Active tectonics in Northern Victoria Land (Antarctica) inferred from theintegration of GPS data and geologic setting

A semi-permanent global positioning system (GPS) network of 30 vertices known as theVictoria Land Network for Deformation Control (VLNDEF) was set-up in the Austral summer of1998 in Northern Victoria Land (NVL), including Terra Nova Bay (TNB), Antarctica. Thelocations were selected according to the known Cenozoic fault framework that is characterizedby a system of NW-SE regional faults with right-lateral, strike-slip kinematics. The TNB1permanent GPS station is within the VLNDEF, and following its installation on a bedrockmonument in October 1998 it has been recording almost continuously. The GPS network hasbeen surveyed routinely every two summers, using high-quality, dual-frequency GPS receivers.In this study, we present the results of a distributed session approach applied to the processing ofthe GPS data of the VLNDEF. An improved reference frame definition was implemented,including a new Euler pole, to compute the Antarctic intra-plate residual velocities. Theprojection of the residual velocities on the main faults in NVL show present-day activities forsome faults, including the Tucker, Leap Year, Lanterman, Aviator, and David faults, with rightlateralstrike-slip kinematics and local extensional/ compressional components. This active faultpattern divides NVL into eight rigid blocks, each characterized by their relative movements andrigid rotations. These show velocities of up to several mm/yr, which are comparable to thosepredicted by plate tectonic theory at active plate margins.