The Italian publication Ilgiornaledellaprotezionecivile spoke with Titti Postiglione, Deputy Chief of the Civil Protection Department (Dipartimento della Protezione civile), to learn more about the importance of this collaborative effort for civil protection efforts.
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| Short-term seismic hazard |
Seismic hazard research and analysis is a never-ending process. In addition, a new collaborative effort has been begun to specify the methods for the potential application of seismic hazard research products in the near future. After a conference held by the Civil Protection Department with the National Institute of Geophysics and Volcanology (INGV), the Regions, and the Autonomous Provinces, this cooperative effort began on an experimental basis and for civil protection objectives.
The International Commission on Earthquake Forecasting for Civil Protection was established in Italy in 2009, with the appointment of geologists and geophysicists from China, France, Germany, Greece, Italy, Japan, Russia, the United Kingdom, and the United States, chaired by Thomas H. Jordan, director of the Southern California Earthquake at the time Center and Professor of Earth Sciences at the University of Southern California.
The Commission, in the conclusion of its work, wrote that it had "identified various interconnected activities that could improve the scientific basis and the reliability of operational forecasting of earthquakes" in order to "use the forecasting techniques currently under investigation studies, for civil protection purposes". The Commission emphasized, in particular, how "the creation of every new operational protocol involves a development in three phases": a research phase, a model assessment phase, and an implementation phase for civil protection objectives.
Following the research and evaluation phases that have engaged the scientific community in recent years, the process of comparison and implementation that is now beginning with the Regions and Autonomous Provinces has the specific goal of verifying, on an experimental basis, the use that could be made of this tool for Civil Code protective actions, in addition to other cognitive elements already used by the system, such as seismic history, seismotectonic structures, and so on. As a result, we discussed it with Titti Postiglione, Deputy Head of the Civil Protection Department, to determine the significance of this research from a civil protection standpoint.
What is short-term seismic hazard?
An earthquake can happen anywhere and at any moment in Italy. Yet, we know that the probabilistic seismic hazard is not constant in space; there are regions where the likelihood of an earthquake of a specific size happening in a given time period is larger than in others. All of this is reflected in long-term seismic hazard probability models that span time periods ranging from tens to hundreds or thousands of years. Nevertheless, seismicity is not constant even over time, and the short-term probabilistic seismic hazard takes this element into consideration.
It refers to a time period that can vary from a few days to a few months and reflects the likelihood of an earthquake of a specific size occurring in a certain place within a short period of time, such as a week. This form of likelihood is based only on seismic event statistics and hence does not take into consideration the physical elements that cause earthquakes, such as fault-related processes. Let's discuss about probabilistic seismic hazard since, to yet, there are no approaches for predicting earthquakes in a deterministic fashion, that is, ways that estimate the size and exact time in which an earthquake will occur with accuracy.
Ingv worked on the design of the "Operational earthquake forecasting-OEF" tool, which processes data in real time, implements scientifically acceptable models, tests and validates them, proposes a new synthesis model, creates databases, and submits the findings to the scientific community. What outcomes have been obtained?
The efforts of experts at the National Institute of Geophysics and Volcanology over the years has culminated in the device we now call OEF, which provides short-term seismic hazard estimations. As a Department, we are initiating a collaborative effort with the Regions and Autonomous Provinces to specify the processes for testing the feasibility of employing these items for experimental and civil protection objectives, while also underlining all of their limits.
To arrive at this tool, the Ingv experts were able to count on real-time analysis of the observation data from the stations of the Institute's seismograph networks, they tested existing statistical models on events that have occurred over the years, and proposed a synthesis approach which they submitted for evaluation by the international scientific community.
What new research will be conducted? Which way will they go?
As the International Commission on Earthquake Forecasting for Civil Protection has stated, all probabilistic forecasting models for operational use should be subjected to continuous verification, both retrospectively and prospectively, in order to better and better "record" their reliability and effectiveness. The national and international scientific community that works on these specific topics will be increasingly involved in this, demonstrating precisely the reliability and effectiveness of short-term forecasting models compared to consolidated reference models, such as those that are time-independent. Because to "convert", so to speak, the estimates of the probability of occurrence of earthquakes in the short term into possible risk mitigation actions– which should be the ultimate goal – these models need to be robust.
Is it feasible to forecast the location, time, and magnitude of earthquakes in the future? Is there any progress in this regard?
It is extremely difficult to forecast what will be feasible in the future due to scientific study, not just in the realm of seismic danger. What is still unclear is how the outcomes of scientific study may be put to use for practical goals. Certain and consistent investments over time, participation of competent Italian institutions in international programs aimed at assessing the reliability and effectiveness of short-term seismic hazard instruments, comparison with civil protection systems of foreign countries that are equally exposed to seismic risk as ours: these are all critical elements for future progress.
Last September, the Significant Risks Commission determined that the time has come to work within the civil protection system on a framework for assessing short-term hazard. Is there an incident (such as previous earthquakes), a situation, or a specific discovery that motivated the commission to make this determination?
Well, there hasn't been a specific discovery or a contingent fact, simply years of patient analysis. The Major Risks Commission, which serves as a link between the National Civil Protection Service and the scientific community, and is tasked with providing technical-scientific opinions and recommendations on how to improve the ability to evaluate, forecast, and prevent various risks, has followed scientific research work in the field of short-term seismic hazards over the years and believes that these, having reached a certain level of solidity, can now begin to be implemented.