VLNDEF PROJECT FOR CRUSTAL DEFORMATION CONTROL I N NORTH VICTORIA LAND

1. VLNDEF PROJECT FOR CRUSTAL DEFORMATION CONTROL IN NORTH VICTORIA LAND A. Capra1, S. Gandolfi2, F. Mancini2, P. Sarti3, L. Vittuari2 1Politecnico di Bari, Facoltà di Ingegneria, Taranto, Italy - Viale del Turismo, 8 - Zip Code 74100 2DISTART, Università di Bologna, Viale Risorgimento 2, 40136 Bologna - Italy 3Istituto di Radioastronomia, CNR, Centro di Geodesia Spaziale – ASI – Zip Code 75100 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. Data processing and results Deformation (if present) VLNDEF Project • 1999-2000 expedition: 20 station established and 19 surveyed • 2000-2001 expedition: 5 station established and 10 surveyed • 2002-2003 (planned) complete network survey

5. VLNDEF: the network

6. Stations position planning • Stations distribution based on; • tectonics map that shows principal and secondary fault systems • Landsat Imagery • USGS 1:250000 maps • Geometry

7. VLNDEF:documentation

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

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

12. 1999-2000 expedition 1999-2000 expedition VLNDEF Solutions: Bernese v4.2 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 2003. *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. VLNDEF TAMDEF TAMDEF South GPS along VL

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.

20. 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, 1996. 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.498-503, Springer 1998 ArmadilloE., Bonaccorso A., Caneva G., Capra A., Falzone P.,FerraccioliF., Mancini F., PriviteraE., 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, 2000. [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. 379-385, 2001 Capra A.,Gandolfi S.,Mancini F., Negusini M. , Sarti P., Vittuari L. Terra Nova Bay GPS Permanent station. On press on Terra Antarctica