Sergio Guardato

National Institute of Geophysics and Volcanology | INGV · Vesuvius Observatory

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 mo...

Seafloor deformation monitoring is now performed in the marine sector of the Campi Flegrei volcanic area. MEDUSA infrastructure consists of 4 buoys at depths of 40-96m equipped with cGPS receivers, accelerometers and magnetic compasses to monitor buoy status and a seafloor module with a bottom pressure recorder. We study the seafloor deformation in...

An innovative fiber-optic hydrophone (FOH) was developed and investigated via an experiment at sea; it is capable of operating at a very low frequency of the seismic spectrum and detecting small magnitude earthquakes. The FOH exploits an optical fiber coil wrapped around a sensitive mandrel in a Michelson interferometric configuration. The FOH oper...

We developed and experimented at sea an innovative fiber optic hydrophone (FOH) capable of operating at very low frequency of the seismic spectrum and for detecting small magnitude earthquakes. The FOH exploits an optical fiber coil wrapped around a sensitive mandrel in a Michelson interferometric configuration. The FOH operated for about seven day...

In this paper, we report on the development and field test of a fiber optic seismic hydrophone. The seismic hydrophone was designed to offer performance suitable to operate with resolution down to the sea state zero in underwater environments. The sensing configuration exploits a fiber coil interferometer in Michelson configuration, wrapped around...

L'Istituto Nazionale di Geofisica e Vulcanologia (INGV) è componente del Servizio Nazionale di Protezione Civile, ex articolo 6 della legge 24 febbraio 1992 n. 225 ed è Centro di Competenza per i fenomeni sismici, vulcanici e i maremoti per il Dipartimento della Protezione Civile Nazionale (DPC). L’Osservatorio Vesuviano, Sezione di Napoli dell’ING...

The InSEA project (“Initiatives in Supporting the consolidation and enhancement of the EMSO research infrastructure consortium (ERIC) and related Activities”) has the objective, as the full name of the project indicates, to consolidate and strengthen the infrastructures concerning the EMSO (“European Multidisciplinary Seafloor and water column Obse...

Earthquake magnitude calibration using hydrophone records has been carried out at Campi Flegrei caldera, an active area close to the highly populated area of Naples city, partly undersea. Definite integrals of the hydrophone records amplitude spectra, between the limits of 1 and 20 Hz, were calculated on a set of small volcano-tectonic earthquakes...

We present the main features of the permanent monitoring system managed by the Istituto Nazionale di Geofisica e Vulcanologia-Osservatorio Vesuviano in the Campi Flegrei caldera. Eruptive history of this active volcano shows that the majority of the eruptive events has been characterised by high explosivity and was accompanied by pyroclastic densit...

Here, we report on the development and field test of a fiber optic seismic hydrophone. The sensing configuration exploits a fiber coil interferometer in Michelson configuration, wrapped around a sensitive composite cylinder. The materials and the size of the hydrophone were selected by numerical analysis in order to offer performance suitable to op...

We present 4 years of continuous seafloor deformation measurements carried out in the Campi Flegrei caldera (Southern Italy), one of the most hazardous and populated volcanic areas in the world. The seafloor sector of the caldera has been monitored since early 2016 by the MEDUSA marine research infrastructure, consisting of four instrumented buoys...

We show the equivalence of earthquake‐induced ground acceleration and water‐pressure waveforms for the case of collocated hydrophones and seafloor seismometers installed in shallow water. In particular, the comparison of the waveforms and amplitude spectra of the acceleration and water‐pressure signals confirms the existence of a frequency range of...

Measuring seafloor motion in shallow coastal water is challenging due to strong and highly variable oceanographic effects. Such measurements are potentially useful for monitoring near‐shore coastal subsidence, subsidence due to petroleum withdrawal, strain accumulation/release processes in subduction zones and submerged volcanoes, and certain fresh...

General description of infrastructure M.E.D.U.S.A (Monitoring Elastic-bacon Devices and Underwater Sensors Acquisition system)

We present an assessment of vertical seafloor deformation in the shallow marine sector of the Campi Flegrei caldera (Southern Italy) obtained from GPS and Bottom Pressure Recorder (BPR) data, acquired over the period April 2016 – July 2017 in the Gulf of Pozzuoli by a new marine infrastructure, MEDUSA. This infrastructure consists of four fixed buo...

