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For more than 13 years a multi-temporal data-analysis method, named Robust Satellite Techniques (RST), has been being applied to satellite Thermal InfraRed (TIR) monitoring of seismically active regions. It gives a clear definition of a TIR anomaly within a validation/confutation scheme devoted to verify if detected anomalies can be associated or not to the time and location of the occurrence of major earthquakes. In this scheme, the confutation part ( i.e. verifying if similar anomalies do not occur in the absence of a significant seismic activity) assumes a role even much important than the usual validation component devoted to verify the presence of anomalous signal transients before (or in association with) specific seismic events. Since 2001, RST approach has been being used to study tens of earthquakes with a wide range of magnitudes (from 4.0 to 7.9) occurred in different continents and in various geo-tectonic settings. In this paper such a long term experience is exploited in order to give a quantitative definition of a significant sequence of TIR anomalies ( SSTA ) in terms of the required space–time continuity constraints ( persistence ), identifying also the different typologies of known spurious sequences of TIR anomalies that have to be excluded from the following validation steps. On the same basis, taking also into account for the physical models proposed for justifying the existence of a correlation between TIR anomalies and earthquakes occurrence, specific validation rules (in line with the ones used by the Collaboratory for the Study of Earthquake Predictability – CSEP – Project) have been defined to drive the validation process. In this work, such an approach is applied for the first time to a long-term dataset of night-time GMS-5/VISSR (Geostationary Meteorological Satellite/Visible and Infrared Spin-Scan Radiometer) TIR measurements, comparing SSTAs and earthquakes with M > 4 which occurred in a wide area around Taiwan, in the month of September of different years (from 1995 to 2002). In this dataset the Chi-Chi earthquake ( M W = 7.6) which occurred on September 20, 1999 represents the major, but not unique, event. The analysis shows that all identified SSTAs occur in the pre-fixed space–time window around (in terms of time and location) earthquakes with M > 4. The false positive rate remains zero even if only earthquakes with M > 4.5 are considered. In the case of the Chi-Chi earthquake, 3 SSTAs were identified (all within the established space–time correlation window), one of them appearing about 2 weeks before and very close to the epicentre of the earthquake just along the associated tectonic lineaments. The wide considered space–time window, together with the high seismicity of the considered area, surely positively conditioned the achieved results, so that further analyses should be carried out by using longer datasets and different geographic areas. However, also considering the coincidence with other (possible) precursor phenomena, independently reported (particularly within the iSTEP project) at the time of the Chi Chi earthquake, achieved results seem already sufficient (at least) to qualify TIR anomalies (identified by RST) among the parameters to be considered in the framework of a multi-parametric approach to a time-Dependent Assessment of Seismic Hazard ( t-DASH ). [ABSTRACT FROM AUTHOR]

Abstract: A robust satellite data analysis technique (RAT) has been recently proposed as a suitable tool for satellite TIR surveys in seismically active regions and already successfully tested in different cases of earthquakes (both high and medium–low magnitudes). In this paper, the efficiency and the potentialities of the RAT technique have been tested even when it is applied to a wide area with extremely variable topography, land coverage and climatic characteristics (the whole Indian subcontinent). Bhuj–Gujarat''s earthquake (occurred on 26th January 2001, M S ∼7.9) has been considered as a test case in the validation phase, while a relatively unperturbed period (no earthquakes with M S ≥5, in the same region and in the same period) has been analyzed for confutation purposes. To this aim, 6 years of Meteosat-5 TIR observations have been processed for the characterization of the TIR signal behaviour at each specific observation time and location. The anomalous TIR values, detected by RAT, have been evaluated in terms of time–space persistence in order to establish the existence of actually significant anomalous transients. The results indicate that the studied area was affected by significant positive thermal anomalies which were identified, at different intensity levels, not far from the Gujarat coast (since 15th January, but with a clearer evidence on 22nd January) and near the epicentral area (mainly on 21st January). On 25th January (1 day before Gujarat''s earthquake) significant TIR anomalies appear on the Northern Indian subcontinent, showing a remarkable coincidence with the principal tectonic lineaments of the region (thrust Himalayan boundary). On the other hand, the results of the confutation analysis indicate that no meaningful TIR anomalies appear in the absence of seismic events with M S ≥5. [Copyright &y& Elsevier]

Abstract: The RST approach (robust satellite technique) is a multi-temporal scheme of satellite data analysis already successfully used to monitor volcanoes at different geographic locations. In this work, the results of a long-term validation analysis of RST-based hot spot products are presented. This study was performed processing fourteen years of NOAA-AVHRR (National Oceanic and Atmospheric Administration-Advanced Very High Resolution Radiometer) records acquired over Mt. Etna area between 1 January 1995 and 31 December 2008, at different overpass times (day/night), and analyzing hundreds of volcano bulletins reporting information on Mt. Etna eruptive activity, provided by visual observations and ground-based measurements. An optimized configuration of the RST approach, named RSTVOLC, is also, for the first time, presented and discussed here. This method, thanks to a better tradeoff between reliability and sensitivity, may be particularly suitable to support operational systems for volcano monitoring and hazard mitigation. [Copyright &y& Elsevier]

Treating the time dimension (i.e., the 4th dimension) of geospatial parameters, likewise the other dimensions is important for some applications to better understand the possible space-time relations among the physical parameters underlying the dynamics of complex phenomena. In this paper we present the potential of an innovative solution, named 4 Dimensions Environmental ObServation (4DEOS), which is a platform able to handle the 4th dimension in an asynchronous way (i.e., to visualize more signals, holding some of them fixed in the time domain while moving others over time). 4DEOS is based on a Client-Broker-Server architecture for the easy integration and visualization of heterogeneous, asynchronous, geospatial products. The prototype system was evaluated in the case of earthquake prediction studies where the asynchronous visualization of independent observations could allow a timely identification of the spatial correlations appearing at different time lags, which could be missed using other existing 4D Geographic Information System software. [ABSTRACT FROM AUTHOR]