The Seismometric Network of Collalto (Treviso, Italy)

SCIENTIFIC STAFF: Enrico Priolo1, Marco Romanelli1, Milton Plasencia1, Paolo Bernardi1, Marco Garbin1, Paolo Marotta2
1Centro Ricerche Sismologiche, Istituto Nazionale di Oceanografia e Geofisica Sperimentale, Cussignacco (UD) e Sgonico (TS)
2External collaboration

The Collato permanent network aims at monitoring the gas storage activity performed by Edison Stoccaggio s.p.a. in the underground natural reservoir named "Montello-Collalto", located in the Veneto Region near the town of Susegana (Treviso). The network is registered with FDSN with code EV. Since this network aims at recording both the natural seismicity and the induced seismicity, it has been designed with features of high sensitivity, high dynamics and wide frequency range.

This network is operating since December 1st, 2012. Continuous data can be freely downloaded.

The network consists of 10 sites, specifically built-up for the purpose (Fig. 1). However, the monitoring system acquires some other stations of the North-Eastern Italy Broad-Band and Short-Period permanent networks managed by OGS (network codes NI and FV, respectively). All the EV sites hosts the seismometric sensors within boreholes, at dephts ranging from 5m to 155m (Table 1).

Figure 1. Maps of the Collalto seismometric network. Left: general overview; right: detail of the area. Symbols denote: T=10s seismometer (light blue circles); T=10s seismometers + accelerometer (yellow circle); T=120s seismometer + accelerometer (red circle); short-period seismometer of the FV network (light blue triangle); broad-band seismometer of the NI network (red square).

All the seismological instrumentation is made by Guralp Ltd. Modern 3- or 6-channel 24-bit acquisition units (mod. CMG-DM24) are used to record the data. Each site has a seismometric sensor with the following properties: 9 of them are short-period-type sensors (mod. CMG-SP1) with proper period extended to 10s, one site is equipped with a mod. CMG-3T broad-band sensor with proper period of T=120s. At four sites, mod. CMG-5TC accelerometers hav been deployed, as well, for recording strong ground motion. All the seismometric sensors have the frequency upper-band limit set at 100Hz, and sampling frequency of the acqusition system is set at 200Hz. All the stations are connected to the CRS acquisition center in Udine by GPRS. The data are continuously acquired and stored by a Ring Server. The processing system is based on the EarthWorm system.