428 research outputs found

    Recent deformation at Campi Flegrei caldera (Italy) detected by DinSar and leveling techniques

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    The Campi Flegrei caldera, a volcanic and densely populated area located to the west of Napoli (Italy), was characterized by rapid ground deformation during 1970-72 and 1982-84, for a total amount of 3.5 m in the city of Pozzuoli. Since 1985 a slow deflation was active, with episodic microcrises of uplifts. A new and consistent uplift event is now going on, beginning in November 2004, as revealed by spatial and terrestrial geodetic techniques. In particular, we adopt almost all the available ENVISAT ASAR data acquired from both ascending and descending orbits during 2002-2006, to generate mean deformation velocity maps and time series with spatial resolution of about 100 m. The maps are computed following the Small BAseline Subset (SBAS) approach (Berardino et al., 2002), that implements an appropriate combination of differential interferograms generated from SAR data pairs (60 SAR images for this work). In addition to satellite observations, we show data from the high precision levelling network of the INGV-Osservatorio Vesuviano, consisting in about 320 benchmarks. Levelling measurements are regularly carried out on both the whole network and along the coast line; in case of a bradyseismic crisis, the temporal sampling is strongly increased. Both DInSAR and levelling data evidence the maximum value of the vertical displacement near the city of Pozzuoli. We model the observed deformation by means of 3D pressurized point-source and extended source, performing inversions to constrain their shape and location. The resulting sources are also compared with that inverted for the 1982-84 unrest.UnpublishedWienope

    Recent deformation at Campi Flegrei caldera (Italy) detected by DinSar and leveling techniques

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    The Campi Flegrei caldera, a volcanic and densely populated area located to the west of Napoli (Italy), was characterized by rapid ground deformation during 1970-72 and 1982-84, for a total amount of 3.5 m in the city of Pozzuoli. Since 1985 a slow deflation was active, with episodic microcrises of uplifts. A new and consistent uplift event is now going on, beginning in November 2004, as revealed by spatial and terrestrial geodetic techniques. In particular, we adopt almost all the available ENVISAT ASAR data acquired from both ascending and descending orbits during 2002-2006, to generate mean deformation velocity maps and time series with spatial resolution of about 100 m. The maps are computed following the Small BAseline Subset (SBAS) approach (Berardino et al., 2002), that implements an appropriate combination of differential interferograms generated from SAR data pairs (60 SAR images for this work). In addition to satellite observations, we show data from the high precision levelling network of the INGV-Osservatorio Vesuviano, consisting in about 320 benchmarks. Levelling measurements are regularly carried out on both the whole network and along the coast line; in case of a bradyseismic crisis, the temporal sampling is strongly increased. Both DInSAR and levelling data evidence the maximum value of the vertical displacement near the city of Pozzuoli. We model the observed deformation by means of 3D pressurized point-source and extended source, performing inversions to constrain their shape and location. The resulting sources are also compared with that inverted for the 1982-84 unrest

    MONITORING THE CAMPI FLEGREI CALDERA BY EXPLOITING SAR AND GEODETICAL DATA: RECENT RESULTS AND FUTURE APPLICATIONS

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    Geodetical monitoring of the Campi Flegrei caldera (Naples, Italy), has been historically carried out by ground networks giving an information related only to a certain number of measuring points; this limitation can be greatly relieved by exploiting the space-borne DInSAR which allows to extract the geodetic information on wide areas, with a good time coverage in comparison with the mean repetition time of the campaign measurements. In this work we will show recent results on Campi Flegrei, obtained by using all the ENVISAT ASAR available data from both ascending and descending orbits. The processed data revealed that the uplift phase of Campi Flegrei, which became very clear in summer 2005 with an average velocity of about 2.8 mm/year, has definitely reduced the uplift velocity since spring 2007. This conclusion is consistent with independent deformation measurements carried out by the Vesuvius Observatory (INGV-OV). Differences, in terms of limits and potentialities of DInSAR with respect to classical geodetic techniques and vice-versa and the way they can be compared/integrated, is still a very interesting matter of debate suggesting, as an optimal solution for monitoring purposes in active volcanic areas, the integration of all the available techniques.UnpublishedFrascati1.10. TTC - Telerilevamentoope

    Geodetic model of the 2016 Central Italy earthquake sequence inferred from InSAR and GPS data

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    We investigate a large geodetic data set of interferometric synthetic aperture radar (InSAR)and GPS measurements to determine the source parameters for the three main shocks of the 2016Central Italy earthquake sequence on 24 August and 26 and 30 October (Mw6.1, 5.9, and 6.5,respectively). Our preferred model is consistent with the activation of four main coseismic asperitiesbelonging to the SW dipping normal fault system associated with the Mount Gorzano-Mount Vettore-Mount Bove alignment. Additional slip, equivalent to aMw~ 6.1ā€“6.2 earthquake, on a secondary (1) NEdipping antithetic fault and/or (2) on a WNW dipping low-angle fault in the hanging wall of the mainsystem is required to better reproduce the complex deformation pattern associated with the greatestseismic event (theMw6.5 earthquake). The recognition of ancillary faults involved in the sequencesuggests a complex interaction in the activated crustal volume between the main normal faults and thesecondary structures and a partitioning of strain releas

