Acoustic depth soundings are routinely collected on Australian Antarctic Division voyages. This metadata record links to child records which describe processed soundings datasets from voyages since 1985. Documentation is included with the datasets.

The data processing was done by the Royal Australian Navy's (RAN) Deployable Geospatial Support Team (DGST) and was provided to the Australian Antarctic Data Centre by the Australian Hydrographic Office. The dataset is titled HI483A because the processing was done on a 2010/11 voyage to Mawson and HI 483 was going to be a RAN survey at Mawson. The RAN survey wasn't feasible because of sea ice. The data processed (12KHz EDO 323HP echo sounder data) was collected on the following voyages: 2006/07 V2, V4, V6 2007/08 SIP, V3, V6 2008/09 V0, V1, V2, V3, V5 2009/10 V0, V1, V2, V3, V4, V5, V7 2010/11 Trials, V1, V2, V3, VE2, VMS All voyage data sets were processed in the following manner. As the Aurora Australis sails from either Hobart, Tasmania or Fremantle, Western Australia all the shallow water data files containing depths less then 200m around these ports were not processed and deleted. If the sea floor image was too hard to determine during the voyage either parts of day lines were not processed or the whole line deleted depending on the quality of the data. This is evident with some day *.CSV files containing a second or third file, these files had the same file name and were given a end character of _2 or _3. Unfortunately the program Echoview is meant to allow the user to span gaps when processing a line but more often than not, this was not the case. So if there was a requirement to a have gap in the daily file then usually a second file was created. Regularly throughout all voyages files were observed that had no GPS data associated with the depths. Any raw files without GPS data could not be processed, all these files have been deleted. Occasionally corrupt files were experienced, and these corrupt files have also been deleted. When the Aurora Australis was at anchor off an Antarctic Station these files too were deleted. With the various problems with the raw data files, no voyage has complete sounding data for the whole voyage. Some voyages have large sections of data missing, but unfortunately this data was not able to processed due to one of the above factors. All soundings were processed utilising the spheroid, WGS84 and only geographic co-ordinates have been determined. UTM grid co-ordinates were not calculated during the processing stages due to software limitations. Grid co-ordinates were not calculated for the final HTF files. Scripts were developed to apply depth water corrections, tide offsets if shallower than 200m of water and the layback of the sounder with respect to the Ashtech GPS. The processing of the data from 2007/08 V3, 2007/08 V6 and 2010/11 V3 was incomplete. Complete processing of the data from these voyages was done as part of HI513 which is described by the metadata record with ID AAD_voyage_soundings_HI513. The data has not been through the verification process for use in charts.

A high resolution bathymetric grid of the nearshore area at Casey station, Antarctica was produced by Geoscience Australia by combining data from two multibeam hydrographic surveys: 1) A survey conducted by the Royal Australian Navy in 2013/14. Refer to the metadata record 'Hydrographic survey HI545 by the RAN Australian Hydrographic Service at Casey, December 2013 to January 2014' with ID HI545_hydrographic_survey. 2) A survey conducted by Geoscience Australia and the Royal Australian Navy in 2014/15. Refer to the metadata record 'Hydrographic survey HI560 by the RAN Australian Hydrographic Service at Casey, December 2014 to February 2015' with ID HI560_hydrographic_survey and the metadata record 'Seafloor Mapping Survey, Windmill Islands and Casey region, Antarctica, December 2014 - February 2015' with ID AAS_3326_seafloor_mapping_casey_2014_15. The grid has a cell size of one metre and is stored in a UTM Zone 49S projection, based on WGS84. Further information is available from the Geoscience Australia website (see a Related URL).

The soundings were digitized from bathymetric chart: Bathymetry of Lutzow-Holm Bukta (Lutzow-Holm Bay) by the Japanese, National Institute of Polar Research (NIPR) from Special Map Series of National Institute of Polar Research No. 4b, 2002 - map number 12852 in the SCAR map catalogue. These data have been created by the Japanese, but as such no metadata record for the data exists in the Japanese portal of the Antarctic Master Directory. Australian users of these data should use this metadata record (providing credit to the Japanese), until a Japanese version has been created.

