ALBERT

Description: Magmas often experience severe disequilibrium conditions during their migration through the Earth's crust and the subsequent emplacement on its surface. During their transport, magmas are subjected to a wide range of cooling (q) and deformation rates (), generating physico-chemical perturbations in the magmatic system able to inhibit or promote crystallization processes. Quantifying the magnitude and timescale of kinetic effects is essential to correctly constrain the rheological evolution of magmas and their ability to flow. Here we present a suite of cooling deformation experiments (CDE) conducted on a basalt from Mt. Etna (Sicily, Italy) to disentangle and model the concurrent effects of q (from 1 to 10 °C/min) and (from 1 to 10 s−1) on the rheology of the system. The analysis of the temporal evolution of viscosity indicates that both q and strongly affect the onset of crystallization and achievement of a rheological cut-off over time, which represents the steep viscosity increase responsible for inhibiting magma flow. Both these rheological thresholds occur at lower T and earlier in time with increasing q, as well as at higher T and earlier in time with increasing . To reproduce the observed effects of crystallization on the apparent viscosity, we adopt a stretched exponential function that identifies two main crystallization regimes: i) a first shear-induced crystallization regime, characterized by a gentle viscosity increase and ii) a second cooling-dominated regime, marked by a steeper viscosity increase. The relative extent of these crystallization regimes strictly depends on the interplay between q and on the crystallization kinetics and suggest a first order control of q and a subordinate role of .

Description: Published

Description: 117725

Description: 3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici

Description: JCR Journal

Description: The characterization of the fling-step represents a challenging task due to the shortage of near-source records with permanent tectonic displacement and the limitation in retrieving the fling-amplitude from accelerometric waveforms. In recent years, innovative ground-motion processing techniques have been developed for a more accurate estimation of both fling-displacements and spectral displacements in contrast to traditional bandpass filtering, although their application is still unusual. In this paper, we exploit the newly released dataset of the Near-Source Strong-motion records (NESS2) uniformly processed with the extended BASeline COrrection technique (eBASCO), against which we propose: (1) a new empirically-based ground motion model (GMM) for the prediction of the fling-step, and (2) an adjustment factor of the spectral displacements predicted by a reference GMM to account for the contribution of the fling-step at long periods. Such models are in agreement with observations and existing GMMs, and thus could be advantageously employed in seismic hazard analyses.

Description: Published

Description: 107294

Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica

Description: JCR Journal

Description: The 1915, Mw6.7, Fucino earthquake is one of the most destructive events occurred in the central-southern Apennines (Central Italy) in pre-instrumental era, involving normal faulting in a deep alluvial basin. This study shows the application of the empirical non-ergodic approach (NESK method) for mapping ground shaking related to this historical event, taking into account the regional features of source, propagation and site contributions. Corrections of the source-region and spatially correlated maps of site and path residuals are combined with median prediction at the reference rock (i.e. without site amplification) to generate spatially variable ground shaking and associated variability in terms of peak ground acceleration and spectral ordinates at vibration periods from 0.01s to 2s. The method captures the main spatial non-stationarities and anisotropies of the shaking fields produced by this earthquake in and around the Fucino basin. In particular, we obtain patterns of seismic motion quite in accordance with the results of other methods and the macroseismic intensity field. Marked amplifications of the shaking in the long-periods are also captured, due to the coupling of 3D site effects, especially in the deeper portion of the basin, with propagation effects mainly focused towards the eastern part of the fault. These results confirm that the non-ergodic shaking scenarios from NESK can provide useful indications even in the case of very complex seismological and geological contexts, such as in the case of strong events in deep sedimentary basins.

