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Large silicic magma chambers at the Moho depth characterize the multi-level plumbing system of back-arc spreading ridges
No full textThe plumbing system of volcanoes in crustal convergent settings consists of vertically superimposed, sill-like reservoirs. The shallower reservoirs are generally filled by less dense and SiO2-richer magmas. The plumbing systems of spreading ridges are supposed to be simpler and characterized by prevailing sub-parallel vertical dykes. Here, we present the results of thermo-barometric determinations from minerals and modelling of potential field data at the Marsili spreading ridge in the Southern Tyrrhenian Sea back-arc oceanic basin. The Marsili plumbing system consists of sill-like, large SiO2-rich magma reservoirs located at the Moho depth and sub-vertical basaltic dykes crossing the whole oceanic crust. The formation of deep-seated silicic reservoirs is associated with a decrease in the back-arc spreading rate. The geometry of the plumbing system of spreading ridges may be not dissimilar from that of volcanoes at convergent margins.Published107325OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
On the external forcing of global eruptive activity in the past 300 years
No full textThe decryption of the temporal sequence of volcanic eruptions is a key step
in better anticipating future events. Volcanic activity is the result of a
complex interaction between internal and external processes, with time scales
spanning multiple orders of magnitude. We review periodicities that have been
detected or correlated with volcanic eruptions/phenomena and interpreted as
resulting from external forces. Taking a global perspective and longer time
scales than a few years, we approach this interaction by analyzing three time
series using singular spectral analysis: the global number of volcanic
eruptions (NVE) between 1700 and 2022, the number of sunspots (ISSN), a proxy
for solar activity, the polar motion (PM) and length of day (lod), two proxies
for gravitational force. Several pseudo-periodicities are common to NVE and
ISSN, in addition to the 11-year Schwabe cycle that has been reported in
previous work, but NVE shares even more periodicities with PM. These
quasi-periodic components range from ~5 to ~130 years. We interpret our
analytical results in light of the Laplace's paradigm and propose that,
similarly to the movement of Earth's rotation axis, global eruptive activity is
modulated by commensurable orbital moments of the Jovian planets, whose
influence is also detected in solar activity.Published1254855OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Wildfire Detection Using Convolutional Neural Networks and PRISMA Hyperspectral Imagery: A Spatial-Spectral Analysis
No full textThe exacerbation of wildfires, attributed to the effects of climate change, presents substantial risks to ecological systems, infrastructure, and human well-being. In the context of the Sustainable Development Goals (SDGs), particularly those related to climate action, prioritizing the assessment and management of the occurrence and intensity of extensive wildfires is of utmost importance. In recent times, there has been a significant increase in the frequency and severity of widespread wildfires worldwide, affecting several locations, including Australia, Italy, and the United States of America. The presence of complex phenomena marked by limited predictability leads to significant negative impacts on biodiversity and human lives. The utilization of satellite-derived data with neural networks, such as convolutional neural networks (CNNs), is a potentially advantageous approach for augmenting the monitoring capabilities of wildfires. This research examines the generalization capability of four neural network models, namely the fully connected (FC), one-dimensional (1D) CNN, two-dimensional (2D) CNN, and three-dimensional (3D) CNN model. Each model’s performance, as measured by accuracy, recall, and F1 scores, is assessed through K-fold cross-validation. Subsequently, T-statistics and p-values are computed based on these metrics to conduct a statistical comparison among the different models, allowing us to quantify the degree of similarity or dissimilarity between them. By using training data from Australia and Sicily, the performances of the trained model are evaluated on the test dataset from Oregon. The results are promising, with cross-validation on the training dataset producing mean precision, recall, and F1 scores ranging between approximately 0.97 and 0.98. Especially, the fully connected model has superior generalization capabilities, whilst the 3D CNN offers more refined and less distorted classifications. However, certain issues, such as false fire detection and confusion between smoke and shadows, persist. The aforementioned methodologies offer significant perspectives on the capabilities of neural network technologies in supporting the detection and management of wildfires. These approaches address the crucial matter of domain transferability and the associated dependability of predictions in new regions. This study makes a valuable contribution to the ongoing efforts in climate change by assisting in monitoring and managing wildfires.Published48555IT. Osservazioni satellitariJCR Journa
