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  • Articles  (352,526)
  • Elsevier  (269,262)
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  • 101
    Publication Date: 2024-03-31
    Description: Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2= 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2= 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (〉66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions.
    Keywords: community assembly ; dispersal limitation ; environmental selection ; evolutionary principal ; component analysis ; indicator lineage analysis ; Moran's eigenvector maps ; neotropics ; Niche ; conservatism ; tropical rain forests
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
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  • 102
    Publication Date: 2024-04-03
    Description: This article has been accepted for publication in Geophysical Journal International ©:The Author(s) 2023. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Uploaded in accordance with the publisher's self-archiving policy. All rights reserved.
    Description: Estimation of local seismic response plays a key role in assessing local seismic hazard and particularly in the design of shaking scenarios. Modelling local seismic response involves knowing of the shear wave velocity (Vs) and quality factor (Qs) profiles for the site in question. The many techniques that have been developed to assess Vs in surface deposits produce reliable measurements of Vs , but these rarely correspond to direct measurements of Qs . The latter is often considered through damping measures from laboratory tests on small-scale soil samples, which can provide information primarily on intrinsic attenuation, neglecting the contribution of scattering effects. In this paper, using seismic recordings obtained at the surface and in boreholes at 100 m depth, we estimate an average value of Qs of some characteristic alluvial deposits of the Po Plain (northern Italy). Data come from a microseismic network which sampled an almost uniform lithology in the central Po Plain and consisted of three surface and four borehole stations with an interstation distance of about 2 km. The average value of Qs of the shallowest 100 m of the sedimentary strata, Qs100, is estimated by considering: (1) the high-frequency attenuation of seismic waves due to propagation through the corresponding stratigraphy and (2) the interference between incident and surface-reflected waves observed at borehole stations. We parametrize the first through k0_100, the difference between the values of the spectral decay parameter kappa (k) estimated at the surface and at the boreholes depth, respectively. We use the second in order to compute Vs100, the time-averaged Vs referred to the uppermost 100 m stratigraphy. We obtain: k0_100 = (11 ± 3) ms, Vs100 = (309 ± 11) m s −1 and Qs100 = 31 ± 10. At the surface, the estimated values of the site-specific kappa, k0, are found to range from 75 to 79 ms. As expected, these results are in good agreement with studies performed in other sites characterized by sandy or clayey lithologies, and can be usefully used in site response analysis at sites where the rigidity is mainly controlled by lithostatic pressure.
    Description: Comune di Minerbio (grant: “Sperimentazione ILG Minerbio”; grant number: 0913.010).
    Description: Published
    Description: 2075–2094
    Description: OST2 Deformazione e Hazard sismico e da maremoto
    Description: JCR Journal
    Keywords: Earthquake ground motions ; Seismic attenuation ; Site effects ; Wave propagation ; Wave scattering and diffraction ; 04.06. Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 103
    Publication Date: 2024-04-08
    Description: Dissolved organic matter (DOM) plays a crucial role in the biogeochemistry of coastal ecosystems, particularly nutrient cycling and distribution. Little is known about these processes in the highly productive Southern Patagonian shelf. This study was conducted to better understand the sources, composition, and behavior of DOM and inorganic nutrients in the sector between 51 and 56°S and 64–69°W with particular emphasis on inorganic nitrogen and DOM fractions. Surface water samples taken during late austral summer from the Beagle Channel (BCW), Subantarctic (SAW), Subantarctic Shelf (SASW), Grande Bay (GBW) and Tierra del Fuego Waters (TFW) and were analyzed for properties of fluorescent DOM (FDOM), dissolved organic carbon (DOC) and inorganic nutrients. Data were related to hydrographic and plankton conditions. Highest values of ammonium, DOC, humic-like FDOM (FDOMC and FDOMM peaks) and humification index (HIX) were found in BCW, and the lowest in SAW, suggesting that terrigenous input is a main source of ammonium and refractory carbon in this region, which is supported by a highly significant inverse correlation of these parameters with salinity. In contrast, nitrate, phosphate, silicate and the fluorescence index (FI) were positively correlated with salinity, pointing to the contribution of autochthonous FDOM from the saltier and nutrient-rich Antarctic Circumpolar Current to the Southern Patagonian shelf. In TFW and GBW, high nitrite concentrations, accompanied by elevated values of BIX (biological activity index of DOM), circulation patterns and high particle residence times computed from model results suggest the occurrence of regeneration processes that deserve further investigation of the poorly known dynamics of the nitrogen-rich water in this region.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 104
    Publication Date: 2024-04-08
    Description: In the microscopy realm, a large body of dark biodiversity still awaits to be uncovered. Unarmoured dinophytes are particularly neglected here, as they only present inconspicuous traits. In a remote German locality, we collected cells, from which a monoclonal strain was established, to study morphology using light and electron microscopy and to gain DNA sequences from the rRNA operon. In parallel, we detected unicellular eukaryotes in ponds of the Botanical Garden Munich-Nymphenburg by DNA-metabarcoding (V4 region of the 18S rRNA gene), weekly sampled over the course of a year. Strain GeoK*077 turned out to be a new species of Borghiella with a distinct position in molecular phylogenetics and characteristic coccoid cells of ovoid shape as the most important diagnostic trait. Borghiella ovum, sp. nov., was also present in artificial ponds of the Botanical Garden and was the second most abundant dinophyte detected in the samples. More specifically, Borghiella ovum, sp. nov., shows a clear seasonality, with high frequency during winter months and complete absence during summer months. The study underlines the necessity to assess the biodiversity, particularly of the microscopy realm more ambitiously, if even common species such as formerly Borghiella ovum are yet unknown to science.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 105
    Publication Date: 2024-04-05
    Description: Understanding the interactions between surface and deep Earth processes is important for research in many diverse scientific areas including climate, environment, energy, georesources and biosphere. The TOPO-EUROPE initiative of the International Lithosphere Program serves as a pan-European platform for integrated surface and deep Earth sciences, synergizing observational studies of the Earth structure and fluxes on all spatial and temporal scales with modelling of Earth processes. This review provides a survey of scientific developments in our quantitative understanding of coupled surface-deep Earth processes achieved through TOPO-EUROPE. The most notable innovations include (1) a process-based understanding of the connection of upper mantle dynamics and absolute plate motion frames; (2) integrated models for sediment source-to-sink dynamics, demonstrating the importance of mass transfer from mountains to basins and from basin to basin; (3) demonstration of the key role of polyphase evolution of sedimentary basins, the impact of pre-rift and pre-orogenic structures, and the evolution of subsequent lithosphere and landscape dynamics; (4) improved conceptual understanding of the temporal evolution from back-arc extension to tectonic inversion and onset of subduction; (5) models to explain the integrated strength of Europe's lithosphere; (6) concepts governing the interplay between thermal upper mantle processes and stress-induced intraplate deformation; (7) constraints on the record of vertical motions from high-resolution data sets obtained from geo-thermochronology for Europe's topographic evolution; (8) recognition and quantifications of the forcing by erosional and/or glacial-interglacial surface mass transfer on the regional magmatism, with major implications for our understanding of the carbon cycle on geological timescales and the emerging field of biogeodynamics; and (9) the transfer of insights obtained on the coupling of deep Earth and surface processes to the domain of geothermal energy exploration. Concerning the future research agenda of TOPO-EUROPE, we also discuss the rich potential for further advances, multidisciplinary research and community building across many scientific frontiers, including research on the biosphere, climate and energy. These will focus on obtaining a better insight into the initiation and evolution of subduction systems, the role of mantle plumes in continental rifting and (super)continent break-up, and the deformation and tectonic reactivation of cratons; the interaction between geodynamic, surface and climate processes, such as interactions between glaciation, sea level change and deep Earth processes; the sensitivity, tipping points, and spatio-temporal evolution of the interactions between climate and tectonics as well as the role of rock melting and outgassing in affecting such interactions; the emerging field of biogeodynamics, that is the impact of coupled deep Earth – surface processes on the evolution of life on Earth; and tightening the connection between societal challenges regarding renewable georesources, climate change, natural geohazards, and novel process-understanding of the Earth system.
    Description: Published
    Description: 104140
    Description: OST1 Alla ricerca dei Motori Geodinamici
    Description: OSA5: Energia e georisorse
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 106
    Publication Date: 2024-04-05
    Description: The Krafla geothermal system is located within a volcanic center that periodically erupts basaltic lavas, and has recently attracted an economic interest due to supercritical fluids forming near a shallow magma intrusion (~ 2 km depth). Here, we discuss new soil CO2 flux and stable isotope data of the CO2 efflux (δ13C) and hydrothermal calcites (δ13C, δ18O) of drill cuttings to estimate both the current magmatic outgassing from soils and the thermal flows in the geothermal system. Soil CO2 emission is controlled by tectonics, following the NNE-SSW fissure swarm direction and a WSW-ENE trend, and accounts for ~62.5 t/d. While the δ18O of the H2O in equilibrium with deep calcites is predominantly meteoric, both the δ13C of the soil CO2 efflux and of the fluids from which calcite precipitated have a clear magmatic origin, overlapping the δ13C estimated for the Icelandic mantle (–2.5 ± 1.1 ‰). Estimates based on the soil CO2 emission from the southern part of the system show that these fluxes might be sustained by the ascent and depressurization of supercritical fluids with a thermal energy of ~800 MW. Such significant amount of energy might reach 1.5 GW if supercritical conditions extended below the whole investigated area. Finally, we report an increase in the soil CO2 emission of about 3 times with respect to 14 years ago, likely due to recent changes in the fluid extracted for power production or magmatic activity. Pairing the soil CO2 emission with stable isotopes of the efflux and calcite samples has important implications for both volcano monitoring and geothermal exploration, as it can help us to track magmatic fluid upflows and the associated thermal energy.
    Description: Published
    Description: 108032
    Description: OSA5: Energia e georisorse
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 107
    Publication Date: 2024-04-05
    Description: Risk mitigation in long-dormant volcanic provinces is a challenge due to the absence of collective memory of past disasters as well as the scarcity, and subtlety, of unrest signals that can be monitored. In this study, the impact of a potential limnic eruption is assessed at the 92-m-deep lake Pavin (French Massif Central). The lake is hosted in a maar crater formed during the last eruptive event in metropolitan France (∼7 ka) and contains dissolved CO2 in the deepest water layer, below 60 m. Carbon dioxide (CO2) emissions measured at the lake surface (0.44 km2) reach up to 10.1 tons/day during the winter. Beyond this (limited) continuous degassing of the lake, the current CO2 budget in the monimolimnion layer (at a depth of 60 m to 92 m) was estimated at 1750 tons, of which about 450 tons are available for release in case of overturn of the lake. Scenarios for CO2 dispersion in the lower atmosphere were simulated with the DISGAS and TWODEE-2 models by varying (i) meteorological conditions, (ii) the amount of CO2 released, (iii) and the mechanisms of degassing during a potential limnic eruption. The simulations allowed identification and delimitation of areas potentially impacted by hazardous CO2 levels in the air down-valley from the lake and directly around the lake. The spatio-temporal evolution of the potential CO2 cloud raises issues regarding the impacts of such a hypothetical event in the close vicinity of the lake and, given the area is populated and highly visited, needs to be considered in future risk mitigation strategies.
    Description: Published
    Description: 108024
    Description: OSV1: Verso la previsione dei fenomeni vulcanici pericolosi
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 108
    Publication Date: 2024-04-05
    Description: We use geophysical data together with a recent subglacial bedrock map (BEDMACHINE model) to obtain and investigate a new three-layer sediment model for Antarctica that locally improves the global sediment model. We provide a combined, continuous, sediment model for Antarctica and surrounding oceans by joining such improved continental sedimentary model with an existing global one (GlobSed). Our results reveal large differences between sedimentary basins for Antarctica due to their age and origin. The maximum thickness of sediments is reached under Filchner-Ronne Ice Shelf and off the Weddell Sea coast (10–12 km); further offshore, towards the ocean, the thickness of sediments drops to 4–5 km. We divide the sediment cover into three layers to distinguish material with different velocities. The lower sediment layer (deeper than 7 km) with high P-wave velocities (4.0–4.9 km/s) is found only for Lambert Rift and Filchner-Ronne basin. The middle layer (2–7 km) has large variations for different sedimentary basins: 3.5–3.7 km/s for Lambert Basin; 4.0–4.3 km/s for Ross, Byrd and Bentley basins; 3.3–4.0 km/s for Filchner-Ronne Basin. The upper sediment layer (0–2 km) has large velocity variations, from 2.0 km/s for Ross and Lambert basins (young sediments) to 4.7 km/s for Dronning Maud Land basins. We suggest that P-wave velocities larger than 4 km/s represent old, compacted sediments which belong to the Beacon Supergroup; about 3 km/s refer to Mesozoic (rifted?) sediments; and less than 3 km/s relate to young Cenozoic sediments. According to this criterion, Dronning Maud Land, Bentley and Byrd basins belong to the Beacon Supergroup, while more complex and thicker Ross, Lambert and Filchner-Ronne basins contain sediments from Beacon Supergroup in the middle or lower layer, respectively. Other sedimentary basins with more moderate velocities possibly belong to the East Antarctic Rift System which formed later during Gondwana breakup.
    Description: Published
    Description: 229662
    Description: OST1 Alla ricerca dei Motori Geodinamici
    Description: JCR Journal
    Keywords: 04.06. Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 109
    Publication Date: 2024-04-17
    Description: Over the past decades, significant efforts have been made to understand the nature, dynamics and evolution of volcanic systems. In parallel, the continuous demographic expansion and extensive urbanization of volcanic areas have increased the exposure of our society to these natural phenomena. This increases the need to improve our capacities to accurately assess projected volcanic hazards and their potential socioeconomic and environmental impact, and Antarctica and the sub-Antarctic islands are no exception. More than a hundred volcanoes have been identified in Antarctica, some of which are entirely buried beneath the ice sheet and others as submarine volcanoes. Of these, at least eight large (basal diameters 〉 c. 20-30 km) volcanoes are known to be active and pose a considerable threat to scientific and ever-increasing tourism activities being carried out in the region. Despite the scientific and socioeconomic interest, many aspects of the past volcanic activity and magmatic processes in Antarctica, and current volcanic hazards and risks, remain unknown. Moreover, many of Antarctica’s volcanoes preserve a remarkable history of the eruptive environment, from which multiple parameters of past configurations of the Antarctic ice sheet (AIS) can be deduced. Given the critical role that the AIS plays in regulating Earth’s climate, Antarctica’s volcanoes therefore can be regarded as the ground truth for current models of past climates derived from modelling and studies of marine sediments. Here, we provide a succinct overview of the evolution of volcanism and magmatism in Antarctica and the sub-Antarctic region over the past 200 million years. Then, we briefly review the current state of knowledge of the most crucial aspects regarding Antarctica’s volcanic and magmatic processes, and the contributions volcanic studies have made to our understanding of ice sheet history and evolution, geothermal heat flow, as well as present-day and future volcanic hazard and risk. A principal objective is to highlight the problems and critical limitations of the current state of knowledge and to provide suggestions for future potential directions of volcanic-driven investigations in Antarctica. Finally, we also discuss and assess the importance and scope of education and outreach activities specifically relating to Antarctic volcanism, and within the context of broader polar sciences.
    Description: Published
    Description: 107941
    Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 110
    Publication Date: 2024-04-17
    Description: We present the results of the tephrochronology study of a 14.49 m long marine sediment core (TR 17–08) collected in the Edisto Inlet, Ross Sea (Antarctica). The core contains four cryptotephra layers at 55–56, 512–513, 517–518, and 524–525 cm of depth, which have been characterised by a detailed description of the texture, mineral assemblage, and single glass shards major and trace element geochemistry. The age model of the investigated sedimentary sequence, based on radiocarbon dating, indicates that the topmost cryptotephra correlates with the widespread 1254 CE tephra erupted by a historical eruption (696 ± 2 cal yrs BP) of Mount Rittmann, in northern Victoria Land. Deeper cryptotephra layers were derived from previously unknown explosive eruptions of Mount Melbourne volcano and were emplaced between 1615 cal yrs BP and 1677 cal yrs BP, e.g. between the 3rd and 4th centuries CE. This discovery demonstrates that the Mount Melbourne volcanic complex has been highly active in historical times allowing significant progress in the current understanding of regional eruptive history. Moreover, from a tephrochronological point of view, the detected cryptotephra provide new regional isochron markers to facilitate high-precision correlations and help stratigraphically constrain changes in environmental and climatic conditions that are identified by multidisciplinary studies.
    Description: Published
    Description: 100079
    Description: OSA3: Climatologia e meteorologia spaziale
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 111
    Publication Date: 2024-04-16
    Description: Phototrophic protists are a fundamental component of the world's oceans by serving as the primary source of energy, oxygen, and organic nutrients for the entire ecosystem. Due to the high thermal seasonality of their habitat, temperate protists could harbour many well-adapted species that tolerate ocean warming. However, these species may not sustain ecosystem functions equally well. To address these uncertainties, we conducted a 30-day mesocosm experiment to investigate how moderate (12C) and substantial (18C) warming compared to ambient conditions (6C) affect the composition (18S rRNA metabarcoding) and ecosystem functions (biomass, gross oxygen productivity, nutritional quality – C:N and C:P ratio) of a North Sea spring bloom community. Our results revealed warming-driven shifts in dominant protist groups, with haptophytes thriving at 12 C and diatoms at 18 C. Species responses primarily depended on the species' thermal traits, with indirect temperature effects on grazing being less relevant and phosphorus acting as a critical modulator. The species Phaeocystis globosa showed highest biomass on low phosphate concentrations and relatively increased in some replicates of both warming treatments. In line with this, the C:P ratio varied more with the presence of P. globosa than with temperature. Examining further ecosystem responses under warming, our study revealed lowered gross oxygen productivity but increased biomass accumulation whereas the C:N ratio remained unaltered. Although North Sea species exhibited resilience to elevated temperatures, a diminished functional similarity and heightened compositional variability indicate potential ecosystem repercussions for higher trophic levels. In conclusion, our research stresses the multifaceted nature of temperature effects on protist communities, emphasising the need for a holistic understanding that encompasses trait-based responses, indirect effects, and functional dynamics in the face of exacerbating temperature changes.
    Repository Name: EPIC Alfred Wegener Institut
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  • 112
    Publication Date: 2024-05-02
    Description: The recent ability to investigate the features of magnetic field fluctuations at ion/sub-ion scales employing both measurements and simulations has clearly demonstrated how, at these scales, the current has a filamentary structure, i.e., it is not a compact structure. This points toward the idea that the current and the dissipation field may have a fractal structure. An intriguing question immediately arises: is there a relationship between the fractal topology of currents at ion/sub-ion scales and the observed spectral features at the same scales? The goal of this work is to investigate the fractal topology of currents at the Low-end of MHD inertial domain and at ion scales using Hall-MagnetoHydroDynamics and Hybrid Vlasov-Maxwell simulations. The results show a clear relationship between the fractal dimension of the current pattern and the spectral features at ion scales. The relevance of this link is discussed in connection with the dynamics of coherent plasma structures at these scales.
    Description: Published
    Description: 114253
    Description: OSA3: Climatologia e meteorologia spaziale
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 113
    Publication Date: 2024-05-02
    Description: Topography plays an important yet uncertain role in modulating the temporal and spatial evolution of the in- ternal structure of pyroclastic density currents (PDCs). Understanding such changes is critical to characterize PDC transport regimes and their hazard. Here we combine paleomagnetic data from PDC deposits of the 18 May 1980 Mt. St. Helens eruption with numerical outcomes to capture spatio-temporal temperature variations induced by topography. We show that emplacement temperatures along the northwest flank of the volcano are ≃ 100◦C colder than those recorded along the northeast flank in response to proximal topographic drops. We further report that such vertical drops lead to an initial transient regime where the PDC internal temperature, velocity, and concentration stratification is altered for periods of time that are proportional to the ratio between the drop height and the square root of the current thickness. The topographic control on PDC dynamics is attenuated moving away from the drops or when a stationary phase is attained. Collectively, our results highlight that topographic regions promoting the flow separation/reattachment process are associated with vigorous entrainment of ambient air in the lower portion of PDCs. Low temperature variability is observed in the absence of such topographic irregularities. Based on our findings, we propose a local sedimentation rate of ≃ 150 ± 100 mm s−1 for PDC deposits in a proximal reattachment region. This investigation demonstrates the importance of transient processes in PDC dynamics, introducing a new methodology to measure sedimentation rates, and highlighting that flow-topography feedbacks should be considered to assess hazards.
