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  • 1
    Publikationsdatum: 2022-12-01
    Beschreibung: An accurate survey of old and new datasets allowed us to probe the nature and role of fluids in the seismogenic processes of the Apennines mountain range in Italy. New datasets include the 1985–2021 instrumented seismicity catalog, the computed seismogenic thickness, and geodetic velocities and strains, whereas data from the literature comprise focal mechanism solutions, CO2 release, Moho depth, tomographic seismic velocities, heat flow and Bouguer gravity anomalies. Most of the inspected datasets highlight differences between the western and eastern domains of the Apennines, while the transition zone is marked by high geodetic strain, prevailing uplift at the surface and high seismic release, and spatially corresponds with the overlapping Tyrrhenian and Adriatic Mohos. Published tomographic models suggest the presence of a large hot asthenospheric mantle wedge which intrudes beneath the western side of the Apennines and disappears at the southern tip of the southern Apennines. This wedge modulates the thermal structure and rheology of the overlying crust as well as the melting of carbonate-rich sediments of the subducting Adriatic lithosphere. As a result, CO2-rich fluids of mantle-origin have been recognized in association with the occurrence of destructive seismic sequences in the Apennines. The stretched western domain of the Apennines is characterized by a broad pattern of emissions from CO2-rich fluids that vanishes beneath the axial belt of the chain, where fluids are instead trapped within crustal overpressurized reservoirs, favoring their involvement in the evolution of destructive seismic sequences in that region. In the Apennines, areas with high mantle He are associated with different degrees of metasomatism of the mantle wedge from north to south. Beneath the chain, the thickness and permeability of the crust control the formation of overpressurized fluid zones at depth and the seismicity is favored by extensional faults that act as high permeability pathways. This multidisciplinary study aims to contribute to our understanding of the fluid-related mechanisms of earthquake preparation, nucleation and evolution encouraging a multiparametric monitoring system of different geophysical and geochemical observables that could lead the creation of a data-constrained and reliable conceptual model of the role of fluids in the preparatory phase of earthquakes in the Apennines.
    Beschreibung: The INGV Earthquake Department Strategic Project FURTHER “The role of FlUids in the pReparaTory pHase of EaRthquakes in Southern Apennines”
    Beschreibung: Published
    Beschreibung: 104236
    Beschreibung: 1T. Struttura della Terra
    Beschreibung: 2T. Deformazione crostale attiva
    Beschreibung: 3T. Fisica dei terremoti e Sorgente Sismica
    Beschreibung: 4T. Sismicità dell'Italia
    Beschreibung: 9T. Geochimica dei fluidi applicata allo studio e al monitoraggio di aree sismiche
    Beschreibung: JCR Journal
    Schlagwort(e): CO2 Earth degassing ; Earthquakes ; Mantle wedge ; Subduction ; Apennines ; 04.06. Seismology ; Geochemistry ; 04.03. Geodesy
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Publikationsdatum: 2021-04-14
    Beschreibung: In February 2016, 47 ingots were found in the seabed of Contrada Bulala (Gela, CL, Italy) near the site where 40 ingots had previously been recovered. The ingots composition was determined to be a Cu - Zn alloy, dated by the archaeologist to the VI century B.C. This specific alloy was then known as Orichalcum. From an archaeological point of view, the first question raised about the new discovery was whether the ingots of the first and the second excavations belonged to the same shipwreck. Following the previous study, an elemental analysis was performed on the ingots from the second finding by using ICP-OS and ICP-MS techniques. The chemometric treatment of the analytical results obtained on both sets, i.e. ingots from first and second discovery, confirms their similarity. Therefore, the two findings can be considered to belong to the same naval load. The lead isotopic ratios were determined on selected/representative ingots to improve the knowledge about this treasure. Results can provide information about probable location of the lead sources, that could be very useful for the reconstruction of the ancient trade routes in the Mediterranean Sea.
    Beschreibung: Published
    Beschreibung: 102901
    Beschreibung: 2IT. Laboratori analitici e sperimentali
    Beschreibung: JCR Journal
    Schlagwort(e): Orichalcum ingots ; Lead Isotopic ratio ; ICP-OES ICP-MS ; Chemometric approach ; 05.09. Miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Publikationsdatum: 2020-11-25
    Beschreibung: In this paper a new approach for processing arrays of data is proposed. It is based on fuzzy logic and the concepts of cellular computation. Arrays of simple, identical processing elements (called fuzzy cells) are defined by using fuzzy rules. Moreover, each fuzzy cell interacts with its local neighbors. The overall behavior of these locally interacting fuzzy systems is used to process arrays of data. Some examples of practical applications are proposed. Among these, the new approach is applied to image-processing problems, and to the simulation of heat diffusion phenomena.
    Beschreibung: This work was partially supported by the Italian National Research Council (C.N.R.) under the special project "Reti neurali per i sistemi di controllo".
