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Multiparametric Monitoring System of Mt. Melbourne Volcano (Victoria Land, Antarctica)
No full textVolcano monitoring is the key approach in mitigating the risks associated with volcanic phenomena. Although Antarctic volcanoes are characterized by remoteness, the 2010 Eyjafjallajökull eruption and the 2022 Hunga eruption have reminded us that even the farthest and/or least-known volcanoes can pose significant hazards to large and distant communities. Hence, it is important to also develop monitoring systems in the Antarctic volcanoes, which involves installing and maintaining multiparametric instrument networks. These tasks are particularly challenging in polar regions as the instruments have to face the most extreme climate on the Earth, characterized by very low temperatures and strong winds. In this work, we describe the multiparametric monitoring system recently deployed on the Melbourne volcano (Victoria Land, Antarctica), consisting of seismic, geochemical and thermal sensors together with powering, transmission and acquisition systems. Particular strategies have been applied to make the monitoring stations efficient despite the extreme weather conditions. Fumarolic ice caves, located on the summit area of the Melbourne volcano, were chosen as installation sites as they are protected places where no storm can damage the instruments and temperatures are close to 0 °C all year round. In addition, the choice of instruments and their operating mode has also been driven by the necessity to reduce energy consumption. Indeed, one of the most complicated tasks in Antarctica is powering a remote instrument year-round. The technological solutions found to implement the monitoring system of the Melbourne volcano and described in this work can help create volcano monitoring infrastructures in other polar environments.Published75946V. Pericolosità vulcanica e contributi alla stima del rischioJCR Journa
The tsunamigenic potential of landslide-generated tsunamis on the Vavilov seamount
No full textThe investigation of submarine volcanoes and the tsunamigenic potential of possible movements on their flanks is arduous. In most cases, the lack of specific information about the eruptions' history and their consequences does not allow a comprehensive analysis in terms of hazard. Nevertheless, useful clues on the possible occurrence of mass movements on seamounts can be obtained from a series of research fields. These account for morphological studies, observations of hydrothermal activity, collection of geophysical data (for example, detailed DEM, seismic profiles, magnetic data), etc. In this context, this study presents new bathymetric data of the Vavilov submarine volcano (Tyrrhenian Sea, Italy) and a detailed morphological analysis of the structure. The latter allows the identification of zones potentially prone to mass movements and the development of numerical scenarios to investigate the tsunami potential associated to these movements on the Vavilov flanks. Results prove that the waves generated by the mass displacements in the proposed scenarios (involving sliding volumes between 0.32 km3 and 1.7 km3) reach maximum values in the order of centimetres, not considering dispersive effects. Eventually, a scenario involving the partial collapse of the west flank of the Vavilov Seamount is simulated, although the occurrence of such an event in the past is still debated due to the uncertainties related to the origin and development of the volcano dome. In this scenario, water elevation as high as 10 m are found in large portions of the Tyrrhenian coasts: waves are large enough to emplace sizeable tsunami deposits onshore, that could have been preserved until today in some specific stretches of the coast and could be detected by a finalised geological search. This study belongs to a series of works devoted to the submarine structures of the Tyrrhenian Sea aiming to disclose the tsunamigenic potential of submarine mass movements on their flanks.Published1077453A. Geofisica marina e osservazioni multiparametriche a fondo mareJCR Journa
Il bradisismo ai Campi Flegrei
No full textLo studio dell’andamento del bradisismo ai Campi Flegrei, a partire dal IV sec. d.C. nel corso dei secoli fino ai tempi moderni, è stato possibile grazie a osservazioni compiute sulle rovine di un monumento situato a poche decine di metri dal porto di Pozzuoli: il Macellum, meglio noto come Tempio di Serapide o Serapeo. La sua peculiarità è la presenza, a varie altezze sulle tre colonne ancora erette, di fori di litodomi che sono indice del livello marino nel passato. Grazie alla datazione di tali fori è stato possibile ricostruire le oscillazioni del livello del mare dovute al sollevamento o abbassamento del suolo a Pozzuoli nel tempo.UnpublishedCittà della Scienza -NapoliOSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametric
