The main aim of the article was to analyse the actual accuracy of determining the vertical movements of the Earth’s crust (VMEC) based on time series made of four measurement techniques: satellite altimetry (SA), tide gauges (TG), fixed GNSS stations and radar interferometry. A relatively new issue is the use of the persistent scatterer InSAR (PSInSAR) time series to determine VMEC. To compare the PSInSAR results with GNSS, an innovative procedure was developed: the workflow of determining the value of VMEC velocities in GNSS stations based on InSAR data. In our article, we have compiled 110 interferograms for ascending satellites and 111 interferograms for descending satellites along the European coast for each of the selected 27 GNSS stations, which is over 5000 interferograms. This allowed us to create time series of unprecedented time, very similar to the time resolution of time series from GNSS stations. As a result, we found that the obtained accuracies of the VMEC determined from the PSInSAR are similar to those obtained from the GNSS time series. We have shown that the VMEC around GNSS stations determined by other techniques are not the same.

The sea surface is variable in time and space; therefore, many researchers are currently interested in searching for dependencies and connections with the elements influencing this diversity, e.g., with the seabed topography. An important problem is combining or comparing models obtained based on different data sets with different accuracies and spatial resolutions. These studies are designed to discover the relationship that may exist between observations of the shape of the seabed and changes in sea level. The aim of this study is to investigate the relationship by checking the correlation between the observations from the point recording of satellite altimetry measurements and the bathymetric data. The object of research is the capital city of Gabon—Libreville, located on the west coast of Africa and three point in Las Palmas. The results present sea level, salinity, and potential temperature variations in selected points. The highest trends of sea level changes occur, at one point, in the open ocean (P6) and at coastal points (Libreville, P3, Pointe Noire). The study indicates that, from 1993 to 2020, the temperature trend at the assessed points is on average 0.018 ± 0.012 °C·year⁻¹, while the average salinity trend is 0.008 ± 0.005 1e⁻³ year⁻¹. The correlation coefficients for the sea water temperature trend and the sea water salinity trend—determined at 0.20 and 0.08—present a weak linear relationship. Correlation takes slightly higher values for elevation, which is determined at 0.38. Research shows that there is a relationship between satellite and bathymetric observations on the east coast of Africa; however, the strength of the correlation depends on the location.

Studying changes in the sea level is essential for the sustainable development of coastal areas. The aim of this study was to analyse time series and investigate the regional variability of the sea surface and the effect of individual factors on its behaviour. In this study, we utilised the most recent satellite altimetry data (over a period of 29 years, i.e., from 1993 to 2022) and tide gauge observations (long-term time series) in order to estimate changes in the sea level. Unlike in previous studies, the rates of the sea level changes around the entire African coast were determined. In addition, time series of the changes in the sea surface temperature and salinity were used to determine the rate of changes arising from the thermal expansion of the ocean. The regional rate of the sea level rise between 1993 and 2022 deviated significantly from the global average, with values ranging from 2.48 to 5.44 mm/year (based on satellite altimetry data, depending on the location of the point).