Description: Published

Description: 107622

Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica

Description: JCR Journal

Description: The geological carbon cycle has played a key role in controlling climate throughout Earth’s history. For the last ∼ 3 billion years plate tectonics has driven subduction. Subducted slabs have transported CO_2 from the lithosphere, hydrosphere, and atmosphere into the Earth, from where it may be released back to the surface through processes such as arc volcanism or can be stored in the deep interior over geological time. Carbonate-bearing sediments and basalts of altered oceanic crust are the primary media by which carbon is subducted. Therefore, quantifying the depth and amount of CO_2 released from different carbonate-bearing lithologies during subduction is fundamental to understanding whether CO_2 is recycled through arc volcanism or buried in the mantle. The magnitude of CO_2 released from subducting slabs at fore- and sub-arc depths is controlled by processes including ocean crust alteration (i.e., carbonation), metamorphic decarbonation, carbonate dissolution and slab-melting. However, the relative contribution of these processes to overall slab decarbonation is still debated, and will be complex given the variety of sedimentary lithologies and subduction geodynamics. Here, we present a global arc-by-arc lithology-specific analysis of the magnitude of slab CO_2 released purely by metamorphic decarbonation of carbonate-bearing sediment and basalt during subduction of altered oceanic crust, using a thermodynamically rigorous model. We find that metamorphic decarbonation is highly efficient in low carbonate sediments, such as carbonated clay, and in carbonated basalts of altered oceanic crust, causing all of their CO_2 to be removed. Sediments with medium and higher carbonate contents, such as chalk and limestone, are only partially decarbonated, but the combination of metamorphic decarbonation and carbonate dissolution promotes efficient carbon loss. Together they can explain observed magmatic CO_2 emissions in carbonate-rich arcs. Warm slabs, such as Mexico and Cascadia, produce complete metamorphic decarbonation of carbonate minerals beneath fore-arcs. Under more common cold and intermediate thermal regimes metamorphic decarbonation of carbonate minerals occurs at depths between ∼ 80 and 170 km ( ∼ 2.3 to 5.5 GPa) promoting CO_2 input into the mantle sources of volcanic arcs. Overall, our results demonstrate that sub-arc decarbonation is typically considered an important potential source of slab-derived CO_2 , which needs to be considered together with carbonate dissolution to explain observed volcanic CO_2 emissions. In many arcs the modelled CO_2 flux from sediment and basalts of altered oceanic crust into the wedge exceeds the observed CO 2 output suggesting that the mantle wedge and arc lithosphere may sequester some CO_2 .

Description: Published

Description: 117945

Description: 2V. Struttura e sistema di alimentazione dei vulcani

Description: JCR Journal

Description: This chapter aims at introducing the reader to general concepts about the main forcings of the Mediterranean Sea, in terms of exchanges through the Strait of Gibraltar, and air-sea exchanges of heat, freshwater, and momentum. These forcings are also responsible for the peculiar characteristics of Mediterranean water masses. Therefore, the chapter continues with giving a general explanation on water mass analysis, and then it describes the properties and vertical and horizontal distributions of the main Mediterranean water masses. To conclude, the reader is introduced to the use of other (biogeochemical, and chemical) tracers of water masses, with a focus on the Mediterranean Sea.

