The International Bathymetric Chart of the Southern Ocean Version 2 (IBCSO v2)

The Southern Ocean surrounding Antarctica is a region that is key to a range of climatic and oceanographic processes with worldwide effects, and is characterised by high biological productivity and biodiversity. Since 2013, the International Bathymetric Chart of the Southern Ocean (IBCSO) has represented the most comprehensive compilation of bathymetry for the Southern Ocean south of 60°S. Recently, the IBCSO Project has combined its efforts with the Nippon Foundation – GEBCO Seabed 2030 Project supporting the goal of mapping the world’s oceans by 2030. New datasets initiated a second version of IBCSO (IBCSO v2). This version extends to 50°S (covering approximately 2.4 times the area of seafloor of the previous version) including the gateways of the Antarctic Circumpolar Current and the Antarctic circumpolar frontal systems. Due to increased (multibeam) data coverage, IBCSO v2 significantly improves the overall representation of the Southern Ocean seafloor and resolves many submarine landforms in more detail. This makes IBCSO v2 the most authoritative seafloor map of the area south of 50°S

Radio-echo sounding investigation of the western Dronning Maud Land and north-eastern Coats Land, East Antarctica (Scale 1:2 500 000)

During two Antarctic field seasons, western Dronning Maud Land and eastern Coats Land were covered by airborne radio-echo sounding surveys, conducted in combination with magnetic and gravity measurements along the 50 NW-SE-directed tracks, totaling about 11200 km and spaced 20 km apart. The data were collected in analogue form and then processed to compile ice surface, ice thickness and bedrock topography maps in I : 2 500 000 scale which gave a new and/or more detailed information on the region than previous compilations. The maps show that western Dronning Maud Land is dominated by a large mountainous area with altitudes up to 2800 m including rock outcrops of Annandagstoppane, Borgmassivet, Kirwanveggen and Heimefrontfjella. Upland terrains of Vestfjella and Mannefallknausane have an isolated position and are surrounded by a plain with bedrock depressions of 600 m deep below sea level. A narrow strip of north-eastern Coats Land studied by radio-echo soundings exhibits a smooth subice relief with altitudes close to sea level. The structural style of bedrock topography was mostly determined by extensional tectonics

Paleobathymetry and sediment thickness of the Southern Ocean since 34 Ma

Paleobathymetric models and sediment thickness estimations give insight into the development of the Antarctic Ice Sheets, Southern Ocean current systems and opening of the Southern Ocean Gateways since the Eocene/Oligocene Boundary. A more sophisticated assessment of the paleobathymetry and the sediment deposition in the Southern Ocean are essential for robust reconstructions of paleoclimate and paleooceanographic scenarios. For this reconstruction, we used all available reflection seismic data (refer to Hochmuth et al. (2020) Fig. 1 for data coverage) and borehole information within the Southern Ocean. Paleobathymetric grids are calculated using the backstripping method as implemented in the BalPal code (Wold et al. 1992). Plate tectonic reconstruction follows Müller et al. (2018). The following paleobathymetric reconstruction time slices are available: Eocene/Oligocene Boundary (34 Ma), early Oligocene (27 Ma), Oligocene/Miocene Transition (24 Ma), early Miocene (21 Ma), middle Miocene (14 Ma), late Miocene (10.5 Ma), early Pliocene (5 Ma), Pliocene/Pleistocene Boundary (2.6 Ma) and middle Pleistocene (0.65 Ma). The sediment thickness maps presented here include pre- and post-34 Ma sediment deposition as well as the specific time intervals of the early Oligocene (34 Ma – 27 Ma), late Oligocene to early Miocene (27 Ma – 24 Ma), early Miocene (24 Ma – 21 Ma), early to middle Miocene (21 Ma – 14 Ma), middle to late Miocene (14 Ma – 10.5 Ma), late Miocene (10.5 Ma – 5 Ma), Pliocene (5 Ma – 2.65 Ma) and Pleistocene (2.6 Ma to recent)

