Study On Seismic Thermal Anomalies By Using Thermal Infrared Remote Sensing Data

This paper uses the Black Body Temperature(TBB)data of the Chinese FY-2G geostationary satellite,based on the wavelet transform and the relative power spectrum method of the relative power spectrum(TF RPS),extracts the thermal infrared anomalies of the 96 earthquakes in the data coverage area2007-2018(Earthquakes that occur on the mainland with magnitudes greater than 6,Earthquakes that occur on the ocean with magnitudes greater than 7).We selected the parameters such as characteristic period,abnormal amplitude,abnormal shape and abnormal evolution characteristics.The anomalous feature information of a large number of earthquakes and the thermal infrared anomalies of active block boundaries are summarized and analyzed.We obtained the following main results and conclusions:(1)Using wavelet transform and Fourier relative power spectrum method can extract seismic thermal infrared anomaly information effectively.Among the 96 earthquakes in the study area,91 earthquakes have obvious thermal infrared anomalies(about 95%),and only 5 earthquakes have no obvious anomalies,one of which occurred in the mainland and four occurred in the sea.(2)The thermal infrared anomaly spread patterns of earthquakes have similarities: Strip-like anomalies distributed along the fault zone or flaky anomalies distributed on one side of the fault zone.During the development of abnormal migration,the high-value area exhibits a shape similar to the overall anomaly and is distributed at the fracture zone.The earthquakes around the basin have a certain similarity in the thermal infrared anomaly distribution,and the anomaly is distributed on the basin side,with obvious “basin effect”.The thermal infrared anomalies of the sea area earthquakes are often distributed on the land side,and the epicenter is located on one side edge.The earthquake anomaly distribution pattern in Japan is consistent with the shape of the Japanese land area.(3)The anomalous evolution process as a whole shows the process of “abnormal occurrence-migration increase-weakening-disappearance”,which is repeated in some earthquakes.The abnormally weakened phase shows a change that rapidlyweakens and disappears.Earthquake abnormality lasts for more than 30 days and the relative power spectrum anomaly amplitude is concentrated more than 6 times.The larger the abnormal area and amplitude of some earthquakes,the longer the abnormality lasts.(4)Analysis of the thermal infrared anomaly characteristics of the active block boundary,we found: The strip-shaped anomalies on the southern boundary of the Qinghai-Tibet block and the Tianshan block are distributed along the boundary zone,and the abnormally high value centers are often located in the boundary zone.In the process of migration change,the anomaly at the boundary zone between Bayan Hara block and South China block often occur inside of the block.The thermal infrared anomaly of the western boundary of the Yunnan-Burma block is distributed inside the Dianxi block or on the side of the boundary zone.In the study of seismic infrared anomaly characteristics,it is found that there are obvious seismic thermal infrared anomalies before and after the earthquake.The regularity of anomalies: The anomalies migrate along the fault zone.The relative power spectrum amplitude is more than 6 times of the normal value and the duration is more than 30 days.In this paper,combined with the anomalous distribution pattern,the relationship between the anomaly change and the epicenter position,and the characteristics of strong earthquakes within the boundary zone,it can be used to predict and predict the location of the earthquake.The seismic time is within 2 months before and after the peak value of relative power spectrum and has high reliability to the time prediction index.The relationship between the time of earthquake and the change process of relative amplitude has high reliability to the time prediction index.The thermal infrared anomaly can reflect the tectonic activity well.Especially in the active block boundary zone where great earthquakes occurred,there is a significant thermal anomaly before the earthquake.However,the abnormal area,abnormal amplitude and so on are not significantly related to the magnitude,and there are certain difficulties in determining the magnitude and other factors.