John P. Makris

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.

Strong motion sensor networks deployed in metropolitan areas are able to provide valuable information for civil protection Decision Support Systems (DSSs) aiming to mitigate seismic risk and earthquake social-economic impact. To this direction, such a network is installed and real-time operated in Chania (Crete Island, Greece), city located in the vicinity of the seismically active south front of the Hellenic Subduction Zone. A blend of both traditional and advanced analysis techniques and interpretation methods of strong ground motion data are presented, studying indicative cases of Chania shaking due to earthquakes in the last couple years. The orientation independent spectral acceleration as well as the spatial distribution of the strong ground motion parameters such as the Peak Ground Acceleration (PGA), Peak Ground Velocity (PGV), Peak Ground Displacement (PGD) and Arias Ιntensity observed at the urban area of Chania are presented with the use of a Geographic Information System (GIS) environment. The results point to the importance of the strong ground motion networks as they can provide valuable information on earthquake hazards prior to and after detrimental seismic events to feed rapid systems supporting civil protection decisions for prevention and emergency response.

The method of Hybrid Adaptive Filtering (HAF) aims to recover the recorded electric field signals from anomalies of magnetotelluric origin induced mainly by magnetic storms. An adaptive filter incorporating neuro-fuzzy technology has been developed to remove any significant distortions from the equivalent magnetic field signal, as retrieved from the original electric field signal by reversing the magnetotelluric method. Testing with further unseen data verifies the reliability of the model and demonstrates the effectiveness of the HAF method.