Study on the Outgoing longwave radiation changes of earthquakes based on the China Fengyun Satellite - taking the Luxian earthquake in Sichuan Province in 2021 and the Turkey earthquake in 2023 as examples

An earthquake is a process during which the Earth’s tectonic stress accumulates to a certain intensity, breaking through the critical value of rock elastic rupture and releasing energy quickly. Previous studies have shown that thermal infrared radiation (TIR) changes relative to stress in loaded rocks. The results of mechanical rock loading and fracture tests show that the infrared radiation generated during rock failure exhibits a time series phase change with respect to microintensification–intensification–attenuation–intensification–quietness synchronization, which provides a physical basis, monitoring content, and abnormal evaluation criteria for infrared remote sensing earthquake monitoring and prediction. Tidal force (TF) is an essential external mechanical factor that triggers earthquakes when crustal stress reaches a critical state. It is also the only physical parameter of earth deformations that can be calculated in advance and has an indicative advantage over time. Therefore, the extraction of seismic thermal anomalies based on tidal forces is helpful for obtaining infrared anomalies that conform to the radiation variation law of rock stress rupture as it can improve the recognition level of seismic infrared anomalies in time and space. In this study, the relationship between OLR and earthquake was studied by combining the celestial tide generating force with the OLR data of China Fengyun satellite, and the breeding and occurrence process of earthquake was discussed. The results show that the tidal force of celestial bodies has an induced effect on the earthquake, and the anomaly of long-wave radiation may be the radiation characterization of stress and strain in the process of earthquake incubation. After that, the abnormal period was tracked and verified by using NOAA satellite OLR product data, and it was found that the characteristics of the two results were relatively consistent, which further demonstrated that the FY satellite OLR data can be better applied to seismic anomaly monitoring.