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Peeking inside the mantle structure beneath the Italian region through SKS shear wave splitting anisotropy: a review
No full textOver the years, seismic anisotropy characterization has become one of the most popular methods to study and understand the Earth’s deep structures. Starting from more than 20 years ago, considerable progress has been made to map the anisotropic structure beneath Italy and the Central Mediterranean area. In particular, several past and current international projects (such as RETREAT, CAT/SCAN, CIFALPS, CIFALPS-2, AlpArray) focused on retrieving the anisotropic structure beneath Italy and surrounding regions, promoting advances in the knowledge of geological and geodynamical setting of this intriguing area. All of these studies aimed at a better understanding the complex and active geodynamic evolution of both the active and remnant subduction systems characterising this region and the associated Apennines, Alps and Dinaric belts, together with the Adriatic and Tyrrhenian basins. The presence of dense high-quality seismic networks, permanently run by INGV and other institutions, and temporary seismic stations deployed in the framework of international projects, the improvements in data processing and the use of several and even more sophisticated methods proposed to quantify the anisotropy, allowed to collect a huge amount of anisotropic parameters. Here a collection of all measurements done on core refracted phases are shown and used as a measure of mantle deformation and interpreted into geodynamic models. Images of anisotropy identify well-developed mantle flows around the sinking European and Adriatic slabs, recognised by tomographic studies. Slab retreat and related mantle flow are interpreted as the main driving mechanism of the Central Mediterranean geodynamics.PublishedSE215OST1 Alla ricerca dei Motori GeodinamiciJCR Journa
Fracture Energy and Breakdown Work During Earthquakes
No full textLarge seismogenic faults consist of approximately meter-thick fault cores surrounded by hundreds-of-meters-thick damage zones. Earthquakes are generated by rupture propagation and slip within fault cores and dissipate the stored elastic strain energy in fracture and frictional processes in the fault zone and in radiated seismic waves. Understanding this energy partitioning is fundamental in earthquake mechanics to explain fault dynamic weakening and causative rupture processes operating over different spatial and temporal scales. The energy dissipated in the earthquake rupture propagation along a fault is called fracture energy or breakdown work. Here we review fracture energy estimates from seismological, modeling, geological, and experimental studies and show that fracture energy scales with fault slip. We conclude that although material-dependent constant fracture energies are important at the microscale for fracturing grains of the fault zone, they are negligible with respect to the macroscale processes governing rupture propagation on natural faults.Published217-252OST3 Vicino alla fagliaJCR Journa
Risultati del sondaggio Politiche e infrastrutture per l’Open Access per pubblicazioni e letteratura grigia
No full textIl presente lavoro prende l’avvio all’interno del Gruppo di lavoro (GdL) Open Science della CoPER, istituito nel 2021 dalla Consulta dei Presidenti degli Enti Pubblici di Ricerca (EPR) per favorire la promozione delle istanze dell'Open Science tra gli EPR, con le Università rappresentate dalla CRUI e anche con i diversi soggetti che, a vario titolo, partecipano alle tematiche della Scienza Aperta.
Il suddetto GdL si è poi suddiviso in Gruppi Tematici che, su base volontaria, provvedono alla preparazione di documenti e alla finalizzazione di azioni per la promozione e il sostegno delle politiche di scienza aperta in Italia, così come pianificato nel documento programmatico, in collaborazione con altri attori operanti sulla scena nazionale.
La necessità di monitorare lo stato di attuazione della Scienza Aperta e aprire la successiva collaborazione tra EPR su questi temi ha guidato la scelta del sondaggio. Il modello proposto alle università dal Gruppo Open Access della CRUI è sembrato la scelta migliore, seppure si sono resi necessari alcuni adattamenti legati alla diversa struttura organizzativa degli EPR.
Il presente documento fornisce una panoramica della struttura e dei risultati ottenuti dal monitoraggio condotto con la collaborazione dei rappresentanti degli EPR.COPER, INGV, INAF, ENEAPublishedOST5 Verso un nuovo Monitoraggi
Wartime earthquakes in borderlands
No full textThe amount of traces that an earthquake may leave in historical records depends on many variables: its size, the relevance (political, economic, and cultural) of the area affected by it, the historical period in which it occurred, the space/time concomitance of other major geopolitical events that may overshadow the earthquake and hinder the production and circulation of information on its effects. If an earthquake is less than destructive and affects a marginal or border area, the likeliness that its memory will be quickly effaced is particularly high in wartime.
Such an earthquake occurred during the French phase of the Thirty Years' War (first half of the 17th century) in the Duchy of Savoy, an Alpine region and the main Italian theatre of war. It left only vague traces in a few seismological and historical compilations (Italian and European), none of the European parametric catalogues picked it up. The chance discovery of a short description of its effects in a diplomatic dispatch recently led us to undertake its study.
