Complex space-time modeling and functional analysis for probabilistic forecast of seismic events

Progetto: Research project

Description

this new research group, in order to increase the global ability in earthquakes forecasting.In the project, such ability will be evaluated in collaboration with the CSEP (the Collaboratory for the Study of EarthquakePredictability), that is an international structure to evaluate and compare models developed in different countries.For a valid approach of prediction of seismic events in space and time, a proper estimation of the intensity function thatidentifies the generator process is a crucial issue.For this purpose, several models have been proposed in the literature, but since the complexity of the seismic generatorprocess, also at multiple scales, even better attempts are possible.In particular, we think that it could be interesting to develop more complex models that account for both attractive andrepulsive nature of data and also for specific covariates, that is to considerfurther information than the usual space-time-magnitude hyphocentral coordinates.Among these covariates, we could consider some main physical variable like the distance from faults, faults dislocation, focalmechanism, etc.For this reason an advanced study of seismic waves by functional analysis could be an interesting point.Indeed, the similarity identification among curves allows a better comprehensions and identification of common sources forevents that are far each other. This would improve our previous global knowledge of this complex phenomenon and,therefore, could provide useful results in terms of the seismic risk reduction, that is, of increasing the safety of thepopulation.More specifically, this project aims at improving the Probabilistic Seismic Hazard Analysis of the Italian territory, thoughresults could be extended also in other world areas.

Layman's description

Earthquake forecasting plays a fundamental role in seismology. It demarcates the interface between seismology and society,being the basic scientific component of any sound seismic risk mitigation action. At the same time, earthquake forecasting isthe ultimate scientific challenge for seismologists.The importance of forecasting natural events is summarized by AAAS (1989) in a statement that aims at describing thedistinctive features of Science with respect to all other human enterprises: "The growing ability of scientists to makeaccurate predictions about natural phenomena provides convincing evidence that we really are gaining in our understandingof how the world works". This statement reminds scientists that any increase of knowledge about the earthquake occurrenceprocess has to be proved through a better definition, or improvement, of forecasting capability. In practice, this can be madetesting the consistency (accuracy) of forecasting models with the available data and measuring their relative forecasting skill(precision). In this research activity we pursue this objective, embedding our efforts in an ongoing international activity thathas having similar goals. In this way, beyond testing the consistency and skill of the models proposed in this project, we canalso compare them with the most reliable models so far adopted at global scale. In particular we want to refer to CSEP (theCollaboratory for the Study of Earthquake Predictability) testing centers (Jordan 2006; Zechar et al. 2010). For this reasonthe main purpose of this project is to find proper model for earthquake forecast and compare them by operative results asthe ones provided by CSEP.In particular, we will refer to the analysis of the Italian seismicity, although in this project we aim at the extension of the possible results to other important seismic areas (e.g. Chile), providing tools/models for earthquake forecast that account forthe studied region features. Italian seismicity results from the relative motion between the African and Eurasian platesaccommodated by a complex system of fault systems that developed during the processes of subduction and collision in theAlpine and Apennine belts. The entire Italian territory, with the exception of Sardinia, the Salento peninsula, and some areasof the Alps and Sicily, is characterized by high seismic risk (Crowley et al. 2008) with maximum seismic activity concentratedalong the Alps, Apennines, Calabrian axis, and part of Sicily. In the last century, many destructive earthquakes haveoccurred in Italian territory, since the Messina (1908) to the most recent Aquila (2009) and Emilia (2012) earthquakes.After the destructive Irpinia earthquake, the Italian Seismic Network of the Istituto Nazionale di Geofisica e Vulcanologia(ISN-INGV) was improved with about 100 short-period vertical instruments. Since the 2005 the ISN-INGV has beentechnologically renovated and has now reached more than 300 digital seismic stations equipped with three-componentbroadband high sensitivity sensors. The high quality data are daily analysed and stored at the INGV earthquake centre. Thecurrent magnitude completeness threshold of different seismogenic areas of the Italian territory is less than 1.5 ML(Schorlemmer et al. 2010; D’Alessandro et al. 2011).Seismogram from the INGV seismic network are available in digital form, from 1980 to the present. It is so possible toachieve location accuracy that is smaller than the dimension of the earthquake sources. This allows a quantitative assess ofthe geometric relationship of one earthquake to another and t

Key findings

Altro
StatoFinito
Data di inizio/fine effettiva2/5/172/5/20