Editorial: Science full of unknowns
Science is full of doubt and unknowns.
That is precisely why scientists carry out research and then cautiously preface their findings with a level of uncertainty. Rarely do scientists know anything with close to 100 per cent conviction.
Conviction of a different kind has come to six Italian seismologists and one official in the wake of the 6.3-magnitude April 2009 L'Aquila earthquake, which killed 309 people, made tens of thousands homeless and destroyed much of the city of 73,000.
A mind-numbingly preposterous sentence has now been handed down to them of six years' jail for manslaughter for not properly communicating the risk of a potentially deadly quake following tremors in the months before the main shock.
The experts are expected to appeal the judgment, a process which could take years to complete. In the meantime, Luciano Maiami, the head of Italy's national disaster committee, has quit in outrage that scientists who, he said, had spoken in good faith and about the impossibilities of predicting earthquakes, should be castigated for doing so.
Maiami, and scientists and science bodies around the world who have watched the events in utter astonishment, have sounded a warning that should concern all who live with the threat of earthquakes. They say this sentencing will make experts think twice in future about giving advice to their political masters.
From this distance, these convictions seem like petty revenge, a desire to blame someone for a natural event that is clearly beyond human ability to control or even predict. As Cantabrians now realise only too well, it is impossible to know what is going on below our feet. While meteorologists can watch the clouds, astronomers can view the stars and vulcanologists can see volcanoes, seismologists can largely only react to whatever unpleasant surprises the Earth throws up at us.
Seismology must be a most frustrating discipline for that reason. Yet while full-blown prediction of a quake's magnitude, time and location is but a dream, there are patterns of aftershock behaviour that can be recognised and extrapolated from. It would be of grave concern if this information were to be withheld from the Government and the public for fear of possible prosecution if it turned out to be wrong.
After the September 2010 Darfield earthquake, experts warned of the probable risk of a magnitude-6 aftershock and of ongoing tremors for months, possibly years. Both those broad forecasts have proved to be right.
Unfortunately, the deadly nature of that major aftershock could not be predicted, nor could its location - closer to Christchurch than the first magnitude-7.1 quake. Since then the public has been kept informed of possible quake activity with frequent probability forecasts from GNS Science.
Our government scientists were quite rightly questioned at the Canterbury Earthquakes Royal Commission about whether they issued adequate warnings of a large aftershock and if they told the public everything they needed to know.
There is some suggestion they could have been overcautious in the latter case, but nobody would suggest they should be prosecuted for that.
Scientists have to be able to operate without fear and to be encouraged to provide the best possible guidance. Any moves that curtail that, and reduce their confidence to advise, must be strongly resisted.