EPMA maps unveil the actual chemical variations and crystallisation sequence of pyroxene and plagioclase solidified from a basaltic liquid at variable cooling rates
No full textCrystal-chemical variations of pyroxene (px) and plagioclase (plg) have been analysed by X-ray electron-microprobe (EPMA) mapping to quantify their actual chemical dispersions. These phases were experimentally crystallised from a basaltic liquid (B100, MORB from Iceland) at cooling rates of 1, 7, 60 and 180 °C/h from 1300 °C down to 800 °C. Experiments were run at ambient conditions applying defined temperature paths mirroring characteristic cooling rates from innermost to outermost portions of metre- to centimetre-thick lavas, dikes and bombs emplaced under submarine to subaerial conditions. As the cooling rate increases from 1 to 180 °C/h, the run-products become progressively enriched in pyroxene and depleted in plagioclase, while spinel is invariably low (few area%) and glass is significant only at 180 °C/h. An increase of cooling rate generally leads to enrichment of Al2O3 and depletion of MgO in px, while the opposite behaviour is observed for plg; these trends are mirrored by calculated cations (apfu: atom per formula unit) and components. Average variations as a function of cooling rate are similar to those already observed through classical analysis performed by single point EPMA. However, the actual chemical distributions of CaO versus MgO, Al2O3 and FeOtot oxides unveil the presence of a wider range in pyroxene chemistry. In particular, one px (px-1, CaO-rich, diopsidic type) is present at all the applied cooling rates; a very low CaO-px (px-2, pigeonite or orthopyroxene type) is detected at 1 °C/h; and, finally, once more population of px (px-3, CaO-poor diopsidic type) appears at 60 and 180 °C/h. By contrast, plg analyses yield invariably identical compositions. Textural variations as a function of cooling rate and geothermometric estimations indicate that px-1 crystallised at high-T (or low ΔT), while plg mainly grew in the residual melt produced by the saturation of px. If only textures were evaluated, this order of segregation would like remain unrecognised since px at low cooling rates is smaller than plg. The abundance of phases, their crystal-chemical features, and their order of segregation can be regarded through a theoretical framework of a time-temperature-transformation (TTT) diagram. The most significant chemical variations are displayed by MgO and Al2O3 for both px and plg, which faithfully capture the evolution of cooling conditions. The chemical compositions of px-1 is close to the thermodynamic equilibrium only at 1 °C/h. As the cooling rates increase, the px chemistry indicates disequilibrium conditions. Finally, this study shows that as ΔT/Δt increases, the most abundant px (px-1) and plg are forced towards compositions that become progressively closer to those of the parental liquid.Published121752OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Characterizing Seismogenic Fault Structures of the Lake Pertusillo Reservoir Induced Seismicity (Southern Italy) Using a Relocated Template-Matching Catalog
No full textWe present a detailed analysis of the small magnitude (ML < 3) Reservoir Induced Seismicity associated with the Pertusillo water reservoir located in the high seismic hazard zone of Val d'Agri (Southern Italy). We apply template-matching detection to a 13-month-long dense passive survey, obtaining a final high-precision double-difference catalog of 5,070 earthquakes (−0.7 < ML < 2.6, MC = 0.2). The new catalog allows precisely tracking the spatiotemporal distribution of the swarm-seismicity and to map the b-value of the Gutenberg-Richter law. We combine seismicity data with available subsurface geophysical data, fostering an improved interpretation of the induced seismicity. We identify four seismicity-clusters showing rapid changes in seismic rate which correlate to severe seasonal oscillations. Seismicity unravels new km-scale faults or better define faults partially-illuminated by template earthquakes. b-value shows a significant spatial variability, with very-high b-value (up to 2) within areas of distributed seismicity and lower (∼1.3) b-value for on-fault seismicity featuring larger magnitude events. Seismicity is confined within a brine-saturated fractured carbonate reservoir, while earthquake distribution and rate are controlled by the fault architecture and rock properties (e.g., inherited fluid pathways, rock fracturing, pore fluid pressure). In particular, most earthquakes reactivate, with extensional kinematics, pre-existing reverse/transpressional faults favorably oriented in the present-day extension. All observations suggest that a poroelastic stress transmission mechanism, due to the seasonal water level oscillation, can explain the Pertusillo lake seismicity. This study confirms the importance of investigating the complex interaction among stress changes caused by human activities, pre-existing faults and local stress field to correctly assess the hazard posed by induced seismicity.PRIN-MUSE-4D project of the Italian PRIN-MIUR program (Grant 2017KT2MKE).Publishede2022JB025879OST3 Vicino alla fagliaJCR Journa
