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Pondrelli, Silvia
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Pondrelli, Silvia
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silvia.pondrelli@ingv.it
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staff
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- PublicationOpen AccessThe role of women in the geosciences: the case of INGV in preparing and managing the emergencies(2024-09-03)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; It is well known that in the geosciences (as in all STEM disciplines), the percentage of women in top positions decreases in favor of men, despite comparable academic careers and, sometimes, even better results for women. The authors of this contribution hold managerial roles in preparing and managing seismic and tsunami emergencies at INGV. It has been a long journey, but it is now a positive reality. But it has sometimes been different! Since its establishment in 1999, the INGV has undergone significant growth and transformation. De Lucia et al. in 2021 [1] analyzed gender diversity within the organization, revealing that the workforce comprised 38% female and 62% male. While these proportions have remained relatively stable over subsequent years, nuances emerge when examining gender distribution with higher representation of women in administrative roles and men in technical positions. What is slowly changing in recent years is the presence of women in research and managerial leadership positions. Notably, between 2016-2020, a woman served as General manager and, since 2017, one of the three Department Directors (Environment, Earthquakes and Volcanoes) is a woman. Currently, 4 out of the 10 Directors of the INGV Offices are women, reflecting a positive trend towards gender parity in leadership roles. Additionally, both the recently elected INGV members of the Scientific Council are women, underscoring the growing influence of female voices in shaping scientific discourse and decision-making. In the present day, an increasing number of women fulfill pivotal roles across research, technical, and administrative realms, actively contributing to coordination and leadership. Notable instances include women actively engaged in the preparation and execution of seismic, volcanic and tsunami emergency protocols. Their responsibilities encompass crucial tasks and providing support services for emergency response teams (including operational rooms for seismic, volcanic, and tsunami surveillance, network monitoring infrastructures, or emergency response teams). In this contribution, the authors recount their experiences.33 7 - PublicationOpen AccessHighlights on mantle deformation beneath the Western Alps with seismic anisotropy using CIFALPS2 data(2024-07-15)
; ; ; ; ; ; ; ; ; ; ; ; ; ;Milano-Bicocca ; ;; ; ;There are still open questions about the deep structure beneath the Western Alps. Seismic velocity tomographies show the European slab subducting beneath the Adria plate, but all these images did not clarify completely the possible presence of tears, slab windows, or detachments. Seismic anisotropy, considered an indicator of mantle deformation and studied using data recorded by dense networks, allows a better understanding of mantle flows in terms of location and orientation at depth. Using the large amount of shear wave-splitting and splitting-intensity measurements available in the Western Alps, collected through the CIFALPS2 temporary seismic network, together with already available data, some new patterns can be highlighted, and gaps left by previous studies can be filled. Instead of the typical seismic anisotropy pattern parallel to the entire arc of the Western Alps, this study supports the presence of a differential contribution along the belt that is only partly related to the European slab steepening. A nearly north–south anisotropy pattern beneath the external Western Alps, a direction that cuts the morphological features of the belt, is clearly found with the new CIFALPS2 measurements. It is, however, confirmed that the asthenospheric flow from central France towards the Tyrrhenian Sea is turning around the southern tip of the European slab.8 4 - PublicationEmbargoReappraising the 25 February 1695 Asolano Earthquake(2024)
; ; ; ; ; ; ; The 1695 Asolano earthquake (Mw 6.4) is the southernmost of the six largest earthquakes to have occurred in NE Italy or nearby (the others being: 1348, Mw 6.6, Eastern-Alps; 1511, Mw 6.3, Friuli-Slovenia; 1873, Mw 6.2, Alpago-Cansiglio; 1936, Mw 6.1, Alpago-Cansiglio; 1976, Mw 6.4, Friuli). The 1695 earthquake is generally associated with the Montello thrust, most recent studies locating it on the eastern slope of the Montello hill. A full-scale reappraisal of all available historical data leads this study to a more robust macroseismic localization of the 1695 earthquake and to open toward other possible locations of the seismic source that produced it. In particular, it becomes feasible to place its epicenter at the foothills of the Monte Grappa massif, the major morphological expression of the Bassano-Valdobbiadene thrust fault. Here we describe the reasons that make this fault a possible alternative to previous hypotheses.53 3 - PublicationOpen AccessReproducing complex anisotropy patterns at subduction zones from splitting intensity analysis and anisotropy tomography(2023-08-31)