    A Genome-Wide Screening and SNPs-to-Genes Approach to Identify Novel Genetic Risk Factors Associated with Frontotemporal Dementia

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    Frontotemporal dementia (FTD) is the second most prevalent form of early onset dementia after Alzheimerā€™s disease (AD). We performed a case-control association study in an Italian FTD cohort (n = 530) followed by the novel SNPs-to-genes approach and functional annotation analysis. We identified two novel potential loci for FTD. Suggestive SNPs reached p-values ~10-7 and OR > 2.5 (2p16.3) and 1.5 (17q25.3). Suggestive alleles at 17q25.3 identified a disease-associated haplotype causing decreased expression of -cis genes such as RFNG and AATK involved in neuronal genesis and differentiation, and axon outgrowth, respectively. We replicated this locus through the SNPs-to-genes approach. Our functional annotation analysis indicated significant enrichment for functions of the brain (neuronal genesis, differentiation and maturation), the synapse (neurotransmission and synapse plasticity), and elements of the immune system, the latter supporting our recent international FTD-GWAS. This is the largest genome-wide study in Italian FTD to date. Although our results are not conclusive, we set the basis for future replication studies and identification of susceptible molecular mechanisms involved in FTD pathogenesis

    MONITORING THE CAMPI FLEGREI CALDERA BY EXPLOITING SAR AND GEODETICAL DATA: RECENT RESULTS AND FUTURE APPLICATIONS

    Get PDF
    Geodetical monitoring of the Campi Flegrei caldera (Naples, Italy), has been historically carried out by ground networks giving an information related only to a certain number of measuring points; this limitation can be greatly relieved by exploiting the space-borne DInSAR which allows to extract the geodetic information on wide areas, with a good time coverage in comparison with the mean repetition time of the campaign measurements. In this work we will show recent results on Campi Flegrei, obtained by using all the ENVISAT ASAR available data from both ascending and descending orbits. The processed data revealed that the uplift phase of Campi Flegrei, which became very clear in summer 2005 with an average velocity of about 2.8 mm/year, has definitely reduced the uplift velocity since spring 2007. This conclusion is consistent with independent deformation measurements carried out by the Vesuvius Observatory (INGV-OV). Differences, in terms of limits and potentialities of DInSAR with respect to classical geodetic techniques and vice-versa and the way they can be compared/integrated, is still a very interesting matter of debate suggesting, as an optimal solution for monitoring purposes in active volcanic areas, the integration of all the available techniques

    The 21 August 2017 Ischia (Italy) Earthquake Source Model Inferred From Seismological, GPS, and DInSAR Measurements

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    The causative source of the first damaging earthquake instrumentally recorded in the Island of Ischia, occurred on 21 August 2017, has been studied through a multiparametric geophysical approach. In order to investigate the source geometry and kinematics we exploit seismological, Global Positioning System, and Sentinel-1 and COSMO-SkyMed differential interferometric synthetic aperture radar coseismic measurements. Our results indicate that the retrieved solutions from the geodetic data modeling and the seismological data are plausible; in particular, the best fit solution consists of an E-W striking, south dipping normal fault, with its center located at a depth of 800 m. Moreover, the retrieved causative fault is consistent with the rheological stratification of the crust in this zone. This study allows us to improve the knowledge of the volcano-tectonic processes occurring on the Island, which is crucial for a better assessment of the seismic risk in the area.Published2193-22023T. Sorgente sismicaJCR Journa

    Comment on ā€œThe 21 August 2017 M d 4.0 Casamicciola Earthquake: First Evidence of Coseismic Normal Surface Faulting at the Ischia Volcanic Islandā€ by

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    We are writing this comment because many aspects of the analysis presented by Nappi et al. (2018) are debatable. In particular, a major issue is relevant to the conclusion suggested by Nappi et al. (2018) about a seismogenic normal fault with northward dip. This finding is not wellā€founded because the authors do not really present a causative source model. In addition, their statement is clearly not consistent with the Differential Interferometric Synthetic Aperture Radar (DInSAR), Global Positioning System (GPS) and seismological measurements presented in the article previously published by De Novellis et al. (2018). Moreover, we also report an evident error in the geologic map proposed by Nappi et al. (2018, their fig. 3).Published313-3156V. PericolositĆ  vulcanica e contributi alla stima del rischioJCR Journa
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