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Deformation and Stress Status of a Cable-Stayed Bridge Revealed by Incorporating Ascending-Descending Time Series Interferometric SAR Fusion and Finite Element Modeling
No full textTime series interferometric synthetic aperture radar (TS-InSAR) is a noncontact active satellite observation technology that has gradually revealed its potential in bridge deformation monitoring with unprecedented point density and accuracy. Similarly, the finite element modeling (FEM) has also been conducted to analyze deformation and stress distribution of bridge structures, estimating the structural health status. However, previous studies typically utilized sparse in-situ deformation measurements, which only capture the stress of the main components, making it difficult to obtain the local distribution. To address this issue, this study proposes a method that incorporates high-resolution ascending-descending TS-InSAR fusion measurements with FEM, improving the bridge deformation and stress distribution analysis. Taking a cable-stayed bridge as an example, the structural deformation is extracted from ascending TerraSAR-X and descending COSMO-SkyMed SAR images, serving as a constraint for stress state analysis. The experimental results show that the area most significantly affected by temperature deformation are located at both ends of the main bridge, with the maximum longitudinal thermal deformation rates of −0.71 and 0.88 mm/°C, respectively. Moreover, the TS-InSAR measurements are highly consistent withPublishedJCR Journa
Comparison of Stochastic and Enhanced Earthquake Detection Techniques in Mitigating Time-Varying Incompleteness
No full textAlthough not specifically conceived for tackling short-term aftershock incompleteness (STAI), earthquake detection methods such as template matching (TM) and machine learning (ML) can help mitigate the under-reporting of aftershocks after large earth- quakes by detecting low-magnitude events hidden in seismic noise. So far, the ability of TM and ML to address STAI has not been evaluated against benchmark data sets reconstructed by independent methods. In this study, we use events reconstructed by RESTORE (REal catalogs STOchastic REplenishment), a Python toolbox specifically designed to tackle STAI, as a stochastic benchmark to assess the ability of TM and ML in recovering the bulk statistical properties of aftershocks missed during STAI period. Our results show overall good compatibility between the TM/ML detections and the RESTORE benchmark in the space–time–magnitude domain, though some discrepancies in detection rates and in the upper bounds of magnitudes are noted. This study also highlights the complementary use of stochastic and enhanced detection tech- niques. Stochastic algorithms like RESTORE can be implemented for immediate STAI mitigation in short-term forecasting and operational earthquake forecasting, whereas enhanced detection techniques can be used over longer time scales to precisely recover unrecorded events.PublishedJCR Journa
A target-based, multi-hazard assessment approach as a tool for supporting decision-making in volcanic areas: a case study in Mt. Etna, Italy
No full textMulti-hazard assessment aims at evaluating the potential impacts of various natural and humaninduced hazards in a given area of interest and time period. The analysis can include hazards of different nature-such as volcanic eruptions, earthquakes, floods, landslides, and industrial accidents-considering their interdependencies and cumulative effects. Multi-hazard assessments can provide critical insights into the potential impact of multiple hazards, enabling decision makers to adopt a wider view of the problem with respect to the approach of analyzing single hazards independently. Volcanoes are interesting targets for implementing multi-hazard analyses because they are intrinsically a multi-hazard source due to the variety of phenomena usually related to volcanic eruptions (e.g. volcano seismicity, lava flows, tephra fall, lahars, etc.). This paper presents a target-based approach for multi-hazard analysis at Etna volcano (Italy) in which the output of probabilistic single hazard assessment can be harmoniously integrated and used for assessing a wide number of scenarios. The findings underscore the advantages of adopting such a kind of approach for supporting decision makers when using the results of multiple probabilistic hazards assessments for performing tasks of planning, mitigation, or emergency preparedness. This work has been performed in the framework of the INGV project "Pianeta Dinamico"-PANACEA, a project developed for implementing multi-hazard and multi-risk assessments at Etna volcano.PublishedOSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Geochemical and Isotopic Features of Geothermal Fluids Around the Sea of Marmara, NW Turkey