    Description: Published
    Description: 118441
    Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 114
    Publication Date: 2024-05-02
    Description: In this work we describe the implementation of a processing chain for a fully automatic modeling of the seismic source parameters and its slip distribution through the inversion of the InSAR displacements generated from the EPOSAR service. This processing chain consists of a suite of procedures and algorithms handling a sequence of steps: selection of the highest quality InSAR datasets, definition of the area of interest, image sampling, nonlinear and linear inversions to get, respectively, the source geometry and its slip distribution. A set of side procedures and interfaces also allows an interactive refinement and the publication of results, consisting of scientific data and graphical outputs. The whole procedure has been developed, tested and validated by considering 100 events with magnitudes between 5.5 and 8.2, worldwide distributed and covering an exhaustive range of mechanisms and tectonic contexts. Main aim of this work is describing the implementation of the automatic modeling procedures, used to produce solutions in real time, already during the emergency phase. These sources, validated by experts before their publication, can be a reference for operational purposes and initial scientific analyses. The creation of this repository sets also the framework to store, out of the emergency time, more sophisticated solutions, manually revised and/or with peer-review quality.
    Description: Published
    Description: 103445
    Description: OST3 Vicino alla faglia
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 115
    Publication Date: 2024-05-02
    Description: The plumbing systems of subduction-zone volcanoes consist of magma reservoirs with different degrees of evolution at multiple depths. The geometries of plumbing system of intraplate monogenetic volcanic fields are generally characterized by basaltic magma ascending from the mantle and/or a shallower reservoir along dikes. However, the shape and vertical extent of these plumbing systems are largely unknown due to the rareness of robust geophysical data. The possible role of faults and mountain chains in controlling the geometry of magma reservoirs is also poorly understood. To address these limitations, we present a three-dimensional resistivity structure beneath the Holocene Jingpohu Monogenetic Volcanic Field (JMVF) in the Zhangguangcai Range (ZGC), northeastern China. The resistivity model was derived from the magnetotelluric data in a dense net-like array. We identified an inverted cone-shaped high-resistivity (~10,000 Ω m) anomaly below the ZGC. This anomaly traverses almost the entire crust. We interpret this high-resistivity anomaly to be the stiff basement of the ZGC. At the base of the resistive volume, we resolved a sill-like, low-resistivity anomaly that occurs at the top of the lithospheric mantle. Sheet-like low-resistivity anomalies surrounding the high-resistivity body depart from the lithospheric mantle. We interpret these sill- and sheet-like anomalies as a trans-crustal saucer-shaped magma plumbing system beneath the JMVF. This system involves multi-level magma reservoirs, including basaltic magma at its base, basaltic dikes/sills swarms in the middle and sill intrusions in the upper crust. We propose that the stiff crustal root and the topographic loading of the ZGC work together to deflect the upward magma propagation towards the edges of the ZGC. The magma ascent to the surface is probably controlled by preexisting, lithospheric faults. Our data show how mountain chains, together with the crustal structure, play a key role in controlling the geometry of multi-level plumbing systems of intraplate monogenetic volcanic fields.
    Description: Published
    Description: 118523
    Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Description: JCR Journal
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  • 116
    Publication Date: 2024-05-02
    Description: Between Permian to Triassic, the Earth experienced climatic and biotic crises, included the greatest mass extinction at the Permian-Triassic boundary. These climatic and biological changes are reflected in both marine and terrestrial depositional systems. Over this time span, the Gondwana supercontinent hosted numerous large basins that may preserve the paleoenvironment response to global changes in the sedimentary record. This study provides a lithostratigraphic reappraisal of the latest Paleozoic-Mesozoic alluvial Beacon Supergroup at Allan Hills (Convoy Range), which is one of the most complete sedimentary sequences in Antarctica. Fieldwork stratigraphic-lithological observation, facies analysis, and petrographic characterization of sedimentary rocks allow the identification of six depositional units. The investigations point out for a conformable relationship between depositional and lithostratigraphic units, characterized by changes in the fluvial style. The reconnaissance of a “transitional interval” showing intermediate features between the Permian Weller Coal Measures and the Triassic Feather Conglomerate strengthen the conformable nature of the sequence across the Permian-Triassic boundary in this region. The lithological features of such interval strongly resemble those observed in the coeval deeply studied Eastern Australia successions crossing the Permian-Triassic boundary as well as the end-Permian extinction. More precisely, the uppermost coal occurrence, just above a glossopterid macroflora-bearing carbonaceous mudstone within the “transitional interval”, marks the disappearance of coal-peat forming Permian vegetation which corresponds with the terrestrial end-Permian extinction, thus representing one of the few end- Permian extinction records in Antarctica.
    Description: Published
    Description: 111741
    Description: OSA2: Evoluzione climatica: effetti e loro mitigazione
    Description: JCR Journal
    Keywords: Gondwana ; Southern Victoria ; Land Stratigraphy ; Permian-Triassic boundary ; Beacon ; Supergroup ; Allan Hills
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  • 117
    Publication Date: 2024-05-02
    Description: Thanks to the computational power of modern cluster machines, numerical simulations can provide, with an unprecedented level of details, new insights into fluid mechanics. However, taking full advantage of this hardware remains challenging since data communication remains a significant bottleneck to reaching peak performances. Reducing floating point precision is a simple and effective way to reduce data movement and improve the computational speed of most applications. Nevertheless, special care needs to be taken to ensure the quality and convergence of computed solutions, especially when dealing with complex fluid simulations. In this work, we analyse the impact of reduced (single and mixed compared to double) precision on computational performance and accuracy for computational fluid dynamics. Using the open source library OpenFOAM, we consider incompressible, compressible, and multiphase fluid solvers for testing on relevant benchmarks for flows in the laminar and turbulent regime and in the presence of shock waves. Computational gain and changes in the scalability of applications in reduced precision are also discussed. In particular, an ad hoc theoretical model for the strong scaling allows us to interpret and understand the observed behaviours, as a function of floating point precision and hardware specifics. Finally, we show how reduced precision can significantly speed up a hybrid CPU–GPU implementation, made available to OpenFOAM end-users recently, that simply relies on a GPU linear algebra solver developed by hardware vendors.
    Description: Published
    Description: 1-16
    Description: OSV1: Verso la previsione dei fenomeni vulcanici pericolosi
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 118
    Publication Date: 2024-05-02
    Description: In the Apennine Mountains of the Italian Peninsula, GPS data display 3–4 mm/yr of divergent motion oriented N50°E between the Adriatic and Tyrrhenian coastlines. However, the mechanisms driving this extension remain debated and along-strike variations of extension within the actively deforming belt remain poorly constrained. Here, we derived the first large-scale extensional and vertical velocity field for the Apennines by multi-temporal InSAR analysis of 7 years of Sentinel-1 data at the scale of the entire range, improving the spatial resolution and vertical accuracy of existing GPS measurements. The results reveal along-strike variations of extensional rates and gradients, with extension concentrated on single fault systems in the north, consistent with the loci of seismicity and recent moderate earthquakes, and distributed throughout the central Apennines, where the range is widening. Vertical surface displacements do not resolve any active long-wavelength uplift of the orogenic belt and, on average, show more subsidence than uplift relative to the Tyrrhenian and Adriatic coasts. This work provides the first InSAR-based geodetic map of differential extension and uplift within the Italian Peninsula. Our results are compatible with a pure shear extensional model of the crust, driven by both boundary and gravitational forces.
    Description: Published
    Description: 230076
    Description: OST1 Alla ricerca dei Motori Geodinamici
    Description: JCR Journal
    Keywords: 04.07. Tectonophysics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 119
    Publication Date: 2024-05-02
    Description: We analyze frictional motion for a laboratory fault as it passes through the stability transition from stable sliding to unstable motion. We study frictional stick-slip events, which are the lab equivalent of earthquakes, via dynamical system tools in order to retrieve information on the underlying dynamics and to assess whether there are dynamical changes associated with the transition from stable to unstable motion. We find that the lab seismic cycles characteristics of a low-dimensional system with average dimension similar to that of natural slow earthquakes ($〈$5). We also investigate local properties of the attractor and find maximum instantaneous dimension $\gtrsim$10, indicating that some regions of the phase space require a high number of degrees of freedom (dofs). Our analysis does not preclude deterministic chaos, but the lab seismic cycle is best explained by a random attractor based on rate- and state-dependent friction whose dynamics is stochastically perturbed. We find that minimal variations of 0.05\% of the shear and normal stresses applied to the experimental fault influence the large-scale dynamics and the recurrence time of labquakes. While complicated motion including period doubling is observed near the stability transition, even in the fully unstable regime we do not observe truly periodic behavior. Friction's nonlinear nature amplifies small scale perturbations, reducing the predictability of the otherwise periodic macroscopic dynamics. As applied to tectonic faults, our results imply that even small stress field fluctuations ($\lesssim$150 kPa) can induce coefficient of variations in earthquake repeat time of a few percent. Moreover, these perturbations can drive an otherwise fast-slipping fault, close to the critical stability condition, into a mixed behavior involving slow and fast ruptures.
    Description: Published
    Description: 117995
    Description: OST4 Descrizione in tempo reale del terremoto, del maremoto, loro predicibilità e impatto
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 120
    Publication Date: 2024-05-03
    Description: Although many studies have demonstrated that arc magmas are more oxidized than mid-ocean ridge (MORB) and oceanic island basalts (OIB), the oxidation state of their mantle source is still debated. This ongoing debate is mainly due to contradictory fO2 values obtained from different proxies (e.g., Fe3+/ΣFe of olivine-hosted melt inclusions and glasses; Zn/ΣFe, V/Sc, V/Ga of lavas). On the one hand, some studies using V/Sc, V/Ga and Zn/ ΣFe of lavas tend to show that the oxidation state of the mantle beneath arcs cannot be distinguished from that of the MORB mantle. On the other, Fe3+/ΣFe of glasses and olivine-hosted melt inclusions suggest that the sub-arc mantle is more oxidized than the mantle beneath ridges. Here, we estimate the oxygen fugacity of high-Mg olivine-hosted melt inclusions from various mid-ocean ridges and arcs, from one hot spot (Reunion Island) and Mount Etna using two fO2 proxies: the Fe3+/ΣFe of melts and the partition coefficient of V between olivine and melt (Dv Ol/Melt). After assessing the role of secondary processes such as volatile degassing and fractional crystallization on the fO2 of melts and reconstructing primary melt compositions, we show that (1) fO2 values derived from Fe3+/ΣFe and Dv Ol/Melt are comparable and (2) arc and Mount Etna primary melts are more oxidized than mid-ocean ridge and Reunion Island primary melts. We then demonstrate, from Zr/Nb, that the observed variability in primary melt fO2 is not due to chemical variability of the mantle source. Finally, the correlations between incompatible trace element ratios such as Th/La, Ba/La, Ba/Th and La/Yb and the fO2 of primary melts reveal a link between the oxidized nature of arc and Mount Etna primary magmas to slab fluid and/or sediment melt influence. Our arc dataset displays a variety of subduction influences, from fluid-dominated (Aoba and Mount Meager) to sediment melt-dominated (La Sommata) influences. The origin of the oxidation of Mount Etna magmas is more complicated to identify and the nature of the oxidized metasomatic fluids that likely percolated through the mantle source before magma generation is yet to be determined. 1.
    Description: Published
    Description: 121701
    Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Description: JCR Journal
    Keywords: 04.08. Volcanology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 121
    Publication Date: 2024-05-03
    Description: Radon is a radioactive gas and a major source of ionizing radiation exposure for humans. Consequently, it can pose serious health threats when it accumulates in confined environments. In Europe, recent legislation has been adopted to address radon exposure in dwellings; this law establishes national reference levels and guidelines for defining Radon Priority Areas (RPAs). This study focuses on mapping the Geogenic Radon Potential (GRP) as a foundation for identifying RPAs and, consequently, assessing radon risk in indoor environments. Here, GRP is proposed as a hazard indicator, indicating the potential for radon to enter buildings from geological sources. Various approaches, including multivariate geospatial analysis and the application of artificial intelligence algorithms, have been utilised to generate continuous spatial maps of GRP based on point measurements. In this study, we employed a robust multivariate machine learning algorithm (Random Forest) to create the GRP map of the central sector of the Pusteria Valley, incorporating other variables from census tracts such as land use as a vulnerability factor, and population as an exposure factor to create the risk map. The Pusteria Valley in northern Italy was chosen as the pilot site due to its well-known geological, structural, and geochemical features. The results indicate that high Rn risk areas are associated with high GRP values, as well as residential areas and high population density. Starting with the GRP map (e.g., Rn hazard), a new geological-based definition of the RPAs is proposed as fundamental tool for mapping Collective Radon Risk Areas in line with the main objective of European regulations, which is to differentiate them from Individual Risk Areas.
    Description: Published
    Description: 169569
    Description: OSA5: Energia e georisorse
    Description: JCR Journal
    Keywords: Collective Radon Risk Areas; Geogenic Radon Potential; Machine learning; Pusteria Valley; Radon risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 122
    Publication Date: 2024-05-03
    Description: Uncertainty concerning the processes responsible for slip-rate fluctuations associated with temporal clustering of surface faulting earthquakes is a fundamental, unresolved issue in tectonics, because strain-rates accommodated by fault/shear-zone structures are the key to understanding the viscosity structure of the crust and seismic hazard. We constrain the timing and amplitude of slip-rate fluctuations that occurred on three active normal faults in central Italy over a time period of 20–30 kyrs, using in situ 36Cl cosmogenic dating of fault planes. We identify five periods of rapid slip on individual faults lasting a few millennia, separated time periods of up to 10 millennia with low or zero slip-rate. The rapid slip pulses migrated across the strike between the faults in two waves from SW to NE. We replicate this migration with a model where rapid slip induces changes in differential stress that drive changes in strain-rate on viscous shear zones that drive slip-rate variability on overlying brittle faults. Earthquakes increase the differential stress and strain-rate on underlying shear zones, which in turn accumulate strain, re-loading stress onto the overlying brittle fault. This positive feedback produces high strain-rate episodes containing several large magnitude surface faulting earthquakes (earthquake clusters), but also reduce the differential stress on the viscous portions of neighbouring fault/shear-zones slowing the occurrence of large-magnitude surface faulting earthquakes (earthquake anticlusters). Shear-zones on faults experiencing anticlusters continue to accumulate viscous strain at a lowered rate, and eventually this loads the overlying brittle fault to failure, initiating a period of rapid slip through the positive feedback process described above, and inducing lowered strain-rates onto neighbouring fault/shear-zones. We show that these patterns of differential stress change can replicate the measured earthquake clustering implied by the 36Cl data. The stress changes are related to the fault geometry in terms of distance and azimuth from the slipping structure, implying that (a) strain-rate and viscosity fluctuations for studies of continental rheology, and (b) slip-rates for seismic hazard purposes are to an extent predictable given knowledge of the fault system geometry.
    Description: Published
    Description: 105096
    Description: OST2 Deformazione e Hazard sismico e da maremoto
    Description: JCR Journal
    Keywords: Active Faults ; Central Apennines ; Fault interaction
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 123
    Publication Date: 2024-05-03
    Description: Identifying potential dust sources of Loess-Paleosol-Sequences (LPS) is important to understand past climatic and environmental conditions. For loess deposits of Central Italy different hypothesis on particle sources have been proposed, but none of them has been tested using a comprehensive geochemical approach yet. Here we present geochemical, mineralogical and grain-size data from selected deposits of a LPS situated at Ponte Crispiero (Marche, Central Italy) to obtain first insights on the provenance of particles deposited here. Loess deposits within the Ponte Crispiero succession are rather coarse (mostly coarse silt and fine sand) indicating a dominance of proximal dust sources. Applied geochemical indices suggest the alluvial plains of the Po River (Northern Italy) and its discharging area as major particle sources. According to these findings, the so-called “Great Po Plain” hypothesis, that claims the presence of a vast alluvial landscape related to the sea-level drop of the Adriatic Sea during the Pleniglacial (i.e. Marine Isotope Stage MIS 4–2), may be considered as a realistic scenario. Such a considerable alluvial plain would have the potential as major source for silt and sand particles not only for the Ponte Crispiero LPS, but also for the loess on the Adriatic side of Central Italy. The main geochemical characteristics of Ponte Crispiero loess are the low concentrations of Zr and Hf and the high contents of carbonate and transition elements compared to the Upper Continental Crust and other European loess sections. Overall, this study contributes towards a better understanding of the provenance and origin of Italian loess. However, for further testing the “Great Po Plain” hypothesis, more (geochemical) investigations need to be conducted, especially in the surrounding areas of the Po plain.
    Description: Published
    Description: 107064
    Description: OSA2: Evoluzione climatica: effetti e loro mitigazione
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 124
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    Elsevier
    In:  EPIC3Journal of Sea Research, Elsevier, 199, pp. 102497-102497, ISSN: 1385-1101
    Publication Date: 2024-05-03
    Description: Biological monitoring of planktonic animals is greatly dependent on the deployment of traps. A variety of specialized traps have been designed for surface plankton and vertebrates. However, certain groups, such as planktonic larvae of benthic marine invertebrates remain underrepresented in sampling efforts. Catching them has proven to be more challenging because of their size, swimming ability, location, and abundance. In the present study a successful light trap for sampling American lobster larvae in New Brunswick, Canada, is evaluated on the island of Helgoland (German Bight, North Sea). Our results showed the traps were successful in catching larvae in laboratory experiments but were unable to catch European lobster larvae in the field. Traps deployed in the field were successful in capturing other benthic and pelagic zooplankton predominantly consisting of crustaceans from the orders: Cumacea, Amphipoda, Mysida and Isopoda. The low density of lobster larvae, the island's topography, and their unique photactic response possibly limited the success rate of the light traps. Future research is needed to construct a specialized trap to sample Helgoland's lobster larvae and provide information on the current larval fitness and population numbers.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 125
    Publication Date: 2024-05-03
    Description: The Wadden Sea is a transition area between land, rivers, and the North Sea. It is of great ecological importance for a wide range of fish species that use it in the course of their life cycle for various purposes. It is a highly dynamic environment and is subject to strong seasonal patterns and annual variations in abiotic conditions. The Sylt-Rømø Bight (SRB) is a semi-enclosed tidal basin in the northern Wadden Sea between the islands of Sylt (Germany) and Rømø (Denmark). Monthly monitoring data of juvenile fish taken in the SRB from 2007 to 2019 were analyzed to determine the changes in species composition in comparison to previous monitoring programs (1989–1995). The long-term trends, common patterns, and potential effects of environmental parameters (sea surface temperature (SST), salinity, chlorophyll a, and the North Atlantic Oscillation (NAO) winter indices) were determined. In total, 55 species were recorded and only 22 of these together accounted for more than 95% of the total abundance for the entire monitoring. Results showed a changed species composition as we did not find two boreal, one Lusitanian, and one circum-temperate species recorded in the previous programs. Instead, one boreal, six Lusitanian, and one Atlantic species were observed for the first time. The fish community was dominated by high seasonal fluctuations of abundance with either dome-shaped, increasing, or decreasing trends. Dynamic Factor Analysis (DFA) partitioned the fish community into three seasonal assemblages based on SST preferences. Redundancy Analysis (RDA) revealed that environmental parameters explained 29 % of the variations in the fish community. These variances were partly a result of the spring immigration of Lusitanian species and the emigration of boreal species and vice versa in autumn. The absence of four previously reported species and the addition of eight new species support the hypothesis that warm-adapted species are increasing in the Wadden Sea. The inclusion of these seasonal variations into conservation and management practices is critical to the sustainable management of marine and coastal ecosystems covering spawning, nursery, and feeding grounds.
