SIORNET Permanent GPS network:

The SIORNET GPS network is aimed at monitoring deformation cycles along two faults belonging to the Timpe system. This network is a follow up to the studies started by APAT after the Etna’s volcanic and tectonic events of 2002 and is a useful enrichment to the Ithaca project database.
The network, managed by APAT’s Geophysics Service, intends to control the faults of S. Tecla-Linera and Acicatena by means of permanent and non-permanent GPS stations. The first fault has a relaxing kinematic regime with a right-hand side component and it is activated when there are strong earthquakes. The second one has the same kinematics but is characterized by both coseismic and aseismic movements.
This GPS monitoring network has the aim of controling and quantifying movements related to seismic activity and aseismic creep along these tectonic lines. The monitoring network’s topology is divided into two subnetworks (Linera and Acicatena) with stations placed on the hangingwall and footwall of the faults bearing the same name. They are aligned in a perpendicular way to their extension direction. Each subnetwork is divided into two sections. The first section acquires continuous data and has a telematic measurement system managed by the APAT Geophysics Department. The second is a non-permanent section that takes periodical measurements.
Currently, the stations of SCAC, ACSA, CAFA and SERB are active. The first two belong to the continuous sections of the Acicatena subnetwork, while the others are placed along the Linera subnetwork. These stations are endowed with TOPCON receivers and Choke-ring aerials and acquire 24-hour data with a sampling interval of 30 seconds. Data are then transmitted with a GSM modem to the Collection Processing and Control Centre, which is located in Rome at the APAT Geophysics Department. Here, data is converted into Rinex format and submitted to quality tests. Data are processed with BERNESE scientific software in BPE mode. The processing strategy adopted, which has already been experimented on other APAT GPS networks, is the one suggested by the BERNESE software handbook for regional surveys, with duplicity elimination and double coordinate estimation (QIF + ELIMIN strategy).

For further information: retesiornet@apat.it