Seismic Surveillance of Active Volcanoes: The Osservatorio Vesuviano Seismic Network (OVSN, Southern Italy)

Since 1970 the Osservatorio Vesuviano (Vesuvius Observatory of Naples, Italy) has maintained local seismic networks to monitor the active volcanoes of the Neapolitan area (Vesuvio, Campi Flegrei, Ischia island) as well as the most active seismic zone of the Campania Region and Southern Apennines. During 2000-2001 the local seismic networks in the volcanic regions and the regional network were restructured and unified to form the Osservatorio Vesuviano Seismic Network (OVSN) with the purpose of improving the quality of the recorded data and the consistency of data processing

A new standard for seismic station installation of the Osservatorio Vesuviano Surveillance Network (INGV, Napoli)

Seismic networks are worldwide diffuse to monitor both volcanic and tectonic seismogenetic areas. Some differences, such the basement on which the seismometer is located and the environmental conditions, characterize the installation of seismic stations in volcanic and tectonic areas. Nevertheless, some basic principles are common. To obtain good quality seismic data is very important to realize a high grade installation of all the instruments equipping a seismic station. Several procedure must be taken into account to optimize the instrument setting up. Electronic noise may be minimize using proper connecting line and adequate grounding. Effective lightning protections are essential to save instruments from both surges and strikes. Good seismometer ground coupling improves the signal quality and the signal-to-noise ratio. These procedures have been carried out at the Osservatorio Vesuviano to improve the existing seismic network as well as the installation of the new stations. As a result of this action an improvement of both the signal-to-noise ratio and the network reliability has been obtained

Stazioni sismiche obsolete: il recupero del Sistema Lennartz PCM 5800

The modern digital seismic stations are provided with 24 bit A/D converters, high capacity recording systems and broad-band seismometers. Nevertheless, few tens year old seismic stations can be still able to give an useful contribution to seismic monitoring. Some out-of-date seismic stations, such as the Lennartz PCM 5800, are characterized by the data acquisition in trigger mode on magnetic tape, allowing a continuous recording time of about 90 minutes. We have checked the possibility to substitute the Uher tape recorder of the Lennartz PCM 5800 stations with modern digital recorder, in order to give a new life to these stations. Several type of digital recorders have been tried. According to the results of our trials, the Hi-MiniDisc (Hi-MD) recorder is resulted the most useful one. This apparatus records on 1GB magneto-optical disks with a continuous recording time up to about 8 hours. This time allows to record about 500 trigger windows of about 50-60 seconds on one disk, about 5 time the old magnetic tape. According with these results, the Lennartz PCM 5800 digital seismic stations can be useful during seismic experiments or as a support of the Permanent Seismic Networks at local and regional scale

Full Spectrum

Reaching an organization's highest levels — ascending to the “C-suite” as it is often termed — is the goal of leaders in both the academic and corporate world. To reach the highest ranks of an organization is not only difficult, but is also a journey hampered by many obstacles. It is not sufficient to be technically proficient and have people skills. It is also imperative to be politically savvy, possess tremendous resilience, and have superior networking capabilities

La Rete Sismica Permanente dell'Osservatorio Vesuviano

A partire dal Febbraio 2000 è stata effettuata la ristrutturazione delle attività di monitoraggio sismologico dell’Osservatorio Vesuviano che ha determinato l’omogeneizzazione tecnologica delle singole reti operanti sulle aree vulcaniche attive napoletane ed a scala regionale inglobandole in un’unica Rete Sismica Permanente a Corto Periodo con le caratteristiche salienti di un’alta standardizzazione dei siti e delle installazioni nonché dell’intera catena strumentale. Questa iniziativa è stata intrapresa per garantire l’ottimale coordinamento delle attività di monitoraggio nonché per migliorare la qualità dei dati raccolti e standardizzare i criteri di installazione delle singole stazioni sismiche. Tenendo presente che la maggior parte delle stazioni è installata all’interno di aree densamente urbanizzate, e quindi caratterizzate da un elevato rumore di fondo, particolare attenzione è stata posta nel posizionamento dei sismometri, migliorando l’accoppiamento con il substrato. E’ stato incrementato, inoltre, il numero delle stazioni installate ottenendo geometrie di rete ottimali per le singole aree sismogenetiche. Sono state realizzate, infine, specifiche procedure per la calibrazione (automatica e periodica) delle catene strumentali per ottenere un controllo costante sui livelli di risposta degli strumenti installati. Un altro passo importante compiuto in quest’anno è stato l’installazione di stazioni della Rete Sismica Digitale a Larga Banda Centralizzata, strumento importante per lo studio di segnali sismici legati all’attività magmatica. In questo rapporto vengono illustrati i criteri di miglioramento ed ottimizzazione seguiti, gli standard qualitativi raggiunti e le schede tecniche di tutte le stazioni della Rete Sismica Permanente