October 25, 2012

Science on Trial

Surely among the most absurd judicial decisions in recent memory is the verdict by an Italian court that sends seven Italian earthquake experts to jail for six year terms. Their alleged crime, worthy of convictions for manslaughter and damage claims of $10.2 million, was for minimizing the risks of an earthquake to the residents of an Italian town after tremors struck the region. In the subsequent earthquake, over 300 people died. Though the prosecutors insist that the crime was not for failing to predict an earthquake, it amounts to the same thing. The guilty verdict must elicit incredulity; it presumes knowledge that does not exist, in effect postulating certainty in what is clearly a vastly uncertain enterprise. Though one expert says that the decision will lead scientists to keep their mouths shut, the more likely consequence (pointed out in the BBC piece below) is a mountain of false alarms. 

Seven prominent Italian earthquake experts were convicted of manslaughter on Monday and sentenced to six years in prison for failing to give adequate warning to the residents of a seismically active area in the months preceding an earthquake that killed more than 300 people.

Speaking in a hushed courtroom in L’Aquila, the city whose historic center was gutted by the April 2009 earthquake, the judge, Marco Billi, read a long list of names of those who had died or been injured in the disaster before he handed down the sentences to six scientists and a former government official. The defendants, who said they would appeal the decision, will also have to pay court costs and damages of $10.2 million.

The seven, most of them seismologists and geologists, were members of the National Commission for the Forecast and Prevention of Major Risks, which met shortly before the quake struck — after weeks of frequent small tremors — but did not issue a safety warning.

The verdicts jolted the international scientific community, which feared they might open the way to an onslaught of legal actions against scientists who evaluate the risks of natural hazards. “This is the death of public service on the part of professors and professionals,” said Luciano Maiani, the current president of the risks commission, according to the news agency Ansa. The legal and media pressure prompted by the trial have made it impossible to carry out professional consultancies for the state, he said, adding, “This doesn’t happen anywhere else in the world.”

Thomas H. Jordan, a professor at the University of Southern California, led a commission that after the disaster advised the Italian government about better ways to communicate earthquake risks to the public. He described the verdicts as incredible, “given that they have just convicted scientists for basically doing their job during a time of crisis.”

“I’m afraid it’s going to teach scientists to keep their mouths shut,” he added.

Scientists said the case raised the issue of when a public warning is appropriate. While predicting the exact time and location of an earthquake is not possible, seismologists are increasingly able to forecast the likelihood that a quake might occur in a certain area within a certain time. But if the likelihood is very low — as it was in this case, despite the increased seismic activity in the weeks before — a warning may do more harm than good. Lawyers for the defendants were unanimous on Monday in their condemnation of the sentence, which exceeded the prosecution’s request of four years in prison, and vowed to appeal.

“I wasn’t expecting this,” said Alfredo Biondi, a defense lawyer. He described the ruling as one of the most erroneous that he had encountered in his long career.

“This was a trial that should not have been held in L’Aquila” because the emotional impact of the quake is still felt so strongly in the city, said Filippo Dinacci, who represents two of the defendants.

More than three years after the earthquake, L’Aquila, in the Abruzzo region east of Rome, has yet to recover fully. Its architecturally rich center is still largely abandoned, and residents are still mourning the dead. There are some sporadic signs of reconstruction around the center, including the inauguration last month of an auditorium designed by Renzo Piano, but the overall mood in the city speaks more of discouragement and dismay.

The city and surrounding towns were felled by the magnitude 6.3 quake in the early hours of April 6, 2009. The disaster left thousands homeless and killed 309, many of them in their sleep.

Six days before the quake, the risks commission met to assess the situation after the period of frequent small quakes. The seismic activity had made the public anxious, as had a series of specific quake predictions — none of which proved to be accurate — by a local man who is not a scientist. After the meeting, some commission members gave encouraging statements to the news media, which prosecutors said gave residents an overly reassuring picture of the risks they faced. The commission, prosecutors charged, did not uphold its mandate and consequently did not allow residents to make informed decisions about whether to stay or leave their homes.

In his closing arguments on Monday the prosecutor, Fabio Picuti, cited a United States court ruling that blamed the Army Corps of Engineers for “monumental negligence” for some of the flooding from Hurricane Katrina, Ansa reported. That case, Mr. Picuti said, demonstrates that it is possible to fall short of preventing and predicting a risk, according to Ansa.

