Satellite and Ground-Based Observation of Pre-Earthquake Signals—a Case Study on the Central Italy Region Earthquakes

The complexity in earthquake occurrences has forced scientists to adopt an interdisciplinary approach for the development short-term forecasting model. In this manuscript, the authors have presented an interdisciplinary scheme involving pre-earthquake signals like geo-electrical measurements, relative humidity (RH) and outgoing longwave radiation (OLR). Prior to the occurrence of earthquakes, these parameters show exceptional deviation and indicate the nucleation of the earthquakes at the seismically active zones. Variations in the geo-electrical potential are observed prior to the occurrence of the earthquakes due to the physical and chemical interactions between hydrogen and Earth’s interior, which in turn facilitates the migration of the H+ ions through the interior of the earth. Also, this migration process weakens lithosphere, which produces non-synchronous stress variations along the fault interface. Due to the increased stress, the radioactive radon comes out from the voids of the rocks, ionizes the atmospheric air, which leads to the release of latent heat, and can be observed in the form of anomalous drop in RH and rise in OLR. Prior to the occurrence of Central Italy region earthquakes of the year 2016 (M > 6.0), the above-mentioned parameters have shown a significant variation than ± 2σ level.