– Contributed by Alix Post, on behalf of the International Bathymetric Chart of the Southern Ocean (IBCSO) Expert Group
Over two consecutive summers, 2013-14 and 2014-15, a collaborative bathymetric survey, employing small science workboats (pictured), collected a high-resolution multibeam sonar dataset covering an area of ca. 33 km2 in the vicinity of the Windmill Islands, East Antarctica, adjacent to the Australian Research Station, Casey. The survey was completed as a joint programme by the Australian Antarctic Division (AAD), Geoscience Australia (GA) and the Royal Australian Navy (RAN) to improve understanding of the shallow-water near-shore environment adjacent to Australia’s research stations and to update maritime navigational charts of the region.
These new data permit visualisation of the seafloor morphology in unprecedented detail. A range of geomorphic features are evident, including linear bedrock fault sets, networks of sub-glacial meltwater channels, glacial lineations and sets of ‘push moraines’. Minor post-glacial sedimentation is preserved in several small isolated basins. For further detail see the accompanying flythrough and the recent paper published in Geomorphology.
The bathymetric data collected met or exceeded International Hydrographic Organization (IHO) order 1a specifications and a revised navigational chart has been published by the Australian Hydrographic Office (AUS 601, 4th edition, November 2015). The datasets from the survey can be downloaded from the Geoscience Australia website.
For more information on bathymetric surveying in the Southern Ocean, visit the IBCSO Expert Group’s section.