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This paper explores multi-instrument space-borne observations in order to validate physical concepts of Lithosphere-Atmosphere-Ionosphere Coupling (LAIC) in relation to major seismic events. In this study we apply already validated observation to identify atmospheric and ionospheric precursors associated with some of recent most destructive earthquakes: M8.6 of March 25, 2005 and M8.5 September 15, 2007 in Sumatra, and M7.9 May 12, 2008 in Wenchuan, China. New investigations are also presented concerning these three earthquakes and for the M7.3 March 2008 in the Xinjiang-Xizang border region, China (the Yutian earthquake). It concerns the ionospheric density, the Global Ionospheric Maps (GIM) of the Total Electron Content (TEC), the Thermal Infra-Red (TIR) anomalies, and the Outgoing Longwave Radiation (OLR) data. It is shown that all these anomalies are identified as short-term precursors, which can be explained by the LAIC concept proposed by Pulinets and Ouzounov (2011). [ABSTRACT FROM AUTHOR]

The occurrence of intense CO2 degassing processes generating hundreds of cold CO2- rich gas emissions is typical of the central Apennines. In 2009, significant anomalies were detected coinciding with the L'Aquila seismic sequence as a consequence of a wide degassing process. Over the same time-span, space-time anomalies in Thermal InfraRed (TIR) satellite imagery possibly related to the increase of green-house gas (such as CO2, CH4, etc.) emission rates were detected in central Italy during the seismic swarm by a Robust Satellite Technique (RST) data analysis. A gas geochemical survey carried out in the L'Aquila area confirms the deep crustal origin of the anomalous gas emission detected by ground measurements. Anomalous fluid related signals were recorded some days before the mainshock coinciding with the most marked TIR anomalies independently detected by the RST analysis over 3 different types of satellite data. Anomalous gas emissions detected by ground measurements lasted some weeks, putting in evidence relationships with crustal deformative processes associated with the seismic sequence. Together with previous ground observations in the Umbria-Marche area, present ground and satellite TIR observations, are compatible with the hypothesis that a central Apennines area, much wider than the L'Aquila (March-April 2009) epicentral one, was actually affected by anomalous increases in CO2 release thus providing new tools to better understand the processes occurring behind a seismic shock. [ABSTRACT FROM AUTHOR]

In this study, Earth's emitted Thermal InfraRed (TIR) radiation measured from geostationary satellite sensors has been analyzed by using an original data analysis approach in order to evaluate possible space-time correlation with earthquakes (M=4.0) occurrence. A clear definition of SSTA (Significant Sequence of Thermal Anomaly) concept is given and correlation rules are established in order to evaluate the potential of SSTAs among the parameters to be included in a pre-operational system for time- Dependent Assessment of Seismic Hazard (t-DASH). On the considered time period (July 2012 - June 2013) and testing areas (Italian southern Apennines and Po Plain) a false positive rate lesser than 33% has been obtained. Notwithstanding a missing rate up to 67% (mostly because of the presence of clouds preventing the continuity of observations), as confirmed by other independent studies performed on longer period of time and different geographic areas, seems to strongly support the inclusion of SSTAs [identified by the RST (Robust Satellite Technique) methodology] among the parameters whose continuous monitoring and integration with all the other relevant information available, could strongly improve our present capabilities to dynamically assess seismic hazard in a pre-operational context. [ABSTRACT FROM AUTHOR]

The synergic use of satellite data at moderate spatial resolution (i.e., 20-30 m) from the new Collection 2 (C2) Landsat-8/9 (L8/9) Operational Land Imager (OLI) and Sentinel-2 (S2) Multispectral Instrument (MSI) provides a new perspective in the remote sensing applications for gas flaring (GF) identification and monitoring, thanks to a significant improvement in the revisiting time (up to ~3 days). In this study, the daytime approach for gas flaring investigation (DAFI), recently developed for identifying, mapping and monitoring GF sites on a global scale using the L8 infrared radiances, has been ported on a virtual constellation (VC) (formed by C2 L8/9 + S2) to assess its capability in understanding the GF characteristics in the space-time domain. The findings achieved for the regions of Iraq and Iran, ranked at the second and third level among the top 10 gas flaring countries in 2022, demonstrate the reliability of the developed system, with improved levels of accuracy and sensitivity (+52%). As an outcome of this study, a more realistic picture of GF sites and their behavior is achieved. A new step aimed at quantifying the GFs radiative power (RP) has been added in the original DAFI configuration. The preliminary analysis of the daily OLI- and MSI-based RP, provided for all the sites by means of a modified RP formulation, revealed their good matching. An agreement of 90% and 70% between the annual RPs computed in Iraq and Iran and both their gas-flared volumes and carbon dioxide emissions were also recorded. Being that gas flaring is one of the main sources of greenhouse gases (GHG) worldwide, the RP products may concur to infer globally the GHGs GF emissions at finer spatial scales. For the presented achievements, DAFI can be seen as a powerful satellite tool able to automatically assess the gas flaring dimension on a global scale.

The Normalized Hotspot Indices (NHI) tool is a Google Earth Engine (GEE)-App developed to investigate and map worldwide volcanic thermal anomalies in daylight conditions, using shortwave infrared (SWIR) and near infrared (NIR) data from the Multispectral Instrument (MSI) and the Operational Land Imager (OLI), respectively, onboard the Sentinel 2 and Landsat 8 satellites. The NHI tool offers the possibility of ingesting data from other sensors. In this direction, we tested the NHI algorithm for the first time on Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data. In this study, we show the results of this preliminary implementation, achieved investigating the Kilauea (Hawaii, USA), Klyuchevskoy (Kamchatka; Russia), Shishaldin (Alaska; USA), and Telica (Nicaragua) thermal activities of March 2000-2008. We assessed the NHI detections through comparison with the ASTER Volcano Archive (AVA), the manual inspection of satellite imagery, and the information from volcanological reports. Results show that NHI integrated the AVA observations, with a percentage of unique thermal anomaly detections ranging between 8.8% (at Kilauea) and 100% (at Shishaldin). These results demonstrate the successful NHI exportability to ASTER data acquired before the failure of SWIR subsystem. The full ingestion of the ASTER data collection, available in GEE, within the NHI tool allows us to develop a suite of multi-platform satellite observations, including thermal anomaly products from Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+), which could support the investigation of active volcanoes from space, complementing information from other systems.

Satellite-based Earth observation plays a key role for monitoring volcanoes, especially those which are located in remote areas and which very often are not observed by a terrestrial monitoring network. In our study we jointly analyzed data from thermal (Moderate Resolution Imaging Spectrometer MODIS and Visible Infrared Imaging Radiometer Suite VIIRS), optical (Operational Land Imager and Multispectral Instrument) and synthetic aperture radar (SAR) (Sentinel-1 and TerraSAR-X) satellite sensors to investigate the mid-October 2019 surtseyan eruption at Late'iki Volcano, located on the Tonga Volcanic Arc. During the eruption, the remains of an older volcanic island formed in 1995 collapsed and a new volcanic island, called New Late'iki was formed. After the 12 days long lasting eruption, we observed a rapid change of the island's shape and size, and an erosion of this newly formed volcanic island, which was reclaimed by the ocean two months after the eruption ceased. This fast erosion of New Late'iki Island is in strong contrast to the over 25 years long survival of the volcanic island formed in 1995.