The Temporary Seismometric Network at Spoleto (Perugia, Italy)

SCIENTIFIC STAFF: Alessandro Vuan1, Marco Romanelli1, Carla Barnaba1, Andrea Restivo1, Lara Lovisa1, Enrico Priolo1, Giuliana Rossi1, Riccardo Cardinali2, Alessio Buccioli2, RESPONSIBLE SCIENTIST: Enrico Priolo1
1Centro Ricerche Sismologiche, Istituto Nazionale di Oceanografia e Geofisica Sperimentale, Cussignacco (UD) e Sgonico (TS)
2Comune di Spoleto (PG)

In 2005-2007, OGS was charged by the Spoleto Municipality (Comune di Spoleto) with the task of performing a geophysical study in view of the future microzonation of the historical centre. This study encompassed the registration of earthquakes through a temporary seismic network, the acquisition of environmental seismic noise, and the estimation of the shear wave velocity through active seismic methods.

The temporary network ---whose sites and data have been include into the OASIS database--- was deployed in December 2005 and remained effective till October 2006. Among other regional earthquakes, the network recorded the aftershock sequence of the ML4.2 local earthquake occurred on December 15, 2005. The temporary network of Spoleto was implemented using 11 seismological stations in synchronous acquisition. The instrumentation included different kinds of acquisition units (i.e. Reftek 130, Nanometrics Orion, and Lennartz MarsLite) all equipped with Lennartz 3D-Lite 1s short-period seismometer. A total of 17 sites, including one reference site, was monitored in two successive phases of acquisition (Fig. 1). Sites were chosen within or close to public or historical buildings (e.g. schools, hospitals, churches, ancient buildings, ...), according to the italian regulations and the indications provided by the Spoleto Municipality (Table 1). The reference site was located on rock on the top of the Spoleto hill.

Figure 1. Maps of the temporary seismometric network of Spoleto. Left: general overview; right: detail of the area.

Table 1. Summary of the sites of the temporary network deployed in Spoleto.