A Study from Space of Anomalous Variations of Various Geophysical Fields during the Preparation of a Series of Strong Earthquakes in Italy in 2016-2017

A time series of the occurrence of thermal anomalies, aerosol optical-depth anomalies, and total electron content of the ionosphere during the preparation of strong earthquakes with magnitudes of M = 5.2-6.6 in Central Italy in 2016-2017 is revealed based on the joint analysis of various geophysical fields recorded from space. The values of temperatures of the surface, the near-surface layer of the atmosphere, and the outgoing longwave radiation detected by the AIRS instrument (Aqua satellite) are used to analyze thermal fields. Changes in the aerosol optical-depth values are investigated using the MCD19A2 product (Terra and Aqua satellites). Global ionospheric maps obtained from data of global satellite navigation systems and ground-based GPS stations located within a radius of 100 km from earthquake epicenters are used to study anomalies in the ionosphere. It is found that the first precursory changes in geophysical fields occurred in areas with radii of 200 km, the centers of which coincided with the centers of high earthquake risk zones, and were detected 11-15 days before the main seismic shocks.