Geodetic GNSS observations disclose the response of the solid Earth to changing ice masses in Dronning Maud Land, East Antarctica

• Main Authors: Buchta, E., Scheinert, M., Willen, M., Kappelsberger, M., Eberlein, L., Schröter, B., Knöfel, C., Horwath, M.
• Format: Conference Object
• Language: English
• Published: 2023
• Subjects: Antarctic; Antarctic Peninsula; Dronning Maud Land; East Antarctica; The Antarctic; Victoria Land; West Antarctica; Antarc*; Antarctica
• Online Access: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019542

Geodetic GNSS measurements on bedrock allow to determine secular trends of solid Earth deformation and, therefore, provide valuable constraints for modelling glacial-isostatic adjustment (GIA). There is a high discrepancy in GIA model predictions of vertical displacement rates in Antarctica regarding their spatial pattern and magnitude. While in West Antarctica, in the Antarctic Peninsula and in parts of Victoria Land a comparably large number of GNSS stations exists, East Antarctica exhibits big gaps in the GNSS coverage. The sparsity of bedrock outcrops and the difficult accessibility and logistics are reasons for this.In order to improve the spatial coverage we established a GNSS network in western and central Dronning Maud Land, East Antarctica, with first observations carried out already in the mid-1990ies and a latest observation campaign realized in the Antarctic season 2022/2023. Here we present results of a consistent processing of all episodic and permanent GNSS measurements in that region. We discuss how the long time basis of more than 20 years helps to improve the accuracy of the secular trend inferred from the GNSS time series. We remove the elastic deformation due to present-day ice-mass changes utilizing satellite altimetry observations and surface mass balance models. We discuss our resulting trends in comparison to existing GIA models in a region sparsely covered by GNSS prior to this study.