Using RST approach and EOS-MODIS radiances for monitoring seismically active regions: a study on the 6 April 2009 Abruzzo earthquake

Abstract

Abstract.In the last few years, Robust Satellite data analysis Techniques (RST) have been proposed and successfully applied for monitoring major natural and environmental risks. Among the various fields of application, RST analysis has been used as a suitable tool for satellite TIR surveys in seismically active regions, devoted to detect and monitor thermal anomalies possibly related to earthquake occurrence. In this work, RST has been applied, for the first time, to thermal infrared observations collected by MODIS (Moderate Resolution Imaging Spectroradiometer) -the sensor onboard EOS (Earth Observing System) satellites -in the case of Abruzzo (Italy) earthquake occurred on 6 April 2009 (M L ∼5.8). First achievements, shown in this work, seem to confirm the sensitivity of the proposed approach in detecting perturbations of the Earths emission thermal field few days before the event. The reliability of such results, based on the analysis of 10 years of MODIS observations, seems to be supported by the results achieved analyzing the same area in similar observation conditions but in seismically unperturbed periods (no earthquakes with M L ≥5) that will be also presented.

A study on the Abruzzo 6 April 2009 earthquake by applying the RST approach to 15 years of AVHRR TIR observations

“…In particular very intense and extended anomalies appear near tectonic lineaments since 30 March (few hours before the foreshock with M L ∼4.1) during the same period interested by anomalous variations of different geophysical parameters independently reported by several authors (e.g., Caporali, 2009;Pergola et al, 2010;Martinelli et al, 2009;Rozhnoi et al, 2009;Plastino et al, 2010). Among the others, particularly important seems the V P /V S seismological observations that Lucente et al (2009) …”

Pre-seismic Thermal Anomalies from Satellite Observations: A Review

“…This method considers the statistical characteristics of the historical data of seismically active areas to discriminate the possible pre-seismic abnormal behavior of current thermal signals. It is also considered applicable to different atmosphere and surface conditions and different satellite observation geometries, and can reduce the probability of occurrence of false thermal anomalies (Filizzola et al, 2004;Pergola et al, 2010).…”

“…The RETIRA index is further used to indicate the relationship with future seismic activity. Generally, a value greater than 3 to 4 is used as the threshold for the presence of thermal anomalies that are associated with possible earthquake occurrences (Eleftheriou et al, 2016;Lisi et al, 2010;Lisi et al, 2015 If continuous and large-scale thermal anomalies appear from a time series of images within study areas, then they can be 365 considered pre-seismic thermal anomalies (Aliano et al, 2008). Therefore, an index of significant sequences of thermal anomalies (SSTAs), which measures the persistence and continuity of thermal anomalies in temporal and spatial patterns, is defined to remove problematic values as far as possible (Genzano et al, 2015;Lisi et al, 2015).…”

“…At present, RST, which is extensively used in thermal anomaly detection, is a multi-temporal statistical method for analyzing long-term satellite records with similar observation conditions (e.g., same month, same time of day, and same sensor data) (Genzano et al, 2015;Lisi et al, 2010;Pergola et al, 2010;Tramutoli et al, 2005). RST combines the neighborhood difference in the eddy field method and the normalization of the reference field in the ZS method, and it clearly defines the mathematical 350 expression of the thermal anomaly in statistics.…”

“…Whether thermal anomalies detected in one earthquake case are general or incidental phenomena is often controversial. One of the general strategies is based on the validation and confutation method for verification (Genzano et al, 2015;Lisi et al, 2010;Lisi et al, 2015;Xiong et al, 2013). In the validation phase, thermal anomalies associated with earthquakes should be found; however, no thermal anomalies should be confirmed in the confutation phase.…”