; ; ; ; ; ; ; ; ; ; ; ; ; Measurements of seismic anisotropy provide a lot of information on the deformation and structure as well as flows of the Earth’s interior, in particular of the upper mantle. Even though the strong and heterogeneous seismic anisotropic nature of the upper mantle has been demon- strated by a wealth of theoretical and observational approaches , most of standard teleseismic body-wave tomography studies overlook P- and S-wave anisotropy, thus producing artefacts in tomographic models in terms of amplitude and localization of heterogeneities. Conven- tional methods of seismic anisotropy measurement have their limitations regarding lateral and mainly depth resolution. To overcome this problem much effort has been done to develop tomographic methods to invert shear wave splitting data for anisotropic structures, based on finite-frequency sensitivity kernels that relate model perturbations to splitting observations. A promising approach to image the upper mantle anisotropy is the inversion of splitting intensity (SI). This seismic observable is a measure of the amount of energy on the transverse component waveform and, to a first order, it is linearly related to the elastic perturbations of the medium through the 3-D sensitivity kernels, that can be therefore inverted, allowing a high-resolution image of the upper mantle anisotropy. Here we present an application of the SI tomography to a synthetic subduction setting. Starting from synthetic SKS waveforms, we first derived high-quality SKS SI measurements; then we used the SI data as input into tomographic inver- sion. This approach enables high-resolution tomographic images of upper-mantle anisotropy through recovering vertical and lateral changes in anisotropy and represents a propaedeutic step to the real cases of subduction settings. Additionally this study was able to detect regions of strong dipping anisotropy by allowing a 360◦ periodic dependence of the splitting vector.54 20 - PublicationOpen AccessPeeking inside the mantle structure beneath the Italian region through SKS shear wave splitting anisotropy: a review(2023)
; ; ; ; ; ; ; ; ; Over 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.180 73 - PublicationOpen AccessEsercitazione nazionale “Exe Sisma dello Stretto 2022” 04-06 novembre 2022. Rapporto di sintesi del Gruppo Operativo SISMIKO.(2022-12-05)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Da venerdì 4 novembre a domenica 6 novembre 2022, si è tenuta una esercitazione nazionale denominata “Exe Sisma dello Stretto 2022” in un'area del territorio della Regione Calabria e della Regione Sicilia caratterizzata da una elevatissima pericolosità sismica. L’esercitazione è stata indetta e coordinata dal Dipartimento della Protezione Civile e aveva l’obiettivo di verificare la risposta operativa a un evento sismico significativo del Servizio Nazionale della Protezione Civile, di cui anche l’Istituto Nazionale di Geofisica e Vulcanologia fa parte. Durante le tre giornate, l’INGV ha avuto modo di testare tutte le procedure che l’Istituto ha codificato a partire da quelle del “Protocollo di Ente per le emergenze sismiche e da maremoto”. Dopo che INGV ha dato l’avvio all’intera esercitazione simulando il terremoto di magnitudo MW 6.2 (ML 6.0) alle ore 09:00 UTC in provincia di Reggio Calabria (5 km a SW dal comune di Laganadi), e ha, quindi, inviato il messaggio per il potenziale maremoto con un livello di allerta arancione; inoltre, il Presidente INGV ha prontamente convocato l’Unità di Crisi e attivato tutti Gruppi Operativi. Questi ultimi, nell’ambito dello scenario esercitativo, hanno verificato che i flussi di comunicazione interna e tutte le attività necessarie in emergenza sismica, presenti nei relativi protocolli operativi, risultassero rispettati. L’obiettivo primario dell’esercitazione è stato quindi quello di validare le attività previste e di aggiornare il personale afferente ai Gruppi Operativi stessi. Tra di essi, SISMIKO, che rappresenta il GO dedicato al coordinamento delle reti sismiche mobili INGV in emergenza, nelle settimane precedenti l’esercitazione ha predisposto tutte le attività che intendeva testare, descrivendole brevemente nel Documento d’impianto INGV e con maggior dettaglio in quello del Gruppo Operativo. A pochi giorni dalla chiusura dell’esercitazione, un terremoto di magnitudo ML 5.7 (MW 5.5) registrato alle ore 06:07 UTC del 09 novembre 2022 ha spostato l’attenzione dalla simulazione alla realtà.432 122 - PublicationRestrictedAlong-strike variations in the fossil subduction zone of the Western Alps revealed by the CIFALPS seismic experiments and their implications for exhumation of (ultra-) high-pressure rocks(2022-11-15)
; ; ; ; ; ; ; ; ; ; ; ; ; ;; ; ; ;; ; ; ; ;In complex plate-boundary settings, a reliable 3-D geophysical characterization of the deep tectonic structure is a fundamental starting point for a breakthrough in the analysis of processes controlling plate subduction and (U)HP rock exhumation. The Western Alps host one of the best-studied fossil subduction zones worldwide, with a well-defined deep structure in 2-D based on recent geophysical experiments. However, a full 3-D characterization of its deep tectonic structure is still lacking. Here we present a series of new receiver function cross-sections across the northern and southern Western Alps, validated and complemented by a S-wave velocity model from ambient-noise tomography that provides additional constraints between the profiles. We document a marked change in Moho attitude from the northern Western Alps, where the eastward-dipping European Moho reaches ∼45 km depth beneath the Gran Paradiso dome, to the southern Western Alps, where the European Moho reaches ∼70 km depth beneath the equivalent Dora-Maira dome. This change in Moho attitude takes place over a few tens of kilometers and was likely emphasized by deformation of the slab during subduction. The Western Alps subduction wedge is much thicker in the south than in the north, and the mantle-wedge rocks are deeply involved in orogeny exclusively in the south, where coesite is found in continental (U)HP rocks at several locations. Our detailed information on the 3-D structure of the subduction wedge provides first-order constraints for the next-generation of thermo-mechanical numerical models and may help explain the lateral variations in exhumation style revealed by the geologic record.183 2 - PublicationOpen AccessSeismic anisotropy across Adria plate, from the Apennines to the Dinarides(2022-08-25)
