In 2009, an earthquake smashed through the Italian city of L’Aquila. Three hundred and nine people were killed. Now, six scientists have been sentenced to six years in jail for it.
They haven’t, of course, been jailed for causing the earthquake (although, perhaps ironically, today we learn that that statement isn’t as ridiculous as you might think). They have been jailed, along with a former government official, for not giving sufficient warning of the risks.
In the days before the quake, there had been a large number of smaller tremors. Half of all major earthquakes are preceded by clusters of so-called “foreshocks”; should that not have been a sign? Well, no, because the equation doesn’t work so well the other way around: only about one time in 50 does a cluster of small quakes herald a big one.
The fundamental point is that it is, at present, impossible to predict an earthquake. There are various mooted techniques – radon gas detection, electromagnetic changes, seismic anisotropy. But none of them has been shown to work.
Why, then, have six scientists been jailed, apparently for failing to do the impossible? Two reasons. The first is that their evidence led the government official to tell the public that there was “no risk” (and, notoriously, that they should go home and have a glass of wine and relax). That was, of course, not true. There’s always a risk: even in seismically inactive regions. In Gujarat, India, in 2001, 12,000 people died when an “intraplate” earthquake smashed the ground thousands of miles from the nearest plate boundary. In a place like L’Aquila, on a faultline, after days of shocks, there was of course a possibility that something bigger was coming. It’s just that the possibility still wasn’t very big.
The other reason is that in the days before the quake, a local technician was loudly predicting that a disastrous earthquake was about to strike. He used the radon gas detection method – it is hypothesised that rock under stress releases the radioactive gas in detectable amounts. However, even his prediction was off by several miles and a week, and while it may be that he has beaten the world’s seismology departments to the invention of a reliable earthquake detector, that would be a surprising turn of events.
The L’Aquila disaster is an extraordinary tragedy, of course. And it is fair to say that the government official should not have issued a statement saying that there is “no risk” – instead, a full breakdown of the risks as they were known would have been better, small though they appeared to be. But this appears to be a classic example of seeking someone to blame because of the emotional demands of such a vast tragedy, rather than because there is a rational reason. As Alan Leshner, the CEO of the American Academy for the Advancement of Science, says in an open letter to the President of Italy: “Years of research, much of it conducted by distinguished seismologists in your own country, have demonstrated that there is no accepted scientific method for earthquake prediction that can be reliably used to warn citizens of an impending disaster.” He calls the sentence “unfair and naive”.
The L’Aquila seven will have to live with what happened for the rest of their lives. But jailing scientists for making a (presumably honest) prediction to the best of their knowledge is a startlingly stupid idea. The next time there are concerns about earthquakes in Italy, what foolhardy seismologist would make a prediction at all?