Antarctic free-air and complete Bouguer gravity anomaly grid

Gravity surveying is challenging in Antarctica because of its hostile environment and inaccessibility. Nevertheless, many ground-based, airborne, and shipborne gravity campaigns have been completed by the geophysical and geodetic communities since the 1980s. We present the first modern Antarctic-wide gravity data compilation derived from 13 million data points covering an area of 10 million km**2, which corresponds to 73% coverage of the continent. The remove-compute-restore technique was applied for gridding, which facilitated leveling of the different gravity data sets with respect to an Earth gravity model derived from satellite data alone. The resulting free-air and Bouguer gravity anomaly grids of 10 km resolution are publicly available. These grids will enable new high-resolution combined Earth gravity models to be derived and represent a major step forward toward solving the geodetic polar data gap problem. They provide a new tool to investigate continental-scale lithospheric structure and geological evolution of Antarctica

The International Bathymetric Chart of the Southern Ocean Version 2 (IBCSO v2)

The International Bathymetric Chart of the Southern Ocean Version 2 (IBCSO v2) is a digital bathymetric model (DBM) for the area south of 50° S with special emphasis on the bathymetry of the Southern Ocean. IBCSO v2 has a resolution of 500 m × 500 m in a Polar Stereographic projection (EPSG: 9354). The total data coverage of the seafloor is 23.79% with a multibeam-only data coverage of 22.32%. The remaining 1.47% include singlebeam and other data. IBCSO v2 is the most authoritative seafloor map of the area south of 50°S. IBCSO is a regional mapping project of the General Bathymetric Chart of the Ocean (GEBCO) supported by the Nippon Foundation – GEBCO Seabed 2030 Project. GEBCO is a project under the auspices of the International Hydrographic Organization (IHO) and the Intergovernmental Oceanographic Commission (IOC) with the goal to produce the authoritative map of the world's oceans. The IBCSO Project is also an integral part of the Antarctic research community and an expert group of the Scientific Committee on Antarctic Research (SCAR). For further information about the IBCSO Project, please visit http://www.ibcso.org

The International Bathymetric Chart of the Southern Ocean Version 2.

The Southern Ocean surrounding Antarctica is a region that is key to a range of climatic and oceanographic processes with worldwide effects, and is characterised by high biological productivity and biodiversity. Since 2013, the International Bathymetric Chart of the Southern Ocean (IBCSO) has represented the most comprehensive compilation of bathymetry for the Southern Ocean south of 60°S. Recently, the IBCSO Project has combined its efforts with the Nippon Foundation - GEBCO Seabed 2030 Project supporting the goal of mapping the world's oceans by 2030. New datasets initiated a second version of IBCSO (IBCSO v2). This version extends to 50°S (covering approximately 2.4 times the area of seafloor of the previous version) including the gateways of the Antarctic Circumpolar Current and the Antarctic circumpolar frontal systems. Due to increased (multibeam) data coverage, IBCSO v2 significantly improves the overall representation of the Southern Ocean seafloor and resolves many submarine landforms in more detail. This makes IBCSO v2 the most authoritative seafloor map of the area south of 50°S

Antarctic Bedmap data: FAIR sharing of 60 years of ice bed, surface and thickness data [in review]

Over the past 60 years, scientists have strived to understand the past, present and future of the Antarctic Ice Sheet. One of the key components of this research has been the mapping of Antarctic bed topography and ice thickness parameters that are crucial for modelling ice flow and hence for predicting future ice loss and ensuing sea level rise. Supported by the Scientific Committee on Antarctic Research (SCAR), the Bedmap3 Action Group aims not only to produce new gridded maps of ice thickness and bed topography for the international scientific community, but also to standardize and make available all the geophysical survey data points used in producing the Bedmap gridded products. Here, we document the survey data used in the latest iteration, Bedmap3, incorporating and adding to all of the datasets previously used for Bedmap1 and Bedmap2, including ice-bed, surface and thickness point data from all Antarctic geophysical campaigns since the 1950s. More specifically, we describe the processes used to standardize and make these and future survey and gridded datasets accessible under the ‘Findable, Accessible, Interoperable and Reusable’ (FAIR) data principles. With the goals to make the gridding process reproducible and to allow scientists to re-use the data freely for their own analysis, we introduce the new SCAR Bedmap Data Portal (bedmap.scar.org, last access: 18 October 2022) created to provide unprecedented open access to these important datasets, through a user-friendly webmap interface. We believe that this data release will be a valuable asset to Antarctic research and will greatly extend the life cycle of the data held within it. Data are available from the UK Polar Data Centre: https://data.bas.ac.uk