Detection of Brightness Temperature Anomalies Using Multiple Methods Before the 2009 L’aquila Earthquake

Abstract

Detecting the Thermal Infrared Anomalies (TIA) prior to earthquakes has always been an important issue in seismic studies. Several approaches have been proposed to recognize weak abnormal signals under strong backgrounds noise. The Z-Score (ZS), Robust Satellite Technique (RST), and Eddy Field (EF) methods were considered here to detect Brightness Temperature (BT) anomalies before the L’Aquila earthquake jolted central Italy on April 6, 2009. The results illustrated that the EF method is not suitable to extract BT anomalies before this occurrence. In addition, it was found that the RST method is not sensitive enough to determine the epicenter of forthcoming earthquakes. The ZS method has been observed to reflect the negative correlation between the spatial distance from the epicenter and abnormal values before the earthquake. Moreover, sudden changes in the BT warming approximately 10 days before the shock were recognized using this method. Therefore, the ZS method is considered to be suitable to extract the BT anomalies associated with the L’Aquila earthquake.