Relatives of the victims cheered the decision. “It’s just a tiny bit of justice so that it doesn’t happen again,” said an unidentified woman on Sky television.

The court did not rule on whether earthquakes can be predicted. But Fabio Alessandroni, a civil lawyer who represents the relatives of more than a dozen victims, said the sentence showed that it is possible to have a “culture of prevention.”

“It is possible to predict a risk and to adopt measures that mitigate that risk,” Mr. Alessandroni said. “It’s what the commission is supposed to do,” taking various elements, like a city’s seismic history, into account. “And this was not done in L’Aquila.”

Elisabetta Povoledo and Henry Fountain, “Italy Orders Jail Terms for 7 Who Didn’t Warn of Deadly Earthquake,” New York Times, October 22, 2012.

* * *

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. To expect more of science at this time is unreasonable. It is manifestly unfair for scientists to be criminally charged for failing to act on information that the international scientific community would consider inadequate as a basis for issuing a warning. Moreover, we worry that subjecting scientists to criminal charges for adhering to accepted scientific practices may have a chilling effect on researchers, thereby impeding the free exchange of ideas necessary for progress in science and discouraging them from participating in matters of great public importance.

 * * *

A report from the BBC provides further detail on the state of the scientific understanding, noting that predicting an earthquake is extremely difficult:

When a large amount of stress is built up in the Earth's crust, it will mostly be released in a single large earthquake, but some smaller-scale cracking in the build-up to the break will result in precursor earthquakes. These small quakes precede around half of all large earthquakes, and can continue for days to months before the big break.

Some scientists have even gone so far as to try to predict the location of the large earthquake by mapping the small tremors. The "Mogi Doughnut Hypothesis" suggests that a circular pattern of small precursor quakes will precede a large earthquake emanating from the centre of that circle.

While half of the large earthquakes have precursor tremors, only around 5% of small earthquakes are associated with a large quake. So even if small tremors are felt, this cannot be a reliable prediction that a large, devastating earthquake will follow. "There is no scientific basis for making a prediction", said Dr Richard Walker of the University of Oxford. . . .

The minute changes in the movement, tilt, and the water, gas and chemical content of the ground associated with earthquake activity can be monitored on a long term scale. Measuring devices have been integrated into early warning systems that can trigger an alarm when a certain amount of activity is recorded.

Such early warning systems have been installed in Japan, Mexico and Taiwan, where the population density and high earthquake risk pose a huge threat to people's lives. But because of the nature of all of these precursor reactions, the systems may only be able to provide up to 30 seconds' advance warning.

"In the history of earthquake study, only one prediction has been successful", explains Dr Walker. The magnitude 7.3 earthquake in 1975 in Haicheng, North China was predicted one day before it struck, allowing authorities to order evacuation of the city, saving many lives. But the pattern of seismic activity that this prediction was based on has not resulted in a large earthquake since, and just a year later in 1976 a completely unanticipated magnitude 7.8 earthquake struck nearby Tangshan causing the death of over a quarter of a million people. The "prediction" of the Haicheng quake was therefore just a lucky unrepeatable coincidence.

A major problem in the prediction of earthquake events that will require evacuation is the threat of issuing false alarms. Scientists could warn of a large earthquake every time a potential precursor event is observed, however this would result in huge numbers of false alarms which put a strain on public resources and might ultimately reduce the public's trust in scientists.

"Earthquakes are complex natural processes with thousands of interacting factors, which makes accurate prediction of them virtually impossible," said Dr Walker.

Seismologists agree that the best way to limit the damage and loss of life resulting from a large earthquake is to predict and manage the longer-term risks in an earthquake-prone area. These include the likelihood of building collapsing and implementing emergency plans.

"Detailed scientific research has told us that each earthquake displays almost unique characteristics, preceded by foreshocks or small tremors, whereas others occur without warning. There simply are no rules to utilise in order to predict earthquakes," said Dr Dan Faulkner, senior lecturer in rock mechanics at the University of Liverpool.

"Earthquake prediction will only become possible with a detailed knowledge of the earthquake process. Even then, it may still be impossible."

Leila Battison, “Can we predict when and where quakes will strike?” BBC News, September, 20, 2011.

No comments: