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Guardato, Sergio
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Guardato, Sergio
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sergio.guardato@ingv.it
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staff
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37047106100
41 results
Now showing 1 - 10 of 41
- PublicationOpen AccessA new method to assess long-term sea-bottom vertical displacement in shallow water using a bottom pressure sensor: Application to Campi Flegrei, Southern Italy(2016-11-28)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; We present a new methodology using bottom pressure recorder (BPR) measurements in conjunction with sea level, water column, and barometric data to assess the long-term vertical seafloor deformation to a few centimeters accuracy in shallow water environments. The method helps to remove the apparent vertical displacement on the order of tens of centimeters caused by the BPR instrumental drift and by seawater density variations. We have applied the method to the data acquired in 2011 by a BPR deployed at 96m depth in the marine sector of the Campi Flegrei Caldera, during a seafloor uplift episode of a few centimeters amplitude, lasted for several months. The method detected a vertical uplift of the caldera of 2.5 +/-1.3 cm achieving an unprecedented level of precision in the measurement of the submarine vertical deformation in shallow water. The estimated vertical deformation at the BPR also compares favorably with data acquired by a land-based GPS station located at the same distance from the maximum of the modeled deformation field. While BPR measurements are commonly performed in deep waters, where the oceanic noise is relatively low, and in areas with rapid, large-amplitude vertical ground displacement, the proposed method extends the capability of estimating vertical uplifts from BPR time series to shallow waters and to slow deformation processes.730 39 - PublicationOpen AccessCUMAS: a seafloor multi-sensor module for volcanic hazard monitoring - First long-term experiment and performance assessment(2009)
; ; ; ; ; ; ;Iannaccone, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Guardato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Vassallo, M.; AMRA, Analisi e Monitoraggio dei Rischi Ambientali ;Stabile, T. A.; AMRA, Analisi e Monitoraggio dei Rischi Ambientali ;Elia, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Beranzoli, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; ; ; ; ; ; ;EOS; AGUA seafloor multi-sensor module with real-time data transmission, named CUMAS (Cabled Underwater Module for Acquisition of Seismological data), has been deployed in January 2008 in the Gulf of Pozzuoli, in the Campi Flegrei caldera (southern Italy), which is one of the most active volcanic areas in the world. The sensors installed in CUMAS were selected to monitor a set of signals related to the local seismicity as well as the ground uplift and subsidence of the seafloor that are related to the bradyseismic phenomenon. In particular, together with a broad-band three-component seismometer and a low-frequency hydrophone, a seafloor water-pressure sensor is used to assess the feasibility of measurements of the slow vertical movement of the seafloor (bradyseism). Further sensors are acquired by two embedded Linux computers, namely tilt and heading sensors for the measure of the actual module orientation on the seafloor, and status sensors that monitor the state of health of the vessel (e.g., internal temperature, power absorption, water intrusion). The underwater acquisition systems are linked to a support infrastructure, a floating buoy (elastic beacon), through an electro-mechanical cable with an Ethernet line. The buoy provides the needed power supply thanks to batteries charged by solar panels and a wind- generator. A Wi-Fi antenna on the buoy is used to transmit the seafloor data from the sea surface to the land acquisition centre in the city of Naples. A meteorological station is also mounted on the buoy, to allow the correlation of the air and seafloor data. CUMAS, although based on commercial sensors, relies on an original system for the centralized management of a wide set of geophysical and physical oceanographic sensors, that handles the continuous data acquisition and real-time data transmission. After the installation in the Gulf of Pozzuoli at about 100 m w.d., and after a test period, CUMAS uninterruptedly operated from May 2008 to June 2009, thus providing continuous geophysical data to the Monitoring Center of the Campi Flegrei volcanic areas, managed by the Istituto Nazionale di Geofisica e Vulcanologia. The long-term operational performance of CUMAS is presented here, together with the first results from the analysis of the geophysical long time-series acquired. Examples of the acquired signals, especially geophysical data, will be presented to point out the high quality in term of signal-to-noise ratio. In particular, earthquake recordings obtained from the hydrophone resulted of comparable quality to the seismic data acquired on land by the permanent network, thus demonstrating the suitability of hydrophones to monitor the seismic activity of the caldera.184 130 - PublicationOpen Access
