1. New geodetic and gravimetric maps to infer geodynamics of antarctica with insights on Victoria land
- Author
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Leonardo Martelli, Francesco Salvini, P. Sterzai, Alessandro Capra, Luca Vittuari, Monia Negusini, Marco Dubbini, Francesco Mancini, Antonio Zanutta, Paola Cianfarra, ITA, Zanutta, A., Negusini, M., Vittuari, L., Martelli, L., Cianfarra, P., Salvini, F., Mancini, F., Sterzai, P., Dubbini, M., Capra, A., Zanutta, Antonio, Negusini, Monia, Vittuari, Luca, Martelli, Leonardo, Cianfarra, Paola, Salvini, Francesco, Mancini, FRANCESCO MARIA, Sterzai, Paolo, Dubbini, Marco, and Capra, Alessandro
- Subjects
Gravity anomaly ,PNRA ,010504 meteorology & atmospheric sciences ,Lineament ,Science ,Crustal deformation ,010502 geochemistry & geophysics ,GNSS time serie ,Neo-tectonics ,01 natural sciences ,neo-tectonics ,Crustal deformations ,VLNDEF ,gravity anomaly ,GNSS time series ,Antarctica geodynamics ,crustal deformations ,0105 earth and related environmental sciences ,Antarctica geodynamic ,Neo-tectonic ,Subsidence ,Crust ,Post-glacial rebound ,Antarctica geodynamics, Crustal deformations, GNSS time series, Gravity anomaly, Neo-tectonics, PNRA ,VLNDEF, Earth and Planetary Sciences (all) ,Geodynamics ,Geodesy ,Tectonics ,General Earth and Planetary Sciences ,Earth and Planetary Sciences (all) ,Bouguer anomaly ,Geology - Abstract
In order to make inferences on the geodynamics of Antarctica, geodetic and gravimetric maps derived from past and new observations can be used. This paper provides new insights into the geodynamics of Antarctica by integrating data at regional and continental scales. In particular, signatures of geodynamic activity at a regional extent have been investigated in Victoria Land (VL, Antarctica) by means of Global Navigation Satellite System (GNSS) permanent station observations, data from the VLNDEF (Victoria Land Network for Deformation control) discontinuous network, and gravity station measurements. At the continental scale, episodic GNSS observations on VLNDEF sites collected for 20 years, together with continuous data from the International GNSS Service (IGS) and Polar Earth Observing Network (POLENET) sites, were processed, and the Euler pole position assessed with the angular velocity of the Antarctic plate. Both the Bouguer and the free-air gravity anomaly maps were obtained by integrating the available open-access geophysics dataset, and a compilation of 180 gravity measurements collected in the VL within the Italian National Program for Antarctic Research (PNRA) activities. As a result, new evidence has been detected at regional and continental scale. The main absolute motion of VL is towards SE (Ve 9.9 ±, 0.26 mm/yr, Vn &minus, 11.9 ±, 0.27 mm/yr) with a pattern similar to the transforms of the Tasman and Balleny fracture zones produced as consequence of Southern Ocean spreading. Residual velocities of the GNSS stations located in VL confirm the active role of the two main tectonic lineaments of the region, the Rennick&ndash, Aviator and the Lillie&ndash, Tucker faults with right-lateral sense of shear. The resulting VL gravity anomalies show a NW region characterized by small sized Bouguer anomaly with high uplift rates associated and a SE region with low values of Bouguer anomaly and general subsidence phenomena. The East and West Antarctica are characterized by a different thickness of the Earth&rsquo, s crust, and the relative velocities obtained by the observed GNSS data confirm that movements between the two regions are negligible. In East Antarctica, the roots of the main subglacial highlands, Gamburtsev Mts and Dronning Maud Land, are present. The Northern Victoria Land (NVL) is characterized by more scattered anomalies. These confirm the differences between the Glacial Isostatic Adjustment (GIA) modeled and observed uplift rates that could be related to deep-seated, regional scale structures.
- Published
- 2018