VLNDEF PROJECT FOR CRUSTAL DEFORMATION CONTROL IN NORTH VICTORIA LAND A. Capra 1, S. Gandolfi 2, F. Mancini 2, P. Sarti 3, L. Vittuari 2 1 Politecnico di Bari, Facoltà di Ingegneria, Taranto, Italy - Viale del Turismo, 8 - Zip Code DISTART, Università di Bologna, Viale Risorgimento 2, Bologna - Italy 3 Istituto di Radioastronomia, CNR, Centro di Geodesia Spaziale – ASI – Zip Code Matera, Italy

2 Italian Geodetic Activities in Antarctica Before 2000: Local geodetic reference frame establishment; GPS control network (area of Terra Nova Bay); Mt. Melbourne volcano monitoring; GPS Permanent Station (TNB1). Today: Victoria Land Network for crustal DEFormation Control (VLNDEF); Data Integration Between Regional Networks Between the existing Network

3 Italian Geodetic Activities in Antarctica: Strategies Connection to regional and continental network: TAMDEF (USA), SCAR GPS Epoch; Absolute Reference Determination: IGS; ITRF; Comparison between different processing strategies: Bernese; Gipsy Oasis II; Pages.

4 VLNDEF Project expedition: 20 station established and 19 surveyed expedition: 5 station established and 10 surveyed Data processing and results (planned) complete network survey Deformation (if present)

5 VLNDEF: the network

6 Stations position planning Stations distribution based on; tectonics map that shows principal and secondary fault systems Landsat Imagery USGS 1: maps Geometry

7 VLNDEF:documentation

8 Processing strategies: Bernese v4.2 Based on the baseline determination; Measurements as long as possible (Long Time Series)

9 Processing strategies: Bernese v4.2 IGS97 and IGS00 precise orbit files; Minor constrains on TNB1 station; Precise a-priori coordinates file QIF (Quasi-Iono-Free) baseline solutions Site-specific troposphere parameters estimation Stacking of Normal Equation

10 Processing strategies: Gipsy Oasis II JPL precise orbit files; Zero constrains (no fixed stations); Precise Point Position (PPP) strategy Tropospheric modelling Stocastic zenith tropospheric delay

11 ITRF translation Solutions defined in ITRF (and epoch); Solutions into a single ITRF if compared, by; 1) 3D rototraslation 2) Rates to the reference epoch

12 VLNDEF Solutions: Bernese v expedition On common points <5 mm differences

13 Bernese v4.2 vs Gipsy Oasis II Bernese shows a good accuracy and high repeatability on time series; Gipsy shows a good accuracy but low repeatability on time series; Double difference (baseline based) strategy is the most suitable for Antarctic environment.

14 VLNDEF & TAMDEF* (USA) VLNDEF and TAMDEF have run at the same time since the beginning; The data is being combined to give a better picture of the crustal environment in Victoria Land (in progress); TAMDEF is planned to be extended farther south in * The TransAntarctic Mountains DEFormation project

15 TAMDEF Courtesy of Mike Willis (BPRC-Ohio State University)

16 TAMDEF Courtesy of Mike Willis (BPRC-Ohio State University)

17 TAMDEF South GPS along VL VLNDEF

18 VLNDEF: the future Local deformation control constraining TNB1; Antarctic plate motions using extra-plate stations

19 Conclusions No deformations clearly observed in the last decade in the area of Terra Nova Bay; Repetition of measurements for Mt.Melbourne deformation control; zero measurements on the VLNDEF; Integration with TAMDEF; Local constraints Extra-plate constraints Tectonics info; ITRF in Antarctica? International agreements for standardization of processing procedures and data exchange.

References Al Bayari O., Capra A.,Radicioni F., Vittuari L. GPS network for the deformation control in the Mount Melbourne area (Antarctica) : preliminary results of third measurements campaign. Reports on Surveying and geodesy, editor M.Unguendoli, Pubblicazione del DISTART, Università di Bologna, pp.64-72, Edizioni Nautilus, Bologna, Capra A., Gubellini A., Radicioni F., Vittuari L. Italian Geodetic activities in Antarctica. In Italian Geophysical Observatories in Antarctica, edito da A.Meloni e A.Morelli, Editrice Compositori, Bologna,1996 Capra A., Radicioni F., Vittuari L. Italian Geodetic network as reference frame for geodynamics purposes (Terra Nova Bay- Victoria Land-Antarctica). IAG Symposia, vol.119, Geodesy on the move- Gravity, Geoid, Geodynamics and Antarctica, edited by R.Forsberg, M.Feissel and R.Dietrich, IAG Scientific Assembly, Rio De janeiro, September 1997, Brazil, pp , Springer 1998 Armadillo E., Bonaccorso A., Caneva G., Capra A., Falzone P.,Ferraccioli F., Mancini F., Privitera E., VGeophysical features of the Mt. Melbourne area and first results from the integrated network for monitoring the volcano (Antarctica).Proceedings of VII ISAES (International Symposium on Antarctic Earth Sciences), Wellington, July 1999, [7 Capra A., Gandolfi S., Mancini F.,Sarti P., Vittuari L. VLNDEF project: geodetic contribution to geodynamics study of Victoria land, Antarctica. Proceedings of Gravity, Geoid and Geodynamics GG2000 IAG symposium, Banff, Alberta, Canada, July 2000,pp , 2001 Capra A., Gandolfi S.,Mancini F., Negusini M., Sarti P., Vittuari L. Terra Nova Bay GPS Permanent station. On press on Terra Antarctica