38 research outputs found
Optimal Setting of Earthquake-Related Ionospheric TEC (Total Electron Content) Anomalies Detection Methods: Long-Term Validation over the Italian Region
Over the last decade, thanks to the availability of historical satellite observations that have begun to be significantly large and thanks to the exponential growth of artificial intelligence techniques, many advances have been made in the detection of geophysical parameters such as seismic-related anomalies. In this study, the variations of the ionospheric Total Electron Content (TEC), one of the main parameters historically proposed as a seismic-connected indicator, are analyzed. To make a statistically robust analysis of the complex phenomena involved, we propose a completely innovative machine-learning approach developed in the R programming language. Through this approach, an optimal setting of the multitude of methodological inputs currently proposed for the detection of ionospheric anomalies is performed. The setting is optimized by analyzing, for the first time, multi-year—mostly twenty-year—time series of TEC satellite data measured by global navigation satellite systems (GNSS) over the Italian region, matched with the corresponding multi-year time series of seismic events. Seismic events including all the countries of the Mediterranean area, up to Turkey, are involved in the analysis. Tens of thousands of possible combinations of input methodological parameters are simulated and classified according to pre-established criteria. Several inputs examined return clear results. These results combined with each other highlight the presence of anomalous seismic-related sequences that have an extremely low probability of having been detected randomly (up to 2 out of 1 million). The anomalies identified represent the most anomalous behaviors of the TEC recorded during the entire period under investigation (e.g., 20 years). Some of the main conclusions are that, at mid-latitudes, ①the detection of seismic-TEC anomalies can be more efficient looking for punctual rather than persistent phenomena; ② the optimal thresholds for the identification of co-seismic anomalies can assume different values depending on type of anomaly (positive or negative) and type of observation; ③ single GNSS receiver data can be useful for capturing local earthquake-ionospheric effects and Global Ionospheric Maps (GIM) data can be functional in detecting large-scale earthquake-ionospheric effects; ④ earthquakes deeper than 50 km are less likely to affect the ionosphere
Landslides Detection and Mapping with an Advanced Multi-Temporal Satellite Optical Technique
Landslides are catastrophic natural phenomena occurring as a consequence of climatic,
tectonic, and human activities, sometimes combined among them. Mostly due to climate change effects, the frequency of occurrence of these events has quickly grown in recent years, with a consequent increase in related damage, both in terms of loss of human life and effects on the involved infrastructures. Therefore, implementing properly actions to mitigate consequences from slope instability is fundamental to reduce their impact on society. Satellite systems, thanks to the advantages offered by their global view and sampling repetition capability, have proven to be valid tools to be used for these activities in addition to traditional techniques based on in situ measurements. In this
work, we propose an advanced multitemporal technique aimed at identifying and mapping landslides using satellite-derived land cover information. Data acquired by the Multispectral Instrument (MSI) sensor aboard the Copernicus Sentinel-2 platforms were used to investigate a landslide affecting Pomarico city (southern Italy) in January 2019. Results achieved indicate the capability of the proposed methodology in identifying, with a good trade-off between reliability and sensitivity, the area affected by the landslide not just immediately after the event, but also a few months later. The
technique was implemented within the Google Earth Engine Platform, so that it is completely automatic and could be applied everywhere. Therefore, its potential for supporting mitigation activities of landslide risks is evident
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
RST Analysis of Anomalous TIR Sequences in Relation with Earthquakes Occurred in Turkey in the Period 2004–2015
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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)
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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
Aerial remote sensing hyperspectral techniques for rocky outcrops mapping
