From the moment an earthquake occurs, the signals produced are recorded by the National Seismic Network and are immediately analyzed by the staff on duty in the INGV Operations Room in Rome. But how is this information transmitted to citizens? Where is it possible to find reliable information without running into some fake news? To answer these and other questions, we interviewed Emanuele Casarotti, an INGV seismologist, who told us, from the seismogram to the tweet, how information about the earthquake reaches citizens.
What happens in the INGV Operations Room in Rome when an earthquake is registered?
When a seismic event occurs, the signals it produces are recorded by the National Seismic Network and subsequently analyzed by staff working 24 hours a day. The earthquake is localized by calculating the geographical coordinates and the depth of the hypocenter and its magnitude is estimated using the Richter magnitude, also known as the local magnitude - Ml. Within a few minutes, the preliminary automatic parameters are immediately communicated to the Civil Protection Department, so as to provide a clear overview of what is happening in a given territory. The data is subsequently confirmed or modified by the analysis of the seismologist and published on the website terremoti.ingv.it.
In the era of real-time, how important is it to provide the most timely information on the seismic phenomenon in progress?
In recent years the need to have very rapid information has grown more and more, even if not completely reliable at first. The times necessary for the manual analysis of the waveforms, in fact, are around ten - fifteen minutes, too many in the age of social networks. Users generally communicate their experience of the earthquake very quickly and want to have the fastest possible information on what is happening, this is understandable. To meet this need we have modified our procedures and today, under certain conditions, we are able to provide an estimate in just two minutes for earthquakes with a magnitude greater than three.
How is it possible to provide the first information on a seismic event in such a short time? What happens operationally?
In the presence of certain quality parameters, it is possible to provide an accurate estimate calculated by computer systems, with low uncertainty, in just a few minutes. This happens operationally: the earthquake is recorded in real time and within a minute the solution processed by the computer systems is already available, which is further refined after about two minutes. In the event that the quality parameters of the seismic event are good enough, the information is transmitted to the population.
What are the channels on which this information can be found?
The channels on which we communicate the automatic solution are Twitter and on the web page , where an orange banner appears. A couple of minutes after the earthquake, for seismic events with a magnitude greater than 3, a tweet is released with the automatic estimation of the epicenter and the magnitude. This information is "tweeted" on the sidelines of the communication that the INGV Operations Room makes to the Civil Protection Department. The revised and definitive information is subsequently disseminated through the INGVterremoti social channels of Twitter and Facebook.
Are these lightning-fast estimates accurate? Is there a margin of error?
The speed of the information can go to the detriment of its accuracy and some imprecision in the communication of the preliminary data is possible. For this reason, magnitude and epicenter are initially communicated without indicating specific values, but providing an interval for the magnitude, while as regards the epicenter, the province where it falls is initially indicated. Despite this, about 5% of the events may not fall within the parameters indicated in the automatic solution. It should be emphasized that the quality and accuracy of information on the seismic event improve over time, as more data becomes available in the following moments, making more sophisticated analyzes possible. In particular, the same magnitude, on the basis of the new data, is analyzed again, returning a more significant estimate called moment magnitude (Mw).
Was the timeliness of information via Twitter a winning strategy? What is the mood of the users?
The speed of the automatic localization transmitted via social media allows us to considerably reduce the fake news that can be generated precisely in that interval of time between the earthquake and the communication to the citizen of the revised estimate by the seismologist. In terms of social views, the automatic localization is much more visualized than the magazine one, due to the functioning of the algorithms of the social networks. It rarely happens that someone criticizes, most of our Twitter users are enthusiastic about the initiative and thank us.
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