Description: We present here the results of a five-years-long earthquake educational project aiming to commemorate the hundredth anniversaries of five large Northern Apennines earthquakes occurred between 1916 and 1920 in the areas of: Rimini (1916, Mw 6.1), Valtiberina (1917, Mw 5.9), Romagna Apennines (1918, Mw 5.9), Mugello (1919, Mw 6.3) and Garfagnana (1920, Mw 6.5) earthquakes. We saw these anniversaries as the occasion for leading the Northern Apennines people to rediscover their past, in a positive way, and to improve their awareness of the earthquake as a natural feature of the regions in which they live. The activities that we planned for schools students encouraged them to go hunting for traces of the earthquakes of one hundred years ago in their home towns and to rediscover the memories and traditions of their communities. Together with their teachers, we also led the teenagers to find creative ways to involve the grownups in the process of discovery and knowledge. The Project had to cope with two emergencies: the great Central Italy earthquake of 2016-2017 and the Covid-19 epidemic. However, these stumbling blocks did not deter teachers and students from taking part in the process actively and even enthusiastically. Their families and communities were actively involved too. This experience taught us some valuable lessons. First of all, we learned to adapt the project, as we had conceived it at the start, to a wide gamma of social and cultural contexts. Not all the involved communities were equally aware of the level of seismic risk they are exposed to. On the affluent Adriatic coast, where tourism is the main source of income, past earthquakes are something best forgotten, by citizens and administrators alike. On the contrary, in the poorer inland mountain areas (Forlivese Apennines, Mugello, Garfagnana and Lunigiana) a more down-to-earth attitude prevails: earthquakes are looked upon as something that can and does happen and people are quick to grasp how important it is to contribute to initiatives whose aim is reducing seismic risk. Thus, we had to adapt our approach to the different contexts, modifying each time the activities we proposed to the schools with the aim of obtain the best possible results from each situation. Presentiamo i risultati di un progetto di educazione al rischio sismico attivato in occasione dei centenari di cinque terremoti storici che hanno colpito l’Appennino settentrionale tra gli anni 1916 e 1920 e precisamente i terremoti di Rimini 1916 (Mw 6.1), Valtiberina 1917 (Mw 5.9), Appennino romagnolo 1918 (Mw 5.9), Mugello 1919 (Mw 6.3) e Garfagnana 1920 (Mw 6.5). Abbiamo pensato di utilizzare questi anniversari come punto di partenza per accompagnare i cittadini a riappropriarsi del loro passato in modo positivo, facendo crescere la loro consapevolezza del terremoto come un carattere del loro ambiente naturale. A tal fine, nelle attività realizzate con le scuole, abbiamo incoraggiato gli studenti a cercare le tracce dei terremoti di un secolo fa nell’ambiente urbanizzato e a indagare le memorie e le tradizioni ancora presenti nelle comunità. Insieme ai loro insegnanti abbiamo spinto i ragazzi a trovare modi creativi per coinvolgere gli adulti in questo processo di scoperta e conoscenza. Il progetto è stato messo alla prova dal forte terremoto dell’Italia centrale (2016­2017) e dall’epidemia di Covid­19, ma nonostante queste difficoltà insegnanti e studenti hanno partecipato con grande interesse a questo percorso e hanno coinvolto nelle attività del progetto le famiglie e le comunità locali. Anche noi abbiamo imparato nuove lezioni. Un aspetto importante che abbiamo appreso è il bisogno di adattare il progetto a contesti sociali e culturali che si sono rivelati molto diversi. Le comunità coinvolte non condividono lo stesso livello di consapevolezza del rischio: sulla costa adriatica, a vocazione turistica, i terremoti sono qualcosa che è meglio dimenticare, sia da parte dei cittadini che dalle amministrazioni. Al contrario, nell’Appennino forlivese, nel Mugello, in Garfagnana e Lunigiana, i terremoti sono una presenza costante e le persone si sono sentite subito coinvolte in un processo attivo di riduzione del rischio e di attenzione quotidiana. Questo ci ha spinto ad adattare ogni volta l’approccio ai diversi contesti, modificando le proposte di attività che abbiamo realizzato nelle scuole.

Description: Lavoro realizzato nell’ambito della Convenzione fra INGV e Dipartimento della Protezione Civile, Allegato A, tematica “M”.

Description: Published

Description: 1-40

Description: 5SR TERREMOTI - Convenzioni derivanti dall'Accordo Quadro decennale INGV-DPC

Description: JCR Journal

Description: New constraints were set on the age of marine deposits in the Pontine Plain and of the related sea level indicators on the Tyrrhenian Sea coast of central Italy by twelve new 40Ar/39Ar dates on detrital sanidine from these deposits. By combining a new geomorphologic analysis and previous morpho-pedostratigraphic studies with these geochronological constraints we reconstructed the geometry of four marine terraces and correlated these with the highstands during the marine isotopic stages (MIS) 9.3, 7.5, 5.5 and 5.3. Results point to a progressive tilting of the terraces, the elevation increasing from the SE to the NW due to differential tectonic uplift that occurred over the last 300 ka. We identified a MIS 9 sea level at 30 - 25 m asl in the northwestern sector, whereas the MIS 7.5 sea level reached a maximum of 24 m asl in the NWand descended to 18 m asl in the central sector. Moderate tilting affected the MIS 5.5 sea level, with an elevation of 12 to 9.5 m asl in between the Anzio and Circeo headlands. Finally, an undeformed MIS 5.3 sea level at ca. 3 m asl is indicated throughout this coastal reach, confirming previous data suggesting a much higher absolute sea level during this highstand with respect to the d18O-derived predicted level.