In this work the MIVIS (Multispectral Infrared and Visible Imaging Spectrometer) hyperspectral data, acquired during aerial campaigns made in 1998 over the Pollino National Park in the framework of the «Progetto Pollino», have been used to set up a supervised technique devoted to identify the presence of selected rocky outcrops. Tests have been performed over an extended area characterised by a complex orography. Within this area, serpentinite was chosen as a test-rock because it is present in isolated outcrops, distributed all over the test-area, besides subtending important problems of environmental nature as it contains asbestos. Geological information, coming from field observations or geological maps, was used to trigger the algorithms and as ground truth for its validation. Two spectral analysis techniques, SAM (Spectral Angle Mapper) and LSU (Linear Spectral Unmixing), have been applied and their results n combined to automatically identify serpentinite outcrops and, in some cases, to mark its boundaries. The approach used in this work is characterised by simplicity (no atmosphere and illumination corrections were performed on MIVIS data), robustness (material of interest is identified for certainty) and intrinsic exportability (the method proposed can be applied on different geographic areas and, in theory, to identify any kind of material because no datum about atmospheric and illumination conditions is required)
Fire Characterization by Using an Original RST-Based Approach for Fire Radiative Power (FRP) Computation
Fire radiative power (FRP) is a basic parameter for fire characterization since it represents the heat emission rate of fires. Moreover, its temporal integration (fire radiative energy, FRE) is used as a proxy for estimating biomass burning and emissions. From satellite, FRP is generally computed by comparing the Medium InfraRed (MIR) signal of the fire pixel with the background value on the event image. Such an approach is possibly affected by some issues due to fire extent, clouds and smoke over the event area. The enlargement of the background window is the commonly used gimmick to face these issues. However, it may include unrepresentative signals of the fire pixel because of very different land use/cover. In this paper, the alternative Background Radiance Estimator by a Multi-temporal Approach (BREMA), based on the Robust Satellite Technique (RST), is proposed to characterize background and compute FRP. The approach is presented using data from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) onboard the Meteosat Second Generation (MSG) platform. Moreover, BREMA is here combined with the RST-FIRES (RST for FIRES detection) technique for fire pixel identification and the -SEVIRI retrieval algorithm for transmittance evaluation. Results compared to the operational SEVIRI-based FRP-PIXEL product, although highly correlated in terms of background radiance (r2=0.95) and FRP values (r2=0.96), demonstrated a major capability of BREMA to estimate background radiances regardless of cloudiness or smoke presence during the event and independently on fire extent. The possible impact of the proposed approach on the estimates of CO2 emissions was also evaluated for comparison with the Global Fire Emissions Database (GFED4s)
Adenoma hipofisiario en una paciente embarazada, evolución y manejo: Reporte de caso y revisión de la literatura
Se reporta el caso de una paciente de 32 años quien consulta al servicio de endocrinologÃa por crecimiento acral, hiperhidrosis, amenorrea, cefalea y cambios faciales. Se encuentra test de hormona de crecimiento postsupresión con 100 g de glucosa positivo e imagen de resonancia magnética nuclear con macroadenoma hipofisiario con quiasma libre. Se ordena resección de la masa e inicio de análogo de somatostatina; sin embargo, la paciente no inicia la medicación, además hay pérdida en el seguimiento clÃnico. Tiempo después consulta de nuevo al servicio de endocrinologÃa en estado de embarazo. Se decide mantener en observación clÃnica durante la gestación, sin evidenciarse complicaciones secundarias a su patologÃa ni en la madre ni en el neonato. Presentamos aquà la secuencia de hechos con sus resultados y una revisión de la literatura.
Abstract
This is the case of a 32-year-old female who was seen at the Endocrinology service complaining of acral growth, hyperhidrosis, amenorrhea, headache and facial changes. The post-suppression growth hormone test with 100 g of glucose was positive and her MRI showed a pituitary macroadenoma without chiasm compression. Resection of the mass was scheduled followed by the use of a somatostatin analogue. However, the patient did not initiate the medication, and was lost for follow-up. Later on she visited again the Endocrinology Service while pregnant. It was decided to keep her under clinical observation during her pregnancy, with no evidence of complications secondary to the condition neither for the mother nor for the newborn. We report here the sequence of events with their results and a review of the literature
Mt. Etna Paroxysms of February–April 2021 Monitored and Quantified through a Multi-Platform Satellite Observing System
On 16 February 2021, an eruptive paroxysm took place at Mt. Etna (Sicily, Italy), after
continuous Strombolian activity recorded at summit craters, which intensified in December 2020. This
was the first of 17 short, but violent, eruptive events occurring during February–April 2021, mostly
at a time interval of about 2–3 days between each other. The paroxysms produced lava fountains
(up to 1000 m high), huge tephra columns (up to 10–11 km above sea level), lava and pyroclastic
