Bathymetry is the measurement of the seafloor topography. Unlike the land surface, the sea bed surface cannot be measured directly via airborne optical methods (e.g. radar). It requires an echo sounder, which sends out an acoustic signal, which is reflected on the seafloor and received again by the echo sounder. Such multibeam echo sounders are permanently installed on the large research vessels.
Only about 10% of the global seafloor has been mapped with high-resolution bathymetry by now. And for the polar regions this percentage is still significantly smaller. At the AWI high-resolution bathymetric data is used as basic key parameter for many marine processes. They are necessary to understand ocean currents, mass transports (e.g. landslides) and tectonic processes. Also for habitat studies these data is becoming increasingly important.
Bathymetric data is useful for the reconstruction of ice history in the polar regions: large icebergs and ice sheets left their marks as scratches in the seabed. Their direction, depth and mutual superposition can be seen on high-resolution bathymetric maps. Together with high-resolution seismics and sediment cores, the bathymetry is used for the interpretation of glacial processes.