    Repository Name: EPIC Alfred Wegener Institut
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  • 126
    Publication Date: 2024-05-13
    Description: This paper positions possibilities for human geographies of the sea. The growing volume of work under this banner has been largely qualitative in its approach, reflecting, in turn, the questions posed by oceanic scholars. These questions necessitate corresponding methods. Whilst this is not necessarily a problem, and the current corpus of work has offered many significant contributions, in making sense of the human dimensions of maritime worlds, other questions—and methods—may generate knowledge that is useful within this remit of work. This paper considers the place of quantitative approaches in posing lines of enquiry about shipping, one of the prominent areas of concern under the banner of ‘human geographies of the seas’. There is longstanding work in transport geographies concerned with shipping, logistics, freight movement and global connections, which embraces quantitative methods which could be bridged to ask fresh questions about oceanic spatial phenomena past and present. This paper reviews the state of the art of human geographies of the sea and transport geographies and navigates how the former field may be stimulated by some of the interests of the latter and a broader range of questions about society-sea-space relations. The paper focuses on Automatic Identification Systems (or AIS) as a potentially useful tool for connecting debates, and deepening spatial understandings of the seas and shipping beyond current scholarship. To advance the argument the example of shipping layups is used to illustrate or rather, position, the point.
    Repository Name: EPIC Alfred Wegener Institut
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  • 127
    Publication Date: 2024-05-09
    Description: This article has been accepted for publication in Geophysical Journal International ©:The Author(s) 2023. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Uploaded in accordance with the publisher's self-archiving policy. All rights reserved.
    Description: In a recent work, we applied the every earthquake a precursor according to scale (EEPAS) probabilistic model to the pseudo-prospective forecasting of shallow earthquakes with magni- tude M 5.0 in the Italian region. We compared the forecasting performance of EEPAS with that of the epidemic type aftershock sequences (ETAS) forecasting model, using the most recent consistency tests developed within the collaboratory for the study of earthquake predictabil- ity (CSEP). The application of such models for the forecasting of Italian target earthquakes seems to show peculiar characteristics for each of them. In particular, the ETAS model showed higher performance for short-term forecasting, in contrast, the EEPAS model showed higher forecasting performance for the medium/long-term. In this work, we compare the performance of EEPAS and ETAS models with that obtained by a deterministic model based on the occur- rence of strong foreshocks (FORE model) using an alarm-based approach. We apply the two rate-based models (ETAS and EEPAS) estimating the best probability threshold above which we issue an alarm. The model parameters and probability thresholds for issuing the alarms are calibrated on a learning data set from 1990 to 2011 during which 27 target earthquakes have occurred within the analysis region. The pseudo-prospective forecasting performance is as- sessed on a validation data set from 2012 to 2021, which also comprises 27 target earthquakes. Tests to assess the forecasting capability demonstrate that, even if all models outperform a purely random method, which trivially forecast earthquake proportionally to the space–time occupied by alarms, the EEPAS model exhibits lower forecasting performance than ETAS and FORE models. In addition, the relative performance comparison of the three models demonstrates that the forecasting capability of the FORE model appears slightly better than ETAS, but the difference is not statistically significant as it remains within the uncertainty level. However, truly prospective tests are necessary to validate such results, ideally using new testing procedures allowing the analysis of alarm-based models, not yet available within the CSEP.
    Description: Published
    Description: 1541–1551
    Description: OST4 Descrizione in tempo reale del terremoto, del maremoto, loro predicibilità e impatto
    Description: JCR Journal
    Keywords: Computational seismology ; Earthquake interaction, forecasting and prediction ; Statistical seismology ; Comparison betwee earthquake forecasting methods
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 128
    Publication Date: 2024-05-09
    Description: To understand the seismic hazard of a subduction zone, it is necessary to know the geometry, location and mechanical characteristics of the interplate boundary below which an oceanic plate is thrust downward. By considering the azimuthal dependence of converted P-to-S (Ps) amplitudes in receiver functions, we have detected the interplate boundary in the Makran subduction zone, revealing significant seismic anisotropy at the base of the accretionary wedge above the slab before it bends down beneath the Jaz Murian basin. This anisotropic feature aligns with a zone of reduced seismic velocity and a high primary/secondary wave velocity ratio (Vp/Vs), as documented in previous studies. The presence of this low-velocity highly anisotropic layer at the base of the accretionary wedge, likely representing a low-strength shear zone, could possibly explain the unusually wide accretionary wedge in Makran. Additionally, it may impact the location and width of the locked zone along the interplate boundary.
    Description: Iranian National Science Foundation (INSF)
    Description: Published
    Description: 64-74
    Description: OST1 Alla ricerca dei Motori Geodinamici
    Description: JCR Journal
    Keywords: Earthquake hazards, Seismic anisotropy, Crustal structure, Subduction zone processes ; 04.06. Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 129
    Publication Date: 2024-05-09
    Description: The integrated interpretation of high-resolution multibeam bathymetry, seismic profiles and backscatter data in the S. Eufemia Gulf (SEG; Calabro-Tyrrhenian continental margin, south-eastern Tyrrhenian Sea) documents the relationship between postglacial fault activity and morpho-sedimentary processes. Three systems of active normal faults that affect the seafloor or the shallow subsurface, have been identified: 1) the S. Eufemia fault system located on the continental shelf with fault planes mainly oriented N26E-N40E; 2) the offshore fault system that lies on the continental slope off Capo Suvero with fault planes mainly oriented N28E-N60E; 3) the Angitola Canyon fault system located on the seafloor adjacent to the canyon having fault planes oriented N60E- N85E. The faults produce a belt of linear escarpments with vertical displacement varying from a few decimeters to about 12 m. One of the most prominent active structures is the fault F1 with the highest fault length (about 9.5 km). Two main segments of this fault are identified: a segment characterised by seafloor deformation with metric slip affecting Holocene deposits; a segment characterised by folding of the seafloor. A combined tectono- stratigraphic model of an extensional fault propagation fold is proposed here to explain such different deformation. In addition to the seabed escarpments produced by fault deformation, in the SEG, a strong control of fault activity on recent sedimentary processes is clearly observed. For example, canyons and channels frequently change their course in response to their interaction with main tectonic structures. Moreover, the upper branch of the Angitola Canyon shows straight flanks determined by fault scarps. Tectonics also determined different sediment accumulation rates and types of sedimentation (e.g., the accumulation of hanging wall turbidite deposits and the development of contourite deposits around the Maida Ridge). Furthermore, the distribution of landslides is often connected to main fault scarps and fluids are locally confined in the hanging wall side of faults and can escape at the seabed, generating pockmarks aligned along their footwall.
    Description: Published
    Description: 108775
    Description: OST2 Deformazione e Hazard sismico e da maremoto
    Description: JCR Journal
    Keywords: High-resolution mapping ; Active faults ; Submarine landslides ; Tectonic geomorphology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 130
    Publication Date: 2024-05-09
    Description: This article has been accepted for publication in Geophysical Journal International ©:The Author(s) 2023. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Uploaded in accordance with the publisher's self-archiving policy. All rights reserved.
    Description: The Every Earthquake a Precursor According to Scale (EEPAS) forecasting model is a space– time point-process model based on the precursory scale increase (ψ ) phenomenon and associated predictive scaling relations. It has been previously applied to New Zealand, Cal- ifornia and Japan earthquakes with target magnitude thresholds varying from about 5–7. In all previous application, computations were done using the computer code implemented in Fortran language by the model authors. In this work, we applied it to Italy using a suite of computing codes completely rewritten in Matlab. We first compared the two software codes to ensure the convergence and adequate coincidence between the estimated model parameters for a simple region capable of being analysed by both software codes. Then, using the rewritten codes, we optimized the parameters for a different and more complex polygon of analysis using the Homogenized Instrumental Seismic Catalogue data from 1990 to 2011. We then perform a pseudo-prospective forecasting experiment of Italian earthquakes from 2012 to 2021 with Mw ≥ 5.0 and compare the forecasting skill of EEPAS with those obtained by other time in- dependent (Spatially Uniform Poisson, Spatially Variable Poisson and PPE: Proximity to Past Earthquakes) and time dependent [Epidemic Type Aftershock Sequence (ETAS)] forecasting models using the information gain per active cell. The preference goes to the ETAS model for short time intervals (3 months) and to the EEPAS model for longer time intervals (6 months to 10 yr).
    Description: Published
    Description: 1681–1700
    Description: OST4 Descrizione in tempo reale del terremoto, del maremoto, loro predicibilità e impatto
    Description: JCR Journal
    Keywords: Computational seismology ; Earthquake interaction ; forecasting and prediction ; Statistical seismology ; Earthquake forecasting
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 131
    Publication Date: 2024-05-09
    Description: Tectono-stratigraphic analysis coupled with digital 3D surface modelling derived from high-resolution seismic profiles is performed along a narrow turbidite basin offshore E-Sicily in order to increase understanding on the processes that contributed to the shaping of the Western Ionian Basin. Seismic-reflector patterns of the identified Pliocene-Quaternary sequence point to syn-depositional deformation during the Pliocene associated with the simultaneous activity of regional faults and underlying ductile units. Long-wavelength sediment fanning results from the extensional activity of the Malta Escarpment faults. Conversely, internal reflector architecture and lateral terminations indicate localized subsidence associated with the growth of uprising structures in the easternmost part of the basin. Lateral shifting of basin depocenters is in line with withdrawal effects observed in basins floored by ductile units (salt or shale). 3D modelling of time-reference surfaces highlights sub-circular depressions associated with nearby structural culminations. This pattern is similar to salt-withdrawal mini- basins commonly reported in evaporite-floored basins. Accordingly, salt migration/flow triggered by sediment loading, locally enhanced by fault activity, is proposed as the process controlling basin evolution during the Pliocene in the Western Ionian Domain. Nevertheless, the possibility of shale/mud tectonics as the ductile source of deformation cannot be discounted
    Description: Published
    Description: 104932
    Description: OST2 Deformazione e Hazard sismico e da maremoto
    Description: JCR Journal
    Keywords: Syn-depositional deformation ; Ductile flow ; Turbidite basin ; Western Ionian Basin
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 132
    Publication Date: 2024-05-09
    Description: The chemical composition of volatile organic compounds (VOCs) in interstitial soil gases from hydrothermal areas is commonly shaped by both deep hydrothermal conditions (e.g., temperature, redox, sulfur fugacity) and shallow secondary processes occurring near the soil-atmosphere interface. Caldara di Manziana and Solfatara di Nepi, i.e., two hydrothermal systems characterized by diverse physicochemical conditions located in the Sabatini Volcanic District and Vicano-Cimino Volcanic District, respectively (Central Italy), were investigated to evaluate the capability of VOCs in soil gases to preserve information from the respective feeding deep fluid reservoirs. Hierarchical cluster analyses and robust principal component analyses allowed recognition of distinct groups of chemical parameters of soil gases collected from the two study areas. The compositional dissimilarities from the free-gas discharges were indeed reflected by the chemical features of soil gases collected from each site, despite the occurrence of shallow processes, e.g., air mixing and microbial degradation processes, affecting VOCs. Four distinct groups of VOCs were recognized suggesting similar sources and/or geochemical behaviors, as follows: (i) S-bearing compounds, whose abundance (in particular that of thiophenes) was strictly dependent on the sulfur fugacity in the feeding system; (ii) C4,5,7+ alkanes, n-hexane, cyclics and alkylated aromatics, related to relatively low-temperature conditions at the gas source; (iii) C2,3 alkanes, benzene, benzaldehyde and phenol, i.e., stable compounds and thermal degradation products; and (iv) aliphatic O-bearing compounds, largely influenced by shallow processes within the soil. However, they maintain a chemical speciation that preserves a signature derived from the supplying deep-fluids, with aldehydes and ketones becoming more enriched after intense interaction of the hypogenic fluids with shallow aquifers. Accordingly, the empirical results of this study suggest that the chemical composition of VOCs in soil gases from hydrothermal areas provides insights into both deep source conditions and fluid circulation dynamics, identifying VOCs as promising geochemical tracers for geothermal exploration.
    Description: Published
    Description: 169047
    Description: JCR Journal
    Keywords: Central Italy; Geochemical tracers; Hydrothermal reservoirs; Soil gases; VOCs
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 133
    Publication Date: 2024-05-16
    Description: The China Seismo-Electromagnetic Satellite (CSES) was launched successfully in February 2018. It is China's first satellite to measure geophysical fields with scientific goals in both space and solid earth physics. In this work, we used CSES scalar magnetic data to derive a global lithospheric magnetic field model between ±65° geographic latitudes. The nightside data from March 2018 to November 2022 under quiet space weather conditions were selected. Then, the core and external fields were removed with the CHAOS-7 model. After further data quality control, the data were used to build a lithospheric magnetic field model using a spherical harmonic analysis. The obtained CSES model was compared with the CHAOS-7, CM6, and MF7 models in terms of power spectra and anomaly details, which confirmed that the CSES scalar data had good quality and could provide a reliable lithospheric magnetic field model up to degree 42.
    Description: Published
    Description: 107036
    Description: OSA1: Variazioni del campo magnetico terrestre, imaging crostale e sicurezza del territorio
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 134
    Publication Date: 2024-05-16
    Description: The Caviahue-Copahue Volcanic Complex is one of the most studied active volcanic systems in the South American Andean range, and yet little research has focused on trace and rare-earth elements of waters, especially during an eruptive cycle. In this study, we sampled and investigated natural waters from 23 sites (involving the crater lake, hot springs, streams, rivers, and bubbling pools) in two campaigns in 2017 and 2018, using physi cochemical parameters, major, trace and rare-earth elements concentrations. With this novel dataset, it was possible to identify, characterize and compare three groups of waters with distinctive hydrofacies. Indeed, the normalization of water compositions against host rock concentrations showed a particular trace element pattern for each group of waters. Although the absolute concentrations of the elements in each sampling site changed from 2017 to 2018, the normalized patterns did not. Boron, As, Cd, Tl, Se, and Te, commonly recognized as volatile, are the main trace elements that magmatic gases supply to the system headwaters, whereas elements such as Ca, K, and Ba are affected by precipitation of secondary minerals (gypsum, anhydrite, barite, jarosite, and alunite). Furthermore, the main river draining the summit volcano shows a steep decrease in As, Cr, and V concentrations correlated to the precipitation of Fe and Al hydroxysulfates (schwertmannite and basaluminite, respectively). Moreover, it is the first time that a comparison between the different water groups is made using the patterns of the rare-earth elements, allowing us to identify and separate depletion patterns due to dilution processes from those due to precipitation processes.
    Description: Published
    Description: 121602
    Description: JCR Journal
    Keywords: Copahue volcano ; Hydrological system ; Geothermal ; Trace elements ; Rare earth elements
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 135
    Publication Date: 2024-05-16
    Description: In this work, we present new biostratigraphic and paleoecological data from the Mignone River valley, located in the central sector of the Tyrrhenian Sea margin and part of the wider Tarquinia basin, and cores in the area of Rome. By combining the new paleontological information with a review of the extant literature, we re-examine the stratigraphic architecture of the Pliocene succession in the central sector of the northwestern Tyrrhenian Sea margin, spanning the Zanclean (MPl1; 5.33–5.08 Ma) through the early Piacenzian (MPl4b; 3.57–3.31 Ma), and of the following Pleistocene transgressive-regressive sequence, comprising the Gelasian (MPl6; 2.59–1.81 Ma) through the Santernian (MPl1; 1.81–1.5 Ma). We propose a revision of the paleogeographic evolution of the central Tyrrhenian Sea basins throughout the Pliocene-Lower Pleistocene interval, by coherently framing it within the chronology of the volcanic phases that occurred in this region. In particular, our reconstruction points toward the presence of a single Transgressive- Regressive (T-R) sequence starting with the Zanclean reflooding of the Mediterranean after the Messinian Salinity Crisis and ending in the Piacenzian, as opposed to the previously proposed occurrence of two depositional T-R sequences separated by an erosional phase affecting part of the Globorotalia puncticulata biozone.
    Description: Published
    Description: 1-20
    Description: OST2 Deformazione e Hazard sismico e da maremoto
    Description: OSA2: Evoluzione climatica: effetti e loro mitigazione
    Description: OSA4: Ambiente marino, fascia costiera ed Oceanografia operativa
    Description: JCR Journal
    Keywords: Pliocene ; Pleistocene ; Biostratigraphy ; Tyrrhenian sea margin ; Paleoenvironments ; Depositional T-R sequence
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 136
    Publication Date: 2024-05-16
    Description: The Latin American Giant Observatory (LAGO) is a ground-based observatory studying solar or high-energy astrophysics transient events. LAGO takes advantage of its distributed network of Water Cherenkov Detectors (WCDs) in Latin America as a tool to measure the secondary particle flux reaching the ground. These secondary particles are produced during the interaction between the modulated cosmic rays flux and the atmosphere. The LAGO WCDs are sensitive to secondary charged particles, high energy photons through pair creation and Compton scattering, and even neutrons thanks to, e.g., the deuteration of protons in the water volume. The pulse shape generated by these particles depends on several factors, such as the detector geometry, the water purity, the sensor response, or the reflectivity and diffusivity of the inner coating. Due to the decentralized nature of LAGO, these properties are different for each node. Additionally, the pulse shape depends on the convolution between the response of the central photomultiplier (PMT) to individual photons and the time distribution of the Cherenkov photons reaching the PMT. Typically, a WCD gives pulses with a sharp rise time ( 10 ns) and a longer decay time ( 70 ns). In this work, the WCD data used is acquired using the original LAGO data-acquisition system that digitizes pulses at a sampling rate of 40 MHz and 10 bits resolution on time windows of 400 ns. Here, we apply unsupervised machine learning techniques to find patterns in the WCDs data and subsequently create groups, through clustering, that can be used to provide particle separation. We use data acquired from an individual WCD, showing that density-based clustering algorithms are suitable for automatic particle separation producing good candidate groups. Improved separation would help LAGO to reconstruct in situ the properties of primary cosmic rays flux. These results open the possibility to deploy machine learning-based models in our distributed detection network for onboard data analysis as an operative prototype, allowing detectors to be installed at very remote sites.
    Description: Published
    Description: 168557
    Description: JCR Journal
    Keywords: 05.07. Space and Planetary sciences
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 137
    Publication Date: 2024-05-17
    Description: Volcanic ashes can threaten the human respiratory system through inhalation. In this study we investigated the physical and chemical characteristics of volcanic ashes from the Pomici di Avellino (PdA) eruption, an Early Bronze Age (ca. 3.9 ka) Plinian event from Somma-Vesuvius volcano, southern Italy, whose wide dispersal affected most of the Italian peninsula. In particular, we analysed particle size, shape, composition, and surface reactivity of samples from both proximal and distal locations. Our results indicate that some tephra layers north of Rome have a phonolitic composition and match that of PdA eruption; they reach grain-sizes 〈2 μm (~13.5%), thus having the potential to enter the deep respiratory system. Furthermore, the reactivity in free radical generation makes these products potentially able to cause oxidative stress within cells. While commonly no volcanic hazard assessment is made in areas far from active volcanoes, this study highlights that fine ashes from future similar large eruptions, producing high amount of highly fragmented material, can pose a health hazard even in remote, non-volcanic areas, hundreds of km away from the vent, suggesting that further studies on ash toxicity (e.g., in vitro toxicity studies) are required.
    Description: Published
    Description: 107826
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 138
    Publication Date: 2024-05-17
    Description: Several high spatial resolution thermal infrared (TIR) missions are planned for the coming decade and their data will be crucial to constrain volcanic activity patterns throughout pre- and post-eruption phases. Foundational to these patterns is the subtle (1−2 K) thermal behavior, which is easily overlooked using lower spatial resolution data. In preparation for these new data, we conducted the first study using the entire twenty-two-year archive of higher spatial, lower temporal resolution TIR data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor. This archive presents a unique opportunity to quantify low-magnitude temperature anomalies and small plumes over long time periods. We developed a new statistical algorithm to automatically detect the full range of thermal activity and applied it to 〉5000 ASTER scenes of five volcanoes with well-documented eruptions. Unique to this algorithm is its ability to use both day and night data, account for clouds, quantify accurate background temperatures, and dynamically scale depending on the anomaly size. Results improve upon those from the more commonly used lower spatial resolution data, despite the less frequent temporal coverage of ASTER, and show that high spatial resolution TIR data are equally as effective. Significantly, the smaller, subtle thermal detections served as precursory signals in ∼81% of eruptions, and the algorithm's results create a framework for classifying future eruptive styles.
