Mt Mayon is a beautiful volcano. The only work I’ve done on it was some years ago during my PhD, when I was doing a little analysis on volcano profiles. I was struck by its incredible symmetry. So I can understand the mentality of those wanting to climb it. However, it’s also worth noting that Mayon has what is described as a ‘Permanent Danger Zone’ – a 6km circle of constant hazard. Yet still, regular tours up the volcano bring dozens of people to its summit every day. 3 seperate tours were on the volcano when it erupted, killing 5 people including one guide.
The eruption today was phreatomagmatic – that is it was driven by steam. Groundwater circulates and gets heated by the magma, steam gets trapped, pressure builds up, and the overlying rock is blasted into the air. It’s important to note that at this point there are no reports of any kind of magmatic activity. There would have been no precursor seismic warning, just a blast, and a rain of boulders.
I think what this demonstrates beautifully is the hazard volcanoes pose which people get complacent about. As volcanologists we look at sites like Naples and Yogjakarta – cities adjacent to very dangerous and active volcanoes – with an expression something like that of a person watching a car go out of control in slow motion. Yet as individuals we will happily go and climb up Vesuvius or Merapi because the chances of it doing anything on a particular day are so tiny.
There is always a risk something might happen on an active volcano. But as volcanologists I think we sometimes forget how used we are to that uncertainty. In a world where weather forecasts are becoming almost reliable, and people are used to having huge amounts of data about everything around them, I think there’s a genuine concern to be had that the general public have little idea how little we know about when an eruption might occur. We can cover them in instruments and we still might get no warning. There’s no doubt we’re getting better, and we can put exclusion zones around things to our hearts content, but as numerous cases have shown -the ‘it won’t happen to me’ mentality gets people killed. In 1991 Unzen in Japan claimed the lives of 43 scientists and journalists who got caught out by a pyroclastic flow that flowed where they didn’t expect it to. The eruption at Tongariro last year (which I wrote about here), with the very popular walking route across it could easily have seen the same outcome that Mayon produced today.
Now, I’m not saying that we should stop climbing volcanoes and I’m certainly not suggesting that exclusion zones should be enforced for every potentially active site in the world. But I am suggesting that perhaps this event should serve as a reminder to people to ensure they are informed about the realities of risks when you’re in any volcanic zone.