Comparing the use of ship and satellite data for geodynamic studies
CNRS UMR 6538,
Institut Universitaire Europeen de la Mer,
The availability for scientists of global data sets on satellite free air anomalies and predicted bathymetry changed considerably the research on marine geology and geophysics. These data sets allowed for the first time to have a global view of the morphology of the ocean floor. Geodynamic studies which were hindered by the lack of good quality regional morphology data especially benefited from these new data sets. Marine gravity studies also benefited from a more homogeneous coverage since most of the marine surveys are localized, with gravity data being acquired along ship tracks.
Although satellite derived free air anomalies and predicted bathymetry are very useful for regional and global studies, they lack the fine scale quality required for detailed studies. Moreover, predicted bathymetry is the result of a model calculation and, although constrained by real bathymetry data, for many studies it cannot fully replace it. In this short paper, I will present some studies done with both ship and satellite data and discuss the advantages of using merged data sets for regional studies. However, detailed local studies require the fine scale features that can only be acquired by good quality ship data. It is certain that the arrival of a new generation of satellite data will improve the quality of the global grids and allow the use of these grids for more detailed studies.