Robust Satellite Techniques for mapping thermal anomalies possibly related to seismic activity of March 2021, Thessaly Earthquakes.

Abstract

In recent years, there is a growing interest concerning the development of a multi-parametric system for earthquakes’ short term forecast identifying those parameters whose anomalous variations can be associated to the complex process of such events. In this context, the Robust Satellite Technique (RST) has been adopted herein with the aim to detect and map thermal anomalies probably related with the strong earthquake of M6.3 occurred near the city of Larissa, Thessaly on March 3rd 2021 10:16:07 UTC. For this purpose, 10 years (2012-2021) of daily Night-time Land Surface Temperature (LST) remotely sensed data from Moderate Resolution Imaging Spectroradiometer (MODIS), were analyzed. Pixels characterized by statistically significant LST variations on a daily scale were interpreted as an indicator of variations in seismic activity. Quite intense (Signal/Noise ratio > 2.5) and rare, spatially extensive and time persistent, TIR signal transients were identified, appearing twenty five days before the Thessaly main shock (pre-seismic anomalies: February 6th, February 11th March 1st), the day of the main earthquake (co-seismic anomaly) and after the main shock (post-seismic anomalies: March 4th, 10th and 17th). The final dataset of thermal anomalies was combined with geological and structural data of the area of interest, such as active faults, composite seismogenic sources, earthquake epicenter and topography in order to perform preliminary spatial analysis.