Using Robust Satellite Technique (RST) to determine thermal anomalies before a strong earthquake: A case study of the Saravan earthquake (April 16th, 2013, MW = 7.8, Iran)
Employing an efficient and robust prediction system along with early warnings is useful to reduce the effects of devastating earthquakes. Thermal anomaly, as an earthquake precursory, is widely confirmed. In this study, to characterize the thermal anomalies within a 10-year specific observation interval of Land Surface Temperature (LST), satellite data products obtained from MODIS-Aqua (March 16th to May 16th, every year from 2004 to 2013) were analyzed using Robust Satellite Technique (RST) method. The Saravan earthquake (April 16th, 2013, MW = 7.8, Iran) were used for validation phase, and the year 2012, as a relatively seismically unperturbed year (no earthquakes with Mw > 3.5 regarding target time and region), was taken for confutation phase. For the first time, to reduce the effects of the topography with respect to vegetation cover, using unsupervised classification, the study area was divided into the low and high elevation regions. The results of the present study showed the Significant Sequences of LST Anomalies (SSLAs) from several days before and immediately after the Saravan earthquake appeared in the north, south, and center of the study area. However, no anomalies were observed in a seismically unperturbed year (2012). Therefore, the results confirmed the existence of space-time thermal anomalies related to destructive earthquakes and revealed that the RST method is a reliable approach to detect disturbances of the Earth's thermal emission.