No full textThis article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) licensePublishedJCR Journa
Multi-instrument analysis of medium-scale travelling ionospheric disturbances generated by an intense tropospheric jet-front system with severe convection in Europe in August 2023
No full textTropospheric jet-front systems and intense convection are known to be potential sources of atmospheric gravity waves (AGWs), which can propagate upward. When AGWs reach the height of the coupled thermosphere-ionosphere system, they interact with the ionised medium and cause wave-like oscillations known as travelling ionospheric disturbances (TIDs). The main purpose of the present study is to investigate medium-scale TID (MSTID) activity during the passage of a jet-front system using different observational techniques, namely: vertical ionospheric soundings at seven European ionosonde stations, Continuous Doppler Sounding System (CDSS) in Czech Republic, oblique Digisonde-to-Digisonde (D2D) sounding, and Total Electron Content (TEC) measurements provided by ground-based Global Navigation Satellite System (GNSS) receivers co-located with the ionosondes. A strong jet-front system accompanied by intense convection passed through continental Europe between 25 and 29 August 2023. The severe convection and the unusually persistent meridional jet stream caused a strong vertical wind shear across the entire troposphere, which was favourable to the generation of atmospheric gravity waves. During the event, the geomagnetic activity can be considered calm. The most intense MSTID activity was observed in ionograms, in the single station detrended TEC (dTEC) measurements, and also in the CDSS Doppler shift records during the daytime (~06-13 UT) on 27 August, when the jet stream reached its highest velocities (~200 km/h) over continental Europe. Signatures of MSTIDs were also observed during other analysed time periods of the event. Based on the ionospheric and meteorological observations, the location and time of these enhanced TID activities coincided with local thunderstorms and a Mesoscale Convective System (MCS) event. According to the records, the dominant periods of the disturbances varied between 15 and 70 min. When summarizing, our multi-instrumental observations confirmed that jet-front systems accompanied by severe tropospheric convection could be significant sources of AGWs, which reach the ionosphere and trigger MSTIDs.PublishedJCR Journa
Geomorphological Observations and Physical Hypotheses About Martian Dune Gullies
No full textProponiamo l'ipotesi che i gullies dunali e le manifestazioni "meteorologiche" stagionali osservate sulle stesse dune (ad esempio, la formazione di brina) possano avere un'origine comune. Questi particolari gullies sono difficili da spiegare attraverso l'azione di un flusso liquido. L'esistenza di una sorgente che sgorga dalla cresta di una duna sembra non è un'ipotesi realistica. Tuttavia, questi fenomeni potrebbero avere origine dall'impatto del vento sui profili di alcune grandi dune marziane. Questo effetto aerodinamico potrebbe generare stagionalmente tutti i fenomeni meteorologici che osserviamo su queste dune (corpi di ghiaccio, brina, scie di umidità e nubi di vapore) i quali possono di conseguenza produrre canaloni con una morfologia peculiare, diversa dallo standard Alcove-Channel-Apron (ACA). Pertanto, i gullies dunali potrebbero avere origine da liquidi meteorologici ma attraverso un processo diverso da quelli noti sulla Terra. Le osservazioni fatte sui crateri Kaiser, Russell e Korolev supportano la possibilità di un ciclo parziale dell'acqua (un semiciclo) che rappresenta presumibilmente il residuo di un antico ciclo completo.We propose the hypothesis that dune gullies and seasonal “meteorological” appearances observed on the same dunes (e.g., frosting) may have a common origin. These gullies are difficult to explain through the action of liquid flow. The occurrence of a spring flowing from the crest of a dune seems impossible to explain. However, these phenomena could originate from the impact of wind on the profiles of some large Martian dunes. This aerodynamic effect could seasonally generate all the meteorological phenomena we observe on these dunes (bodies of ice, frost, moisture trails, and vapor clouds) and as a result, produce gullies with a peculiar morphology different from the standard. Thus, dune gullies could originate from meteorological liquids, but through a process unlike those known on Earth. Evidence from the Kaiser, Russell, and Korolev Craters supports the possibility of a partial water cycle (a half-cycle), potentially the remnant of a complete ancient cycle.PublishedOSA3: Climatologia e meteorologia spazialeOSA2: Evoluzione climatica: effetti e loro mitigazioneJCR Journa
Submarine volcanic edifices in the Bransfield Strait (Antarctica): towards a unified toponymy