36 29 - PublicationOpen AccessProtocollo di comunicazione del sistema di acquisizione dati Quanterra Q330(2007)
; ; ;Guardato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Iannaccone, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; 100 112 - PublicationRestrictedA new Multidisciplinary Marine Monitoring system for the surveillance of Volcanic and seismic areas(2009-03)
; ; ; ; ; ;Iannaccone, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Guardato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Vassallo, M.; Dipartimento di Scienze Fisiche, Università di Napoli “Federico II”; Analisi e Monitoraggio del Rischio Ambientale Scarl ;Elia, L.; Analisi e Monitoraggio del Rischio Ambientale Scarl ;Beranzoli, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; ; ; ; A seafloor multisensor module with real-time data transmission, known as CUMAS, has been successfully deployed in the Gulf of Pozzuoli, in the Campi Flegrei caldera, which is one of the most hazardous volcanic areas in the World. CUMAS records seismological signals and provides measurements related to the water-current system. A test for the detection of sea level changes, potentially related to the seafloor uplift or subsidence, is ongoing with the use of the pressure gauge data. A surface buoy is equipped with additional sensors for meteorological measurements and receives the continuous scientific and status data streams from the CUMAS station via cable. These data are then transmitted by a wireless system to the INGV monitoring center in Naples. CUMAS is fully integrated into the geophysical land-based monitoring system that is managed by INGV, and it is the first off-shore station of the local network. An Earthworm-based system provides userfriendly data visualization and retrieval, which was adopted to straightforwardly integrate all of the data acquired by CUMAS with the land data, which is managed by a similar system. Following the results of a previous investigation performed using two ocean-bottom seismometers that were deployed in Pozzuoli Bay (Vassallo et al. 2008), CUMAS was deployed in a site that was selected to improve the performance of the present seismic network in terms of the detection threshold of the local seismicity and of hypocenter errors. CUMAS will provide long time-series data that will allow, for the first time, the study of the evolution of the volcanic activity and related phenomena in the marine sector of the Campi Flegrei caldera, which to date has only been investigated on the basis of land data. CUMAS is the first node of a marine network that is at present the subject of a feasibility study that will cover most of the submerged Campi Flegrei volcanic area and will be integrated into the local monitoring systems.393 35 - PublicationOpen AccessInterfaccia RS-485 per il GPS degli acquisitori Kinemetrics(2005)
; ; ;Guardato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Iannaccone, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; 155 561 - PublicationOpen AccessCUMAS (Cabled Underwater Module for Acquisition of Seismological data): a new seafloor module for geohazard monitoring of the Campi Flegrei volcanic area(2007)
; ; ; ; ;Iannaccone, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Guardato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Vassallo, M.; Dipartimento di Scienze Fisiche, Università degli Studi di Napoli Federico II, Italy ;Beranzoli, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; 183 223 - PublicationRestrictedLong-term seafloor experiment with the CUMAS module: performance, noise analysis of geophysical signals, and hints towards the design of a permanent network(2010)
; ; ; ; ; ; ; ;Iannaccone, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Vassallo, M.; AMRA Scarl, Via Nuova Agnano, 11 - 80125 Napoli, Italy ;Elia, L.; AMRA Scarl, Via Nuova Agnano, 11 - 80125 Napoli, Italy ;Guardato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Stabile, T. A.; Dipartimento di Scienze Fisiche, Università di Napoli “Federico II”, Napoli, Italy ;Satriano, C.; AMRA Scarl, Via Nuova Agnano, 11 - 80125 Napoli, Italy ;Beranzoli, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; ; ; ; ; ; The Campi Flegrei caldera (southern Italy) is one of the most hazardous areas in the World as several hundred thousand people live there and where important socio-economic activities have developed. The caldera includes the western-most part of the city of Naples and extends into the Gulf of Pozzuoli (eastern Tyrrhenian basin; Fig. 1). The main feature of the present volcanic activity of the caldera is the episodic slow and high-amplitude soil movement (bradyseism) accompanied by intense and shallow seismic activity that only occurs during the uplift phase.494 44 - PublicationOpen AccessSpecifiche tecniche del progetto di potenziamento a mare del sistema di sorveglianza dell’area vulcanica dei Campi Flegrei(2015-04-24)
