Fred Niederjasper

High resolution bathymetry of the eastern slope of the Porcupine Seabight

The topography of the eastern margin of the Porcupine Seabight was surveyed in June 2000 utilizing swath bathymetry. The survey was carried out during RV Polarstern cruise ANT XVII/4 as part of the GEOMOUND project. The main objective was to map and investigate the seafloor topography of this region. The investigated area contains a variability of morphological features such as deep sea channels and giant mounds. The survey was planned and realized on the basis of existing data so as to guarantee the complete coverage of the margin. In order to achieve a resolution of the final digital terrain model (DTM) that meets the project demands, data processing was adjusted accordingly. The grid spacing of the DTM was set to 50 m and an accuracy better than 1% of the water depth was achieved for 96% of the soundings.

Applied marine geodetic research in polar regions

At the Alfred Wegener Institute for Polar and Marine Research, several geodetic methods are used to map the seafloor in polar regions. Multibeam bathymetric surveys are regularly conducted in polar regions by the institutes icebreaker Polarstern. These multibeam data are combined with bathymetric data from other sources to create bathymetric maps. The Hydrosweep multibeam system on the Polarstern is presently being modified to have a wider survey swath and the ability to collect sidescan and backscatter data. These modifications will enable researchers to survey the seafloor more efficiently and will provide important information about the seafloor materials. Satellite altimetry data is also used to supply the correlation between the earths geopotential field and the seafloor topography. This correlation can be used to guide bathymetric contouring in areas with little or no bathymetric data. Current efforts involve the study of ERS‐1 altimetry data from the Weddell Sea, Antarctica, where the altimetry d...