flows, expanding 2–4 km towards East and South. The last event, which was characterised by about
3 days of almost continuous eruptive activity (30 March–1 April), generated the most lasting lava
fountain (8–9 h). During some paroxysms, volcanic ash led to the temporary closure of the Vincenzo
Bellini Catania International Airport. Heavy ash falls then affected the areas surrounding the volcano,
in some cases reaching zones located hundreds of kilometres away from the eruptive vent. In this
study, we investigate the Mt. Etna paroxysms mentioned above through a multi-platform satellite
system. Results retrieved from Advanced Very High Resolution Radiometer (AVHRR), Moderate
Resolution Imaging Spectroradiometer (MODIS), and Spinning Enhanced Visible and Infrared Imager
(SEVIRI), starting from outputs of the Robust Satellite Techniques for Volcanoes (RSTVOLC), indicate
that the 17th paroxysm (31 March–1 April) was the most powerful, with values of radiative power
estimated around 14 GW. Moreover, by the analysis of SEVIRI data, we found that the 5th and 17th
paroxysms were the most energetic. The Multispectral Instrument (MSI) and the Operational Land
Imager (OLI), providing shortwave infrared (SWIR) data at 20/30 m spatial resolution, enabled
an accurate localisation of active vents and the mapping of the areas inundated by lava flows. In
addition, according to the Normalized Hotspot Indices (NHI) tool, the 1st and 3rd paroxysm (18 and
28 February) generated the largest thermal anomaly at Mt. Etna after June 2013, when Landsat-8
OLI data became available. Despite the impact of clouds/plumes, pixel saturation, and other factors
(e.g., satellite viewing geometry) on thermal anomaly identification, the used multi-sensor approach
allowed us to retrieve quantitative information about the 17 paroxysms occurring at Mt. Etna. This
approach could support scientists in better interpreting changes in thermal activity, which could lead
to future and more dangerous eruptions
Clinical description and treatment of patients with acute coronary syndrome
Antecedentes: el sÃndrome coronario agudo es una emergencia clÃnica que se manifiesta principal-mente por dolor torácico. Su diagnóstico representa un desafÃo clÃnico y su reconocimiento temprano es fundamental para el tratamiento. Objetivo: describir las caracterÃsticas clÃnicas, identificar abordajes terapéuticos y conocer los desenlaces de los pacientes con diagnóstico definitivo de sÃndrome coronario agudo hospitalizados por el servicio de medicina interna y cardiologÃa entre el 1° de enero de 2009 hasta 31 de diciembre de 2010 en el Hospital San José. Métodos: se realizó una descripción de una cohorte de pacientes con diagnóstico de sÃndrome coronario agudo (infarto miocárdico con y sin elevación del segmento ST y angina inestable). Se analizaron variables demográficas, caracterÃsticas clÃnicas, tratamiento y desenlaces a los cuales se calcularon promedio, desviación estándar y proporciones según la naturaleza de las mismas. Resultados: se reportan 133 pacientes. El 63% correspondió a hombres, el promedio de edad fue de 64.8 años. La frecuencia de eventos fue 45.9% IMEST, 39% IMSEST y 15.1% anginas inestables. El 96.2% de los pacientes consultó por dolor torácico, 50.7% presentaron dolor en las primeras seis horas de evolución. El 93% recibió betabloqueador, 88% IECA, 87% clopidogrel y 97% ASA. Se trombolizó al 82% de los pacientes en ventana. La mortalidad intrahospitalaria fue del 8.7%. Conclusiones: en la población estudiada predominó el sÃndrome coronario agudo sin elevación del segmento ST. La mayorÃa de pacientes consultaron por dolor torácico retroesternal, en las primeras horas de inicio. El porcentaje de uso de los medicamentos fue adecuado. La reperfusión inmediata en pacientes con IMEST fue alta, sin embargo aún tenemos pacientes que no se benefician de esta terapia y el uso de angioplastias primarias fue muy bajo.Background: acute coronary syndrome is a medical emergency that is manifested mainly by chest pain. The diagnosis is a clinical challenge and its early recognition is essential for treatment. Objective: to describe the clinical characteristics, identify therapeutic approaches and recognize the outcomes of patients with a final diagnosis of acute coronary syndrome hospitalized in Internal Medicine and Cardiology services between January 1, 2009 until December 31, 2010 at the Hospital San José. Methods: description of a cohort of patients diagnosed with acute coronary syndrome (myocardial infarction with and without ST segment elevation and unstable angina) was performed. Demographic variables, clinical characteristics, treatment and outcomes were analyzed and average, standard devia-tion and proportions were calculated according to their the nature. Results: 133 patients were reported. 63% were men, the mean age was 64.8 years. The event rate was 45.9% STEMI, 39% NSTEMI and unstable angina 15.1%. 96.2% of patients consulted for chest pain, 50.7% had pain in the first six hours of evolution. 93% received beta-blockers, 88% ACE inhibitors, 87% clopidogrel and 97% ASA. 82% of patients in window underwent thrombolysis. The hospital mortality was 8.7%