; ; ;Guardato, Sergio; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Iannaccone, Giovanni; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; L’Istituto Nazionale di Geofisica e Vulcanologia per lo svolgimento delle attività istituzionali condotte dalla Sezione di Napoli - Osservatorio Vesuviano, ha necessità di estendere in mare il sistema di sorveglian- za dell’area vulcanica dei Campi Flegrei, sita in provincia di Napoli. Il sistema esistente, infatti, è costituito da varie reti di rilevamento di parametri geofisici e geochimici, tutte centralizzate presso la sede dell’Osservatorio, con punti stazione ubicati sulla terraferma. Solo una stazione sperimentale, denominata CUMAS (Cabled Underwater Multidisciplinary Acquisition System), è operativa nel Golfo di Pozzuoli a cir- ca 2.4 km a sud del Rione Terra. (Per una descrizione dei sistemi di monitoraggio gestiti dall’Osservatorio Vesuviano si rimanda al sito www.ov.ingv.it). Il progetto di potenziamento “EMSO-MedIT: Potenziamento delle infrastrutture multidisciplinari di ricerca marina in Sicilia, Campania e Puglia quale contributo alla ESFRI EMSO”, finanziato dal MIUR, ha fornito le risorse per realizzare un sistema di monitoraggio permanente anche nella parte sommersa dei Cam- pi Flegrei. Il presente rapporto tecnico descrive questo sistema di monitoraggio marino costiero per dati geofisici da fondo mare, da installare nel Golfo di Pozzuoli, che prevede l’acquisizione in continuo e la relativa tra- smissione dei dati in tempo reale verso la sala di sorveglianza sismica-vulcanica dell’Osservatorio. Esso sarà costituito da tre sistemi di acquisizione dati indipendenti ognuno composto da una boa (tipo meda elastica e/o a palo) connessa via cavo elettromeccanico (per l’energizzazione e la comunicazione) ad un modulo mul- ti-parametrico posizionato sul fondo del mare, ad una distanza massima di venti metri dal corpo morto (costi- tuente la zavorra a cui è ancorata la boa), ed equipaggiati con strumentazione elettronica di controllo e di ri- levamento di parametri geofisici.163 109 - PublicationOpen AccessOn the seafloor horizontal displacement from cGPS and compass data in the Campi Flegrei caldera(2023)
; ; ; ; ; ; ; ; ;; ; ; ; Seafloor deformation monitoring is now routinely performed in the marine sector of the Campi Flegrei volcanic area (Southern Italy). The MEDUSA infrastructure is formed by four buoys deployed at a water depth ranging from 40 to 96 m, and equipped with cGPS receivers, accelerometers and magnetic compasses to monitor the buoy status and a seafloor module with a bottom pressure recorder and other onboard instruments. The analysis of the time series data acquired by the MEDUSA monitoring infrastructure system allows to study the seafloor deformation in the Campi Flegrei caldera with geodetic accuracy. In a previous work, we show that the time series acquired by the Campi Flegrei cGPS onland network and MEDUSA over the period 2017–2020 are in good agreement with the ground deformation field predicted by a Mogi model which is widely used to describe the observed deformation of an active volcano in terms of magma intrusion. Only for one of the buoys, CFBA (A), the data differ significantly from the model prediction, at a level of 6.9 σ and of 23.7 σ for the seafloor horizontal speed and direction, respectively. For this reason, we devised a new method to reconstruct the horizontal sea bottom displacement considering in the analysis both cGPS and compass data. The method, applied to the CFBA buoy measurements and validated also on the CFBC (C) buoy, uses compass data to correct cGPS positions accounting for the pole inclination. Including also systematic errors, the internal consistency, always within ∼ 3 σ for the speed and ∼ 2 σ for the angle, between the results derived for different maximum inclinations of the buoy pole (up to 3.5◦) indicates that the method allows to significantly reduce the impact of the pole inclination which, if not properly taken into account, can alter the estimation of the horizontal seafloor deformation. In particular, we find a good convergence of the retrieved velocity and deformation angle as we include in the analysis data from increasing values of the buoy pole inclination. Taking the result derived assuming the maximum allowed cutoff and accounting for statistical and systematic errors, we found a speed v = (3.521 ± 0.039 (stat) ± 0.352 (syst)) cm/yr and a deformation direction angle α = (−115.159 ± 0.670 (stat) ± 7.630 (syst))◦ (statistical errors at 1 σ quoted from the rms of their values, main systematic errors added linearly). The relative impact of the main potential systematic (statistical) effects increases (decreases) with the cutoff. Our analysis provides a horizontal speed consistent with the model at a level of 5.2 σ (stat only) or of 0.5 σ (stat and syst added linearly), and a deformation angle consistent with the model at 4.3 σ level (stat only) or at 0.3 σ level (stat and syst added linearly). Correspondingly, the module of the vectorial difference between the velocity retrieved from the data and the velocity of the adopted Mogi model diminishes by a factor of 7.65 ± 1.23 (stat) or ± 5.78 (stat + syst) with respect to the previous work. A list of potential improvements to be implemented in the system and instruments is also discussed.135 5