Why IBCSO?

Significance of the Southern Ocean bathymetry

Depth soundings are more than a 'ping'. Digital depth data provide information about digital elevation model derivatives and hence additional input parameters for ocean models. The provision of digital data enables complex data processing for supervised classification or GIS based modeling and prediction. The Southern Ocean bathymetry is of great importance for the modeling and understanding of ocean gateways and barriers, the nature of the thermohaline circulation with Antarctic bottom water formation, and the relevance of the Antarctic Circumpolar Current for Antarcticas glaciation. The sea floor topography controls ocean circulation and ocean mixing - and has strong influence on global climate.

Therefore the IBCSO Expert Group provides services and products for the scientific community, e.g. hydrographers, oceanographers, climatologists, biologists, geologists and geophysicists. The range of products comprises maps, gridded data, metadata, web services, and an operational scientific group. The significance of the sea floor topography is reflected by the full spectrum of applications in the fields of:

The Sea Floor in Geosciences

Bathymetry is the first key to geo-related seabed processes - tectonic and igneous activities as well as marine sedimentation. The sea floor topography is mainly caused by endogenic processes related to plate tectonics and sea floor spreading, resulting in the geomorphology of the oceanic seabed. The shape and the depth of the sea floor provide information about:

• delimitation of the ocean-continent boundary
• crustal heterogeneities and variations in geophysical anomalies
• crustal behaviour - seismicity - with regards to faults, earthquakes and landslides
• depth and shape as important input parameters in Tsunami Warning Systems

The Sea Floor in Physical Sciences

Bathymetry primarily influences ocean circulation. Unfortunately, the bathymetry is only poorly known in polar regions. Limited access, severe climate conditions and vast sea-ice coverage hamper the continuous data acquisition around the Antarctic continent. Poor knowledge of the bathymetry is the limiting factor for new progress in ocean models. Interactions of bathymetry with oceanography include:

• topographic steering of ocean flows
• transport and mixing of water through ocean gateways
• ocean models are sensitive to bathymetry.
• improvement of ocean models by accurate bathymetry

The Sea Floor in Life Sciences

The transformation of multibeam data into classified products for coastal and marine research supports protection and conservation of marine biodiversity. Bathymetric data provide additional numerical descriptors of terrain variables. Due to the high correlation of topographic features with ecological niches, the knowledge about benthic habitats is of great importance for:

• multi-scale terrain analysis
• predictive habitat modeling (Bathymetric Position Index - BPI)
• characterization of habitats (Terrain Ruggedness Index - TRI)
• description of marine ecosystems (Benthic Terrain Modeler - BTM)

The Sea Floor in Observing Systems

The IBCSO may give impetus on planned programs like the Southern Ocean Observing System (SOOS) in consideration of:

• important ocean model input parameter (e.g. depth, slope, orientation, BIP, TRI)
• improvement of state-of-the-art ocean models
• interactions and coupling of system domains (air, water, ice, rocks, life)
• essential system variables in observing systems
• and implementation of international and interdisciplinary research