19 April 2010
Some reflections on the Eyjafjallajoekull ash cloud
Posted by Dave Petley
Over the weekend I have been watching and reading the media response to the aviation ban resulting from the Eyjafjallajoekull ash cloud, and reading some of the online discussions. I would like to make four observations from a natural hazards perspective:
A. This event is the result of a “perfect storm”.
I have been surprised by the lack of reflection by the media, including by some scientists (see below), that the current event really is the result of an extraordinary set of circumstances. To generate the current crisis, three events had to occur simultaneously.
- The volcano had to suffer an eruption that puts large amounts of ash high into the atmosphere. Many eruptions do not do this, which is why we rarely see these types of crises even though eruptions occur regularly around the world. In fact this volcano has been erupting for a month, but the initial events did not inject ash into the high atmosphere.
- The jetstream needed to be located over Iceland. If the jetstream had been to the south then the ash would not have been brought to Europe.
- The atmospheric conditions over Europe had to be extraordinarily stable. Those of us who live here know that what we are seeing in northern Europe is not typical (though it is not all that rare either). Usually we see a conveyor belt of low pressure systems from the southwest. At the moment we have stable high pressure and no wind, which means the ash is lingering.
If any of these three conditions had been different then this event would not have occurred. It is the rare (and quite unlikely) confluence of these three conditions that have led to where we are.
2. Some pronouncements by scientists really have not helped.
The media are now in a pickle as they have to keep the story on the front page, but finding new angles is a challenge. For this reason, alarming pronouncements by scientists are a goldmine. A number of prominent scientists (no names) have been warning that the eruption could go on for months, or even years, and that Hekla might cause an even bigger eruption. For goodness sake, please stop! There are no indications that Hekla is about to erupt; the linkage between Eyjafjallajoekull and Katla are not clear; if it did erupt, a similar problem is not inevitable if the jetstream or the European weather conditions are different; and it is not helping to raise concerns about another eruption. In a similar manner, suggesting that the volcano might cause us problems for months or years is not helping either. Yes, an eruption may continue, but the chances that it will continue to inject ash into the high atmosphere are not high, and most of the time the ash wouldn’t be brought over Europe.
Unfortunately, doom-laden predictions undermine the credibility of science and scientists when the situation calms down, as it inevitably will. This is not helpful.
3. Environmental science / natural hazards research is grossly underfunded
The third lesson is that these events can have a big impact on our lives and our economy, but our investment in research into them is pitiful. The limited capability that we have in Europe to collect good samples from the upper atmosphere is all to obvious, for example. A comparatively small investment in the science would reap large rewards at a time like this, and would provide financial benefits many times greater than the costs. If there is one thing that should come out of this it is a recognition that we have to invest in hazards research.
4. The general understanding of risk is very poor
It has been extraordinary to see pronouncements that the successful operation of the test flights over the weekend means that the flight ban is an over-reaction. The fact that a small number of flights can successfully operate does not mean that the skies are safe. It may be that the safety of, say, only 1 flight in 10,000 is put at risk by the ash, caused by very isolated pockets od denser / more abrasive material. As there are 28,000 flights per day in Europe, this would not be an acceptable risk. Unfortunately, due to the lack of research we do not know what true probabilities, but the Finnish F-18 engines suggest that they are far from trivial.
Good comments. I have been thinking, though, that the media reporting of this (at least, what I've seen, so there may be a selection bias) has been reasonably measured, on the whole. Or perhaps my expectations are just so low that I'm happy the end of Western civilisation hasn't been proclaimed?
I don't think it's entirely fair to put so much blame on the scientists. I suspect that the problem with some of the "gloom and doom" comments that are coming from recent interviews is that they're mined out of much longer, more restrained discussions of the situation. (Also, pretty much any description of what volcanoes can do sounds alarming if you're not used to hearing about it – none of those comments seem particularly alarmist to me, besides the Hekla bit.)The media will always pick up on the end-member outcomes of any geologic event because it's good for their ratings, but I don't think it's necessarily the fault of the scientists who are being interviewed. Also, a lot of it is probably a symptom of the way people who aren't scientists or emergency planners behave in response to natural hazards – which is to ignore them until they happen. Thus we have a large part of the population that is more susceptible to alarming pronouncements, and then things snowball…Then again, if someone really is only talking about the end-member outcomes, and not explaining that there's a spectrum of behavior the volcano could exhibit, they should quiet down. But I'm inclined to think a lot of the trouble is due to media cherry-picking.
NASA image of the ash cloud:http://rapidfire.sci.gsfc.nasa.gov/gallery/?2010107-0417/Iceland.A2010107.1320.1km.jpg
Hi Dave,Interesting comments about what some scientists have been saying. I feel I should add some more background, as i'm afraid you have not seen the whole story, and are being a bit critical in a fairly different area of research without the benefit of some of the information. The science at this site has been going for some time, and the information sources sits quite outside of what is in the landslide literature (there have been plenty of volcanic blogs following the GPS and seismic data in Iceland for some time at the current eruption site). The Icelandic Met Office had been monitoring (and displaying on the web) the magma chamber filling, and the volcano expanding for several weeks before the eruption began, and, also seeing the seismicity linked to Myrdalsjokull (I hope the scientist was talking about Katla, and not Hekla) – there clearly is a link between the two, and historically, eruptions are often linked between the two. To this end, a group of us travelled out last month to laser scan potential outburst floodways (Gigkokull outlet glacier, which we now know has routed much of the meltwater in floods). In terms of it continuing for months…….well, yes, in 1612 it lasted 3 days, in 1821 it was off and on for a year. The key is if water continues to get in the mix rather than simple lava generation, hopefully much of the melt has taken place in the immediate vicinity of the current eruption site. This is difficult to comment on, but the volcanic dome is an ice-cap…… hopefully we will move to less ash generation and the wind blows the other way (not good news for parts of the US dependign on regulations).I have certainly seen some bold claims by scientists about this event, but overall what I have seen is actually some pretty poor reporting on the science (as Jessica says above), and some odd sets of quotes linked together from various people and times – more distorted science than anything of quality (though Sky did have the Icelandic Met Office on). The lesson is of course scientists need to be careful as this is inevitable to get a 30 sec ‘soundbite’ for the news, and of course the usual round of 'scientists for hire' who appear on various programmes regardless of what their specialism actually is and are too far from the actual cutting edge!
Many thanks Dr Dave for your comment @ Deltoid, I am glad we can now converse on a more friendly basis than previously. That Taiwanese landslide was indeed spectacular (I have seen similar in PNG).