Earthquake prediction is in a strange place these days. On the one hand, scientists have just about done everything they can with available metrics, and they still aren’t terribly good at predicting eruptions. It is as if an unseen trigger is waiting to be discovered. So all they can do is guess at probabilities over a period of time.
On the other hand, scientists in Italy are facing the courts for not letting the public know that they thought an eruption was imminent.
The best you can hope for, in terms of current predictions, is something like “x% chance in the next 30 years”. And then it seems to be 50/50 that it will erupt at all, and if it does, then the time period could be out by a factor of 2-3.
What we need is definitive proof of an eruption within a year – that way people could evacuate in a civilized manner.
News this week about Mt Fuji doesn’t really help. A Japanese professor says that Fuji is overdue for an eruption, but doesn’t give us a time frame. Everyone knows it is overdue – it used to erupt every 30 years and has been dormant for 300. No degree needed to make that observation.
He also says that ash accumulations in some areas could be as high as 60 centimetres. That’s enough to collapse many roofs. But the real threat from ash is the sharpness of the particles – some ash can rip lungs apart and destroy engines. To be useful he really needs to describe the risks of the ash rather than just the amount.