    Description: Published
    Description: 113704
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 139
    Publication Date: 2024-05-17
    Description: This paper presents the results from a geographic information systems (GIS) workflow, which was used to analyze the spatial distribution and temporal evolution of volcanoes in the Mio-Pleistocene monogenetic Bakony- Balaton Highland Volcanic Field (BBHVF), located in the Pannonian Basin, Hungary. Volcanism occurred during the tectonic inversion in a back-arc setting and a compressive/transpressive tectonic regime on the hottest and thinnest lithosphere of continental Europe. The main goal of this study is to clarify the effect of the pre-existing structure of the upper lithosphere in the distribution of the volcanic centers across the volcanic field using an innovative GIS methodology. Orientation of the volcanic field was compared to the orientation of the faults in the BBHVF, and in its larger vicinity, which resulted in correspondence, suggesting the dominance of the SW-NE direction. The directions of the volcanic lineaments fit well to the two main fault directions. The fault-volcano proximity analysis suggests that the fault plane of a thrust fault was an important structural feature during the lifespan of the volcanism. All results suggest that the fault plane of a regionally significant Cretaceous thrust fault (Lit ́er Fault) might have served as a temporary pathway for the ascending magma, whereby (similarly to other, smaller faults) redirecting the magmas causing clustering of the volcanoes. This highlights the importance of major upper crustal structural heterogeneities for magma transport in a compressive tectonic system, espe- cially in the case of active, monogenetic volcanic fields from a volcanic hazard perspective. The present GIS workflow can be effective in analyzing the spatial patterns of the volcanism and its connection with crustal structures at monogenetic volcanic fields worldwide.
    Description: Published
    Description: 107940
    Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 140
    Publication Date: 2024-05-17
    Description: We present the first investigation of Equatorial Plasma Bubble (EPB) intensities across longitudinal sectors of the globe using observations from global navigation satellite system (GNSS) receivers. GNSS data from a total of 93 receiver stations located within ±20 degrees of the geomagnetic equator across the globe were used. The data covered periods of years 2014 and 2019 which are respectively years of high and low solar activity in solar cycle 24. We define a parameter known as the Standard deviation of Residual TEC (SRT) to characterize the EPB intensities. The EPB occurrence was defined by day-night differences of the rate of change of TEC index (ROTI). We observed a high correlation (r ∼ 0.80) between the magnitudes of the SRT and ROTI during the EPB occurrence, but the correlation is low (r ∼ 0.37) during non occurrence of EPB. The EPB intensities are greater during seasons with high occurrence rates. The EPB intensities and occurrence rates are also greater during the high solar activity. We found that the post-sunset intensities are greatest in the Atlantic region, followed by the African region, then the American, Australian, Asian, and Pacific regions in that order. The post-midnight intensities are greatest in the African region, followed by the Atlantic, American, Australian, Asian, and Pacific regions in that order.
    Description: Published
    Description: 106097
    Description: OSA3: Climatologia e meteorologia spaziale
    Description: JCR Journal
    Keywords: 01.02. Ionosphere
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 141
    Publication Date: 2024-05-08
    Description: In the last few years, several works have analyzed rainfall regime changes with the increase of temperature as a result of global warming. These changes, documented mainly in northern Europe, still need to be clarified in the Mediterranean area. Many studies have identified sometimes contradictory trends according to the type of data used, the methodology, and the daily or subdaily types of events. Therefore, an in-depth investigation of the Mediterranean area is required for the definition of more certain future scenarios. In this study, we examined a very large database including 〉1000 raingauges and thermometers in northern and central Italy to analyze the relationship between temperature and rainfall using the relation Clausius-Clapeyron. Furthermore, we analyzed the relationship between temperature and extreme precipitation events (EPEs, defined as the events higher than the 95th percentile) calculating the temperature anomalies occurred during these events. This large database covers a low rainfall accumulation period (RAP) that allowed us to study the relationship between temperature and rainfall and to distinguish rapid from long events related to rainfall intensity. The results show different relationships between rainfall and temperature in relation to seasons, RAPs, rainfall intensity, and geographical factors. The high spatial density of the database made it possible to identify spatial clusters with homogenous characteristics mainly influenced by geographical factors. With an increase in temperature, the wet season is characterized by a general increase in rainfall with a higher surge for intense and fast events. Instead, the dry season shows a general rainfall decrease for less intense and longer events, but an increase in rapid and more intensive rainfall events. This outcome has further implications involving a future decrease in water availability and an increase of the EPEs, causing an extremization of the climate during the dry season for northern and central Italy.
    Description: Published
    Description: 163368
    Description: OSA2: Evoluzione climatica: effetti e loro mitigazione
    Description: JCR Journal
    Keywords: Current global warming; Extreme precipitation events; Italy; Mediterranean; Temperature increase
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 142
    Publication Date: 2024-05-10
    Description: The Changbaishan Tianchi intraplate volcano is one of the most active and hazardous volcanoes of NE Asia, characterized by a summit caldera formed after the 946 CE ‘Millennium’ Plinian eruption. From December 2020 to June 2021, the frequency and magnitude of earthquakes at Tianchi were significantly higher than during background periods, with hundreds of earthquakes (46 events per month in average) and reaching a local magnitude of ML 3.1. This study reports a comprehensive deformation analysis and geophysical inversion scheme aimed to unveil the dynamics of this period. Multi-temporal InSAR analysis results of 32 ALOS-2 images from 2018 to 2022 show that the surface deformation is a combination of seasonal fluctuations (± 25 mm in average, with a maximum ± 45 mm) and a long-term positive component. The least squares linear regression of the deformation time series and temperature data, isolates the seasonal fluctuations, revealing a clear upliftsubsidence process from June 2020 to July 2021 in the caldera area. To constrain the Tianchi plumbing system dynamics, a combined inversion scheme consisting of three deformation sources is designed. The inversion results and the seismic records indicate that Tianchi volcano has experienced a low-level unrest episode from December 2020 to June 2021. The shallower plumbing system, located at about 5–9 km depth and modelled by pressurized spheroids, underwent a cumulative volume increase of 26 × 106 m3 from November 2018 to April 2021, followed by a volume decrease of 9 × 106 m3 from April to July 2021. This suggests magma uprising from the 14 km deep storage zone to the shallower plumbing system, followed by depressurization of the plumbing system due to the escape of fluids. This research provides a comprehensive understanding of the magma and fluid migration dynamics within the Tianchi multi-level plumbing system for the first time.
    Description: Published
    Description: 103775
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 143
    Publication Date: 2024-06-13
    Description: Southern hemisphere humpback whale (Megaptera novaeangliae, SHHW) breeding populations follow a high-fidelity Antarctic krill (Euphausia superba) diet while feeding in distinct sectors of the Southern Ocean. Their capital breeding life history requires predictable ecosystem productivity to fuel migration and migration-related behaviours. It is therefore postulated that populations feeding in areas subject to the strongest climate change impacts are more likely to show the first signs of a departure from a high-fidelity krill diet. We tested this hypothesis by investigating blubber fatty acid profiles and skin stable isotopes obtained from five SHHW populations in 2019, and comparing them to Antarctic krill stable isotopes sampled in three SHHW feeding areas in the Southern Ocean in 2019. Fatty acid profiles and δ13C and δ15N varied significantly among all five populations, however, calculated trophic positions did not (2.7 to 3.1). Similarly, fatty acid ratios, 16:1ω7c/16:0 and 20:5ω3/22:6ω3 were above 1, showing that whales from all five populations are secondary heterotrophs following an omnivorous diet with a diatom-origin. Thus, evidence for a potential departure from a high-fidelity Antarctic krill diet was not seen in any population. δ13C of all populations were similar to δ13C of krill sampled in productive upwelling areas or the marginal sea-ice zone. Consistency in trophic position and diet origin but significant fatty acid and stable isotope differences demonstrate that the observed variability arises at lower trophic levels. Our results indicate that, at present, there is no evidence of a divergence from a high-fidelity krill diet. Nevertheless, the characteristic isotopic signal of whales feeding in productive upwelling areas, or in the marginal sea-ice zone, implies that future cryosphere reductions could impact their feeding ecology.
    Repository Name: EPIC Alfred Wegener Institut
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  • 144
    Publication Date: 2024-06-12
    Description: The Campanian Volcanic Zone (CVZ) comprises multiple active volcanoes and includes the highly productive Campi Flegrei and Ischia caldera systems. These caldera volcanoes have produced probably the largest eruptions in Europe in the past 200 ka, such as the Monte Epomeo Green Tuff (MEGT; Ischia) at ca. 56 ka and the Campanian Ignimbrite (CI; Campi Flegrei) at ca. 40 ka, which form widespread isochrons across the Mediterranean region. These closely-spaced volcanic centres erupt phonolitic to trachytic glass compositions that are similar, and thus it can be challenging to correlate tephra deposits to specific volcanic sources. Here we present a detailed tephrostratigraphy for pre-CI eruption activity using the units preserved within a sequence at the coastal Acquamorta outcrop, on the western side of the CI caldera rim. Both the MEGT and CI units are present in the section, and they bracket twelve eruption units that were logged and sampled. New major and trace element glass chemistry data have been acquired for these Acquamorta tephra deposits. Three eruption deposits from Ischia and nine from Campi Flegrei are identified, which helps constrain the tempo of volcanic activity of these centres between the large caldera-forming eruptions. The three Ischia tephra deposits between the MEGT and the CI are indistinguishable based on both major and trace element glass chemistry and cannot be correlated to a specific or known eruption in this interval, such as the Schiappone tephra. The compositional variations between the Campi Flegrei eruptions reveal temporal shifts in the composition of the tephra deposits that reflect changes in the magmatic system prior to the CI eruption. These deposits indicate that there were at least nine eruptions at Campi Flegrei within 16 ka of the enormous CI eruption, and suggest that there was no significant period of repose before the caldera generating eruption.
    Description: Published
    Description: 107915
    Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 145
    Publication Date: 2024-06-12
    Description: Active volcanoes are a continuous threat for several regions worldwide and cause socio-economic and environmental issues, including the Virunga Volcanic Province (D.R. Congo). There, more than 2 million people are permanently exposed to the hazards of the most active volcanoes in Africa: Nyiragongo and Nyamulagira. However, there is a clear lack of information regarding the impacts of these hazards and how they may be affected by social vulnerability. In this study, a household survey based on semi-structural interviews was performed for rural communities in Virunga. This research aims to (i) investigate the impacts of volcanic hazards on rural communities facing distinct levels of social vulnerability, (ii) understand the adaptive strategies developed by these communities to address these impacts, and finally (iii) identify the main grievances with respect to volcanic hazards raised by these rural communities. The most vulnerable households are those directly affected by volcano-tectonic hazards such as lava flows, mazukus, volcanic gases, ash fallout, and seismic activity. Indirect dangers related to water and food contamination by volcanic emissions are also stronger for the most vulnerable households. Respondents reported that most edible plants and waters are strongly affected by direct volcanic emissions. Drinking waters, which come from traditional drainage, rainfall, and streams, are generally not suitable for human consumption in the study area. Community suggestions for addressing issues related to volcanic-tectonic hazards include efforts to improve water and food quality, enhancement of the sanitary system, timely information on the volcanic activity, volcano monitoring, and capacity building for volcanologists.
    Description: Published
    Description: 103566
    Description: JCR Journal
    Keywords: Volcanic hazards ; Social vulnerability ; Risks perception ; Nyiragongo ; Nyamulagira
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 146
    Publication Date: 2024-06-12
    Description: On December 26, 2018 (2:19 UTC), during a volcanic eruption on the Mt. Etna eastern flank (Sicily, southern Italy), the largest instrumental earthquake ever recorded in the volcano ruptured the Fiandaca Fault, with epicenter between Fleri and Pennisi villages (hypocenter at ca. 300 m a. s. l., Mw 4.9). This was the mainshock of an earthquake swarm and it was accompanied by widespread surface faulting and extensive damage along a narrow belt near the fault trace. Few hours after the mainshock, an episodic aseismic creep event occurred along the Aci Platani Fault, a SE extension of the Fiandaca Fault, which caused several damages in the Aci Platani village. We surveyed and mapped the coseismic and aseismic ground ruptures, and collected structural data on their geometry, displacement, and fault zone fabric. We compared the mapped surface ruptures with topography, lithology, and morphology of the buried top of the sedimentary basement. We conclude that the geometry of the volcanic pile influenced the surface expression of faulting during the December 26, 2018 event. The top surface of the marly clay basement should be considered as a detachment surface for shallow sliding blocks. The earthquake occurred on top of a depression of the sedimentary basement forcing the sliding eastward, causing at surface the re-arrangement of the fault strand pattern and deformation style, switching from shear faulting to a tensile failure. The Fleri earthquake therefore provides an unprecedented dataset for 1) understanding active faulting in the European largest onshore volcano, 2) modeling its complex dynamics, and 3) contributing to a more refined surface faulting hazard assessment at Mt. Etna. Results from this investigation might be useful for characterizing capable faulting in similar volcano-tectonic settings worldwide.
    Description: Published
    Description: 25-41
    Description: JCR Journal
    Keywords: 2018 Fleri earthquake ; Mt. Etna ; Surface faulting ; Geological hazards ; Aseismic creep
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 147
    Publication Date: 2024-06-13
    Description: Volcanic rocks are the prominent host rocks in geothermal and volcanic systems in general, displaying heterogeneity. Although various external factors such as temperature, pressure, time, fluid chemistry, and subsurface geology have been thoroughly researched regarding the source of hydrothermal minerals in geothermal fields, the effect of hydrothermal alteration on volcanic hosts is still controversial in the literature. This review compiles data on the physical and mechanical properties of the host rocks composing volcanic environments exhibiting hydrothermal alteration or remaining unaltered. The considered data is originated from hydrothermal areas from Kuril-Kamchatka (Russia), Los Humeros (Mexico), Ngatamaraki, Rotokawa, Kawerau and Ohakuri geothermal fields and Mt. Ruapehu, Mt. Taranaki, and Whakaari volcanoes (New Zealand), Solfatara (Italy), Reykjanes, Nesjavellir, and Theistarereykir geothermal fields (Iceland), La Soufrière de Guadeloupe (Caribbean) volcano, and Merapi volcano (Indonesia). Analysis of average values displayed in several graphical representations and correlations finds that dense rocks (such as lavas and intrusive rocks) exhibit greater competence and lower porosity than fragmental rocks. However, altered dense rocks display greater variability in mechanical properties compared to pyroclastic rocks, primarily influenced by mineral dissolution leading to rock weakening. Exceptions occur for high-temperature hydrothermal alteration, such as advanced silicification and propylitic alteration, with the latter influenced by minor types of alteration. Fragmental rocks have diverse behaviour with the extent of hydrothermal alteration and welding/compaction. According to the compiled data, an overall strengthening of pyroclastic rocks develops as hydrothermal alteration increases, regardless of the type of hydrothermal alteration. The complexity of hydrothermal systems, the variability shown by different hydrothermal settings and histories in terms of temperature, fluid chemistry and secondary mineral assemblage, and the variety of rock materials with different microstructures contribute to moderate correlations between properties compared to those established in an unaltered state. However, the same trends (linear, nonlinear, positive, negative) are preserved along hydrothermal alteration. This review emphasizes the significance of the type and degree of hydrothermal alteration, along with the rock type and pre-existence of fractures, in shaping the development of alteration in volcanic environments and modifying the properties of host rocks. The relevance of the review relies on the fact that these properties are considered to enhance the productivity of geothermal fields and improve the assessment of volcanic hazards. Future research is expected to expand on this groundwork.
    Description: Published
    Description: 104754
    Description: OSV4: Preparazione alle crisi vulcaniche
    Description: JCR Journal
    Keywords: Hydrothermal alteration ; physical properties ; degree of hydrothermal alteration ; mechanical properties ; hydrothermal alteration facies ; intrusion-related geothermal systems ; 04.08. Volcanology
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  • 148
    Publication Date: 2024-06-13
    Description: Climate change affects human activities, including tourism across various sectors and time frames. The winter tourism industry, dependent on low temperatures, faces significant impacts. This paper reviews the implications of climate change on winter tourism, emphasising challenges for activities like skiing and snowboarding, which rely on consistent snowfall and low temperatures. As the climate changes, these once taken-for-granted conditions are no longer as commonplace. Through a comprehensive review supported by up-to-date satellite imagery, this paper presents evidence suggesting that the reliability of winter snow is decreasing, with findings revealing a progressive reduction in snow levels associated with temperature and precipitation changes in some regions. The analysis underscores the need for concerted efforts by stakeholders who must recognize the reality of diminishing snow availability and work towards understanding the specific changes in snow patterns. This should involve multi-risk and multi-instrument assessments, including ongoing satellite data monitoring to track snow cover changes. The practical implications for sports activities and the tourism industry reliant on snow involve addressing challenges by diversifying offerings. This includes developing alternative winter tourism activities less dependent on snow, such as winter hiking, nature walks, or cultural experiences.
    Description: Published
    Description: 120554
    Description: OSA2: Evoluzione climatica: effetti e loro mitigazione
    Description: JCR Journal
    Keywords: Climate change ; Adaptation ; Tourism losses ; Winter sport ; Multi-date satellite imagery ; 05.09. Miscellaneous
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  • 149
    Publication Date: 2024-06-13
    Description: The topside ionosphere extends from the F2-layer peak, where the electron density reaches its absolute maximum in the ionosphere, to the overlying plasmasphere and magnetosphere. In the topside ionosphere, the electron density decreases with height with a vertical variation rate strongly dependent on height itself. The last version of the International Reference Ionosphere (IRI) model, i.e., IRI-2020, describes this complex behavior through four topside options based on different sub-models (i.e., options) developed from the 1970s to the present. All these options have in common the F2-layer peak as an anchor point, while they differ in their topside electron density profile and/or plasma effective scale height formulations. In this work, we perform a validation of the accuracy of the four IRI-2020 topside options based on the comparison against in-situ electron density observations by Gravity Recovery and Climate Experiment (GRACE), Ionospheric Connection Explorer (ICON), and Defense Meteorological Satellite Program (DMSP) F15 low-Earth-orbit satellites. Datasets used in this study encompass observations recorded from 1999 to 2022, covering different diurnal, seasonal, and solar activity conditions, on a global basis and for the height range 400–850 km above the ground. The nearly two solar cycles dataset facilitated the evaluation of IRI-2020 topside options ability to reproduce the spatial and time variations of the topside ionosphere for different solar activity conditions. The weaknesses and strengths of each IRI-2020 topside option are highlighted and discussed, and suggestions on how to improve the modeling of the challenging topside ionosphere region within the IRI model are provided for future reference.
    Description: In press
    Description: OSA3: Climatologia e meteorologia spaziale
    Description: JCR Journal
    Keywords: Topside ionosphere modeling ; International Reference Ionosphere (IRI) model ; In-situ electron density observations ; Low-Earth-Orbit satellites ; 01.02. Ionosphere
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 150
    Publication Date: 2024-06-21
    Description: The Qinghai-Tibet Plateau (QTP) is characterized by a vast number of frozen and unfrozen freshwater reservoirs, which is why it is also called “the third pole” of the Earth or “Asian Water Tower”. We analyzed testate amoeba (TA) biodiversity and corresponding protozoic biosilicification in lake sediments of the QTP in relation to environmental properties (freshwater conditions, elevation, and climate). As TA are known as excellent bio-indicators, our results allowed us to derive conclusions about the influence of climate warming on TA communities and microbial biogeochemical silicon (Si) cycling. We found a total of 113 TA taxa including some rare and one unknown species in the analyzed lake sediments of the QTP highlighting the potential of this remote region for TA biodiversity. 〉1/3 of the identified TA taxa were relatively small (〈30 μm) reflecting the relatively harsh environmental conditions in the examined lakes. TA communities were strongly affected by physico-chemical properties of the lakes, especially water temperature and pH, but also elevation and climate conditions (temperature, precipitation). Our study reveals climate-related changes in TA biodiversity with consequences for protozoic biosilicification. As the warming trend in the QTP is two to three times faster compared to the global average, our results provide not only deeper insights into the relations between TA biodiversity and environmental properties, but also predictions of future developments in other regions of the world. Moreover, our results provide fundamental data for paleolimnological reconstructions. Thus, examining the QTP is helpful to understand microbial biogeochemical Si cycling in the past, present, and future.
