RST Analysis of Anomalous TIR Sequences in Relation with Earthquakes Occurred in Turkey in the Period 2004–2015

Abstract

The paper provides, for the first time, a long-term (>10 years) analysis of anomalous transients in Earth’s emitted radiation over Turkey and neighbouring regions. The RST (Robust Satellite Techniques) approach is used to identify Significant Sequences of Thermal Anomalies (SSTAs) over about 12 years (May 2004 to October 2015) of night-time MSG-SEVIRI satellite images. The correlation analysis is performed with earthquakes with M ≥ 4, which occurred in the investigated period/region within a pre-defined space-time volume around SSTA occurrences. It confirms, also for Turkey, the possibility to qualify SSTAs among the candidate parameters of a multi-parametric system for time-Dependent Assessment of Seismic Hazard (t-DASH). After analysing about 4000 images (about 400 million of single satellite records), just 155 SSTAs (about 4 every 100 images) were isolated; 115 (74% out of the total) resulted in earthquake-related (false-positive rate 26%). Results of the error diagram confirms a non-casual correlation between RST-based SSTAs and earthquake occurrences, with probability gain values up to 2.2 in comparison with the random guess. The analysis, separately performed on Turkish areas characterized by different faults and earthquakes densities, demonstrates the SSTA correlation with a dynamic seismicity more than with static tectonic settings.

Satellite-Observed Thermal Anomalies and Deformation Patterns Associated to the 2021, Central Crete Seismic Sequence

“…Moreover, the 10 years analysis of continuous data over Greece by [45] showed the general correlation between earthquakes and the thermal anomalies computed by the RST. A similar investigation of RST capabilities recently took place in Turkey and confirmed a nonrandom correlation between RST-based thermal anomalies and earthquake occurrence [20].…”

“…As the stress evolution creates a network of micro-and meso-scaled cracks that superimposed to the already existing faulting system, a pathway is created that supports the discharge of trapped gas buffers. As the earthquake approaches, due to the creation of a significant fracture in the rupture zone, a new rise in degassing activity can occur before normality is gradually restored [20]. The absence of thermal anomalies during October could indicate that after the earthquake occurrence, the stress field relaxed ( [63] and references therein) and thus reduced the above-described processes.…”

“…The cause of this "natural noise" can be the atmospheric weather or several variations in vegetation (natural or planted) or man-made constructions, topography and climate over space and time. As shown in previous works (e.g., [2,19,20,27,28,44,45]), the advantage of the RST methodology compared to other approaches is its ability to isolate residual thermal variations which are probably connected to tectonic activity. Over the past two decades, the RST method has been applied worldwide in several geotectonic regimes and to earthquakes with magnitudes greater than 4.0.…”

“…Several satellite sensors, which have channels in the infrared portion of the electromagnetic spectrum, can monitor Earth's thermal field and generate a Land Surface Temperature (LST) product with variable spatiotemporal resolution depending on the satellite/sensor system chosen [6][7][8][9]. Therefore, LST can be used as a critical guide to the understanding of land surface processes at various scales [10][11][12][13][14][15][16][17][18][19][20] and environments, especially in Remote Sens. 2022, 14, 3413 2 of 20 areas with a variability in geophysical parameters such as vegetation, topography, geology and geomorphometry.…”

Coarse-graining research of the thermal infrared anomalies before earthquakes in the Sichuan area on Google Earth engine

“…(Blackett et al, 2011;Qin et al, 2012;Zoran, 2012). The robust satellite techniques (RST) approach has been widely implemented for environmental problems such as seismic anomaly detection, volcano monitoring, and oil spill events (Zhang and Meng, 2018;Eleftheriou et al, 2021;Filizzola et al, 2022;Genzano et al, 2015;Tramutoli et al, 2018). The RST approach was applied to define and discriminate possible pre-seismic TIR anomalies from other signal variations commonly related to known or unknown natural/observational factors that can be responsible for the" false alarms" proliferation (Wang et al, 2015).…”