Modeling the Topside Ionosphere Effective Scale Height through In Situ Electron Density Observations by Low-Earth-Orbit Satellites
No full textIn this work, we aim to characterize the effective scale height at the ionosphere F2-layer
peak (H0) by using in situ electron density (Ne) observations by Langmuir Probes (LPs) onboard
the China Seismo-Electromagnetic Satellite (CSES—01). CSES—01 is a sun-synchronous satellite
orbiting at an altitude of ~500 km, with descending and ascending nodes at ~14:00 local time (LT) and
~02:00 LT, respectively. Calibrated CSES—01 LPs Ne observations for the years 2019–2021 provide
information in the topside ionosphere, whereas the International Reference Ionosphere model (IRI)
provides Ne values at the F2-layer peak altitude for the same time and geographical coordinates as
CSES—01. CSES—01 and IRI Ne datasets are used as anchor points to infer H0 by assuming a linear
scale height in the topside representation given by the NeQuick model. COSMIC/FORMOSAT—3
(COSMIC—1) radio occultation (RO) data are used to constrain the vertical gradient of the effective
scale height in the topside ionosphere in the linear approximation. With the CSES—01 dataset, we
studied the global behavior of H0 for daytime (~14:00 LT) and nighttime (~02:00 LT) conditions,
different seasons, and low solar activity. Results from CSES—01 observations are compared with those
obtained through Swarm B satellite Ne-calibrated measurements and validated against those from
COSMIC—1 RO for similar diurnal, seasonal, and solar activity conditions. H0 values modeled by
using CSES—01 and Swarm B-calibrated observations during daytime both agree with corresponding
values obtained directly from COSMIC—1 RO profiles. Differently, H0 modeling for nighttime
conditions deserves further investigation because values obtained from both CSES—01 and Swarm
B-calibrated observations show remarkable and spatially localized differences compared to those
obtained through COSMIC—1. Most of the H0 mismodeling for nighttime conditions can probably
to be attributed to a sub-optimal spatial representation of the F2-layer peak density made by the
underlying IRI model. For comparison, H0 values obtained with non-calibrated CSES—01 and Swarm
B Ne observations are also calculated and discussed. The methodology developed in this study for
the topside effective scale height modeling turns out to be applicable not only to CSES—01 satellite
data but to any in situ Ne observation by low-Earth-orbit satellites orbiting in the topside ionosphere.Published2802A. Fisica dell'alta atmosferaJCR Journa
The Lutetian global stratotype section and point at Gorrondatxe revisited: Biomagnetostratigraphic refinements and astronomical tuning
No full textBiomagnetostratigraphic studies carried out at the Ypresian/Lutetian (Eocene) Gorrondatxe section solved major chronostratigraphic calibration discrepancies that had existed for several decades. The new calibration resulted in the definition of the Global Stratotype Section and Point (GSSP) for the Lutetian Stage at the Gorrondatxe layer containing the lowest occurrence (LO) of the calcareous nannofossil Blackites inflatus (base of Subzone CP12b). However, subsequent studies cast some doubt on the reliability of the Gorrondatxe biomagnetostratigraphic data and, consequently, the appropriateness of the criterion used for the definition of the Lutetian GSSP. In order to address the issues raised, the biomagnetostratigraphy of the Gorrondatxe section was revisited and an additional cyclostratigraphic analysis was undertaken using magnetic susceptibility data series. The present study shows that the Gorrondatxe biomagnetostratigraphy is reliable. The spectral analyses showed the dominance of precession (~20 ky) and short (~100 ky) eccentricity forcing on sedimentation, but the influence of obliquity (~38 and ~55 ky) cycles was also detected and modulation by long (405 ky) eccentricity cycles was deduced. The succession was tuned to the 49.122-48.084 Ma interval and the astronomical ages obtained for a significant number of biomagnetostratigraphic events compared well with those derived from other studies. One of the exceptions is the LO of B. inflatus, which seems to be older in Gorrondatxe than in the Mediterranean and Western Atlantic areas. This diachrony most likely also delayed the LO of B. inflatus in historical reference sections of the North Sea area, rendering previous claims that the Lutetian GSSP caused some historical Lutetian sections to be Ypresian in age invalid. In fact, the definition of the base of the Lutetian Stage by the LO of B. inflatus at Gorrondatxe, now astronomically age dated at 48.455 Ma, best guarantees that the original concepts of the Ypresian and Lutetian historical stratotypes are maintained. Combined with secondary biomagnetostratigraphic marker events and an astronomically tuned cyclostratigraphy, the Ypresian/Lutetian Gorrondatxe section provides the globally significant chronostratigraphic reference model expected of any GSSP.Published111669OSA1: Variazioni del campo magnetico terrestre, imaging crostale e sicurezza del territorioJCR Journa