    Repository Name: EPIC Alfred Wegener Institut
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  • 151
    Publication Date: 2024-06-21
    Description: Stromboli (Italy) is an open-vent volcano with persistent explosive activity producing up to five hundred mild explosions per day. Fluctuations in explosion intensity, varying even by orders of magnitude in terms of emitted volume and their subsequent impact on the surrounding regions, sometimes occur abruptly. Consequently, identifying precursors of larger eruptive activities, particularly for more intense (paroxysmal) explosions, is challenging. In order to search for anomalies in the pre-paroxysm activity related to the summer 2019 eruption, we applied a hybrid method to the automatic analysis of geophysical and geochemical time series. This approach is based on the combination of two methods: 1. the Empirical Mode Decomposition (EMD) and 2. the Support Vector Regression (SVR). The aggregation of these two methods allowed us to identify anomalies in the patterns of the geophysical and geochemical parameters measured on Stromboli in a ten-month period including the July–August 2019 eruption. The results of this study are encouraging for an improvement of the monitoring systems and for volcano early warning applications.
    Description: This work has been supported by the INGV project Pianeta Dinamico 2023-2025 - ObseRvation, Measurement and modelling of Eruptive processes (ORME), and partially supported by the Progetto Strategico Dipartimentale INGV 2019 “Forecasting eruptive activity at Stromboli volcano: timing, eruptive style, size, intensity and duration” (FIRST, Delibera n. 144/2020; Scientific Responsibility: S.C.). Furthermore, this research has benefited from the support of Convenzione B2 DPC-INGV 2022-2024, Stromboli, Task 1.3 “Development of a unique activity index and estimation of the probability of the transition between ‘ordinary’ and ‘extraordinary’ eruptive activity”, and of the INGV project “Reti Multiparametriche”, Task A2 “Development of methods for the identification of precursors of Stromboli's paroxysms and major explosions based on multiparametric data analysis and study of possible early warning techniques”.
    Description: In press
    Description: 108131
    Description: OSV1: Verso la previsione dei fenomeni vulcanici pericolosi
    Description: JCR Journal
    Keywords: Stromboli volcano ; Volcanic monitoring ; Data analysis ; Multiparametric geophysics ; Paroxysmal explosions ; 04.08. Volcanology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 152
    Publication Date: 2024-05-23
    Description: This paper positions possibilities for human geographies of the sea. The growing volume of work under this banner has been largely qualitative in its approach, reflecting, in turn, the questions posed by oceanic scholars. These questions necessitate corresponding methods. Whilst this is not necessarily a problem, and the current corpus of work has offered many significant contributions, in making sense of the human dimensions of maritime worlds, other questions—and methods—may generate knowledge that is useful within this remit of work. This paper considers the place of quantitative approaches in posing lines of enquiry about shipping, one of the prominent areas of concern under the banner of ‘human geographies of the seas’. There is longstanding work in transport geographies concerned with shipping, logistics, freight movement and global connections, which embraces quantitative methods which could be bridged to ask fresh questions about oceanic spatial phenomena past and present. This paper reviews the state of the art of human geographies of the sea and transport geographies and navigates how the former field may be stimulated by some of the interests of the latter and a broader range of questions about society-sea-space relations. The paper focuses on Automatic Identification Systems (or AIS) as a potentially useful tool for connecting debates, and deepening spatial understandings of the seas and shipping beyond current scholarship. To advance the argument the example of shipping layups is used to illustrate or rather, position, the point.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
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  • 153
    Publication Date: 2024-05-23
    Description: This paper positions possibilities for human geographies of the sea. The growing volume of work under this banner has been largely qualitative in its approach, reflecting, in turn, the questions posed by oceanic scholars. These questions necessitate corresponding methods. Whilst this is not necessarily a problem, and the current corpus of work has offered many significant contributions, in making sense of the human dimensions of maritime worlds, other questions—and methods—may generate knowledge that is useful within this remit of work. This paper considers the place of quantitative approaches in posing lines of enquiry about shipping, one of the prominent areas of concern under the banner of ‘human geographies of the seas’. There is longstanding work in transport geographies concerned with shipping, logistics, freight movement and global connections, which embraces quantitative methods which could be bridged to ask fresh questions about oceanic spatial phenomena past and present. This paper reviews the state of the art of human geographies of the sea and transport geographies and navigates how the former field may be stimulated by some of the interests of the latter and a broader range of questions about society-sea-space relations. The paper focuses on Automatic Identification Systems (or AIS) as a potentially useful tool for connecting debates, and deepening spatial understandings of the seas and shipping beyond current scholarship. To advance the argument the example of shipping layups is used to illustrate or rather, position, the point.
    Repository Name: EPIC Alfred Wegener Institut
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  • 154
    Publication Date: 2024-05-27
    Description: In this paper we employ a combination of gravity and hydrologic data to constrain a hydraulic model of the Škocjan Caves, an allogenic dominated karstic system in Slovenia. The gravity time-series recorded by a spring-based gravimeter, are carefully analyzed to remove tidal and non-tidal effects and unveil the local hydrologic contribution, which is influenced by the temporary accumulation of water in the cave system during the flood events of the Reka river. We make use of a combined analysis of three large flood events with peak river discharge of about 200, 230 and 300 m3/s, that caused significant water level and gravity variations sensed by the pressure transducer and by the gravimeter. By the integration of hydraulic modelling we study the different coupled gravimetric-hydrologic responses to these flood events: we show that, depending on the peak discharge and duration of the event, different flow conditions are present in the cave system. In addition to the information provided by the pressure transducer, the gravimeter is sensitive to the flow dynamics in a different sector of the cave due to the choice of its location; this configuration helps to better constrain the hydraulic model. Moreover, we find that the autogenic recharge by percolating water can significantly affect the gravity time-series and must be considered in related models. By inclusion of both the hydraulic model outcomes and of the modelling of the autogenic recharge, we are able to better explain the gravity transients during the two smaller magnitude events. In particular, during such events the autogenic contribution produces a transient gravity signal, which is about 4 times larger than the allogenic one, while during the largest flood the allogenic contribution drastically overcomes the autogenic effect by a factor 20. By discussing this case, we prove the potential of terrestrial gravity observation to depict the hydro-dynamics of these complex karstic systems as well as the potential of gravimetry to remotely monitor these storage units.
    Description: Published
    Description: 130453
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 155
    Publication Date: 2024-05-27
    Description: This article has been accepted for publication in Geophysical Journal International ©:The Author(s) 2023. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Uploaded in accordance with the publisher's self-archiving policy. All rights reserved.
    Description: We report on about 20 yr of relative gravity measurements, acquired on Mt. Somma–Vesuvius volcano in order to investigate the hydrological and volcano-tectonic processes controlling the present-day activity of the volcano. The retrieved long-term field of time gravity change (2003–2022) shows a pattern essentially related to the subsidence, which have affected the central part of the volcano, as detected by the permanent GNSS network and InSAR data. After reducing the observations for the effect of vertical deformation, no significant residuals are found, indicating no significant mass accumulation or loss within the volcanic system. In the north-western sector of the study area, at the border of the volcano edifice, however, significant residual positive gravity changes are detected which are associated to ground-water rebound after years of intense exploitation of the aquifers. On the seasonal timescale, we find that stations within the caldera rim are affected by the seasonal hydrological effects, while the gravity stations at the base of the Vesuvius show a less clear correlation. Furthermore, within the caldera rim a multiyear gravity transient is detected with an increase phase lasting about 4 yr followed by a slower decrease phase. Analysis of rain data seem to exclude a hydrological origin, hence, we hypothesize a deeper source related to the geothermal activity, which can be present even if the volcano is in a quiescent state. We infer the depth and volume of the source by inverting the spatial pattern of the gravity field at the peak of the transient. A volume of fluids of 9.5 × 107 m3 with density of 1000 kg m−3 at 2.3 km depth is capable to fit reasonably well the observations. To explain the gravity transient, simple synthetic models are produced, that simulate the ascent of fluids from a deep reservoir up to the depth of 2.3 km and a successive diffusion within the carbonate aquifer hosting the geothermal system. The whole process appears to not significantly affect the seismicity rate and the deformation of the volcano. This study demonstrates the importance of a 4-D gravity monitoring of a volcano to understand its complex gravity signals that cover different spatial and temporal scales. Discriminating the different contributions that mix up in the observed gravity changes, in particular those due to hydrologic/anthropogenic activities form those due to the geothermal dynamics, is fundamental for a complete and reliable evaluation of the volcano state.
    Description: Published
    Description: 1565–1580
    Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 156
    Publication Date: 2024-05-27
    Description: The 28th September 2018 Sulawesi Supershear earthquake (MW 7.5) was one of the deadliest earthquakes in the recent history of Indonesia causing ∼4000 causalities. The earthquake caused a ∼ 177 km long surface rupture along the Palu-Karo fault. Apart from surface rupture, the earthquake caused extensive earthquake environmental effects (EEEs) around the Palu-Donggala area of Central Sulawesi, Indonesia, which includes tsunami, coastal landslide, liquefaction, ground cracks and more than 7300 landslides in hilly areas. Initial post-event analysis and reports assigned a Modified Mercalli Intensity (MMI) of VII to VIII in Palu City and the surrounding area. Building damage and ground effects caused by the earthquake suggested that seismic intensity was understated. Here we applied the EEEs information from field survey data, published reports, and remote sensing tools to determine macroseismic intensity using the Environmental Seismic Intensity (ESI-07) Scale. The ESI-07 intensity derived from the ground effects suggests the maximum intensity of X-XI, which is 3–4° higher than the traditional intensity estimated by the United States Geological Survey (USGS) and the Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG). ShakeMaps were generated considering the ESI-07 values. The ShakeMap was compared with the instrumentally derived ShakeMap for the Palu earthquake, which proves that the ShakeMap prepared from the instrumental data or structural damage data is underrated. We argue that proper documentation of the EEEs is necessary for such damaging earthquakes for future earthquake hazard mapping and planning in the study area and other earthquakes in Indonesia. In addition, this will help in defining the on-fault and off-fault damage zone towards reducing the seismic risk of the Palu Donggala area.
    Description: Published
    Description: 107054
    Description: JCR Journal
    Keywords: Sulawesi Earthquake ; Indonesia ; EEEs ; ESI-07 ; ShakeMap ; Seismic Hazard
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 157
    Publication Date: 2024-05-28
    Description: Nominally anhydrous minerals (NAMs) may contain significant amounts of water and constitute an important reservoir for mantle hydrogen. The colloquial term ‘water’ in NAMs is related to the presence of hydroxyl-bearing (OH􀀀 ) point defects in their crystal structure, where hydrogen is bonded to lattice oxygen and is charge-balanced by cation vacancies. This hydrous component may therefore have substantial effects on the thermoelastic parameters of NAMs, comparable to other major crystal-chemical substitutions (e.g., Fe, Al). Assessment of water concentrations in natural minerals from mantle xenoliths indicates that olivine commonly stores ~0–200 ppm of water. However, the lack of samples originating from depths exceeding ~250 km coupled with the rapid diffusion of hydrogen in olivine at magmatic temperatures makes the determination of the olivine water content in the upper mantle challenging. On the other hand, numerous experimental data show that, at pressures and temperatures corresponding to deep upper mantle conditions, the water storage capacity of olivine increases to 0.2–0.5 wt%. Therefore, determining the elastic properties of olivine samples with more realistic water contents for deep upper mantle conditions may help in interpreting both seismic velocity anomalies in potentially hydrous regions of Earth’s mantle as well as the observed seismic velocity and density contrasts across the 410-km discontinuity. Here, we report simultaneous single-crystal X-ray diffraction and Brillouin scattering experiments at room temperature up to 11.96(2) GPa on hydrous [0.20(3) wt% H2O] Fo90 olivine to assess its full elastic tensor, and complement these results with a careful re-analysis of all the available single-crystal elasticity data from the literature for anhydrous Fo90 olivine. While the bulk (K) and shear (G) moduli of hydrous Fo90 olivine are virtually identical to those of the corresponding anhydrous phase, their pressure derivatives K′ and G′ are slightly larger, although consistent within mutual uncertainties. We then defined linear relations between the water concentration in Fo90 olivine, the elastic moduli and their pressure derivatives, which were then used to compute the sound velocities of Fo90 olivine with higher degrees of hydration. Even for water concentrations as high as 0.5 wt%, the sound wave velocities of hydrous and anhydrous olivines were found to be identical within uncertainties at pressures corresponding to the base of the upper mantle. Contrary to previous claims, our data suggest that water in olivine is not seismically detectable, at least for contents consistent with deep upper mantle conditions. In addition to that, our data reveal that the hydration of olivine is unlikely to be a key factor in reconciling seismic velocity and density contrasts across the 410-km discontinuity with a pyrolitic mantle.
    Description: Published
    Description: 107011
    Description: JCR Journal
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  • 158
    Publication Date: 2024-05-28
    Description: The rapid decline in both quality and availability of freshwater resources on our planet necessitates their thorough assessment to ensure sustainable usage. The growing demand for water in industrial, agricultural, and domestic sectors poses significant challenges to managing both surface and groundwater resources. This study tests and proposes a hybrid evaluation approach to determine Groundwater Quality Indices (GQIs) for irrigation (IRRI), seawater intrusion (SWI), and potability (POT), finalized to the spatial distribution of groundwater suitability involving water quality indicator along with hydrogeological and socio-economic factors. Mean Decrease Accuracy (MDA) and Information Gain Ratio (IGR) were used to state the importance of chosen factors such as level of groundwater above the sea, thickness of the aquifer, land cover, distance from coastline, silt soil content, recharge, distance from river and lagoons, depth to water table from ground, distance from agricultural wells, hydraulic conductivity, and lithology for each quality index, separately. The results of both methods showed that recharge is the most important parameter for GQIIRRI and GQIPOT, while the distance from the coastline and the rivers, are the most important for GQISWI. The spatial modelling of GQIIRRI and GQIPOT in the study area has been achieved applying three machine learning (ML) algorithms: the Boosted Regression Tree (BRT), the Random Forest (RF), and the Support Vector Machine (SVM). Validation results showed that RF has the highest prediction for GQIIRRI, while the SVM model has the highest prediction for the GQIPOT index. It is worth to mention that the future utilization and testing of new algorithms could produce even better results. Finally, GQIIRRI and GQIPOT were combined and compared using two combine and overlay methods to prepare a hybrid map of multi-GQIs. The results showed that 69% of the study area is suitable for irrigation and potable use, due to both geogenic and anthropogenic activities which contribute to make some water resources unsuitable for either use. Specifically, the northern, western, and eastern portions of the study area are in the "very high and high quality" classes while the southern portion shows "very low and low quality" classes. In conclusion, the developed map and approach can serve as a practical guide for enhancing groundwater management, identifying suitable areas for various uses and pinpointing regions requiring improved management practices.
    Description: Published
    Description: 119041
    Description: JCR Journal
    Keywords: Artificial intelligence ; Groundwater suitability ; Quality index ; Vulnerability map
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 159
    Publication Date: 2024-05-29
    Description: Fault creep along the lower eastern flank of Mt. Etna volcano has been documented since the end of the 19th century and significantly contributes to the surface faulting hazard in the area. On 29 October 2002, during a seismic swarm related to dyke intrusions, two earthquakes caused extensive damage and surface faulting in an area between the Santa Venerina and Santa Tecla villages. On the same day after the two earthquakes, an episodic aseismic creep occurred along the Scalo Pennisi Fault close to the Santa Tecla coastline. On 8 February 2022, during another aseismic creep event along the Scalo Pennisi Fault, we observed the reopening of the pre existing 2002 ground ruptures mostly as pure dilational fractures. We mapped the 2002 and 2022 surface ruptures, and collected data on displacement, length, and pattern of ground breaks. Ground ruptures affected structures located along the activated fault segments, including roads, walls and buildings. The 2002 surface faulting propagation can be ascribed to a sliding of the Mt. Etna eastern flank toward the SE, as also suggested by the related shallow seismicity, and InSAR and geodetic data between 2002 and 2005. For the 2022 event, dif ferential InSAR data, acquired in both descending and ascending views, allowed us to decompose Line of Sight (LOS) displacement into horizontal and vertical components. We detect a ~ 700 m long and ~ 500 m wide deformation zone with a downward and eastward motion (max displacement ~1,5 cm) consistent with a normal fault. We inverted the InSAR–detected surface deformation using a uniform-slip fault model and obtained a shallow detachment for the causative fault, located at ~300 m depth, within the volcanic pile. This is the first in depth study along the Scalo Pennisi Fault to suggest a shallow faulting that accommodates Mt. Etna E flank gravitational sliding.
    Description: Published
    Description: 229829
    Description: JCR Journal
    Keywords: Etna ; Aseismic creep ; Earthquake ; Surface faulting ; Volcano-tectonic deformation ; InSAR
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 160
    Publication Date: 2024-05-21
    Description: The increase in summer monsoon precipitation over western Africa during the last interglacial (LIG) relative to the pre-industrial (PI) is well documented, but it is uncertain whether this increase is due to larger rainfall rate alone, an extension of the summer monsoon season or a combination of the two. Due to different orbital config- uration, the boreal summer of the LIG was warmer but shorter than the PI, potentially influencing the summer monsoon duration. In this study, we employ a newly developed isotope-enabled climate model, AWI-ESM-wiso to investigate the intensity and length of the West African Summer Monsoon (WASM) for both LIG and PI time periods. Our model results indicate that, despite an intensification in summer insolation and an enhanced hydro-logical cycle, WASM season in the LIG is 9 days shorter compared to the PI. During the LIG, increased insolation in late spring and early summer strengthens the Saharan heat low (SHL) and its associated sub-systems, facilitating a faster accumulation of potential instability and an earlier WASM onset. However, a substantial earlier withdrawal of the WASM is also detected, driven by an earlier southward shift of insolation maximum. More- over, our findings are further supported by models participating in the 4th phase of the Paleoclimate Modelling Intercomparison Project (PMIP4).
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 161
    Publication Date: 2024-05-22
    Description: Delineating hydrothermal alteration and supergene caps is fundamental for mineral exploration of sulfide ores. The aim of this study is to apply a multi-scale workflow based on hyperspectral remote and proximal sensing data in order to delineate hydrothermal dolomitization and supergene alteration associated with the Mississippi Valley-Type Zn-Pb(-Ag) deposit of Jabali (Western Yemen). The area was investigated through hyperspectral images derived from the new launched Italian Space Agency’s PRISMA satellite, which has a higher spectral resolution compared to multispectral sensors and covers the mineral-diagnostic wavelength regions (such as the 2100 nm to 2300 nm range) with a Signal to Noise Ratio (SNR) ≥ 100. Spectral mineral maps were produced through the band ratios method using specific feature extraction indices applied to the hyperspectral satellite data. The results were validated by using Visible Near InfraRed (VNIR) to Short Wave InfraRed (SWIR) reflectance spectra, mineralogical (XRPD) and geochemical (ICP-ES/MS) analyses on rock samples collected in the Jabali area. The dolomites footprint was mapped using a PRISMA Level 2C image, by enhancing the spectral differences between limestones and dolomites in the SWIR-2 region (major features centered at 2340 nm and 2320 nm, respectively). Gossans were detected due to the Fe3+ absorption band in the VNIR region at 900 nm. The Zn-Pb mineralized area, extended for approximately 25 km2, was thus identified by recognizing gossan occurrences in dolomites. The study demonstrates that the PRISMA satellite is effective in identifying Zn-Pb mineralized outcrops in sedimentary basins.