No full textThe Bransfield Strait stands out as one of the most accessible places to study Antarctic submarine volcanism, hosting seven active principal submarine volcanic edifices (Edifices A, B and C, Three Sisters, Orca, Hook Ridge, G Ridge) and ~100 smaller seamounts. Only two of them have names (Eastern and Western Seamounts), and ~80 are grouped into two named areas: Spanish Rise and Gibbs Rise. During recent decades, numerous studies have assigned different names to the same volcanic edifices, leading to confusion. Only one of them, Orca, is formally registered in the Scientific Committee of Antarctic Research Composite Gazetteer of Antarctica, which is the catalogue collecting all of the official location names in Antarctica. A unified toponymy is essential, particularly to effectively manage regional logistic operations in case of eruption. Therefore, this study compiles the distinct names assigned to these edifices as a toponymy reference for future research. We recommend using the names most commonly cited in previous studies and, when new names are necessary, submitting them to the Scientific Committee of Antarctic Research Composite Gazetteer of Antarctica to avoid further confusion.PublishedJCR Journa
Challenges and Gaps in Understanding and Monitoring Low-Latitude F-region Plasma Irregularities
No full textThe manuscript highlights the role of neutral wind and vertical coupling between the lower and upper atmosphere in the generation and evolution of equatorial plasma depletions (EPDs) and equatorial plasma irregularities (EPIs) during quiescent conditions. These phenomena impact radio wave propagation, leading to signal degradation and loss, which affects communication and navigation systems. Understanding, monitoring, and forecasting EPIs are thus crucial. Forecasting with high accuracy remains challenging and is often limited to predicting EPIs associated with increased solar and geomagnetic activity. Realtime monitoring systems are essential to capture the variability of irregularities and their development, especially since EPDs also occur during quiescent conditions and can extend to mid-latitudes. International collaboration and data sharing are vital for improving monitoring. Ongoing research focuses on better understanding the role of the neutral wind in creating favorable conditions for EPD generation. Whole atmosphere models are currently developed with high enough resolution to self-consistently simulate the wave spectrum in the thermosphere including gravity waves. Gravity waves were shown to be important for the generation of EPD but their role in seeding plasma irregularities is not yet fully understood. The manuscript describes the current physical understanding of evening and postmidnight EPD generation provides an overview of available observations of EPIs and summarizes advances in statistical and numerical model development. It highlights the gaps and needs to advance our understanding of EPD and EPI generation and evolution.SubmittedJCR Journa
Signatures of Confined and Eruptive Solar Flares in Microwave Spectra
No full textPublishedOSA3: Climatologia e meteorologia spazialeJCR Journa
Implementazione di un sistema di replicazione del database unico del Centro Operazionale Avanzato di Stromboli
No full textIl presente rapporto tecnico offre una panoramica dettagliata sull’implementazione di un sistema di replicazione fisica di un database basato su PostgreSQL, progettato per garantire la disponibilità dei dati acquisiti e memorizzati presso il Centro Avanzato Operazione di Stromboli (COA) in caso di malfunzionamenti. La soluzione qui descritta realizza una copia del database unico presente al COA su un’istanza remota, ospitata presso il Centro Elaborazione Dati (CED) dell’Osservatorio Etneo, Sezione di Catania dell’Istituto Nazionale di Geofisica e Vulcanologia (INGV). Questa architettura garantisce: alta disponibilità (High Availability HA), elevata tolleranza ai guasti (fault tolerance) e sincronizzazione continua dei dati, anche nel contesto di connettività limitata tipico dell’ambiente insulare. Il sistema di replicazione implementato, si basa sulla replicazione fisica in streaming di PostgreSQL, che sfrutta il meccanismo Write-Ahead Log (WAL). Tale meccanismo tiene traccia e trasferisce tutte le modifiche apportate ai dati presenti sul database primario sulla replica remota, assicurando la disponibilità dei dati anche in assenza di connessione verso il database primario. L’intero sistema è stato implementato adottando tecniche di deployment moderne, come l’utilizzo dei cosiddetti software containers basati su implementazioni Docker, e l’orchestrazione degli stessi tramite il framework di riferimento Kubernetes. L’implementazione presentata in questo rapporto tecnico assicura un accesso ininterrotto ai dati, requisito essenziale ed indispensabile sia per il monitoraggio operativo sia per la risposta alle emergenze, permettendo di incrementare la resilienza dell’infrastruttura.PublishedN/A or not JC