Boh-Dee-Oh-Dee-Oh... FOOM!

Greatest volcano quote evar:

It was not the first time air traffic has been halted by a volcano, but such widespread disruption has not been seen the Sept. 11, 2001 terror attacks.

"There hasn't been a bigger one," said William Voss, president of the U.S.-based Flight Safety Foundation, who praised aviation authorities and Eurocontrol, the European air traffic control organization, for closing down airspace. "This has prevented airliners wandering about, with their engines flaming out along the way."

Obviously, I find this eruption fascinating and exciting, and I'm reading every last tidbit I can find. I've been surprised at how many people I've talked to today who haven't heard this news yet, and even more surprised at the number of people who have heard of the air travel disruption, but have no idea what caused it. In a way, it seems analogous to someone being aware of airplane groundings on 9/12, but not sure why.

Of course, there is a huge difference: no one died (again, as far as I've read) in the proximal cause of this grounding. But there, in that quote, is a confirmation of something I read and mentioned earlier: apparently, this is the biggest disruption of air travel since the invention of air travel. A question I've been asked over and over, as I described this news to people today, was "how long will the eruption last?" The intended question in most cases was "how long will the air traffic disruption last?"

I've been kind of hedgy in answering. While I have been under the impression that there was a violent eruption yesterday that has sort of simmered down subsequently, I don't know that. The timing of various events can become obscured in traditional journalism; often you get the time the story was filed, if that, and even then it's not always clear where (i.e. what time zone) that happened. So even though what I think I'm seeing in the picture below is a heavy stream of ash headed toward Scotland and Scandinavia, and becoming lighter to the west, I'm not sure, and I don't know exactly when it was acquired.
The next issue is that no one has any idea just how long this eruption will go on. Comments I've read from people who know this stuff much better than I do say these sorts of eruptions can last from weeks to years; the last time this particular volcano erupted, it lasted for 2 or 3 years over a year (from Dec. 1821 to Jan. 1823- see link at followup). Also, the reason so much ash was lofted yesterday is the presence of ice and water. If this turns into a large-volume eruption, presumably it would melt the ice, the water would drain away, and steam explosions tossing ash into the air would decrease, despite the fact that lava extrusion would have increased. Have no doubt, this scenario would cause its own problems, but it would probably have less effect on air travel than spasmodic explosive eruptions like yesterday. So the issue here is "Is the number and size of explosions limited by ice and water, or is it limited by the amount of magma?" And the answer is, we don't know how much magma is down there, nor how much is going to come out.

Finally, even if ashy eruptions continue into the future, day-to-day weather will be the factor determining what areas or regions will be impacted. Air flow changes through time, and it's difficult to predict with any precision more than a few days out, or at all more than a couple of weeks out. Without being able to know just when blasts will occur, and what the weather will be at those times, it's impossible to say how long this volcano will interfere with air traffic.

So my answers to the questions above have basically been, "we can't really say, but it would be a very good idea to simply assume it's going to be a problem for a while." And by a while, I mean until that ice cap is gone, the volcano stops erupting, or both. Yeah, that stinks, but it's better than wandering around in an airliner, unsure whether your engines are going to flame out along the way.

Oh, and I almost forgot... there are some bennies, too. Volcanic sunsets, anyone?

Followup: Michael Welland at Through the Sandglass has the story of his stranding in Philadelphia by this eruption, including links to and excerpts from articles explaining why airplanes and ash don't mix.