Movements in Northern Victoria Land (Antarctica) Estimated by GPS Multi-year Campaigns.

Since the beginning of the VLNDEF (Victoria Land Network for DEFormation control) project, started in 1999 with the aim to detect crustal deformation in Northern Victoria Land, 5 field campaigns have been carried out. Two complete surveys of the network and other partial measurement repetitions have been made. In NVL the TNB1 GPS permanent station is working since 1998, in addition to the Cape Hallett remote station installed in 2004 (supplied with an experimental wind generator). Three other remote stations (Littel Rocks, Mount Keynat, Cape Adare) will be installed during the next 2005-06 Italian expedition. Relative and absolute displacements have been estimated using a local and a regional approach, both able to detect valuable movements and, the second, to refer the network to a global reference frame (ITRF200). In particular, station coordinates in global reference frame have been obtained by processing a core network of extra-Antarctic permanent stations and by combining together regional and local solutions. A reduction in constraint effects was reached. Robust and stable solutions for horizontal and vertical displacements were obtained. Crucial is the vertical component, which is essential in order to detect different effects, such as Post Glacial Rebound in NVL. Some comparisons have been carried out with reliable models available for the NVL area.