Monitoring geodynamic activity in the Victoria Land, East Antarctica: Evidence from GNSS measurements

• Main Authors: ZANUTTA, ANTONIO, NEGUSINI, MONIA, VITTUARI, LUCA, Cianfarra, P., Salvini, F., Mancini, F., Sterzai, P., Dubbini, M., Galeandro, A., Capra, A.
• Other Authors: ITA
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2017
• Subjects: Antarctic; East Antarctica; Peltier; The Antarctic; Victoria Land; Antarc*; Antarctica
• Online Access: https://hdl.handle.net/20.500.12386/27056; https://doi.org/10.1016/j.jog.2017.07.008; https://www.sciencedirect.com/science/article/pii/S0264370717300194?via%3Dihub

GNSS networks in Antarctica are a fundamental tool to define actual crustal displacements due to geological and geophysical processes and to constrain the glacial isostatic models (GIA). A large network devoted to the detection and monitoring of crustal deformations in the Northern Victoria Land (Victoria Land Network for DEFormation control - VLNDEF), was monumented during the 1999-2000 and 2000-2001 field campaigns, as part of Italian National Program for Antarctic Research and surveyed periodically during the Southern summer seasons. In this paper, GPS observations of VLNDEF collected over a more than 15-year span, together with various selected POLENET sites and more than 70 IGS stations, were processed with Bernese Software, using a classical double difference approach. A solution was obtained combining NEQs by means of ADDNEQ2/FODITS tools embedded in Bernese Software. All the Antarctic sites were kept free and a subset of 50 IGS stations were used to frame VLNDEF into ITRF2008. New evidence provided by analysis of GPS time series for the VLNDEF network is presented; also displacements along the vertical component are compared with the recently published GIA models. The absolute velocities indicate an overall displacement of the northern Victoria Land region along the south-east direction (Ve = 10.6 mm/yr, Vn = -11.5 mm/yr) and an average uplift rate of Vu = 0.5 mm/yr. Two GIA models have been analyzed: ICE-6G_C-VM5a proposed by Argus et al. (2014), Peltier et al. (2015) and W12A_v1 by Whitehouse et al. (2012a,b). Up rates, predicted over the VLNDEF sites by the mentioned GIA models, have been extracted and compared with those observed. A preliminary comparison with GPS-derived vertical rates shows that the Victoria Land ICE-6G_C-VM5 and W12A_v1 GIA models predict overestimated uplift rates of 0.7 and 0.9 mm/yr weighted mean residuals respectively. The mean horizontal relative motions within the Victoria Land (VL) area are in most cases negligible, while only a few points exhibit horizontal velocities ...