    Beschreibung: Published
    Beschreibung: 47-52
    Beschreibung: 3IT. Calcolo scientifico
    Beschreibung: JCR Journal
    Schlagwort(e): fuzzy logic ; partial differential equations ; 05.09. Miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Publikationsdatum: 2021-06-25
    Beschreibung: Recent measurements of surface vertical displacements of the European Alps show a correlation between vertical velocities and topographic features, with widespread uplift at rates of up to ~2–2.5 mm/a in the North-Western and Central Alps, and ~1 mm/a across a continuous region from the Eastern to the South-Western Alps. Such a rock uplift rate pattern is at odds with the horizontal velocity eld, characterized by shortening and crustal thickening in the Eastern Alps and very limited deformation in the Central and Western Alps. Proposed me- chanisms of rock uplift rate include isostatic response to the last deglaciation, long-term erosion, detachment of the Western Alpine slab, as well as lithospheric and surface de ection due to mantle convection. Here, we assess previous work and present new estimates of the contributions from these mechanisms. Given the large range of model estimates, the isostatic adjustment to deglaciation and erosion are su cient to explain the full observed rate of uplift in the Eastern Alps, which, if correct, would preclude a contribution from horizontal shortening and crustal thickening. Alternatively, uplift is a partitioned response to a range of mechanisms. In the Central and Western Alps, the lithospheric adjustment to deglaciation and erosion likely accounts for roughly half of the rock uplift rate, which points to a noticeable contribution by mantle-related processes such as detachment of the European slab and/or asthenospheric upwelling. While it is di cult to independently constrain the patterns and magnitude of mantle contributions to ongoing Alpine vertical displacements at present, future data should provide additional insights. Regardless, interacting tectonic and surface mass redistribution processes, rather than an individual forcing, best explain ongoing Alpine elevation changes.
    Beschreibung: Published
    Beschreibung: 589-604
    Beschreibung: 1T. Struttura della Terra
    Beschreibung: 2T. Deformazione crostale attiva
    Beschreibung: JCR Journal
    Schlagwort(e): 04. Solid Earth ; 04.03. Geodesy ; 04.07. Tectonophysics
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Publikationsdatum: 2020-06-10
    Beschreibung: Understanding how long-term subduction dynamics relates to the short-term seismicity and crustal tec tonics is a challenging but crucial topic in seismotectonics. We attempt to address this issue by linking long-term geodynamic evolution with short-term seismogenic deformation in the Northern Apennines. This retreating subduction orogen displays tectonic and seismogenic behaviors on various spatiotemporal scales that also characterize other subduction zones in the Mediterranean area. We use visco-elasto-plastic seismo-thermo-mechanical (STM) modeling with a realistic 2D setup based on available geological and geophysical data. The subduction dynamics and seismicity are coupled in the numerical modeling, and driven only by buoyancy forces, i.e., slab pull. Our results suggest that lower crustal rheology and lithospheric mantle temperature modulate the crustal tectonics of the Northern Apennines, as inferred by previous studies. The observed spatial distribution of upper crustal tectonic regimes and surface displacements requires buoyant, highly ductile material in the subduction channel beneath the internal part of the orogen. This allows protrusion of the asthenosphere in the lower crust and lithospheric delamination associated with slab retreat. The resulting surface velocities and principal stress axes generally agree with present-day observations, suggesting that slab delamination and retreat can explain the dynamics of the orogen. Our simulations successfully reproduce the type and overall distribution of seismicity with thrust faulting events in the external part of the orogen and normal faulting in its internal part. Slab temperatures and lithospheric mantle stiffness affect the cumulative seismic moment release and spatial distribution of upper crustal earthquakes. The properties of deep, sub-crustal material are thus shown to influence upper crustal seismicity in an orogen driven by slab retreat, even though the upper crust is largely decoupled from the lithospheric mantle. Our simulations therefore highlight the effect of deep lower crustal rheologies, self-driven subduction dynamics and mantle properties in controlling shallow deformation and seismicity.
    Beschreibung: Published
    Beschreibung: 228481
    Beschreibung: 1T. Struttura della Terra
    Beschreibung: 2T. Deformazione crostale attiva
    Beschreibung: JCR Journal
    Schlagwort(e): Numerical modeling ; Geodynamics ; Seismotectonics orogen ; Delamination ; Northern Apennines ; 04.06. Seismology ; 04.03. Geodesy ; 05.01. Computational geophysics ; 04.07. Tectonophysics
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Publikationsdatum: 2020-03-03
    Beschreibung: The elevation of an orogenic belt is commonly related to crustal/lithosphere thickening. Here, we discuss the Apennines as an example to show that topography at a plate margin may be controlled not only by isostatic adjustment but also by dynamic, mantle-driven processes. Using recent structural constraints for the crust and mantle we find that the expected crustal isostatic component explains only a fraction of the topography of the belt, indicating positive residual topography in the central Apennines and negative residual topography in the northern Apennines and Calabria. The trend of the residual topography matches the mantle flow induced dynamic topography estimated from regional tomography models. We infer that a large fraction of the Apennines topography is related to mantle dynamics, producing relative upwellings in the central Apennines and downwellings in the northern Apennines and Calabria where subduction is still ongoing. Comparison between geodetic and geological data on vertical motions indicates that this dynamic process started in the early Pleistocene and the resulting uplift appears related to the formation and enlargement of a slab window below the central Apennines. The case of the Apennines shows that at convergent margins the elevation of a mountain belt may be significantly different from that predicted solely by crustal isostasy and that a large fraction of the elevation and its rate of change are dynamically controlled by mantle convection.
