Multibeam seabed bathymetry of the Long-Term Ecological Research observatory HAUSGARTEN (Fram Strait)

The Long-Term Ecological Research observatory HAUSGARTEN was established by the Alfred Wegener Institute for Polar and Marine Research (AWI) in the Fram Strait in summer 1999 to detect and track the impact of large-scale environmental changes on the marine ecosystem in the transition zone between the northern North Atlantic and the central Arctic Ocean. In this area, bathymetric data have been recorded with multibeam echosounders (MBES) during 44 research expeditions since 1984. Based on these data, we present a digital elevation model, geospatial derivatives and quantitative terrain descriptors for subsequent terrain analyses and habitat mapping. Heterogeneity of the bathymetric data, however, resulted in abundant small-scale artefacts in the digital elevation model and derived products that in some places overprint small seabed landforms. This heterogeneity is caused by the data collection with multibeam echosounders in differing technical stages over a period of four decades in different weather and ice conditions. Despite these technical limitations, the accumulated bathymetric data function as a vital physical baseline and environmental parameters for the HAUSGARTEN observatory that cannot be replicated by modern single-cruise surveys.