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Real-time integration of multi-parametric observations\ud is expected to accelerate the process toward improved, and\ud operationally more effective, systems for time-Dependent Assessment\ud of Seismic Hazard (t-DASH) and earthquake short-term (from\ud days to weeks) forecast. However, a very preliminary step in this\ud direction is the identification of those parameters (chemical, physical,\ud biological, etc.) whose anomalous variations can be, to some extent,\ud associated with the complex process of preparation for major earthquakes.\ud In this paper one of these parameters (the Earth’s emitted\ud radiation in the Thermal InfraRed spectral region) is considered for its\ud possible correlation with M C 4 earthquakes occurred in Greece in\ud between 2004 and 2013. The Robust Satellite Technique (RST) data\ud analysis approach and Robust Estimator of TIR Anomalies\ud (RETIRA) index were used to preliminarily define, and then to\ud identify, significant sequences of TIR anomalies (SSTAs) in 10 years\ud (2004–2013) of daily TIR images acquired by the Spinning Enhanced\ud Visible and Infrared Imager on board the Meteosat Second Generation\ud satellite. Taking into account the physical models proposed for\ud justifying the existence of a correlation among TIR anomalies and\ud earthquake occurrences, specific validation rules (in line with the\ud ones used by the Collaboratory for the Study of Earthquake Predictability—\ud CSEP—Project) have been defined to drive a\ud retrospective correlation analysis process. The analysis shows that\ud more than 93 % of all identified SSTAs occur in the prefixed space–\ud time window around (M C 4) earthquake’s time and location of\ud occurrence with a false positive rate smaller than 7 %. Molchan error\ud diagram analysis shows that such a correlation is far to be achievable\ud by chance notwithstanding the huge amount of missed events due to\ud frequent space/time data gaps produced by the presence of clouds\ud over the scene. Achieved results, and particularly the very low rate of\ud false positives registered on a so long testing period, seems already\ud sufficient (at least) to qualify TIR anomalies (identified by RST\ud approach and RETIRA index) among the parameters to be considered\ud in the framework of a multi-parametric approach to t-DASH

Abstract. Space-time fluctuations of Earth's emitted Thermal Infrared (TIR) radiation have been observed from satellite months to weeks before earthquakes occurrence.The general RST approach has been proposed in order to discriminate normal (i.e. related to the change of natural factor and/or observation conditions) TIR signal fluctuations from anomalous signal transient possibly associated to earthquake occurrence. In this work RST approach is applied to the Abruzzo 6 April 2009 event (M L =5.8) by using for the first time MSG-SEVIRI (Meteosat Second Generation -Spinning Enhanced Visible and Infrared Imager) thermal infrared observations. A validation/confutation analysis has been performed in order to verify the presence/absence of anomalous space-time TIR transients in the presence/absence of significant seismic activity. MarchApril 2009 has been analyzed for validation purposes. Relatively unperturbed periods (no earthquakes with M L ≥5) have been taken for confutation. A specific TIR anomalies spacetime persistence analysis as well as a cloud coverage distribution test have been introduced in order to eliminate artifacts and outliers both in the validation and confutation phases. Preliminary results show clear differences in TIR anomalies occurrence during the periods used for validation and confutation purposes. Quite clear TIR anomalies appear also to mark main tectonic lines related to the preparatory phases of others, low magnitude (M L ∼4) earthquakes, occurred in the area.