    Beschreibung: Published
    Beschreibung: 163-174
    Beschreibung: 1T. Struttura della Terra
    Beschreibung: 2T. Deformazione crostale attiva
    Beschreibung: JCR Journal
    Schlagwort(e): 04. Solid Earth ; 04.03. Geodesy
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Publikationsdatum: 2020-07-13
    Beschreibung: A multidisciplinary field campaign was carried out at Nisyros Island (Greece). Hydrothermal gases were sampled and analysed, and CH4 and CO2 fluxes from the soils were measured with the accumulation chamber method. The sampling area (Lakki plain) covers an area of about 0.08 km2, and includes the main fumarolic areas of Kaminakia, Stefanos, Ramos, Lofos and Phlegeton. Flux values measured at 130 sites range from −3.4 to 1420 mg m−2 d−1 for CH4 and from 0.1 to 383 g m−2 d−1 for CO2. The fumarolic areas show very different CH4 degassing patterns, Kaminakia showing the highest CH4 output values (about 0.8 t a−1 from an area of about 30,000 m2) and Phlegeton the lowest (about 0.01 t a−1 from an area of about 2500 m2). The total output from the entire geothermal system of Nisyros should not exceed 2 t a−1. Previous indirect estimates of the CH4 output at Nisyros, based on soil CO2 output and CH4/CO2 ratios in fumarolic gases, were more than one order of magnitude higher. The present work further underscores the utmost importance of direct CH4 flux data because indirect methods totally disregard methanotrophic activity within the soil. Ten soil samples were collected for CH4 consumption experiments and for metagenomic analysis. Seven of the soil samples showed small but significant CH4 consumption (up to 39.7 ng g−1 h−1) and were positive for the methanotrophs-specific gene (pmoA) confirming microbial CH4 oxidation in the soil, notwithstanding the harsh environmental conditions (high temperature and H2S concentrations and low pH).
    Beschreibung: Published
    Beschreibung: 119546
    Beschreibung: 6A. Geochimica per l'ambiente e geologia medica
    Beschreibung: JCR Journal
    Schlagwort(e): Methanotrophy ; Soil degassing ; Hydrothermal systems ; Methane output ; Greenhouse gases ; 05.09. Miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Publikationsdatum: 2020-07-13
    Beschreibung: Greece is a region characterised by intense geodynamic activity that favours the circulation of hydrothermal fluids in the crust transporting volatiles from either the deep crust or the mantle to the surface. Elevated heat flow values are detectable at Sperchios Basin and North Euboea (central Greece), two areas defined by a system of deeply rooted extensional faults and Quaternary volcanic activity. This setting contributed to the formation of numerous hydrothermal systems, which are mostly expressed as CO2-rich thermal springs with intense bubbling. The CO2 output from six bubbling pools has been determined by flux measurements with the use of the floating chamber method. The highest bubbling CO2 output has been found at Thermopyles and Psoroneria (0.6 and 0.84 t/d, respectively), where the outgoing channels have an elevated flow (〉250 l/s) of gas-charged water (〉15 mmol/l of CO2). Although no bubbling is noticed along the stream, the CO2 content decreases by an order of magnitude after few hundreds of metres, indicating an intense degassing from the water. Taking into account the water flow and the amount of CO2 lost to the atmosphere, the CO2 output of the outgoing channels is quantified in 12.5 t/d for Thermopyles and 9.23 t/d for Psoroneria. Output estimation has also been made for the other springs of the area. The diffuse CO2 release from the outgoing channels has always been higher respect to that of the visible bubbling, suggesting that most of the degassing is “hidden”. Furthermore, the loss of CO2 from the water has determined a shift in dissolved carbonate species as demonstrated by the pH increase along the channel that led eventually to an oversaturation in carbonate minerals and therefore travertine deposition. The total CO2 output to the atmosphere of the study area is estimated at ~27 t/d, with the major contribution deriving from the degassing along the outflow channels of the thermal springs. Such output is comparable to that of the single active volcanic systems along the South Aegean Active Volcanic Arc and highlights the importance of “hidden” degassing along CO2-oversaturated streams.
    Beschreibung: Published
    Beschreibung: 104660
    Beschreibung: 6A. Geochimica per l'ambiente e geologia medica
    Beschreibung: JCR Journal
    Schlagwort(e): C-cycle ; degassing sources ; stream outgassing ; 05.09. Miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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