Monitoring lithospheric motions by Satellite geodesy

Understanding of global and local Earth’s dynamic processes is of great importance to the Earth’s system knowledge, human life, and sustainability goals (e.g. climatic change and geo-hazard assessment, etc.). The processes are largely affected by the Earth's mass distribution and redistribution, which can be quantified and modelled using simultaneous and complementary data from various geoscience and environmental near earth-orbiting artificial satellites. In this thesis, which is based on five peer-reviewed papers, we study the lithospheric motion and the Earth’s mass change in terms of gravity variation, using a combination of geodetic satellite data and non-geodetic observations. The first paper is concerned with using of gravimetric approach to model sub-crustal horizontal stresses in the Earth’s mantle and their temporal changes using the Gravity Recovery and Climate Experiment (GRACE) data, caused by geodynamical processes such as mantle convection, in Fennoscandia region. We show that the determined horizontal stresses obtained by a gravimetric method are consistent with tectonics and seismic activities. In addition, the secular rate of change of the horizontal stress, which is within 95 kPa/year, is larger outside the uplift dome than inside in the study area. In the second paper, permafrost thawing and its associated gravity change, in terms of groundwater storage (GWS) anomalies changes is studied using the GRACE data and other satellites (e.g. AIRS) and ground-based observations in the northern high-latitude regions. The results of a preliminary numerical analysis reveal a high correlation between the secular trends of greenhouse gases (CO 2 ), temperature, and the equivalent water thickness in the selected regions. Furthermore, the GRACE-based GWS estimates attributed to the permafrost thawing is increased at the annual rates of 3 to 4 cm/year in selected study areas. The third paper investigates the large-scale GRACE-based GWS changes together with different hydrological models over the major oil reservoirs in Sudan. The outcomes are correlated with the available oil wells production data. Moreover, using the freely available Sentinel-1 data, the ground surface deformation associated with oil and water depletion is studied. Our results show that there is a significant correlation between the GRACE-based GWS anomalies and the extracted oil and water volumes. The trend of GWS anomaly changes due to water and oil depletion varies from -18.5