    Description: Published
    Description: 105244
    Description: OSA5: Energia e georisorse
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 162
    Publication Date: 2024-05-20
    Description: Meta menardi (Latreille, 1804) and M. bourneti Simon, 1922 (Araneae: Tetragnathidae) are ubiquitous inhabitants of the twilight zone of most hypogean sites across Europe. The two species are broadly distributed in Italy, including Sicily, where they show a remarkable segregation along the altitudinal gradient of Mount Etna. Thanks to our recent sampling activities in this area, we create a georeferenced dataset allowing the application of Species Distribution Modelling aiming at evaluating the current and the future habitat in light of the impacts caused by climate change on the local populations. We predicted a relatively wide suitable area for M bourneti, ranging from the sea level up to 1100 m a.sl., whereas for M. menardi the suitable area encompasses a narrow mid altitude strip, extending halfway between the areas suitable for M. bourneti, and the highly unsuitable volcanic uplands, heavily disturbed by the volcanic activity. The averaged future predictions for 2070 under RCP 8.5 scenario, show that M. bourneti will expand its range upwards, in areas that are now suitable for M. menardi. In turn, predictions for M. menardi indicate an extreme reduction of the current strip of suitable habitat, likely determining its local extinction. Our findings are further corroborated by the analysis of the bioclimatic niche of the two species assessed via multidimensional Hutchinsonian hypervolume, being much smaller in M. menardi compared to of M. bourneti. In light of our results, it seems likely that having wider climatic preference, M. bourneti will substitute M. menardi in most of its current range in Sicily. Future interventions aiming at the conservation of M. menardi on Mount Etna are strongly advised.
    Description: Published
    Description: e02699
    Description: OSA2: Evoluzione climatica: effetti e loro mitigazione
    Description: JCR Journal
    Keywords: Cave-dwelling spiders ; Mount Etna ; Lava caves ; Climate change ; Niche segregation ; Species distribution modelling
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 163
    Publication Date: 2024-05-20
    Description: Observations of the tidal response of celestial bodies quantified by the Love numbers are highly relevant in planetary geophysical investigations because they provide unique insight into the interior structures. For example, the high sensitivity of tidal deformations to the properties of the oceans detected beneath the icy surfaces of some moons is of paramount importance for investigations of their habitability. We present here PyALMA3, a software framework developed in Python devoted to the computation of planetary Love numbers. PyALMA3 is based on ALMA3, a previous version developed in Fortran. Conversion to Python significantly improves the accessibility and portability of the software. We tested PyALMA3 by applying it to the exploration of the tidal responses of Europa and the other Galilean moons. We show that accurate modeling of effects such as the viscoelastic deformations of ice and the water density gradient in the ocean (variations of 2–3% on the real part of k2) will be important in the context of geophysical investigations that will be conducted by future missions targeting icy moons, such as Europa Clipper and JUICE.
    Description: Published
    Description: 116120
    Description: JCR Journal
    Keywords: Galilean satellites ; Tides ; Planetary interior ; Ocean planets
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 164
    Publication Date: 2024-05-20
    Description: When approximating elliptic problems by using specialized approximation techniques, we obtain large structured matrices whose analysis provides information on the stability of the method. Here we provide spectral and norm estimates for matrix-sequences arising from the approximation of the Laplacian via ad hoc finite differences. The analysis involves several tools from matrix theory and in particular from the setting of Toeplitz operators and Generalized Locally Toeplitz matrix-sequences. Several numerical experiments are conducted, which confirm the correctness of the theoretical findings.
    Description: Published
    Description: 10-43
    Description: JCR Journal
    Keywords: Toeplitz matrix ; Generating function and spectral symbol ; Approximation of differential operators
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 165
    Publication Date: 2024-05-20
    Description: To ensure the long-term sustainable use of African Great Lakes (AGL), and to better understand the functioning of these ecosystems, authorities, managers and scientists need regularly collected scientific data and information of key environmental indicators over multi-years to make informed decisions. Monitoring is regularly conducted at some sites across AGL; while at others sites, it is rare or conducted irregularly in response to sporadic funding or short-term projects/studies. Managers and scientists working on the AGL thus often lack critical long-term data to evaluate and gauge ongoing changes. Hence, we propose a multi-lake approach to harmonize data collection modalities for better understanding of regional and global environmental impacts on AGL. Climate variability has had strong impacts on all AGL in the recent past. Although these lakes have specific characteristics, their limnological cycles show many similarities. Because different anthropogenic pressures take place at the different AGL, harmonized multilake monitoring will provide comparable data to address the main drivers of concern (climate versus regional anthropogenic impact). To realize harmonized long-term multi-lake monitoring, the approach will need: (1) support of a wide community of researchers and managers; (2) political goodwill towards a common goal for such monitoring; and (3) sufficient capacity (e.g., institutional, financial, human and logistic resources) for its implementation. This paper presents an assessment of the state of monitoring the AGL and possible approaches to realize a long-term, multi-lake harmonized monitoring strategy. Key parameters are proposed. The support of national and regional authorities is necessary as each AGL crosses international boundaries.
    Description: Published
    Description: 101988
    Description: JCR Journal
    Keywords: Fisheries ; Limnology ; Pollution ; Biodiversity ; Climate change ; Erosion
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 166
    Publication Date: 2024-05-23
    Description: Geofluids from natural springs connect with the crust and/or mantle in many cases, and their geochemical anomalies could be significant for the study on faults activity and even earthquakes. Several natural springs are distributed along the Lenglongling fault zone (LLLFZ) in the northeastern margin of the Tibetan Plateau, where the Ms 6.9 Menyuan earthquake occurred on January 8th, 2022. Based on chemical and isotopic compositions (δD, δ18O, δ13C, and 3He/4He) of water and gas samples, the origin of geofluids and their potential correlation with fault activity even including earthquakes are preliminarily assessed in this paper. The δ13CCO2 values and 3He/4He ratios showed that the gas originating from the crust was associated with the metamorphism of carbonate rocks, whereas the δ18O and δD values of water samples indicated that the natural springs were predominantly infiltrated with precipitations from local mountains ranging 3.7 - 5.5 km in height. Obvious changes of Ca2+ and HCO3􀀀 concentrations in SZK spring waters in the surface rupture zones were observed in a short period (about three months) after the main shock, in contrast to those of the GSK springs far from the surface rupture zones. Such variations might be correlated with the stress increase prior to the 2022 Menyuan Ms 6.9 earthquake. The mechanical fracturing of surrounding limestone rocks during the slipping movement of LLLF could facilitate the water-rock interactions. Compared to three-month observations after the main shock, relatively higher concentrations of HCO3􀀀 and heavier δ18OH2O values of the LHG springs were also observed in the short-term period. The shallow stored formation water might be squeezed along the cracks and rose to the surface during earthquake tremors, causing a sandblasting water phenomenon.
    Description: Published
    Description: 105767
    Description: JCR Journal
    Keywords: Menyuan earthquake ; Natural spring ; Fluid geochemistry ; Lenglongling fault ; Tibetan plateau
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 167
    Publication Date: 2024-05-23
    Description: The influence of the hydrothermal circulation on seismicity and uplift observed at the Campi Flegrei caldera (Italy) is a topic of great interest to the scientific community. Recently, Thermo-Poro-Elastic (TPE) inclusions were proposed as likely deformation sources. They are suitable to explain the mechanical effects induced by hot and pressurized hydrothermal fluids, possibly exsolved from underlying magma, and pervading an overlying brittle layer. Recent works show that a TPE inclusion located at approximately 2 km depth below the Campi Flegrei caldera significantly contributed to the large and rapid soil uplift observed during the ‘82-’84 unrest phase. In the present work we demonstrate that such a source of deformation is likely playing a role even in the current unrest phase, which is characterized by a much lower uplift-rate with respect to the one occurred in the previous unrest phase. We will show that the time-series of soil uplift observed in the last 18 years can be reproduced by assuming the reactivation of the same deformation source responsible of the ‘82-’84 unrest located within a shallow brittle layer at about 2 km depth. The presence of a brittle layer has been evidenced in the past by tomographic studies and is confirmed by a sharp variation of the b-value at the corresponding depth.We believe that our results provide very important insights and evidences, supporting the existence and the importance of an active thermo-poro-elastic deformation source, which can be useful for understanding the unrest of the Campi Flegrei caldera, from both a scientific and geohazard perspective.
    Description: Published
    Description: 107930
    Description: JCR Journal
    Keywords: Campi Flegrei ; Hydrothermal fluids ; Caldera ; Uplift ; Induced seismicity ; Deformation source
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 168
    Publication Date: 2024-05-30
    Description: The toxin-producing dinoflagellate Alexandrium pseudogonyaulax has become increasingly abundant in northern European waters, replacing other Alexandrium species. A. pseudogonyaulax produces goniodomins and lytic substances, which can be cytotoxic toward other organisms, including fish, but we still know little about the environmental conditions influencing its growth and toxicity. Here, we investigated the impacts of different nitrogen sources and light intensities, common bottom-up drivers of bloom formation, on the growth and toxin content of three A. pseudogonyaulax strains isolated from the Danish Limfjord. While the growth rates were significantly influenced by nitrogen source and light intensity, the intracellular toxin contents only showed strong differences between the exponential and stationary growth phases. Moreover, the photophysiological response of A. pseudogonyaulax showed little variation across varying light intensities, while light-harvesting pigments were significantly more abundant under low light conditions. This study additionally highlights considerable physiological variability between strains, emphasizing the importance of conducting laboratory experiments with several algal strains. A high physiological plasticity toward changing abiotic parameters points to a long-term establishment of A. pseudogonyaulax in northern European waters.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 169
    Publication Date: 2024-05-30
    Description: The toxin-producing dinoflagellate Alexandrium pseudogonyaulax has become increasingly abundant in northern European waters, replacing other Alexandrium species. A. pseudogonyaulax produces goniodomins and lytic substances, which can be cytotoxic toward other organisms, including fish, but we still know little about the environmental conditions influencing its growth and toxicity. Here, we investigated the impacts of different nitrogen sources and light intensities, common bottom-up drivers of bloom formation, on the growth and toxin content of three A. pseudogonyaulax strains isolated from the Danish Limfjord. While the growth rates were significantly influenced by nitrogen source and light intensity, the intracellular toxin contents only showed strong differences between the exponential and stationary growth phases. Moreover, the photophysiological response of A. pseudogonyaulax showed little variation across varying light intensities, while light-harvesting pigments were significantly more abundant under low light conditions. This study additionally highlights considerable physiological variability between strains, emphasizing the importance of conducting laboratory experiments with several algal strains. A high physiological plasticity toward changing abiotic parameters points to a long-term establishment of A. pseudogonyaulax in northern European waters.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 170
    Publication Date: 2024-06-06
    Description: Aim: The efficiency of animal-mediated seed dispersal is threatened by the decline of animal populations, especially in tropical forests. We hypothesise that large-seeded plants with animal-mediated dispersal tend to have limited geographic ranges and face an increased risk of extinction due to the potential decline in seed dispersal by large-bodied fruit-eating and seed-dispersing animals (frugivores). Location: Atlantic Forest, Brazil, South America. Taxon: Angiosperms. Methods: First, we collected dispersal-related traits (dispersal syndrome, fruit size, and seed size), growth form (tree, climber, and other) and preferred vegetation type (open and closed) data for 1052 Atlantic Forest plant species. Next, we integrated these with occurrence records, extinction risk assessments, and phylogenetic trees. Finally, we performed phylogenetic generalised least squares regressions to test the direct and interactive effects of dispersal-related traits and vegetation type on geographical range size. Results: Large-seeded species had smaller range sizes than small-seeded species, but only for species with animal-mediated dispersal, not for those dispersed by abiotic mechanisms. However, plants with abiotic dispersal had overall smaller range sizes than plants with animal-mediated dispersal. Furthermore, we found that species restricted to forests had smaller ranges than those occurring in open or mixed vegetation. Finally, at least 29% of the Atlantic Forest flora is threatened by extinction, but this was not related to plant dispersal syndromes. Main Conclusions: Large-seeded plants with animal-mediated dispersal may be suffering from dispersal limitation, potentially due to past and ongoing defaunation of large-bodied frugivores, leading to small range sizes. Other factors, such as deforestation and fragmentation, will probably modulate the effects of dispersal on range size, and ultimately extinction. Our study sheds light on the relationship between plant traits, mutualistic interactions, and distribution that are key to the functioning of tropical forests.
    Keywords: defaunation ; extinction risk ; frugivory ; phylogeny ; range size ; seed dispersal ; tropical forest
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
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  • 171
    Publication Date: 2024-06-06
    Description: Aim Species have different distribution patterns across the globe and among biogeographical regions. The Nearctic and Palaearctic regions share lineages because of their parallel biogeographic histories and ecological conditions. As the number of phylogenetic studies increases, there are more insights into past exchange events between these two regions and their effects on the current distribution of diversity. However, several groups have not been tested and an overall generalization is still missing. Here, we analyse the biogeographic history across multiple genera of odonates to elucidate a general process of species exchange, vicariance and species divergence between these two regions. Location The Holarctic, including the entire Nearctic and the East and West Palaearctic. Taxon 14 genera of Odonata (Insecta). Methods We reconstructed a time-calibrated phylogenetic tree for each genus to determine species relationships and divergence time using 3614 COI sequences of 259 species. Biogeographic ancestral range estimation was inferred for each phylogeny using BioGeoBEARS. Preferred habitat (lotic versus lentic) was established for each species. Results Exchange events were not restricted in time, direction or either lentic habitat or lotic habitat. Most genera crossed between both regions only once, and it was mainly across the Beringia, while three diverse anisopteran genera revealed multiple exchanges. Recent exchanges during the Pleistocene were associated with cold-dwelling and lentic species. Main Conclusions Our finding reveals the absence of a generalizable pattern of species exchange and divergence between the Nearctic and Palaearctic regions; instead, we found lineage-specific biogeographic patterns. This finding highlights the complexity of drivers and functional traits that shaped current diversity patterns. Moreover, it emphasizes that general conclusions cannot be formulated based on one single clade.
    Keywords: biogeography ; climate change ; damselflies ; dragonflies ; Holarctic
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
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  • 172
    Publication Date: 2024-06-17
    Description: In the period February–April 2021, seventeen energetic hours-long episodes of intense lava fountaining occurred at Mt. Etna, producing lava flows and ash plumes followed by heavy fallout. Clinopyroxene mesocrysts from these paroxysms show complex sector and concentric zoning patterns, with juxtaposition of Si-Mg-rich (Al-Ti-poor) and Si-Mg-poor (Al-Ti-rich) crystal layers. Clinopyroxene-based equilibrium thermobarometry and hygrometry define an overall crystallization path in the range of ~170–480 MPa, ~1060–1110 °C, and ~ 1.2–2.7 wt% H2O, with a main magma storage region estimated at depths of ~11–15 km. From this perspective, we observe that 2021 lava fountains were fed by hotter magmas of deeper origin with respect to those feeding 2011–2012 paroxysms. Zoning patterns of 2021 clinopyroxene mesocrysts formed in a vertically-extended plumbing system upon the effect of mixing phenomena and crystal recycling caused by recurrent inputs of fresh magmas into interconnected mushy reservoirs. Kinetic growth modeling constrains the formation of 2021 clinopyroxene mesocrysts over timescales of ~30–90 h and small degrees of undercooling ≤28 °C. Fesingle bondMg diffusion chronometry confirms that the time elapsed between the formation of clinopyroxene rim and magma eruption is utterly related to growth kinetics caused by pre-eruptive dynamic transfer of magma at crustal depths. Kinetic effects are exacerbated for clinopyroxene microlites/microcrysts forming at the syn-eruptive stage, when magma decompression, degassing, and cooling become more effective in the last 1.5 km below the vent of Mt. Etna. Kinetic growth modeling reveals that eruption dynamics within the conduit promote an exceptionally rapid disequilibrium growth of clinopyroxene microlites/microcrysts in only ~0.4–3.3 min upon large degrees of undercooling 〉60 °C. The resulting ascent velocity of 2021 magmas within the conduit is ~8–63 m/s, a factor of ~3 higher than the less energetic 2011–2012 paroxysms.
    Description: Published
    Description: 106710
    Description: OSV1: Verso la previsione dei fenomeni vulcanici pericolosi
    Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Description: JCR Journal
    Keywords: Magma dynamics at Mt. Etna ; Clinopyroxene zoning patterns ; P-T-H2O magma crystallization histories ; Magma ascent velocities ; petrology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 173
    Publication Date: 2024-06-17
    Description: Petrological studies of active volcanoes typically focus on eruptive phenomena occurring over long timescales of the order of days to years, aiming at identifying major changes in the physico-chemical state of magma during ascent towards the surface. Exceptionally, we present results from an integrated petrological and statistical approach based on the compilation of ∼5300 major and trace element data for glass and crystals, in combination with volcanological data on eruptive events occurred over timescales of minutes at Stromboli volcano (Sicily). On May 11, 2019, we had the rare opportunity to collect individual fresh fallout ash products from eighteen mostly consecutive explosions, erupted in a 2-h time span and, at the same time, to acquire continuous high frequency (50 Hz) infrared thermal data of the same explosions. Through video analysis, we observe that explosions were more frequent and ash-dominated at the southwestern crater area (SCA, 8–10 events/h) than at the northeastern crater area (NCA, 3–5 events/h), where coarser material was ejected. The statistical analysis of glass and plagioclase compositions reveals differences in the products erupted from the two crater areas. SCA explosions tapped less differentiated magmas (Mg#∼42–46, ∼257–365 LaN, ∼0.7–0.9 Eu/Eu*) in equilibrium with more anorthitic plagioclase cores (An∼72–88), whereas NCA area explosions are more differentiated (Mg#∼40–44, ∼286–387 LaN, ∼0.6–0.8 Eu/Eu*) and in equilibrium with less anorthitic plagioclase cores (An∼68–82). Thermometric calculations based on major and trace element clinopyroxene-plagioclase-melt equilibrium modeling highlight that the SCA explosions were statistically fed by hotter magmas in comparison to NCA explosions. Plagioclase-based diffusion modeling also indicates longer timescales for the dynamic ascent of NCA magmas, leading to preferential groundmass crystallization at the conduit walls and transition from sideromelane to tachylite groundmass textures. The final emerging picture is that in May 2019, concurrent normal eruptions from different crater areas at Stromboli were heralds of compositionally and thermally diverse magmas rising at different rates within the uppermost branched part of the conduit region. High frequency petrological investigations aided by statistical treatment of data have the potential to constrain dynamic conduit processes related to transient, explosive eruptions in persistently active volcanoes, thereby offering new insights on the interplay between magma dynamics, ascent timescales, and eruptive behavior.
    Description: Published
    Description: 107255
    Description: OSV1: Verso la previsione dei fenomeni vulcanici pericolosi
    Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Description: JCR Journal
    Keywords: High-temporal resolution petrology ; Stromboli volcano ; Thermobarometry ; Eruptive timescales ; Plumbing, conduit and eruptive dynamics ; Petrology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 174
    Publication Date: 2024-06-17
    Description: We present undercooling (∆T) experiments aimed at investigating the effect of growth kinetics on the textural and compositional evolution of clinopyroxene crystals growing from a high-K basalt erupted during the 2003 paroxysm of Stromboli volcano (Italy). The experiments were performed at P = 350 MPa, T = 1050–1210 °C, H2Omelt = 0–3 wt%, and fO2 = Ni-NiO + 1.5 buffer. An initial stage of supersaturation was imposed to the melt under nominally anhydrous (∆Tanh = 10–150 °C) and hydrous (∆Thyd = 25–125 °C) conditions. Afterwards, this supersaturation state was mitigated by melt relaxation phenomena over an annealing time of 24 h. Results show that plagioclase is the liquidus mineral phase of the high-K basalt at ∆Tanh = 10 °C and dominates the phase assemblage as the degree of undercooling increases. Conversely, clinopyroxene and spinel co-saturate the melt at ∆Thyd = 25 °C, followed by the subordinate formation of plagioclase. At ∆Tanh/hyd ≤ 50 °C, the textural maturation of clinopyroxene produces polyhedral crystals with {−111} (hourglass) and {hk0} (prism) sectors typical of a layer-by-layer growth mechanism governed by an interface-controlled crystallization regime. At ∆Tanh/hyd ≥ 75 °C, the attainment of dendritic and skeletal morphologies testifies to the establishment of diffusion-limited reactions at the crystal-melt interface. 3D reconstructions of synchrotron radiation X-ray microtomographic data reveal a composite growth history for clinopyroxene crystals obtained at ∆Tanh/hyd ≥ 95 °C. The early stage of melt supersaturation produces rosette-like structures composed of dendritic branches of clinopyroxene radiating from a common spinel grain, which acts as surface for heterogeneous nucleation. As diffusive relaxation phenomena progress over the annealing time, the elongate dendrites that constitute the inner crystal domain are partially infilled by the melt and develop skeletal overgrowths in the outer domain. With the increasing degree of undercooling, TAl and M1Ti cations are progressively incorporated in the lattice site of clinopyroxene at the expense of TSi and M1Mg cations. Because of the effect of H2Omelt on the liquidus depression and melt depolymerization, crystals obtained at ∆Thyd are also more enriched in TAl and M1Ti and depleted in TSi and M1Mg than those growing at ∆Tanh. The emerging picture is that the morphological and geochemical evolution of clinopyroxene is mutually controlled by the combined effects of melt supersaturation and relaxation phenomena. A new empirical relationship based on the cation exchange reactions in the lattice site of clinopyroxene is finally proposed to estimate the degree of undercooling governing the crystallization of augitic phenocrysts erupted during normal and violent explosions at Stromboli.