Monitoring system designed for biological and marine environment observation are equipped with different types of sensors related to different disciplines. For each sensor integrated in the system it is necessary to develop a driver (software/firmware) specific to its operation. This kind of approach limits the system flexibility because the additi...

The following work represents the first vertical deformation measurement of the ground in coastal waters obtained through the use of a BPR sensor (Bottom Pressure Recorder) installed in shallow water, with an accuracy comparable with that of the measures carried out by a GPS network placed on the mainland. The described measurement method allows th...

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 centi...

Con l’estensione in mare del sistema di sorveglianza dell’area vulcanica dei Campi Flegrei [Guardato et al., 2015] nell’ambito del Progetto MIUR “EMSO-MedIT: Potenziamento delle infrastrutture multidisciplinari di ricerca marina in Sicilia, Campania e Puglia quale contributo alla ESFRI EMSO” sono ora disponibili 3 nuove boe (tipo meda elastica e/o...

The monitoring system of the Campi Flegrei caldera is made up of a dense geophysical network of seismological and geodetic instruments with data acquired and processed at the Monitoring Center of INGV in Naples. As one third of the caldera is covered by the sea, a marine monitoring system has been operating since 2008 in the center of the gulf of P...

La grande variabilità dei numerosi fattori fisici, chimici e biologici che caratterizzano in particolare l’ambiente marino, obbliga ad equipaggiare i sistemi progettati per il suo studio e monitoraggio con più tipologie di sensori relativi a differenti discipline, anche al fine di ottimizzare il costo di un’infrastruttura di osservazione sottomarin...

Questo rapporto tecnico nasce con lo scopo di completare il lavoro presentato nel Numero 226 di questa stessa collana editoriale [Guardato, 2012] in cui è ampiamente descritto l’hardware di un sistema di acquisizione dati a basso consumo, basato sul sistema operativo open-source Linux, per l’acquisizione di segnali digitali seriali provenienti da s...

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 sorveglianza dell’area vulcanica dei Campi Flegrei, sita in provincia di Napoli. Il sistema esistente, infatti, è costituito da varie reti di rile...

The marine sector of the Campi Flegrei caldera has started to be monitored over the long-term with a seafloor equipment deployed in the Gulf of Pozzuoli from 2008. The equipment includes a set of geophysical, oceanographic and environmental sensors integrated in a marine platform that was specifically designed for real-time monitoring. This platfor...

Questo rapporto tecnico descrive dettagliatamente l’hardware di un sistema di acquisizione dati, a basso consumo, basato sul sistema operativo open-source Linux, adatto per l’acquisizione di segnali da sensori multiparametrici. Il sistema in oggetto si presta adeguatamente per misure di monitoraggio ambientale effettuate mediante sensori, con uscit...

The continuous measurement of ground deformations is an important contribution to the monitoring of volcanic areas. When the volcano is totally or partially submerged, the traditional geodetic methods cannot be applied and the measures of seafloor deformation are extremely difficult and expensive. This paper describes the installation of a continuo...

Al fine di ottimizzare l’organizzazione e migliorare la sinergia tra le attività svolte presso le diverse Sezioni dell’Istituto Nazionale di Geofisica e Vulcanologia (INGV), a cavallo tra il 2004 il 2005 sono stati istituiti i Temi Trasversali Coordinati (TTC) ovvero delle strutture di coordinamento su argomenti di ricerca che interessavano Sezioni...

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 fea...

A 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 sele...

Geohazards monitoring can benefit greatly from the integration of seafloor and land observations, because many of the most seismogenic zones and active volcanoes are situated in oceanic basins. Similarly, many volcanic and seismic areas located in coastal zones extend their activities into nearby marine sectors. The known features of these marine a...

RaMonA (radon monitoring and acquisition) is a compact device, developed by our laboratory, having the aim to perform the continuous monitoring of radon daughters collected on a silicon detector by an electrostatic field. In this paper the latest version of the system is presented, obtained after an updating process developed with these main object...