Posted on behalf of Nicola Nosengo
The aftershocks of last year’s earthquake in L’Aquila, Italy are not over yet.
After thousands of scientists came out in support of six of Italy’s top seismologists, who are accused of manslaughter for not raising the alarm in the days preceding the earthquake, some are criticizing this solidarity.
Following the indictment of the six, more than 5,000 scientists and other professionals from different countries signed an appeal letter to the President of Italy, Giorgio Napolitano. They sought to remind Italian authorities that scientists should not be held accountable for failing to predict an earthquake, something no seismologist in the world can do.
Now dissenting views have appeared on Volcano Listserv, an online forum administered by Jonathan Fink at Arizona State University. (Some of the indicted scientists belong to Italy’s INGV – the National Institute for Geophysics and Vulcanology.)
Criticism of the letter first came from Lalliana Mualchin, a retired chief seismologist at the California Department of Transportations. Mualchin disagrees with the methods used in Italy, as in most countries, to assess seismic hazard. INGV, she explains, uses a method called Probabilistic Seismic Hazard Assessment. In essence, it builds on the assumption that very violent earthquakes in a given area will only occur once every thousand years, and thus designs emergency plans and building codes around less catastrophic scenarios, which are considered more probable. In Mualchin’s view, this method leads to a systematic underestimation of earthquake risks.
Deterministic Seismic Hazard Assessment (DSHA), instead, uses geology and history to estimate the strongest earthquake each area can have, and assumes that it can effectively happen at any moment. Mualchin wrote in a letter to Nature that “PSHA, which originated mainly from California, has been promoted and pushed for years without open debate, through funding and so many publications.”
To her mind, signing the solidarity appeal without discussing the methods used in L’Aquila is a disservice to citizens.
“To indict them [the Italian scientists] on the basis of not predicting the precise time of the earthquake is extremely problematic and most of us will support them,” she notes, “[but] critical seismic hazard estimates by the ‘indicted’ scientists are missing in the letter and must be discussed.”
A different, and more direct, kind of criticism has come from Flavio Dobran, a Naples based volcanologist, formerly at New York University. Dobran has for years criticized INGV for its eruption risk estimations for the Vesuvius volcano, as well as its related evacuation plans, which he consider inadequate.
In a letter to Nature he wrote that last week’s story in the journal “overstates the solidarity” around the indicted scientists. In his view, the L’Aquila tragedy has revealed typical faults in the Institute’s style of hazard assessment, which could result in a “far greater tragedy” in case of a Vesuvius eruption.
“The indictment is an unfortunate result of the way Italian science is being practised,” he says, referring to a strongly politicized academic environment.
About the indicted scientists he says that “any opposition to their methods spells doom for those who dare to question their ways of seismic and volcanic hazard management in Italy”. Dobran says he finds the supporting letter “misleading”.
“What the international scientists fail to understand is that if they support this letter they will be taken for a ride. Independent research on volcanoes and earthquakes will be suppressed even more,” he claims. Two other Italian researchers have posted similar comments on Listserv.
In the end, there is some hope that such divisions might revive a healthy scientific debate. Mualchin has been invited to organize a workshop with the working title of “DSHA, PSHA, nDSHA – what next to mitigate natural disasters?” at the next Fall Meeting of the American Geophysical Union in San Francisco.