GPS data processing in the Antarctic: crustal movements, postglacial rebound and reference systems

• Main Author: Bouin, Marie-Noelle
• Other Authors: Observatoire de Paris, Université Paris sciences et lettres (PSL), LAboratoire de Recherche en Géodésie (LAREG), Ecole nationale des sciences géographiques (ENSG), Institut géographique national IGN (IGN)-Institut géographique national IGN (IGN), Claude Boucher, C. Vigny (co-directeur)
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 1999
• Subjects: astronomy; Tectonique des plaques; Isostasie; GPS; Astronomie géodésique; [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]; [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics; Antarctic; Balleny Islands; The Antarctic; West Antarctica; Antarc*; Antarctica; Antarctique*; Ice Sheet
• Online Access: https://hal.archives-ouvertes.fr/tel-02071396; https://hal.archives-ouvertes.fr/tel-02071396/document; https://hal.archives-ouvertes.fr/tel-02071396/file/OBSPM_7613.pdf

The subject of this thesis is the processing of GPS data from the permanent stations in Antarctica, for the assessment of vertical and horizontal motions induced by glacial rebound. An accurate knowledge of the current deformations provides information about the validity of the late Pleistocene deglaciation models and the present-day Antarctic ice-sheet behavior. This could largely affect global sea level change. We have analysed 4 years of continuous IGS data from the stations in and around Antarctica. We have improved the processing method in order to take into account the specifities of GPS data analysis in Antarctica, and obtained station position time series, from which we derive significant horizontal and vertical velocities. The horizontal velocities show a very good agreement with a rigide plate motion, which is slightly different from the Nuvell predicted motion, but very coherent with the recent results obtained by Heflin (1999) for the Australian plate motion. The particular case of the Dumont station was good agreement with the recent results obtained investigated to estimate the influence of the March 1998 Balleny Islands earthquake, in relatively good agreement with the dislocation models. From the vertical trends, we detect a global uplift of the whole Antarctic continent, at about 1 cm/yr, consistent with the upper limit of the vicous model predictions. Based upon O’Higgins observations, we see that the Peninsula is affected by a higher rate of 2.5 cm/yr, including a purely elastic part, which reflects the present-day increase of the melting rate over the West Antarctica, confirmed by the glaciological and geodetic observations. The seasonal variations detected for this station on the vertical component haven’t found their explanation yet. Le sujet de cette thèse est l'utilisation des données GPS des stations permanentes antarctiques pour la mesure de mouvements verticaux et horizontaux liés au rebond glaciaire. Les constantes de temps de l'isostasie terrestre sont telles que la croute ...