; ; ; ; ; ; ; ; ; ; ;The Adria microplate has the particular feature to be involved in two subduction systems with slab dipping in opposite directions, one toward west beneath the Apennines and the other to the east beneath the Dinarides. The deep structure of Adria and the shape and characteristics of the slabs have mainly been studied through seismic tomography. However, the uncertainty about the presence and dimensions of tear and windows along the Apennines and the Dinarides slabs is still large. An instrument that can be used to draw mantle flows and to support the possible presence of slab windows or tears is the detection of seismic anisotropy, in particular core phases shear wave splitting. In this paper, to give more light to the structure of Adria slabs and possible mantle circulation beneath this microplate, we benefit from data recorded by seismic stations located along a profile running across the central Adriatic from the Apennines to the edge of the Panonnian basin. The new measurements, together with previous findings, show an evident change of the anisotropic properties when moving along the profile. The distribution of SKS-splitting measurements in the Apennines strongly agree with previous measurements that already described the toroidal flow generated by the slab rollback of the Calabrian arc. In addition, the N-S and NE-SW directions found beneath the Apulia are in agreement with those attributed previously in the outer northern Apennines, to a proper typical pattern of the mantle beneath Adria, which is undeformed by the slab retreat. The pattern of the anisotropy in the Dinarides region shows lateral and vertical variations that together with recent tomographic images that better define the slab window allow us to speculate as follows: the new SKS measurements, interpreted in terms of mantle deformation and flows, agree with the geodynamic model that justifies the mantle circulation beneath Adria with the presence of slab windows in both the Apennines and Dinarides slabs.236 20 - PublicationOpen AccessAn updated area-source seismogenic model (MA4) for seismic hazard of Italy(2022-08)
; ; ; ; ; ; ; ; ; ; ; A new probabilistic seismic hazard model, called Modello di Pericolosità Sismica 2019 (MPS19), has been recently proposed for the Italian territory, as a result of the efforts of a large national scientific community. This model is based on 11 groups of earthquake rupture forecast inputs and, particularly, on 5 area-source seismogenic models, including the so-called MA4 model. Data-driven procedures were followed in MA4 to evaluate seismogenic parameters of each area source, such as upper and lower seismogenic depths, hypocentral-depth distributions, and nodal planes. In a few cases, expert judgement or ad hoc assumptions were necessary due to the scarcity of data. MA4 consists of 20 seismicity models that consider epistemic uncertainty in the estimations of the completeness periods of the earthquake catalogue, of maximum magnitude values and of seismicity rates. In particular, five approaches were adopted to calculate the rates, in the form of the truncated Gutenberg–Richter frequency–magnitude distribution. The first approach estimated seismicity rates using earthquakes located in each area source, while the other approaches firstly calculated the seismicity rates for groups of areas considered tectonically homogeneous and successively partitioned in different ways the values to the area forming each group. The results obtained in terms of seismic hazard estimates highlight that the uncertainty explored by the 20 seismicity models of MA4 is at least of the same order of magnitude as the uncertainty due to alternative ground motion models.495 17 - PublicationOpen AccessPreparazione alle emergenze sismiche. Seconda esercitazione nazionale INGV per posti di comando (20 novembre 2019)(2022-01-12)
; ; ; ; ; On November 20, 2019, an exercise was held at the National Institute of Geophysics and Volcanology (INGV) as part of the activities planned for preparing for seismic emergencies. The training was "tabletop" with the simulation of an earthquake with a magnitude greater than the threshold required for the activation of the intervention procedures, described in the "Protocol of the Authority for the management of seismic and tsunami emergencies and Establishment of the Crisis Unit”, the flow of actions that follow was verified. The exercise involved the entire INGV even if the Rome headquarters was the most involved, and it was the second of this type after that carried out in 2015 [Pondrelli et al., 2016]. Main motivation of this training was the analysis of the efficiency of the Organization Protocol, a document that for the first time at INGV codifies the actions of the Crisis Unit and of the Institute in general on the occurrence of seismic events and / or seismic sequences and / or tsunamis. The Protocol has been formalized on the basis of the numerous experiences that the Institute has supported over many years, to honour its vocation in the monitoring and seismic surveillance of the national territory [Margheriti et al., 2021].384 36