Description: Published

Description: 107866

Description: 2T. Deformazione crostale attiva

Description: JCR Journal

Description: A key requirement for geological CO2 storage is site integrity management and monitoring during operation through to the post decommissioning period. This paper focuses on monitoring deformation of the ground surface and seabed as a proxy for overall deformation in the reservoir and surrounding layers. The objective is to inform, based on deformation data, on how the reservoir is responding to CO2 injection and to ensure any issues with regard to storage integrity are rapidly detected. The magnitude and pattern of deformation at the surface reveals geomechanical/hydromechanical processes that occur in reservoir due to CO2 injection. We acquired deformation data from the In Salah CO2 injection site and from four additional study cases during the course of this study; one in the onshore UK, the other a combined campaign onshore Norway and offshore Germany, and the third in onshore Japan. Significant developments in measurement techniques, processing tools and interpretation algorithms were developed through this project. Models were then developed to simulate the observed data and to couple surface deformation to displacement in the subsurface. The results show millimeter-scale deformations in the subsurface have a signature at the surface that can be captured by the tools and workflows developed in this project. These deformations, particularly the patterns, are important factors to consider when monitoring a CO2 storage site.

Description: The Global Navigation Satellite System (GNSS) represents a primary data source in Solid Earth Sciences. In order to investigate the Earth’s crustal deformation, time series of the estimated daily positions of the stations are routinely analyzed at the Istituto Nazionale di Geofisica e Vulcanologia (INGV) to investigate the deformation of the Earth’s surface caused by tectonic and non-tectonic processes. The GNSS observations of the stations are processed using the three main scientific software: GAMIT/GLOBK, BERNESE, and GIPSY OASIS II. The accuracy and the strength of geodetic solutions often depend on the geometry and spatial density of the network, and the availability and quality of GNSS data. In many circumstances, GNSS networks are deployed for topographic purposes by private or public institutions, and a significant number of GNSS stations in large regions acquire continuous observations. It may happen that such networks do not collect and distribute data according to IGS standards, so it could be difficult to analyze this data using automated data-processing tools. For that reason, this data is often ignored or partially used by the scientific community, despite their potential usefulness in geodynamic studies. We have attempted troubleshooting this problem by establishing a centralized storage facility in order to collect all available GNSS data and standardize both formats and metadata information. Here we describe the processes and functions that manage this unified repository, called MGA (Mediterranean GNSS Archive), which regularly collects GNSS RINEX files from alarge number of CORS (Continuously Operating Reference Station) located across a wide region of mainly the European and African plates. RINEX observation data and metadata information are provided to the analysts through an FTP server and dedicated web-services. The complete data set is stored in a PostgreSQL database in order to easily retrieve pieces of information and efficiently manage the archive content. The system implements many high-level services that include scripts to download files from remote archives and to detect new available data, web applications such as API (Application Program Interface) to interact with the system, and background services that interact with the database. During the development of this product, particular attention was paid to what has already been achieved by EPOS TCS WP10, whose objective was: "[...] to develop an open source platform with programmatic and web interfaces to store and disseminate raw data and metadata from GNSS stations operating in Europe''. Many ideas and tools presented here were inspired by that project.

Description: Published

Description: 1-18

Description: 2T. Deformazione crostale attiva

Description: 1IT. Reti di monitoraggio e sorveglianza

Description: 4IT. Banche dati

Description: N/A or not JCR

Description: 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.

Description: The INGV Earthquake Department Strategic Project FURTHER “The role of FlUids in the pReparaTory pHase of EaRthquakes in Southern Apennines”

Description: Published

Description: 104236

Description: 1T. Struttura della Terra

Description: 2T. Deformazione crostale attiva

Description: 3T. Fisica dei terremoti e Sorgente Sismica

Description: 4T. Sismicità dell'Italia

Description: 9T. Geochimica dei fluidi applicata allo studio e al monitoraggio di aree sismiche

Description: JCR Journal