From visual comparison to robust satellite techniques: 30 years of thermal infrared satellite data analyses for the study of earthquake preparation phases

This review paper reports the main contributions and results achieved after more than 30 years of studies on the possible relationships among space-time variation of Earth’s thermally emitted radiation, measured by satellite sensors operating in the Thermal InfraRed (TIR) spectral range (8-14 m), and earthquake occurrence. Focus will be given on the different existing methods/models to: 1) discriminate a possible pre-seismic TIR anomaly from all the other TIR signal fluctuations; 2) correlate such anomalies with space, time and magnitude of earthquakes; 3) physically justify such a correlation

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

A self adaptive approach (RST, Robust Satellite Technique) has been proposed 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 approach has been applied to 15 years of AVHRR (Advanced Very High Resolution Radiometer) thermal infrared observations in order to study the 6 April 2009 Abruzzo earthquake. Preliminary results show clear differences in TIR anomalies occurrence during the periods used for validation (15 March–15 April 2009) and the one (15 March–15 April 2008) without earthquakes with <i>M</i><sub>L</sub>≥4.5, used for confutation purposes. Quite clear TIR anomalies appears also to mark main tectonic lineaments during the preparatory phases of others, low magnitude(3.9<<i>M</i><sub>L</sub><4.6) earthquakes, occurred in the area in the same period

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

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)similar to 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 presente

Robust satellite techniques (RST) for the thermal monitoring of earthquake prone areas: the case of Umbria-Marche October, 1997 seismic events

Several authors claim a space-time correlation between increases in Earth’s emitted Thermal Infra-Red (TIR) radiation and earthquake occurrence. The main problems of such studies regard data analysis and interpretation, which are often done without a validation/confutation control. In this context, a robust data analysis technique (RST, i.e. Robust Satellite Techniques) is proposed which permits a statistically based definition of TIR «anomaly » and uses a validation/confutation approach. This technique was already applied to satellite TIR surveys in seismic regions for about twenty earthquakes that occurred in the world. In this work RST is applied for the first time to a time sequence of seismic events. Nine years of Meteosat TIR observations have been analyzed to characterize the unperturbed TIR signal behaviour at specific observation times and locations. The main seismic events of the October 1997 Umbria-Marche sequence have been considered for validation, and relatively unperturbed periods (no earthquakes with Mb ≥ 4) were taken for confutation purposes. Positive time-space persistent TIR anomalies were observed during seismic periods, generally overlapping the principal tectonic lineaments of the region and sometimes focusing on the vicinity of the epicentre. No similar (in terms of relative intensity and space-time persistence) TIR anomalies were detected during seismically unperturbed periods

RST analysis of MSG-SEVIRI TIR radiances at the time of the Abruzzo 6 April 2009 earthquake

Space-time fluctuations of Earth's emitted Thermal Infrared (TIR) radiation have been observed from satellite months to weeks before earthquakes occurrence. The general RST approach has been proposed in order to discriminate normal (i.e. related to the change of natural factor and/or observation conditions) TIR signal fluctuations from anomalous signal transient possibly associated to earthquake occurrence. In this work RST approach is applied to the Abruzzo 6 April 2009 event (M(L)=5.8) by using for the first time MSG-SEVIRI (Meteosat Second Generation -Spinning Enhanced Visible and Infrared Imager) thermal infrared observations. A validation/confutation analysis has been performed in order to verify the presence/absence of anomalous space-time TIR transients in the presence/absence of significant seismic activity. March-April 2009 has been analyzed for validation purposes. Relatively unperturbed periods (no earthquakes with M(L)>= 5) have been taken for confutation. A specific TIR anomalies space-time persistence analysis as well as a cloud coverage distribution test have been introduced in order to eliminate artifacts and outliers both in the validation and confutation phases. Preliminary results show clear differences in TIR anomalies occurrence during the periods used for validation and confutation purposes. Quite clear TIR anomalies appear also to mark main tectonic lines related to the preparatory phases of others, low magnitude (M(L)similar to 4) earthquakes, occurred in the area

Robust TIR satellite techniques for monitoring earthquake active regions: limits, main achievements and perspectives

