The Seismometric Network of Conegliano Laudense (Lodi, Italy)

SCIENTIFIC STAFF: Enrico Priolo1, Marco Romanelli1, Milton Plasencia1, Paolo Bernardi1, Denis Sandron1, Eduardo Diez Zaldivar2, Marco Garbin1, David Zuliani1, Paolo Fabris1
1Centro Ricerche Sismologiche, Istituto Nazionale di Oceanografia e Geofisica Sperimentale, Cussignacco (UD) e Sgonico (TS)

The Cornegliano Laudense permanent network aims at monitoring the gas storage activity performed by Ital Gas Storage s.p.a. in the underground natural reservoir of Cornegliano Laudense, located in the Po Plain few kilometers South of the town of Lodi. The network is registered with FDSN with code OL. Since the OL 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.

The OL network has officially started its operations since January 2017, although some stations have already been working since July 2016. Continuous data can be freely downloaded through this site.

The OL network consists of 9 sites, specifically built-up for the purpose (Fig. 1). Each OL station is equipped with a borehole seismometer located at a reference depth of 75 m and an accelerometer located at the ground surface, respectively. The OL network is also integrated by some stations of the National Seismometric Network managed by INGV as well as some stations of the North-East Italy Network managed by OGS, respectively.

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

The seismological instrumentation (Fig. 2) is by Guralp Ltd. The seismometric sensor is ┬ža Radian model, and it incorporates both the sensor and the digitizer. The Radian seismometers are set with a proper period of T=120s. The accelerometer is a Fortis model. The acquisition unit is a Minimus model, and it acquires digital data (3 ch) from the Radian sensor and 3 analogue channels from the Fortis. The digital sampling isi 200 Hz for the Radian seismometer and 100 Hz for the Fortis accelerometer.

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 (free software distributed by IRIS).

Figure 2. a) Guralp-Fortis accelerometer; b) Guralp-Minimus digitiser; c) Guralp-Radian seismometric;