Detection from Space of Anomalous Variations in Thermal Fields during Seismic Events in the Northern Caucasus in 2017-2022

Changes in thermal fields during the period leading up to and during earthquakes (magnitude of 4.2-4.8) in the North Caucasus between 2017 and 2022 are studied based on satellite data. The Earth's surface and near-surface air temperatures, outgoing long-wave radiation, and relative humidity near the surface recorded from space are analyzed. The changes in thermal fields during the preparation of seismic events are compared for earthquakes with epicenters located in zones of similar geological structures, such as the fold-block structures of the Greater Caucasus and the Pre-Caucasian foredeep. Similarities between the variations in the temperature, relative humidity, and fluctuations of outgoing longwave radiation are revealed for a number of earthquakes. The most similar character of the variations is for the normalized values of outgoing long-wave radiation during the preparation of all seismic events analyzed, despite the different positions of their epicenters. Hence, these parameters can be used as short-term precursors of seismic events detectable from space.