Geospatial and field survey data for earthquakes multi-precursors detection

摘要

The main problem for seismic precursors recognition is to extract useful information associated with tectonic activities and to eliminate the effects of non-tectonic factors. Pre-earthquake spatio-temporal developed geophysical, geodetically, and geochemical anomalies are controlled by various factors like as earthquake moment magnitude and its focal depth, geological setting, topography, land covers as well as climate and atmospheric conditions. In this paper, changes before and after some moderate Vrancea earthquakes in the crustal dynamics as well as in the land and atmospheric parameters (surface air temperature- AT and land surface temperature LST anomalies, have been investigated on the basis of timeseries geospatial (NOAA AVHRR and MODIS Terra/Aqua) and field data analysis for 2010-2018 period. Ground surface deformations have been detected through analysis of Synthetic Aperture Radar Interferometry (InSAR) radar satellite Sentinel 1 and high quality in-situ GPS monitoring data. The detected changes show strong evidence of coupling between lithosphere-land surface-atmosphere-ionosphere associated with the Vrancea's earthquakes For some analyzed earthquakes, starting with ten days up to one week prior to a moderate earthquake a transient thermal infrared rise appeared in AT (2-10°C) and LST (20-30°K) higher than the normal values, function of the magnitude and focal depth, which disappeared after the main shock. Ground vertical surface displacements presented on interferometric deformation map are in the range of 4 cm for uplifts and subsidence. The joint analysis of geospatial, geophysical, and geological information is revealing new insights for Vrancea zone seismicity understanding.