GNSS time series and velocities about a slow convergent margin processed on HPC clusters: products and robustness evaluation

Abstract. Global Navigation Satellite Systems are well-known fundamental tools for crustal monitoring projects and tectonic studies, thanks to the high coverage and the high-quality data. In slow convergent margins, in particular, where the deformation rates are of the order of few mm/yr, the GNSS monitoring is beneficial to detect the diffused deformation which is responsible for the tectonic stress accrual. Its strength is the high precision reached by GNSS permanent stations, particularly if long span-data and stable monuments are available at all the stations. North-East Italy is a region which can take the most from continuous and high-precision geodetic monitoring, since it is a tectonically active region located in the northernmost sector of the Adria microplate, slowly converging with the Eurasia plate, but characterised by low deformation rates and moderate seismicity. Furthermore, this region is equipped with a permanent GNSS network providing real-time data and daily observations over two decades. The Friuli Venezia Giulia Deformation Network (FReDNet) was established in the area in 2002 to monitor crustal deformation and contribute to the regional seismic hazard assessment. This paper describes GNSS time series spanning two decades of stations located in the NE-Italy and surroundings, as well as the outcoming velocity field. The documented dataset has been retrieved by processing the GNSS observations with the GAMIT/GLOBK software ver10.71, which allows calculating high-precision coordinate time series, position and velocity for each GNSS station, and by taking advantage of the high-performance computing resources of the Italian High-Performance Computing Centre (CINECA) clusters.

The GNSS observations (raw and standard RINEX formats) and the time series estimated with the same procedure are currently daily continued, collected and stored in the framework of a long-term monitoring project. Instead, velocity solutions are planned to be updated annually. The time series and velocity field dataset documented here is available at https://doi.org/10.13120/b6aj-2s32 (Tunini et al., 2023).