Setting the basis for a high-resolution record of the late Quaternary to present climate variability from Castiglione maar, central Italy: First results from AMUSED project
No full textThe AMUSED (A MUltidisciplinary Study of past global climatE changes from continental and marine archives in the MeDiterranean region) project aims at improving knowledge of late Quaternary climate variability and its expressions in different geological settings of the Mediterranean region. In this framework, the Castiglione maar, in the Colli Albani Volcanic District, central Italy, was selected for acquiring a high-resolution and geochronologically well-constrained multi-proxy record by drilling the entire lacustrine succession. Electrical Resistivity Tomography (ERT) profiles were acquired across the central portion and the SW crater edge to depict the geometry of the sedimentary infilling and select the best drilling site. Two parallel cores (C1 and C2), 116 m- and 126.5 m-depth respectively, were recovered from the central sector of the Castiglione basin, where, according to ERT profiles, the sedimentary succession reaches the maximum thickness. The sedimentary infilling consists of fine-grained sediments: mainly fine sand, silt and clay, with minor gravel intervals and numerous tephra layers and volcaniclastic lenses. Specifically, more than 60 tephras were identified and used, alongside other lithostratigraphic features, to correlate the C1 and C2 cores and to assemble a composite section. The variability in magnetic susceptibility, led by glacial-interglacial cycles, and the geochemical fingerprinting of key tephra layers allowed to establish a preliminary chronological framework for the Castiglione succession which certainly spans the last 365 ka, with a mean sedimentation rate of 0.33 mm/yr. The relatively long time span of the Castiglione maar succession arises as a new potentially meaningful node of the network of Mediterranean records for better reconstructing the late Quaternary climate dynamics on a regional and extra-regional scale.Published1-14OSA1: Variazioni del campo magnetico terrestre, imaging crostale e sicurezza del territorioOSA2: Evoluzione climatica: effetti e loro mitigazioneJCR Journa
Tracking carbon from subduction to outgassing along the Aleutian-Alaska Volcanic Arc
No full textSubduction transports volatiles between Earth's mantle, crust, and atmosphere, ultimately creating a habitable Earth. We use isotopes to track carbon from subduction to outgassing along the Aleutian-Alaska Arc. We find substantial along-strike variations in the isotopic composition of volcanic gases, explained by different recycling efficiencies of subducting carbon to the atmosphere via arc volcanism and modulated by subduction character. Fast and cool subduction facilitates recycling of ~43 to 61% sediment-derived organic carbon to the atmosphere through degassing of central Aleutian volcanoes, while slow and warm subduction favors forearc sediment removal, leading to recycling of ~6 to 9% altered oceanic crust carbon to the atmosphere through degassing of western Aleutian volcanoes. These results indicate that less carbon is returned to the deep mantle than previously thought and that subducting organic carbon is not a reliable atmospheric carbon sink over subduction time scales.Publishedeadf3024OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciOSA2: Evoluzione climatica: effetti e loro mitigazioneJCR Journa
L’infrastruttura di rete per la gestione degli osservatori sottomarini SN1 ed EGIM nel sito EMSO Western Ionian Sea, Catania
No full textStarting from 2001 INGV, in cooperation with INFN, performed several experiments with multidisciplinary submarine observatories installed at deep sea off the coast of Catania at the Western Ionian Sea site, the INGV Regional Facility that today contributes to the EMSO ERIC (European Multidisciplinary Seafloor and water column Observatory - European Research Infrastructure Consortium). Submarine equipment can provide real-time data to shore acquisition systems and are remotely accessible. For the management of several submarine platforms, a computer network was developed to support the systems for data management, acquisition and distribution. This technical report describes the network implementation for the simultaneous management of two submarine observatories and a Junction Box.Published1-203A. Geofisica marina e osservazioni multiparametriche a fondo mareN/A or not JC
Continental subduction of Adria in the Apennines and relation with seismicity and hazard
