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The occurrence of intense CO2 degassing processes generating hundreds of cold CO2- rich gas emissions is typical of the central Apennines. In 2009, significant anomalies were detected coinciding with the L'Aquila seismic sequence as a consequence of a wide degassing process. Over the same time-span, space-time anomalies in Thermal InfraRed (TIR) satellite imagery possibly related to the increase of green-house gas (such as CO2, CH4, etc.) emission rates were detected in central Italy during the seismic swarm by a Robust Satellite Technique (RST) data analysis. A gas geochemical survey carried out in the L'Aquila area confirms the deep crustal origin of the anomalous gas emission detected by ground measurements. Anomalous fluid related signals were recorded some days before the mainshock coinciding with the most marked TIR anomalies independently detected by the RST analysis over 3 different types of satellite data. Anomalous gas emissions detected by ground measurements lasted some weeks, putting in evidence relationships with crustal deformative processes associated with the seismic sequence. Together with previous ground observations in the Umbria-Marche area, present ground and satellite TIR observations, are compatible with the hypothesis that a central Apennines area, much wider than the L'Aquila (March-April 2009) epicentral one, was actually affected by anomalous increases in CO2 release thus providing new tools to better understand the processes occurring behind a seismic shock. [ABSTRACT FROM AUTHOR]

In this study, Earth's emitted Thermal InfraRed (TIR) radiation measured from geostationary satellite sensors has been analyzed by using an original data analysis approach in order to evaluate possible space-time correlation with earthquakes (M=4.0) occurrence. A clear definition of SSTA (Significant Sequence of Thermal Anomaly) concept is given and correlation rules are established in order to evaluate the potential of SSTAs among the parameters to be included in a pre-operational system for time- Dependent Assessment of Seismic Hazard (t-DASH). On the considered time period (July 2012 - June 2013) and testing areas (Italian southern Apennines and Po Plain) a false positive rate lesser than 33% has been obtained. Notwithstanding a missing rate up to 67% (mostly because of the presence of clouds preventing the continuity of observations), as confirmed by other independent studies performed on longer period of time and different geographic areas, seems to strongly support the inclusion of SSTAs [identified by the RST (Robust Satellite Technique) methodology] among the parameters whose continuous monitoring and integration with all the other relevant information available, could strongly improve our present capabilities to dynamically assess seismic hazard in a pre-operational context. [ABSTRACT FROM AUTHOR]

This review paper reports the main contributions and results achieved after more than 30 years of studies on the possible relationships among space-time variation of Earth's thermally emitted radiation, measured by satellite sensors operating in the Thermal InfraRed (TIR) spectral range (8-14 m), and earthquake occurrence. Focus will be given on the different existing methods/models to: 1) discriminate a possible pre-seismic TIR anomaly from all the other TIR signal fluctuations; 2) correlate such anomalies with space, time and magnitude of earthquakes; 3) physically justify such a correlation. [ABSTRACT FROM AUTHOR]