    Description: Published
    Description: 107327
    Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Description: JCR Journal
    Keywords: Clinopyroxene ; Undercooling ; Hourglass ; Crystallization ; Microtomography ; Stromboli ; Experimental Petrology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 175
    Publication Date: 2024-06-17
    Description: Thermobarometry provides a critical means of assessing locations of magma storage and dynamics in the lead-up to volcanic eruptions and crustal growth. A common approach is to utilise minerals that have compositions sensitive to changes in pressure and/or temperature, such as clinopyroxene, which is ubiquitous in mafic to intermediate magmas. However, clinopyroxene thermobarometry may carry significant uncertainty and require an appropriate equilibrium melt composition. In addition, the degree of magma undercooling (ΔT) affects clinopyroxene composition and zoning, with common sector zoning potentially obfuscating thermobarometry results. Here, we use a set of crystallisation experiments on a primitive trachybasalt from Mt. Etna (Italy) at ΔT = 25–233 °C, P = 400–800 MPa, H2O = 0–4 wt % and fO2 = NNO + 2, with clinopyroxene crystals defined by Al-rich zones (prisms and skeletons) and Al-poor zones (hourglass and overgrowths) to assess common equilibrium models and thermobarometric approaches. Under the studied conditions, our data suggest that the commonly applied Fe–Mg exchange (cpx-meltKdFe–Mg) is insensitive to increasing ΔT and may not be a reliable indicator of equilibrium. The combined use of DiHd (CaMgSi2O6 + CaFeSi2O6) and EnFs (Mg2Si2O6 + Fe2Si2O6) models indicate the attainment of equilibrium in both Al-rich and Al-poor zones for almost all investigated ΔT. In contrast, CaTs (CaAl2SiO6) and CaTi (CaTiAl2O6) models reveal substantial deviations from equilibrium with increasing ΔT, particularly in Al-rich zones. We postulate that this reflects slower diffusion of Al and Ti in the melt compared with Ca and Mg and recommend the concurrent application of these four models to evaluate equilibrium between clinopyroxene and melt, particularly for sector-zoned crystals. Thermobarometers calibrated with only isothermal–isobaric experiments closely reproduce experimental P–T at low ΔT, equivalent to natural phenocrysts cores and sector-zoned mantles. Models that also consider decompression experiments are most accurate at high ΔT and are therefore suitable for outermost phenocryst rims and groundmass microlites. Recent machine learning approaches reproduce P–T conditions across all ΔT conditions. Applying our experimental constraints to sector-zoned microphenocrysts and groundmass microlites erupted during the 1974 eccentric eruption at Mt. Etna, we highlight that both hourglass and prism sectors are suitable for thermobarometry, given that equilibrium is sufficiently tested for. The combination of DiHd, EnFs, CaTs and CaTi models identifies compositions closest to equilibrium with the bulk melt composition, and results in smaller differences in P–T calculated for hourglass and prism sectors compared with applying only DiHd and EnFs equilibrium models. This provides a framework to assess crystallisation conditions recorded by sector-zoned clinopyroxene crystals in mafic alkaline settings.
    Description: Published
    Description: egad074
    Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Description: JCR Journal
    Keywords: Experimental Petrology ; Petrology ; Clinopyroxene ; Thermobarometry ; Experimental Petrology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 176
    Publication Date: 2024-06-17
    Description: We investigated the Late Pleistocene-Holocene crustal vertical movements off the coast of Marzamemi village in SE Sicily, Italy. By using a Synchronous Correlation Approach (SCA), we analysed terraced landforms that characterize a submerged sector within one of Southern Italy's most seismically active regions. In this area, the emerging portion of the NE-SW oriented bulge of the African foreland structurally shapes the coastal and marine regions off Marzamemi village. Based on a newly created 17 km2 high-resolution bathymetric map generated from a Multibeam Echosounder (MBES) survey conducted in June 2021, we identified and examined four main paleo-shorelines identifying four submerged terraces. Terraced landforms play a crucial role in reconstructing Quaternary glacial and interglacial stages, offering insights into associated sea level fluctuations. Through the application of the SCA, our goal is to refine the chronology of these recently mapped and submerged marine terraces off the Marzamemi village, thereby contributing to the calculation of associated rates of crustal vertical movements. We demonstrate that these rates persist constantly throughout the Late Pleistocene-Holocene epoch, suggesting overall tectonic stability, with a slight and likely local fault-related subsidence. We explore a few chronology scenarios, raising questions about whether these submerged marine terraces are indeed recording the Late Pleistocene-Holocene limit or not. This research contributes to a better understanding of the geological dynamics in this region and sheds light on the potential factors influencing coastal landscape development over time.
    Description: Published
    Description: 107326
    Description: OST2 Deformazione e Hazard sismico e da maremoto
    Description: JCR Journal
    Keywords: Submarine geomorphology ; Submerged marine terraces ; Marine terraces chronology ; Late Quaternary ; Sea Level Change ; Crustal vertical movements
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 177
    Publication Date: 2024-06-17
    Description: Yedoma is a permafrost deposit widely distributed across the Arctic and found exclusively within the unglaciated regions in northern Siberia, Alaska, and the Yukon, which are the core regions of Beringia. Yedoma deposits accumulated during the late Pleistocene Stage and are characterized by their predominantly fine-grained texture and association with syngenetic perma-frost formation. The very high ground ice content is most commonly present as pore ice and wedge ice that formed contemporaneously with sediment deposition. In the last decade, research has transitioned from debates about the origin of the Yedoma deposits towards increasing attention on the large carbon and nitrogen pools in Yedoma, their vulnerability to thaw, and increasing mobilization as the climate has warmed across the Arctic. In addition to classical cryolithological and sedimentological research, new methods such as stable isotope paleoclimate reconstruction and ancient sedimentary DNA studies have been more widely applied to better understand the characteristics of Yedoma deposits and helped emphasize their value as archives of Quaternary climate and paleoecological conditions during Ice Age Beringia.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Inbook , peerRev
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  • 178
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    Unknown
    Elsevier
    In:  EPIC3Earth and Planetary Science Letters, Elsevier, 640, pp. 118801-118801, ISSN: 0012-821X
    Publication Date: 2024-06-17
    Description: Carbon cycle models used to calculate the marine reservoir age of the non-polar surface ocean (called Marine20) out of IntCal20, the compilation of atmospheric C, have so far neglected a key aspect of the millennial-scale variability connected with the thermal bipolar seesaw: changes in the strength of the Atlantic meridional overturning circulation (AMOC) related to Dansgaard/Oeschger and Heinrich events. Here we implement such AMOC changes in the carbon cycle box model BICYCLE-SE to investigate how model performance over the last 55 kyr is affected, in particular with respect to available 14C and CO2 data. Constraints from deep ocean 14C data suggest that the AMOC in the model during Heinrich stadial 1 needs to be highly reduced or even completely shutdown. Ocean circulation and sea ice coverage combined are the processes that almost completely explain the simulated changes in deep ocean 14C age, and these are also responsible for a glacial drawdown of ∼60 ppm of atmospheric CO2. We find that the implementation of abrupt reductions in AMOC during Greenland stadials in the model setup that was previously used for the calculation of Marine20 leads to differences of less than ±100 14C yrs. The representation of AMOC changes therefore appears to be of minor importance for deriving non-polar mean ocean radiocarbon calibration products such as Marine20, where atmospheric carbon cycle variables are forced by reconstructions. However, simulated atmospheric CO2 exhibits minima during AMOC reductions in Heinrich stadials, in disagreement with ice core data. This mismatch supports previous suggestions that millennial-scale changes in CO2 were probably not driven directly by the AMOC, but rather by biological and physical processes in the Southern Ocean and by contributions from variable land carbon storage.
    Repository Name: EPIC Alfred Wegener Institut
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  • 179
    Publication Date: 2024-06-24
    Description: Organic carbon (OC) in permafrost interacts with the mineral fraction of soil and sediments, representing 〈 1% to ~80% of the total OC pool. Quantifying the nature and controls of mineral-OC interactions is therefore crucial for realistic assessments of permafrost-carbon-climate feedbacks, especially in ice-rich regions facing rapid thaw and the development of thermo-erosion landforms. Here, we analyzed sediment samples from the Batagay megaslump in East Siberia, and we present total element concentrations , mineralogy, and mineral-OC interactions in its different stratigraphic units. Our findings indicate that up to 34 ± 8% of the OC pool interacts with mineral surfaces or elements. Interglacial deposits exhibit enhanced OC-mineral interactions, where OC has undergone greater microbial transformation and has likely low degradability. We provide a first-order estimate of ~12,000 tons of OC mobilized annually downslope of the headwall (i.e., the approximate mass of 30 large aircrafts), with a maximum of 38% interacting with OC via complexation with metals or associations to poorly crystalline iron oxides. These data imply that over one-third of the OC exposed by the slump is not readily available for mineralization, potentially leading to prolonged OC residence time in soil and sediments under stable physicochemical conditions.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 180
    facet.materialart.
    Unknown
    Elsevier
    In:  Ecohydrological Complexity from Catchment to Coast
    Publication Date: 2024-05-17
    Description: The Mekong River Basin: Ecohydrological Complexity from Catchment to Coast, Volume Three presents real facts, data and predictions for quantifying human-induced changes throughout the Mekong watershed, including its estuaries and coasts, and proposes solutions to decrease or mitigate the negative effect and enable sustainable development. This is the first work to link socio–ecological interaction study over the whole Mekong River basin through the lens of ecohydrology. Each chapter is written by a leading expert, with coverage on climate change, groundwater, land use, flooding drought, biodiversity and anthropological issues. Human activities are enormous in the whole watershed and are still increasing throughout the catchment, with severe negative impacts on natural resources are emerging. Among these activities, hydropower dams, especially a series of 11 dams in China, are the most critical as they generate massive changes throughout the system, including in the delta and to the livelihoods of millions of people and they threaten sustainability.
    Type: info:eu-repo/semantics/book
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  • 181
    Publication Date: 2023-01-12
    Description: The surveillance of the Neapolitan volcanic area (Mt. Vesuvius, the Phlegrean Fields and the island of Ischia) represents the principal activity of the Osservatorio Vesuviano. Such an activity is carried out also through the study of ground deformations. This study deals with the use of the GPS as a powerful topographic technique. In the last two years, three GPS networks in the above mentioned area were established, with 8 vertices at Mt. Vesuvius, 20 vertices in the Island of Ischia and 30 vertices in the Phlegrean Fields. In Mt. Vesuvius area a GPS test was carried out, in order to verify the possibility of the installation of a network of GPS permanent stations. In the island of Ischia, three diferent GPS techniques (Static, Fast Static and RTK-Real Time Kinematics) have been used to get a first set of coordinates and to carry out a comparison between these in small extension areas. GPS data of the Phlegrean Fields are still in processing. The results for Mt. Vesuvius area and the island of Ischia are hereby presented and discussed.
    Description: Osservatorio Vesuviano - Napoli, Italy DISTART - Università di Bologna, Italy Università della Calabria - Cosenza, Italy Dipartimento di Costruzioni e Trasporti - Università di Padova, Italy
    Description: Published
    Description: 705-711
    Description: 2V. Struttura e sistema di alimentazione dei vulcani
    Description: JCR Journal
    Keywords: GPS, Geodetical Networks, Static, Fast Static and RTK Survey ; 04.03. Geodesy
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 182
    Publication Date: 2023-01-13
    Description: We demonstrate a synchronous correlation technique to determine the chronology of Quaternary palaeoshorelines to test proposed relationships between tectonics, climate and sea-level change. The elevations of marine palaeoshorelines in Calabria around the active Vibo normal fault have been measured from TIN DEM 10 m data and fieldwork and correlated with global sea-level curves. A synchronous correlation method and new U/Th dates are used to ascertain how the slip-rate on the fault relates to uplift rates across the region. Regional uplift, possibly associated with subduction along the Calabrian trench or due to the cumulative effect of closely-spaced active normal faults, is rapid enough to uplift even the hangingwall of the Vibo normal fault; the actual value for the rate of background uplift can only be ascertained once the rate of slip on the Vibo fault is subtracted. Synchronous correlation of multiple palaeoshorelines sampled along 29 elevation profiles with global sea-levels shows that the resultant uplift rate (background uplift minus local hangingwall subsidence) is constant through time from 0 to 340 ka, and not fluctuating by a factor of 4 as previously suggested. The uplift rate increases from 0.4 mm/yr at the centre of the hangingwall of the fault to 1.75 mm/yr in the hangingwall in the vicinity of the fault tip. Palaeoshorelines can be traced from the hangingwall to the footwall around the fault tip and hence correlated across the fault. The throw-rate on the fault averaged over 340 ka decreases from a maximum at the centre of the fault (1 mm/yr) to zero at the tip. This gradient in throw-rate explains the spatial variation in resultant uplift rates along the fault. We interpret the 1.75 mm/yr resultant uplift rate at and beyond the fault tip as the signature of a regional uplift, presumably related to subduction, although we cannot exclude the possibility that other local faults influence this uplift; the lower uplift rates in the hangingwall of the fault are due to interaction between “regional” uplift and subsidence associated with the local active normal faulting. We discuss (a) how our synchronous correlation technique should trigger a re-appraisal of palaeoshoreline chronologies worldwide, and (b) the implications for the tectonics and seismic hazard of Calabria, suggesting that perturbations in the uplift-rate field are a key criterion to map the locations of active faults, their deformation rates, and hence seismic hazard above subduction zones.
    Description: Published
    Description: 169-187
    Description: 2T. Deformazione crostale attiva
    Description: JCR Journal
    Keywords: Active faults; Palaeoshorelines; Quaternary sea-level; Tectonics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 183
    Publication Date: 2023-01-13
    Description: The Cotentin Peninsula (Normandy, France) displays sequences of marine terraces and rasas, the latter being wide Late Cenozoic coastal erosion surfaces, that are typical of Western European coasts in Portugal, Spain, France and southern England. Remote sensing imagery and field mapping enabled reappraisal of the Cotentin coastal sequences. From bottom to top, the N Cotentin sequence includes four previously recognized Pleistocene marine terraces (T1 to T4) at elevations 〈 40 m as well as four higher and older rasas (R1 to R4) reaching 200 ± 5 m in elevation. Low-standing marine terraces are not observed in the central part of the Peninsula and a limited number of terraces are described to the south. The high-standing rasas are widespread all over the peninsula. Such strandline distributions reveal major changes during the Late Cenozoic. Progressive uplift of an irregular sea-floor led to subaerial exposure of bathymetric highs that were carved into rocky platforms, rasas and marine terraces. Eventually, five main islands coalesced and connected to the mainland to the south to form the Cotentin Peninsula. On the basis of previous dating of the last interglacial maximum terrace (i.e. Marine Isotopic Stage, MIS 5e), sequential morphostratigraphy and modelling, we have reappraised uplift rates and derived: (i) mean Upper Pleistocene (i.e. since MIS 5e ~ 122 +/− 6 ka, i.e. kilo annum) apparent uplift rates of 0.04 ± 0.01 mm/yr, (ii) mean Middle Pleistocene eustasy-corrected uplift rates of 0.09 ± 0.03 mm/yr, and (iii) low mean Pleistocene uplift rates of 0.01 mm/yr. Extrapolations of these slow rates combined with geological evidence implies that the formation of the sequences from the Cotentin Peninsula occurred between 3 Ma (Pliocene) and 15 Ma (Miocene), which cannot be narrowed down further without additional research. Along the coasts of Western Europe, sequences of marine terraces and rasas are widespread (169 preserve the MIS 5e benchmark). In Spain, Portugal, S England and other parts of western France, the sequences morphostratigraphy is very similar to that of Cotentin. The onset of such Western European sequences occurred during the Miocene (e.g. Spain) or Pliocene (e.g. Portugal). We interpret this Neogene-Quaternary coastal uplift as a symptom of the increasing lithospheric compression that accompanies Cenozoic orogenies.
    Description: Published
    Description: 338-356
    Description: 2T. Deformazione crostale attiva
    Description: JCR Journal
    Keywords: Cotentin and Western Europe; Marine terrace; Neogene and Quaternary coastal uplift; Rasa
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 184
    Publication Date: 2023-01-18
    Description: This work describes the development of an underwater anti-intrusion system based on a magnetometer self-informed network, whose purpose is to detect the presence of threats in the proximity of critical infrastructures (e.g, terrorist divers in harbours). In this context, the magnetic network fills the gaps of sonar systems at the critical boundaries of the water volume to be controlled (sea bed, docks, …), where acoustic performances deteriorate due to reflections and attenuations. The system operates in a port-protection scenario, characterized by a medium-high environmental magnetic noise that can hide the diver signal (a diver is a weak, quasi-point-like, moving source). The magnetometer network processes two inputs: the environmental magnetic noise and a signal including the target magnetic signal superimposed to the same noise; the frequencies of a diver signal lie within the noise band, hence frequency filtering proves inadequate for noise removal. The basic idea underlying the system is to measure and use the noise itself to filter the overall signal; measuring noise supports a background-subtraction process that allows to extract the target signal and therefore detect the threat presence. The effectiveness of the procedure depends on the positions of magnetometers: sensors must be close enough to one another to measure the common background noise, and, at the same time, should be distant enough from one another so that just one sensor can measure the target signal. To generate alarms when a threat is detected, a real-time software application processes data and activates a visual and acoustic alarm upon identification of a magnetic anomaly. Sea trials carried out in port areas provided extremely satisfactory results in the detection of intruders. The paper presents experimental results obtained during the method validation tests, when intruders were moving in the surrounding undersea environment.
    Description: Published
    Description: 104743
    Description: 1A. Geomagnetismo e Paleomagnetismo
    Description: 3A. Geofisica marina e osservazioni multiparametriche a fondo mare
    Description: 7SR AMBIENTE – Servizi e ricerca per la società
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 185
    Publication Date: 2023-01-18
    Description: The structure of a caldera may influence its activity, making its understanding crucial for hazard assessment. Here, we analysed high-resolution seismic profiles in the Campi Flegrei (southern Italy) offshore sector. We recognised two main fault systems, including those associated with the formation of the caldera and those affecting the resurgent dome. The former system comprises three broadly concentric fault zones (inner, medial and outer ring fault zones) depicting a nested caldera geometry. Considering the relations between faults and seismic units that represent the marine and volcaniclastic successions filling the caldera, all ring faults were formed during the Campanian Ignimbrite eruption (40 ka) and subsequently reactivated during the Neapolitan Yellow Tuff eruption (15 ka). In this last caldera-forming event, the inner and medial fault zones accommodated most of the collapse and were episodically reactivated during the younger volcano-tectonic activity. The second fault system occurs in the apical zone of the resurgent dome and comprises dominantly high-angle normal faults that are mainly related to the volcanotectonic collapse that followed the Agnano-Monte Spina Plinian eruption (4.55 ka). Finally, we provide a volcano-tectonic evolutionary model of the last 40 kyr, considering the interplay among ring and dome faults activity, volcaniclastic sedimentation, ground deformation and sea-level changes.
    Description: Published
    Description: 104723
    Description: 2V. Struttura e sistema di alimentazione dei vulcani
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 186
    Publication Date: 2023-01-19
    Description: Argnani (2021, hereinafter ARG2021) commented on the paper by Barreca et al. (2021, hereinafter BRC2021) titled: “The Strait of Messina: Seismotectonics and the source of the 1908 earthquake”, in which a new seismotectonic model and constraints on the possible source fault (the so-called W-Fault) for the 1908 disastrous seismic event were provided. Results from BRC2021 led to a revision of most of the previously published papers on the issue. ARG2021 commented both on the recent activity of the W-Fault and even about its existence in the offshore. In fact, according to the author's inferences: “it may belong to a fault system that is no longer active” and, contradictorily, “the offshore occurrence of the W-Fault is not supported by the data”. The comment is mostly based on a new tectonic interpretation that the author performed directly on the BRC2021 figures, where the offshore portion of the W-fault is illustrated. In this reply, we demonstrate that the interpretation provided by ARG2021 is affected by several oversights that led the author to erroneous conclusions about the issue. Accordingly, we strongly confirm both the occurrence of the W-Fault in the offshore and the present-day activity of this structure, the only active fault capable of producing large earthquakes in the Strait of Messina area.
