Anomalies of Thermal Fields Revealed by Satellite Data during the Preparation and Occurrence of Strong Earthquakes in the Region of the Baikal Rift Zone in 2008–2022

Abstract

Long-term changes in thermal fields have been studied before and during strong earthquakes with magnitudes from 5.1 to 5.6 that occurred in the region of the Baikal rift zone in 2008–2022. Satellite data are used for these studies. For analysis we use the values of land surface temperature, temperature of the near-surface layer of the atmosphere, outgoing longwave radiation (OLR), and relative humidity (RH) recorded using the AIRS instrument mounted on the Aqua satellite. During the periods of preparation and occurrence of these seismic events, anomalous variations in the parameters of thermal fields registered with satellite are revealed. They exceed the average long-term values: for land surface temperature and temperature of the near-surface layer of the atmosphere by 5–10%, for OLR by 11–15%, and for RH by 6–10%. A strong negative correlation is found between changes in the temperature of the near-surface layer of the atmosphere and RH (correlation coefficient of –0.75), as well as antiphase oscillations between the values of the OLR and RH. The results can be used for studies of the precursor variability of thermal fields during monitoring of seismic hazard zones.