Since the report was made by geologists that Yellowstone caldera was (once again) bulging, the news has spread through the media like wildfire. Every day, there is another commentary that attempts to move the public one step nearer hysteria. I found this blog yesterday and thought that it was a good dose of reality for anyone who has become alarmed by the media.
Some Yellowstone myths, courtesy of CNN
Some Yellowstone myths, courtesy of CNN
By Gareth Fabbro | January 27th 2011
The background to the video is that a study found that the ground is swelling in Yellowstone, a fact the authors of the study attributed to fresh magma intrusion at depth. While this does increase the chances of an eruption at some point in the future, it is nothing to panic about. Not that that would stop the media.
What first drew my attention to this particular video was who CNN thought it was most appropriate to ask about the implications: the physicist Michio Kaku. Physicists do have a lot to say about volcanoes, from fluid dynamics during eruption to techniques such as InSAR and seismics used to monitor them. Unfortunately, Kaku's field of expertise (string theory) has very little relevance to volcanology.
So to the video. I will highlight each incorrect claim (of both Kaku and the CNN host, Kiran Chetry) in bold, and then briefly explain why it is wrong.
The last time this happened was 640,000 years ago.
The last caldera forming eruption was 640,000 years ago. The last known eruption was 70,000 years ago, and far more gentle. Between 150,000 and 70,000 years ago Yellowstone was highly active, although it formed mostly lava domes and flows. Inflationary events like this recent one are much more common, although this is the largest one in the [brief] instrumental record.
We are due an eruption.
This assertion seems to be based solely on the fact that past caldera collapses have occurred roughly every 600,000 years, and it has been 600,000 years since the last one. Unfortunately, volcanoes don't work like that. Over the several million years Yellowstone has been active, much will have changed beneath the surface. The processes that led to the last caldera collapse may be working slower this time around. While the last three caldera collapses have been happened quite close to 600,000 years apart, other calderas around the world are not as regular.
There then follows a lot of rather sentimental scaremongering. Yes a caldera collapse would be bad, especially for the United States. However, it is the least likely possibility for the next eruption. Kaku then gets thousands and millions mixed up, although for this I will give him the benefit of the doubt. I often say one thing, when in my head I meant something else. However, he continues to say we are due another big eruption. We are not. Volcanoes do not erupt on a schedule.
The 600,000 year cycle is making 'us' very nervous.
It is not making me nervous.
We need to watch the rise of the sea level very carefully.
If I was being generous, I would assume he meant the rise of the ground level. Sea level has nothing to do with anything.
Poisonous gases reaching 500 miles.
Poisonous gasses are one of the least traveled volcanic hazards. While they would pose a danger close by, they quickly become too dilute to cause harm. The biggest threat at this distance is volcanic ash, blown by the wind. Based on past eruptions at Yellowstone, the thickness of ash at 500 miles could be thick enough to damage plants. However, this is only in the worst case scenario. The next eruption at Yellowstone is unlikely to cause that much damage, at least outside of the local area.
It is 'black magic' trying to predict volcanic eruptions.
This bit actually makes me a little angry. Here is one scientist, pretending to be an expert in a discipline he quite clearly isn't, who then proceeds to write off the work of an entire field in his ignorance. While volcano forecasting is still pretty imprecise, the last few decades have seen great leaps in the science. Where a volcano is properly wired up, there is plenty that we can say about the likelihood of an eruption. For example, volcanologists watched Eyjafjallajörkull awaken for over a decade before it finally blew. So, and apologies to any theoretical physicists here, I return the insult: String theory is not real science (it can't make any predictions
about the real world).
A 'supervolcano' like Yellowstone was responsible for the extinction of the dinosaurs.
I was under the impression that we had pretty much settled on the asteroid impact for the K/T extinction, although I admit to my lack of expertise in this area. However, the type of volcanism that has been accused of causing the K/T (along with the Permian-Triassic 250 million years ago) was definitely not a Yellowstone style event. Flood basalts, over a period of thousands of years, may have altered the climate enough to kill off large numbers of species. It was not a one-off 'super-eruption'. The last three Yellowstone caldera collapses did not cause mass extinctions.
You don't get much warning.
See my earlier reply to 'It's black magic'. Also, it is worth pointing out that there is good archaeological evidence to suggest that when Santorini (another caldera) had its last big eruption, the people there had enough warning to evacuate. That was before all our fancy high-tech instruments.
We're still clueless.
No, you're clueless. Those of us who have studied volcanoes for more than 10 minutes before going on air are far less ignorant.
So, rant almost over. I saved the last of my ire for CNN. It was CNN, after all, that decided to interview Kaku as an 'expert'. I think the decision reveals a lot about the attitude of the media towards science. 'Science' is all one subject, so any scientist will do as an expert, whatever their true field of expertise. The more famous the better. Would they have interviewed a rugby player as an expert on soccer? I don't like pointing out other peoples mistakes, because I know I make enough of my own. When your 'expert' displays such incredible ignorance on my subject, however, I am sometimes willing to make an exception.
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