In the last few years, Robust Satellite data analysis Techniques (RST) have been proposed which significantly improved present capabilities to investigate possible relations between TIR signal fluctuations and earthquake occurrence. This paper, starting from a critical survey of results achieved by applying different RST-based algorithms to different satellite sensors to approximately ten earthquakes (two of them are discussed here for the first time) which occurred in three different continents, tries to offer a first assessment of main achievements, residual limits and perspectives of such studies. Even if it is still not possible to relate (or to exclude) observed anomalous TIR transients definitely to impending earthquakes, such studies demonstrate at least: a) the strong improvement of S/N ratio achievable moving from polar to geostationary satellites; b) the further S/N improvement achievable by using TIR sensors which also offer split-window possibilities; c) the crucial role played by a space-time persistence test to select TIR anomalies candidate to be associated to impending earthquakes; d) the possibility of identifying and correctly discarding TIR anomalies related to clouds and to image navigation errors; e) the scarce importance of spatial resolution of observations which encourages the use of passive MW sensors which are less affected by atmospheric conditions

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

first_pagesettings Open AccessArticle RST Analysis of Anomalous TIR Sequences in Relation with Earthquakes Occurred in Turkey in the Period 2004–2015 by Carolina Filizzola 1ORCID,Angelo Corrado 2,Nicola Genzano 2ORCID,Mariano Lisi 1ORCID,Nicola Pergola 1ORCID,Roberto Colonna 2 andValerio Tramutoli 2,*ORCID 1 Institute of Methodologies for Environmental Analysis, National Research Council, 85050 Potenza, Italy 2 School of Engineering, University of Basilicata, 85100 Potenza, Italy * Author to whom correspondence should be addressed. Academic Editor: Stephan Havemann Remote Sens. 2022, 14(2), 381; https://doi.org/10.3390/rs14020381 Received: 12 November 2021 / Revised: 8 January 2022 / Accepted: 11 January 2022 / Published: 14 January 2022 (This article belongs to the Special Issue Advances in Remote Sensing Systems for Disaster Management and Risk Mitigation) Download PDF Browse Figures Citation Export 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

Thermal Radiation Anomalies Associated with Major Earthquakes

Recent developments of remote sensing methods for Earth satellite data analysis contribute to our understanding of earthquake related thermal anomalies. It was realized that the thermal heat fluxes over areas of earthquake preparation is a result of air ionization by radon (and other gases) and consequent water vapor condensation on newly formed ions. Latent heat (LH) is released as a result of this process and leads to the formation of local thermal radiation anomalies (TRA) known as OLR (outgoing Longwave radiation, Ouzounov et al, 2007). We compare the LH energy, obtained by integrating surface latent heat flux (SLHF) over the area and time with released energies associated with these events. Extended studies of the TRA using the data from the most recent major earthquakes allowed establishing the main morphological features. It was also established that the TRA are the part of more complex chain of the short-term pre-earthquake generation, which is explained within the framework of a lithosphere-atmosphere coupling processes

Monitoring temporal variations in the geothermal activity of Miocene Lesvos volcanic field using remote sensing techniques and MODIS - LST imagery

Abstract Many islands of the Aegean Sea show strong geothermal activity due to volcanism in the area. In this paper, Robust Satellite Techniques (RST) are used to isolate, from other known possible sources, those thermal anomalies possibly related to geothermal activity in the Miocene volcanic field of Lesvos Island (Northern Aegean). For this purpose, 12 years (2003–2014) of daily Night-time Land Surface Temperature (LST) products, from Moderate Resolution Imaging Spectroradiometer (MODIS) acquisitions were analyzed. The final dataset contained 770 thermal anomalies whose spatial correlation with geological and structural data of Lesvos - such as caldera rims, ring faults, major tectonic lineaments and hydrothermal alterations mapped by processing SENTINEL-2 MSI satellite images – has been particularly investigated. In the approximately 20 ma geothermal field of Lesvos, geothermal activity seems to be also associated with the extensional regime of the broader area that leads to lithosphere thinning and consequent heat transfer in the multi-fractured terrain of Lesvos through volcanic and tectonic faults. Achieved results seem to confirm the possibility to use RST-based thermal anomalies to identify temporal variations in the geothermal activity probably due to the uplifting and circulation of the hydrothermal waters