    Description: Published
    Description: 103962
    Description: 3T. Fisica dei terremoti e Sorgente Sismica
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 187
    Publication Date: 2023-06-12
    Description: While understanding feeding preferences of herbivores and carnivores is of major importance in ecology, we still know very little on the sensitivity of different functional groups to suboptimal stoichiometric resource quality. Here, we apply concepts of ecological stoichiometry to shed light on differences in the nutritional requirements of herbivores and carnivores, and to make predictions on the influence of suboptimal resource stoichiometric quality on the fitness of these different consumers to. Herbivores generally experience more variation in the quality of their resource than carnivores do, and these differences have likely shaped the extent to which coping mechanisms have evolved. Consequently, we expect 1) herbivores to maintain their stoichiometric homeostasis over a broader range of resource stoichiometry than carnivores, 2) the threshold elemental ratio (TER), i.e. the dietary carbon to nutrient ratio which maximizes fitness, of herbivores to be higher than that of carnivores, 3) a narrower and sharper knife-edge response in carnivores than herbivores and 4) asymmetric knife-edge responses indicating a higher sensitivity to the diet quality that consumers are not used to dealing with, namely nutrient limitation in carnivores and nutrient excess in herbivores. Our study poses that documenting the ranges of resource quality where consumer fitness declines in diverse organisms is a very promising avenue to increase our understanding of community composition and food web functioning.
    Repository Name: EPIC Alfred Wegener Institut
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  • 188
    Publication Date: 2023-03-30
    Description: Seismic Probabilistic Tsunami Hazard Assessment (SPTHA) is a framework for calculating the probability that seismically induced tsunami waves exceed a specific threshold height, over a given time span and a specific region (i.e. regional SPTHA) or site (i.e. local SPTHA). To account for the uncertainty of the possible sources, SPTHA must integrate the results of a large number of computationally demanding tsunami simulations In this work, we innovatively use Parallel density scanned Adaptive Kriging (P-ds AK) to overcome the computational efficiency challenge of local SPTHA within a framework that consists in modeling/retrieving the full spectrum of possible earthquake triggering events at the regional level, filtering sources not relevant for the target, adopting a clustering procedure to select “representative scenarios” for inundation modeling, and, finally, adopt P-ds AK to identify the clusters centroids that most influence the hazard intensity (i.e., wave height) in the areas of interest. This approach is applied in the area of the oil refinery located in Milazzo (Italy). The application shows a consistent reduction of the number of high-resolution tsunami simulations required for the evaluation of the hazard curves over a set of inland Point of Interest (PoIs), either concentrated in one specific area or distributed along the coast.
    Description: Published
    Description: 108441
    Description: 6T. Studi di pericolosità sismica e da maremoto
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 189
    Publication Date: 2023-03-31
    Description: The Colli Albani volcanic district emplaced huge pyroclastic-flow deposits up to 20 m thick in the southeastern suburbs of the City of Rome. The soil quality onto the gentle slopes of the Colli Albani has certainly contribute to the growth of Ancient Rome, a city with one million inhabitants as early as 2000 years ago. Interestingly, the Colli Albani soils developed on K-foiditic pyroclastic rocks with peculiar low silica, high alkali and high CaO composition. In the past, the productivity of the Colli Albani soils was maximized without the understanding of the unique physical, chemical, and mineralogical properties of these soils; now an in-depth knowledge of the Colli Albani soils is necessary to respond to the current and increasingly demand of sustainable soil use.
    Description: Published
    Description: 105430
    Description: 6A. Geochimica per l'ambiente e geologia medica
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 190
    Publication Date: 2023-03-31
    Description: Through the analysis of seven 15 to 30 m deep boreholes drilled in the western sector of the Circus Maximus we reconstruct the aggradational history of one main tributary valley of the Tiber River in Rome, the Murcia Valley ( Vallis Murcia) .
    Description: Published
    Description: 44-53
    Description: 5A. Ricerche polari e paleoclima
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 191
    Publication Date: 2023-03-31
    Description: The Acheulian and early Middle Paleolithic assemblages from Torre in Pietra (Latium, Italy) were never securely dated before. We have now 49 Ar/39Ar dates and ESR-U-series dates which support corrrelations to marine isotope stages. The Acheulian (previously correlated to MIS 9) is now dated to MIS 10 while the Middle Paleolithic is dated to MIS 7. The analysis and comparisons of the two assemblages and comparisons with the Acheulian small tools of Castel di Guido show a culturally transmitted pattern of technology that was shared by the craftsmen of the region.
    Description: Published
    Description: 1-11
    Description: 5A. Ricerche polari e paleoclima
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 192
    Publication Date: 2023-04-04
    Description: With the aim of deepening our understanding of deep-seated fluids upwelling and mixing in large regional aquifers, we performed a hydrogeochemical study of twenty-two springs in the Contursi area (upper Sele river valley, southern Apennines) by means of the measurements of chemical-physical parameters, major ions, trace elements, and stable and radioactive isotopes. Besides, we realized two updated geo-structural cross-sections inorder to reconstruct the groundwater flowpath in the study area. The hydrogeochemical composition, as well a the water temperature allow to identify-three main groups of groundwater: Cold and Low salinity Groundwater (CLGW), Intermediate Salinity Groundwater (ISGW), and Thermal Salinity Groundwater (TSGW). The CLGW group, mostly emerging at the boundary of carbonate aquifers, is characterized by alkaline earth-bicarbonate hydrofacies. Instead, ISGW and TSGW, situated in the inner zone of the valley, show gradually a hydrogeochemical evolution towards sodium-chloride type hydrofacies domain with the highest salinity value. Stable isotope (δ18O-δD) of CLGW reveal the local meteoric origin of groundwater, while isotopic signatures of ISGW and TSGW is associated with the deep fluids inflow. CLGW hydrogeochemistry is clearly related to dissolution of carbonate rocks. On the other hand, for ISGW and TSGW an additional contribution from evaporitic rocks is supported by saturation indices values (gypsum and anhydrite) and validated by isotopic signature of dissolved sulphate (δ34S-δ18O). The application of two models based on tritium data (i.e., the piston-flow and well-mixed reservoir) attributes longer and deeper groundwater flowpaths to TSGW. Through geothermometric calculations (e,g., K-Mg and SiO2-quartz), the equilibrium temperature of deep fluids reservoir is also extrapolated (i.e., 75–96 ◦C). The results of the adopted hydrogeochemical multi-component approach allowed us to propose an interpretative model of groundwater flowpath for the Contursi area, where deep-seated tectonic discontinuities play a significant role for the upwelling of saline deep thermal fluids in shallow aquifers.
    Description: Published
    Description: 129258
    Description: 9T. Geochimica dei fluidi applicata allo studio e al monitoraggio di aree sismiche
    Description: JCR Journal
    Keywords: fluids ; earthquakes ; crust ; geochemistry
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  • 193
    facet.materialart.
    Unknown
    Wiley
    In:  EPIC3PAMM, Wiley, 22(1), ISSN: 1617-7061
    Publication Date: 2023-10-24
    Description: 〈jats:title〉Abstract〈/jats:title〉〈jats:p〉Ice shelves are large floating ice masses, that are formed when glaciers are becoming afloat at the margin of ice sheets. One dominating mass loss mechanism of ice shelves is calving, describing the detachment of icebergs at the front. Ice shelves stabilize inland ice glaciers due to buttressing. If the stabilizing effect of an ice shelf vanishes because of disintegration or thinning, the corresponding glacier accelerates resulting in sea level rise.〈/jats:p〉〈jats:p〉To describe calving and disintegration of ice shelves, it is important to investigate fracture propagation in ice. A powerful method in fracture mechanics is the phase field method which is based on Griffith's theory. It approximates cracks in a diffuse manner by using a continuous scalar field. We propose a phase field fracture model for ice considering its characteristic material properties. The material behavior of ice depends on the considered time scales. On short time scales it behaves like a solid and while it acts like a fluid on long time scales, which classifies it as a viscoelastic material of Maxwell type. This has been verified by observations. The phase field method allows us to simulate typical fracture situations of ice shelves in Antarctica and Greenland.〈/jats:p〉
    Repository Name: EPIC Alfred Wegener Institut
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  • 194
    Publication Date: 2023-10-25
    Description: Boron (B) and Lithium (Li) concentrations were studied in the Platani river, one of the most important catchments of South-Central Sicily which is under semiarid climatic conditions for roughly eight months to a year. In this area, evaporites result in potential B and Li sources for surface waters. Results from river waters have measured ionic strength values between 0.1 and 4.54 M. B and Li distributions in these waters were studied in colloidal (CF, extracted by ultrafiltration from the 0.45 μm filtrate) and total dissolved (TDF) fractions and in fractions extracted from corresponding riverbed sediments, according to changes of the B/Li ratio. In river waters, CF and TDF showed very similar B/Li values, suggesting that only negligible fractionation occurs between Li and B in the aqueous phase. Similar evidence was observed between B/Li values in TDF and the labile sediment fraction, whereas an inverse relationship arose between B/Li values in TDF and in the easily reducible sediment fraction. This relationship indicates that Mn oxy-hydroxides preferentially react with aqueous B species relative to Li at the riverbed sediment interface. The extent of the B-Mn oxy-hydroxide reactions is influenced by the ionic strength, so that only B/Li values below 4 are measured in river waters with ionic strength values above 0.5 M. Comparing B/Li and ionic strength values measured in the Platani river with those from oxic brines worldwide, the same preferential B removal relative to Li is observed. This evidence suggests that B is removed as positively-charged borate ion-pairs, formed in the aqueous phase under higher ionic strength conditions, reacting with negatively charged surfaces of Mn oxy-hydroxides. The observed B reactivity relative to Li could be exploited to bring down the B excess from natural or waste waters, allowing the natural reactions with Mn oxy-hydroxides to take place under natural conditions.
    Description: Published
    Description: 135509
    Description: 1T. Struttura della Terra
    Description: JCR Journal
    Keywords: B/Li ratio; Ionic strength; Mine drainage; Mn-oxyhydroxides; Salt minerals
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 195
    Publication Date: 2023-10-24
    Description: Although explosivity is linked with high decompression rates induced by magma ascent, the quantitative relationships between decompression rate and eruption energy have yet to be properly assessed, especially for open-conduit basaltic volcanoes, where ordinary weak activity can rapidly evolve into more intense eruptions. Here, we selected three eruptions of different explosivity from Mt. Etna’s recent activity to study the relationships between the observed explosive intensities and decompression rates determined through diffusion chronometry, which is based on modeling volatile diffusion along olivine-hosted melt embayments. The approach used in this study has provided important indications on differences in the timescales of decompression-driven degassing for magmas emitted with markedly distinct eruptive dynamics, starting from similar physical and chemical conditions of the magmas involved in the three eruptions. The intense paroxysmal activity at Voragine Crater on December 3, 2015, was fostered by high decompression rate (∼0.36-0.74 MPa/s), slightly higher than in the less energetic paroxysm that occurred on February 19, 2013, at New South-East Crater (NSEC) (∼0.14-0.29 MPa/s). Decompression rates of magmas emitted during lava fountaining are one order of magnitude greater than values obtained for the mild flank eruption that occurred in December 2018 (∼0.045-0.094 MPa/s). Our results indicate that degassing kinetics controlled the intensity of activity at Mt. Etna, thus suggesting that the explosivity does not depend exclusively on the degree of overpressurization of the shallowest reservoir due to injection of gas from the deepest levels of the plumbing system.
    Description: Published
    Description: 117821
    Description: 4V. Processi pre-eruttivi
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 196
    Publication Date: 2023-10-24
    Description: •Anthropogenic CO2 flux can be estimated by stable isotopic surveying. •Gas emissions from human activities force the atmospheric CO2. •The monitoring of stable isotopes allows identifying the CO2 sources in the air. •Several tons per day of CO2 flow through the geosphere in urban zones. •Transient in the air CO2 occurs owing to changes in weather variables.
    Description: Atmospheric carbon dioxide (CO2) concentrations increase due to volcanic emissions, diffuse degassing from fault zones, and various human-caused gas emissions, especially in densely populated urban zones, which play a pivotal role in the ongoing climate change. This study aims to examine changes in the concentration and stable isotopic composition of atmospheric CO2. A laser-based analyzer provided the δ13C and δ18O values based on concentration measurements for various CO2 isotopologues. Multiple linear regression (MLR) showed that almost 30% of the atmospheric CO2 changes are caused by weather variations, while ~70% of the changes involve CO2 from various gas sources related to human activities. The Keeling plot approach was used to identify the isotopic signature of the extra CO2, which points to the gas produced by hydrocarbon combustion. An isotopic mass balance model was designed to show the relation between excess atmospheric CO2 and the flux of human-related gas emissions. Calculating the CO2 flux in the atmosphere based on this isotopic mass balance model showed that several tons of CO2 move daily between geospheres. This study shows that surveying atmospheric CO2 in urban zones allows quantifying the CO2 emissions from various sources.
    Description: Published
    Description: 119302
    Description: 6A. Geochimica per l'ambiente e geologia medica
    Description: 1TR. Georisorse
    Description: 1IT. Reti di monitoraggio e sorveglianza
    Description: 2IT. Laboratori analitici e sperimentali
    Description: 6IT. Osservatori non satellitari
    Description: JCR Journal
    Keywords: CO2 flux ; Carbon stable isotopes ; Oxygen isotope composition ; Atmospheric CO2 ; Geochemical modeling ; Gas Hazard ; Stable isotopes ; Isotopes ; 01.01. Atmosphere ; 04.08. Volcanology ; environmental geochemistry
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  • 197
    facet.materialart.
    Unknown
    Elsevier
    In:  EPIC3Ecological Indicators, Elsevier, 156, pp. 111129-111129, ISSN: 1470-160X
    Publication Date: 2023-11-23
    Description: The performance of herbivore consumers in freshwater ecosystems is influenced by food quality and quantity, which are crucial factors in understanding energy flow. However, the comprehensive effects of these factors on consumer growth based on natural food research remain unclear. To address this gap, we conducted a growth experiment culturing the Cladocera Daphnia similis in natural lake water collected from 30 subtropical lakes. Our results showed that the seston concentration (SC), seston phosphorus (seston P), and seston carbon: phosphorus ratio (seston C:P, in moles) were the most important factors in influencing the growth rate of D. similis according to the Random Forest model. Specifically, the growth rate of D. similis was significantly positive correlated with SC and seston P, and significantly negative correlated with seston C:P. D. similis exhibited the optimal growth performance within the seston C:P range of 32.8 to 69.8, with a sharp decline in growth rate observed at a break point of seston C:P of 70. The combined effect of food quality and quantity on growth rate was that higher SC (≥0.26 mg C/L), lower seston C:P (≤69.80), and higher P (≥0.11 mmol/g) were associated with significantly higher growth rates. Additionally, the growth rate increased significantly with the biomass of cryptophyte, indicating the importance of food composition. Our study shows that the growth rate of D. similis is co-affected by the quality and quantity of natural food. SC, seston C:P, seston P and algae composition are reliable indicators for assessing the growth rate of consumer in freshwater ecosystems. The inhibitory effect of low C:P on consumer growth should be applied with caution when assessing the development of herbivore consumers in natural lakes.
    Repository Name: EPIC Alfred Wegener Institut
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  • 198
    facet.materialart.
    Unknown
    Elsevier
    In:  EPIC3Regional Studies in Marine Science, Elsevier, 66, pp. 103147-103147, ISSN: 2352-4855
    Publication Date: 2023-11-23
    Description: Zooplankton communities vary in space and time. Their composition is strongly influenced by lower trophic levels that are dependent on the availability of light and nutrients. As all marine ecosystems are relying on zooplankton as intermediate trophic step between primary production and higher trophic levels, changes in the zooplankton community composition and biomass can cascade through the food web with important impacts on fish communities and through that on fisheries yields. An intense fisheries exist around the Falkland Islands in the SW Atlantic Ocean, around 51° S, but to the best of our knowledge, no previous study has to date investigated the seasonal variation in zooplankton community composition in these waters. We show that copepods (39.2%), the larvae of the anomurid Grimothea gregaria (33.1%) and euphausiids (10.9%) dominate the local mesozooplankton community by biomass. All species showed seasonal patterns, including ontogenetic behaviour of G. gregaria migrating to deeper waters with development, which were significantly explained by temperature (p 〈 0.001). While overall biomass significantly decreased with distance from shore (p 〈 0.001), mesozooplankton diversity was highest at 30 km from shore. The presented study is the first assessment of the mesozooplankton biomass off the Falkland Islands and provides a first baseline to aid future ecosystem studies in the context of ecosystem based fisheries management in the region.
    Repository Name: EPIC Alfred Wegener Institut
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  • 199
    Publication Date: 2023-12-11
    Description: Phytoplankton are responsible for about 90% of the oceanic primary production, largely supporting marine food webs, and actively contributing to the biogeochemical cycling of carbon. Yet, increasing temperature and pCO2, along with higher dissolved nitrogen: phosphorus ratios in coastal waters are likely to impact phytoplankton physiology, especially in terms of photosynthetic rate, respiration, and dissolved organic carbon (DOC) production. Here, we conducted a full-factorial experiment to identify the individual and combined effects of temperature, pCO2, and N : P ratio on the antioxidant capacity and carbon metabolism of the diatom Phaeodactylum tricornutum. Our results demonstrate that, among these three drivers, temperature is the most influential factor on the physiology of this species, with warming causing oxidative stress and lower activity of antioxidant enzymes. Furthermore, the photosynthetic rate was higher under warmer conditions and higher pCO2, and, together with a lower dark respiration rate and higher DOC exudation, generated cells with lower carbon content. An enhanced oceanic CO2 uptake and an overall stimulated microbial loop benefiting from higher DOC exudation are potential longer-term consequences of rising temperatures, elevated pCO2 as well as shifted dissolved N : P ratios.
    Repository Name: EPIC Alfred Wegener Institut
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  • 200
    Publication Date: 2023-12-11
    Description: Marine community diversity surveys require a reliable assessment to estimate ecosystem functions and their dynamics. For these, non-invasive environmental DNA (eDNA) metabarcoding is increasingly applied in zoological studies to complement or even replace traditional morphological identification methods. However, uncertainties remain about the accuracy of the diversity detected with eDNA to capture the actual diversity in the field. Here, we validate the reliability of eDNA metabarcoding in identifying metazoan biodiversity in highly dynamic marine waters of the North Sea. We analyzed biodiversity from water (eDNA) and zooplankton samples with cytochrome c oxidase subunit 1 (COI) and 18S rRNA (18S) metabarcoding at Helgoland Roads and validated the optimal molecular resolution by morphological and molecular zooplankton identification (metabarcoding) with the result of merely a few false-negative detections. eDNA and zooplankton metabarcoding resolved 354 species from all major and in total 16 metazoan phyla. This molecular genetic species inventory overlapped by 95.9% (COI) and 81.9% (18S) with published inventories of local, morphologically identified species, among them neozoa and rediscovered species. Even though half of all species were detected by both eDNA and zooplankton metabarcoding, the methods differed significantly in their detected diversity. eDNA metabarcoding performed very well in cnidarians and annelids, whereas zooplankton metabarcoding identified higher numbers of fish and malacostraca. Species assemblages significantly differed between the individual sampling events and the cumulative number of identified species increased steadily over the sampling period and did not reach saturation. About a third of the species were detected only once while a core community of 22 species was identified continuously. Our study confirms eDNA metabarcoding to be a powerful tool to identify and analyze North Sea fauna in highly dynamic waters and we recommend investing in high sampling efforts by repetitive sampling and replication using at least 0.45 μm filters to increase filtration volume.
    Repository Name: EPIC Alfred Wegener Institut
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