GNGTS 2016 - Atti del 35° Convegno Nazionale

GNGTS 2016 S essione 1.2 217 by letters A to E, from the best to the worst, and all data with a quality level lower than C were discarded. This means that all the stress orientation included within the map of Montone and Mariucci, 2016 has a maximum associated uncertainty of 25 degrees. D-quality data have an uncertainty between 25 and 40 degrees. INGV, some universities and local administrations developed a network that currently includes over 600 permanent GNSS sites, which are routinely processed according to internationally agreed standards (http://epncb.oma.be/_documentation/guidelines/guidelines_ analysis_centres.pdf) to generate velocities in the latest realization of the ITRF frame (IGb08 at this time). The database of position and velocities maintained at the University of Padova (http://retegnssveneto.cisas.unipd.it ) is updated regularly and provides logsheets, weekly solutions, cumulative solutions (from weekly normal equations stacking), time series and a discontinuity file with the solution numbers introduced to account for discontinuities in the time series of each processed site. Velocities of over 500 sites with at least two years of continuous tracking and accurately verified time series are published (Fig. 2). Fig. 1 – Minimum horizontal stress orientations fromMontone and Mariucci (2016). Only data for boreholes and focal mechanisms are used in this work and shown. Grey poligons represent the analyzed tectonic regions.