Turning the rumor of May 11, 2011 earthquake prediction In Rome, Italy, into an information day on earthquake hazard

Abstract

A devastating earthquake had been predicted for May 11, 2011 in Rome. This prediction was never released officially by anyone, but it grew up in the Internet and was amplified by media. It was erroneously ascribed to Raffaele Bendandi, an Italian self-taught natural scientist who studied planetary motions. Indeed, around May 11, 2011, a planetary alignment was really expected and this contributed to give credibility to the earthquake prediction among people.

During the previous months, INGV was overwhelmed with requests for information about this presumed prediction by Roman inhabitants and tourists. Given the considerable mediatic impact of this expected earthquake, INGV decided to organize an Open Day in its headquarter in Rome devoted to the public who wanted to learn more about the Italian seismicity and the earthquake as natural phenomenon. The Open Day was preceded by a press conference two days before, in which we talked about this prediction, we presented the Open Day, and we had a scientific discussion with journalists about the earthquake prediction and more in general on the real problem of seismic risk in Italy. About 40 journalists from newspapers, local and national tv's, press agencies and web news attended the Press Conference and hundreds of articles appeared in the following days, advertising the 11 May Open Day.

The INGV opened to the public all day long (9am - 9pm) with the following program: i) meetings with INGV researchers to answer scientific questions; ii)visits to the seismic monitoring room, open 24h/7 all year; iii) guided tours through interactive exhibitions on earthquakes and Earth's deep structure; iv) conferences on general topics from the social impact of rumors to seismic risk reduction; v) 13 new short videos on our channel YouTube.com/INGVterremoti to explain the earthquake process and with updates on various aspects of seismic monitoring in Italy; vi) distribution of books and brochures. Surprisingly, more than 3000 visitors came to visit INGV headquarters until 9 p.m.: families, school classes with and without teachers, civil protection groups, journalists. This initiative, built up in a few weeks, had a very large feedback, also due to the media highlighting the presumed prediction. Although we could not rule out the possibility of a strong earthquake in central Italy (with effects in Rome) we tried to explain the real meaning of short term earthquake prediction vs. probabilistic seismic hazard assessment. Despite many people remained with the fear (many decided to take a day off and leave the town or stay in public parks), we contributed to reduce this feeling and therefore the social cost of this strange roman day. Moreover, another lesson learned is that these (fortunately sporadic) circumstances, when people's attention is high, are important opportunities for science communication.

We thank all the INGV colleagues who contributed to the May 11 Open Day, in particular the Press Office, the educational and Outreach laboratory, the Graphics Laboratory and the SissaMedialab.

P.S. no large earthquake happened