Night Thermal Gradient: A New Potential Tool for Earthquake Precursors Studies. An Application to the Seismic Area of L'Aquila (Central Italy)

Relations between ground surface warming-up and earthquakes are presented by means of the analysis of thermal data detected by Meteosat satellite. The analysis has been carried out on the basis of Land Surface Temperature (LST) data, by the application of algorithms for two purposes: the reduction of the effect of cloud coverage and daily weather variability and the improvement in resolution of thermal maps. The main case study has been L'Aquila earthquake on 6th April 2009 with two different observation timeframes: one in absence of significant seismic activity (October 2008), one right before and straight after the same earthquake (January-May 2009). The detected thermal anomalies reveal the possibility to associate surface thermal phenomena to the imminent manifestation of seismic events.