly, as always... the Míla shots are just beautiful.
Update, 15:00: That's some serious rifting:
In other news: Radar measurements of Bárðarbunga's caldera show 15 meters of subsidence, which is assumed by the scientists observing it to be due to the caldera floor descending into the loss of magma underneath, although at what depth the magma is coming form is not made clear. This is the largest subsidence, by an order of magnitude, ever measured in Iceland by modern equipment; Krafla, for example, subsided only two meters - yet this event is far from over. While there has been historical incidents of more subsidence - Askja subsided a whopping 300 meters in 1875 - there was no scientific equipment on hand to document the process. This data is bound to be very useful in the future.
Concerning the likelihood of an eruption from Bárðarbunga herself: "We can say that this does not decrease the likelihood that there could be a volcanic outbreak, and even a serious one in Bárðarbunga herself" says geophysicist Magnús Tumi Guðmundsson.
Volcanologist Þorvaldur Þórðarson says that activity in the eruptive fissures has increased by about 50% in the past day, primarily in the central crater. He says that the gas plume is extremely beautiful in person, and that the sun is blood red through it.
The SO2 plume is now moving over Ireland:
While I write previously that I doubted it'd have much of an effect on the ground... I was wrong. I found every online SO2 meter in Ireland, and all but one are spiking like crazy. Nothing to health alert levels yet, but it's still going up. Also it's worth noting that while Ireland's public health alert levels are at 350µg/m³, WHO recommends no more than 20µg/m³ for 24 hours and no more than 500µg/m³ for 10 minutes.
Sorry, Ireland. :(
Update, 16:30: Of the six monitoring stations, one (Kinsale) appears to be broken, two (Dublin-Rathmines and Dublin-Tallaght) appears to be nearly off the top of the scale, and the other three are now off the top of the scale. I'm going to need to see if I can find the raw data, because otherwise I can't monitor how high this is getting. Clearly they did not anticipate this sort of huge SO2 spike. :(