The International Bathymetric Chart of the Southern Ocean IBCSO - Can we delete the last "White Spots" in Antarctica?

IBCSO is a major project for the entire Ocean and Earth Science community since it not only contributes to international research programmes but also to global mapping projects like the General Bathymetric Chart of the Oceans (GEBCO) and to the production of Nautical Charts in Antarctic waters. The IBCSO Editorial Board comprises representatives from SCAR-nations conducting specific research in the Antarctic Treaty Area and has an interest in developing an improved bathymetric chart of the Southern Ocean for scientific purposes. These include (a) creating a chart of the seafloor for interpreting seabed geology, (b) building the basis for habitat maps and modelling, and (c) mapping and tracing the pathways of deep oceanic currents. The objective of IBCSO is the production of a homogeneous and seamless bathymetric grid for the Southern Ocean with an associated meta-database. Echosounding data in these harsh regions are heterogeneous in terms of age, acquisition system, environmental condition, accuracy, and documentation. In ice-covered regions, systematic multibeam surveys are rare. As a consequence, the production of a bathymetric grid requires special expertise in hydrography and ocean mapping. Metadata is needed for quality assessment and accurate sonar data processing and gridding. Bathymetric grids have been compiled in regions of special research activities around the Antarctic continent (Bellingshausen/Amundsen Seas, Weddell Sea, Prydz Bay, Kerguelen Plateau, Antarctic Peninsula, and Ross Sea). The results of these regional compilations will be used as basis for the production of the first seamless Circum-Antarctic bathymetric map. The IBCSO version 1 will consequently be an assembly of existing grids produced by different research institutes. The regions not covered will be modelled by using single- and multibeam sonar data in combination with predicted bathymetry. Professional production of this bathymetric chart requires the utilization of a Geographic Information System (GIS) for data collection, storage, manipulation, and visualization. The version 1 IBCSO product will cover the ocean and land topography of the Antarctic Treaty Area south of 60°S, and include the coast-line, and toponymic. The current status of data collection and map production will be presented and discussed, including questions about the model parameterization and gridding techniques. The use of predicted bathymetry in regions of permanent ice-coverage (Weddell Sea, Amundsen Sea) will be introduced. It is shown that predicted bathymetry cannot simply be used in place of real sonar measurements, since differences of several hundred meters in depth were noted particularly in coastal and shelf regions. The horizontal resolution of the version 1 grid will be 2km by 2km. After publication in 2012, the IBCSO grid will be made available to the public