Hi. I'd like you to meet Skínandi ("SKEEN-awn-di")
Say "Hi" to Skínandi! Here's another shot:
Quite the looker. His name means "Shining", and he's a waterfall on the Svartá, a tributary of the Jökulsár á Fjöllum. He's a common part of tours in the area. 20 cubic meters of water per second drops half a dozen meters in broad cascades. In the winter the rocks are covered in rime ice.
Okay, that's enough of Skínandi. Say, "bye, Skínandi!"
Because this is goodbye.
Here comes the lava from Holuhraun. According to ÍSOR's analysis, the intersection with Skínandi's river, the Svartá, is pretty much inevitable. Even if the lava doesn't cover the waterfall itself directly, it is expected to dam up the Svartá, creating a large new lake which would either fill this winter or next summer. Skínandi will either way be no more.
The lava from Holuhraun plows on. It keeps pushing the Jökulsár east and has taken over most of its riverbed in places.
Old channels of the Jökulsár are left dry on the other side of the tongues of lava. Perhaps most interesting, there are reports of the detection of pseudocrater explosions. Pseudocraters are rare formations (the most prominent examples in the world being in Iceland) whose formation is ill-documented by science, but is know to involve lava flowing over deeply saturated sediments, such as at the bottom of a lake or riverbed. The trapped steam pressure builds up and ultimately bursts out through the lava, creating a secondary eruption that builds up a "rootless" crater. If this does occur here at any reasonable scale, it could be an invaluable topic for study.
Doing that study is increasingly dangerous. Masks have been needed to even get near the area for most o the day. Norway is in the line of the plume now, and they're complaining about the smell:
I just talked with the VAST team which does ash forecasts, and they've agreed to do regular FLEXPART SO2 forecasts for us. Of course, with limited data on emissions rates they had to guess, so your mileage may vary; regardless, here's the first run of the series:
(Credit: Nina Kristiansen/NILU)
The gas we knew about. More concerningly, however, the character of the Holuhraun eruption has slowly been beginning to change. I noted yesterday that the science team was being pelted by pumice at their shelter at Dreki. Well, now there are reports of what is believed to be ash fall at Hallormsstaður. Let me show you a map:
Which leads to the obvious question:
Why On Earth Is The Airport Not Shut Down?
So far I've agreed with everything the Met Office has done, but I personally find this one inexplicable. The flight code is still orange, despite the fact that presumptive ash is being ejected and flying a hundred kilometers, just a short jaunt from the main public airport in eastern Iceland. Do we really have to measure and quantify the ash and its properties before we do anything? Is the precautionary principle out the window?
Maybe they're just moving slowly. Or maybe they've got their reasons that I'm not aware of. But for now, I'm disappointed.
But back to poor Skínandi.
This series of events makes for a lesson of the impermanence of nature. Everywhere changes - it just usually happens far faster in Iceland than in most places. Near the mouth of the Jökulsár á Fjöllum is a large lake, Skjálftavatn, and a river, Lítlaá. Neither existed until the 1970s when Krafla created them. A jökulhlaup from Bárðarbunga could wipe them out again. The forces here create and destroy, and right now, 100 million cubic meters of lava is bearing down on Skínandi.
But not all forces are created equal.
This evening, with the subsidence now at 20 meters, the public protective service is pulling out all the stops. They're preparing to brief the prime minister tomorrow. Then they'll be having a meeting with the dam operators, to discuss the threat that a major jökulhlaup could potentially run west, putting half of the country's power supply at risk. Due to the subsidence, the possibility of an unthinkable scale jökulhlaup cannot be ruled out.
The operating presumption now seems to be something big is probably going to happen. And if it does, it'll probably be big. And if it is, it could potentially be really big.
Remember that 100 million cubic meters of lava that's erupted over these past ten days? Bárðarbunga has at times unleashed floods that would send that volume's worth of water downhill every half hour or less. The "bowl" of the caldera can retain and then release at once a sizeable chunk of a cubic kilometer of water. Destroying a small waterfall? A historic flood of Bárðarbunga could carve whole new canyons. It's happened multiple times in the past.
But it's all still an unknown. Volcanoes do weird things (there's even one that erupts a blue glow). Bárðarbunga could surprise us.
If so, let's hope it's a "ha ha, you really got us!" surprise, rather than a less-than-pleasant one.
Now for some pictures.
And since the pic was so popular last time, here's a video (Icelandic news report) with clips of Nornahár / Witches' Hair / Pele's Hair doing its best tumbleweed impression. :)