What Have We Learned from the Past? An Analysis of Ground Deformations in Urban Areas of Palermo (Sicily, Italy) by Means of Multi-Temporal Synthetic Aperture Radar Interferometry Techniques
No full textThis study focuses on analyzing and monitoring urban subsidence, particularly in the city of Palermo, Italy. Land subsidence, induced by natural and human factors, poses threats to infrastructure and urban safety. Remote sensing (RS), specifically synthetic-aperture radar interferometry (In-SAR), is employed due to its ability to detect ground displacements over large areas with great precision. The persistent scatterer InSAR (PS-InSAR) technique is utilized to identify stable targets and track millimeter-level surface deformations. This research spans from October 2014 to October 2021, using Sentinel-1 satellite data to capture ground deformation from various angles. The findings are integrated into an accessible web app (ArcGIS) for local authorities that could be used aiding in urban planning and enhancing safety measures. This study’s results offer updated deformation maps, serving as an operational tool to support decision-making and community resilience, emphasizing risk awareness and responsible practices. This study highlights that the exponential expansion of urban areas, which does not take into account historical information, can gravely jeopardize both the integrity of urban infrastructure and the well-being of its inhabitants. In this context, remote sensing technologies emerge as an invaluable ally, used in monitoring and safeguarding the urban landscape.Published2985IT. Osservazioni satellitariJCR Journa
Why Are Some Solar Wind Pressure Pulses Followed by Geomagnetic Storms?
No full textRapid increases in solar wind dynamic pressure, known as solar wind pressure pulses, compress
the Earth's magnetosphere and can rapidly restructure the electrodynamics within. The propagation of
pressure pulse effects into the magnetosphere is known as a geomagnetic sudden commencement (SC). SCs
can be further subdivided into compressions which are rapidly followed by a geomagnetic storm (a sudden
storm commencement, SSC) and those which are not (a sudden impulse, SI). In this paper, SSCs and SIs are
compared and contrasted, and we examine in particular the differences between the pressure pulses that drive
SSCs/SIs, and explore the physical conditions of the magnetosphere before pressure pulse arrival. Firstly, it
is shown that SSCs are more likely to be driven by pressure pulses with higher magnitude and/or shorter rise
time. Secondly, the magnetosphere is primed by stronger driving conditions and higher geomagnetic activity
prior to SSCs than SIs. Finally, there is a solar cycle dependence in the occurrence and magnitude of solar wind pressure pulses.Publishede2022JA0312591A. Geomagnetismo e PaleomagnetismoJCR Journa
CleverRiver: an open source and free Google Colab toolkit for deep-learning river-flow models
No full textIn a period in which climate change is signifcantly varying rainfall regimes and their intensity all over the world, river-fow
prediction is a major concern of geosciences. In recent years there has been an increase in the use of deep-learning models
for river-fow prediction. However, in this feld we can observe two main issues: i) many case studies use similar (or the
same) strategies without sharing the codes, and ii) the application of these techniques requires good computer knowledge.
This work proposes to employ a Google Colab notebook called CleverRiver, which allows the application of deep-learning
for river-fow predictions. CleverRiver is a dynamic software that can be upgraded and modifed not only by the authors but
also by the users. The main advantages of CleverRiver are the following: the software is not limited by the client hardware,
operating systems, etc.; the code is open-source; the toolkit is integrated with user-friendly interfaces; updated releases with
new architectures, data management, and model parameters will be progressively uploaded. The software consists of three
sections: the frst one enables to train the models by means of some architectures, parameters, and data; the second section
allows to create predictions by using the trained models; the third section allows to send feedback and to share experiences
with the authors, providing a fux of precious information able to improve scientifc research.Published1119–11303IT. Calcolo scientificoJCR Journa