It was no easy feat, given the complexity of the socio-political context of the time, characterized by war events affecting all the territories where this earthquake could have been felt, but the effort was worthwhile because this earthquake currently turns out to be the most significant one in the seismic history of a major industrial city of northern Italy.UnpublishedBerlinOST1 Alla ricerca dei Motori Geodinamic
Impact of Site-Response Characterization on Probabilistic Seismic Hazard in the Po Plain (Italy)
No full textWe present a probabilistic seismic hazard analysis (PSHA) for the entire Po Plain sedimentary basin (Italy)—one of the widest Quaternary alluvial basins of Europe, to evaluate the impact of site-response characterization on hazard estimates. A large-scale application of approach 3 of the U.S. Nuclear Regulatory Commission (NRC) to include seismic amplification in the hazard is presented. Both 1D amplification related to stratigraphic conditions and 3D amplification due to basin effects are considered with the associated uncertainties, and their impact on the hazard is analyzed through a sensitivity analysis. Whereas 3D basin effects are considered through the application of an empirical, spatial invariant correction term, 1D amplification was estimated throughout the study area by means of dynamic (equivalent linear) ground-response analysis. To separate aleatory variabilities and epistemic uncertainties related to site response, a partially nonergodic approach is used. The results provide a finer picture of the actual seismic hazard, highlighting those areas where the ground motion is affected by amplification effects due to local or regional geological features. We found that, for a return period of 475 yr, neglecting basin effects produces a 30% underestimation of the seismic hazard in the long-period ( > 1 s) range. Moreover, with reference to the hazard model adopted, such effects are responsible for most of the epistemic uncertainty (up to 80%) in the results. Therefore, such effects deserve special attention in future research related to PSHA in the Po Plain sedimentary basin.Published1269–12855T. Sismologia, geofisica e geologia per l'ingegneria sismicaJCR Journa
Deep and shallow crustal structure control on the late-stage volcanism in Syria Planum (Mars)
No full textvolcanic
provinces with the largest shield volcanoes of the Solar System. However, volcanism on Mars is characterized
also by the occurrence of broad volcanic fields, either in the form of small lava shields or monogenic
volcanic cones. The region of Syria Planum (SP) is located east of the Tharsis province and between Noctis
Labyrinthus to the North and Claritas Fossae to the southwest. It is an example of diffuse volcanism, presenting
hundreds of small edifices (namely Syria Colles) which occur on top of a large bulge roughly 300 km × 200 km in
size. SP exhibits a complex magmatic and volcano-tectonic evolution spanning from the early-Noachian to the
more recent Amazonian. In this work, we investigate the geometry of the plumbing system of the SP volcanic
field as well as the geometries of the volcanic constructs (i.e., vent elongation and vent alignment) that may be
linked to the structures that fed the magma presenting a possible tectonic and volcanic evolution of the
distributed volcanism phase in this area. The spatial distribution of vents and the overall map view shape of the
volcanic field were studied in terms of vent clustering and spatial distribution. We show that the widespread and
diffuse volcanism in SP presents clear vent clusters that are related to a deep source magma reservoir located at
~100 km depth. We also show that Syria Colles vent elongations and azimuth distributions suggest that the
magma exploited the inherited regional structural framework, coherent with the Syria Colles late-stage
Amazonian magmatic event, and highlighting the role of a shallow crustal tectonic framework in shaping the
Martian volcanism.Published107830OST1 Alla ricerca dei Motori GeodinamiciJCR Journa
Exploring microstructure and petrophysical properties of microporous volcanic rocks through 3D multiscale and super-resolution imaging
No full textDigital rock physics offers powerful perspectives to investigate Earth materials in 3D and non-destructively. However, it has been poorly applied to microporous volcanic rocks due to their challenging microstructures, although they are studied for numerous volcanological, geothermal and engineering applications. Their rapid origin, in fact, leads to complex textures, where pores are dispersed in fine, heterogeneous and lithified matrices. We propose a framework to optimize their investigation and face innovative 3D/4D imaging challenges. A 3D multiscale study of a tuff was performed through X-ray microtomography and image-based simulations, finding that accurate characterizations of microstructure and petrophysical properties require high-resolution scans (≤ 4 μm/px). However, high-resolution imaging of large samples may need long times and hard X-rays, covering small rock volumes. To deal with these limitations, we implemented 2D/3D convolutional neural network and generative adversarial network-based super-resolution approaches. They can improve the quality of low-resolution scans, learning mapping functions from low-resolution to high-resolution images. This is one of the first efforts to apply deep learning-based super-resolution to unconventional non-sedimentary digital rocks and real scans. Our findings suggest that these approaches, and mainly 2D U-Net and pix2pix networks trained on paired data, can strongly facilitate high-resolution imaging of large microporous (volcanic) rocks.Published66512V. Struttura e sistema di alimentazione dei vulcaniJCR Journa
Cosimo De Giorgi e l’Abruzzo: ricerche geologiche e sismologiche tra 1876 e 1887
No full textDe Giorgi’s scientific activity in Abruzzi is mainly related to the geological surveys in the second half of the 1870s and to the involvement in the discussion about seismology in 1887, during the First Geodynamic Congress held in L’Aquila. Two scientific contributions on Bollettino del Regio Comitato Geologico d’Italia, published in 1877 and 1878 respectively, summarize the activity of 1870s. The former is related to geological investigations in the Pescara and Aterno river valleys, while the latter is the report of surveys in the area of Campo Imperatore (Gran Sasso chain) for the identification of lignite seams and bituminous schists potentially exploitable for industrial purposes. The work De Giorgi made at L’Aquila in 1887 is summarized in the text of the closing conference at the Geodynamic Congress, which gave him the opportunity to address arguments of overriding importance for Seismology at that time. Some of the points in De Giorgi’s discussion are still relevant today, as the earthquake prediction and the defense against the seismic damage by using appropriate building techniques. In the whole, summaries of the performed activities, considerations and conclusions reported in the publications give us the image of De Giorgi as a cutting-edge researcher, a leading representative of Earth Sciences in the second half of the 19th century, for both the methodological approach and the deep knowledge of the theories governing geology and seismology at that time.Published227-248OS: Terza missioneN/A or not JC
RAPPORTO DEL 2 OTTOBRE 2023
No full textIstituto Nazionale di Geofisica e Vulcanologia (INGV)Unpublished4T. Sismicità dell'Itali
Basin-scale interaction between post-LGM faulting and morpho-sedimentary processes in the S. Eufemia Gulf (Southern Tyrrhenian Sea)
No full textThe 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.Published108775OST2 Deformazione e Hazard sismico e da maremotoJCR Journa