No full textThe subduction of continental lithosphere is a complex process because the buoyancy of the crust is higher than the oceanic and should resist sinking into the mantle. Anyway, studies on the Alpine-Himalayan collision system indicate that a large portion of the continental crust is subducted, while some material is accreted in the orogens. The Apennine is a perfect case for studying how such processes evolve, thanks to high quality seismic images that illuminate a critical depth range not commonly resolved in many collisional settings. In this paper, we show the structure of the Apennines orogen, as jointly revealed by seismicity and deep structure from regional and teleseismic tomography and receiver function profiles. The westward subducting Adria lithosphere is well defined along the orogen showing a mid-crustal delamination. Seismicity within the underthrusting lower crust and velocity anomalies in the mantle wedge highlight how the subduction evolution is entangled with the liberation of fluids. The eclogitization of subducted material enhances the fluid release into the wedge, the delamination and retreat of the Adria plate. This delamination/subduction generates a coupled compression and extension system that migrates eastward following the retreat of the lithosphere, with broad sets of normal faults that invert or interfere with pre-existing compressional structures all over the roof plate. The sparseness and non-ubiquity of intermediate depth earthquakes along the subduction panel suggest that the brittle response of the subducting crust is governed by its different composition and fluid content. Therefore, the lower crust composition appears essential in conditioning the evolution of continental subduction.Published1253443OST1 Alla ricerca dei Motori GeodinamiciJCR Journa
Automatic seismic source modeling of InSAR displacements
No full textIn 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.Published103445OST3 Vicino alla fagliaJCR Journa
Lithosphere-atmosphere-ionosphere coupling associated with four Yutian earthquakes in China from GPS TEC and electromagnetic observations onboard satellites
No full textDuring 2008–2020, four strong earthquakes occurred in Yutian, Xinjiang Uygur Automous Region, northwest
China, in particular, two M7 + and two M6 + earthquakes demonstrating the high tectonic activity of this region.
We systematically use multiple electromagnetic data from satellites and ground, such as GIM TEC (Global
Ionospheric Mapping Total Electron Content) published by JPL (Jet Propulsion Laboratory), and the ULF (Ultra
Low Frequency) electromagnetic waves and plasma parameters onboard DEMETER (Detection of Electro-
Magnetic Emission Transmitted from Earthquake Regions), Swarm and CSES (China Seismo-Electromagnetic
Satellite) satellites. The ionospheric perturbations were revealed frequently around the four case studies, but
mostly within 10 days before, over the epicentral area, and sometimes over its conjugate region at southern
hemisphere. The abnormal amplitude is quite larger in years with high solar activity than in those with low solar
activity. We employ the SAMI2 model to simulate the variations from the effects of E × B under different plasma
background in 2008 and 2014 to explain the great difference in different solar years. The similarity of the
anomalies in this region demonstrates the higher electromagnetic and chemical emissions, implying that the
electric field is possibly generated by the preparation of the seismic events in the epicentral area inducing the
ionospheric disturbances above this area and its conjugate region through this coupling channel.Published101943JCR Journa
Seismic anisotropy to investigate lithospheric-scale tectonic structures and mantle dynamics in southern Italy
No full textSubduction zones may be characterised by deep-seated tectonic structures whose effects propagate to the upper plate through faulting and magmatism. The overall geodynamic framework, as well as the roots of the many active faults affecting such regions, can be investigated by the study of the upper mantle anisotropic patterns, through the analysis of core-transiting teleseismic phases. Here, we discuss the results of XKS waves splitting observed in the central Mediterranean, particularly in southern Italy, which is characterised by the Adriatic-Ionian subduction system. Azimuths of polarisation of the fast wave (fast directions) were found to be generally trench-parallel, as an effect of the subducting slab, albeit a change to a perpendicular direction, in central Italy and Sicily, suggests discontinuities in the structure of the slab itself. However, while in central Italy a gradual rotation of fast directions points to a toroidal upper mantle flow through a tear in the Apenninic slab, in central-eastern Sicily, the splitting parameters show an abrupt change that matches well with the main crustal tectonic structures. There, the rapid trench migration, taking place at the transition between the subduction and continental collision domains, produced a rather complex Subduction Transform Edge Propagator fault system. The sharp variation in the pattern of the upper mantle anisotropy marks the main element of such a fault system and suggests its primary role in the segmentation process of the collisional margin. Our findings further show that the study of seismic anisotropy may be fundamental in investigating whether tectonic structures only involve the crust or extend down to the upper mantle.Published20932OST1 Alla ricerca dei Motori GeodinamiciJCR Journa