This is a derived product containing two products blended together that describes the elevation of the seafloor beneath and out to approximately seaward of the Totten Glacier Ice Shelf cavity as well as the elevation of the ice bottom beneath the ice sheet immediately sounding the ice shelf cavity. The seafloor was inferred by inverting airborne gravity observations; the terrain beneath grounded ice was observed with airborne ice sounding radar measurements. The two products were blended along the grounding line observed with satellite observations [Rignot, E., Mouginot, J. and Scheuchl, B. Antarctic grounding line mapping from differential satellite radar interferometry. Geophys. Res. Lett. 38, L10504 (2011)]. We have provided a text file that contains three columns that may be used to produce a gridded bathymetry of the Totten Glacier Ice Shelf and surrounding area with a cell size of 1-km. The first two columns contain grid coordinates using the Polar Stereographic projection based on WGS84 with true scale at 71 degrees S. The third column contains the vertical coordinate representing the seafloor beneath and the ice-bottom elevation around the Totten Glacier Ice Shelf cavity. The center of the region is located near 115E and 67S and spans an area about 217 km by 131 km. The data are described in detail in the publication and supplementary materials that can be found by following this link: http://www.nature.com/ngeo/journal/v8/n4/abs/ngeo2388.html#supplementary-information

A routine was developed in R ('bathy_plots.R') to plot bathymetry data over time during individual CEAMARC events. This is so we can analyse benthic data in relation to habitat, ie. did we trawl over a slope or was the sea floor relatively flat. Note that the depth range in the plots is autoscaled to the data, so a small range in depths appears as a scatetring of points. As long as you look at the depth scale though interpretation will be ok. The R files need a file of bathymetry data in '200708V3_one_minute.csv' which is a file containing a data export from the underway PostgreSQL ship database and 'events.csv' which is a stripped down version of the events export from the ship board events database export. If you wish to run the code again you may need to change the pathnames in the R script to relevant locations. If you have opened the csv files in excel at any stage and the R script gets an error you may need to format the date/time columns as yyyy-mm-dd hh;mm:ss, save and close the file as csv without opening it again and then run the R script. However, all output files are here for every CEAMARC event. Filenames contain a reference to CEAMARC event id. Files are in eps format and can be viewed using Ghostview which is available as a free download on the internet.

This GIS dataset includes soundings, bathymetric contours and bathymetric areas. The spatial extent of the data ranges from the coast of Kemp Land to the western end of the West Ice Shelf. The data have been formatted according to the SCAR Feature Catalogue (see Related URL). Some of the data are displayed in the map 'Prydz Bay', a 1:1000000 bathymetric map published in September 1997, map number 7 in the SCAR Map Catalogue (see Related URL). Does not conform to Australian Antarctic Spatial Model.

From February to March 2010, Geoscience Australia (GA) conducted a multibeam sonar survey of the coastal waters of the Vestfold Hills in the Australian Antarctic Territory. The survey was conducted jointly with Australian Antarctic Division (AAD) and the Deployable Geospatial Survey Team (DGST) of the Royal Australian Navy. The survey was aimed primarily at understanding the character of the sea floor around Davis Station to better inform studies of the benthic biota and the possible impacts of the Davis sewage outfall. DGST were involved to ensure that the bathymetric data could be used to update and extend the nautical charts of the Davis area. The survey was conducted using GA's Kongsberg EM3002D multibeam echo sounder and C-Nav Differential GPS system mounted on the AAD work boat Howard Burton. Sixteen under water videos were also collected using the GA Raytech camera system and 3 grabs were also collected to compliment an intensive sampling program by AAD divers and a sampling program conducted in the 1990's by University of Tasmania (Franklin, 1996). An area of 42 km2 was surveyed intensively immediately off Davis and additional survey lines were run to Long Fjord in the north and to Crooked Fjord and the Sorsdal Glacier in the south. The main survey area had between 150% and 200% coverage as the seabed was esonified from opposing angles to resolve and provide detail to the numerous features of the seafloor such as rocky reefs, iceberg scours, boulders, anchor chain drag marks and grounded icebergs. The new high resolution data provided detailed maps of sea bed morphology and texture classification to complement sample data. Sixteen video transects were collected and 3 grab samples collected in water too deep for the Australian Antarctic Division Diving program. New high resolution bathymetric grids have been prepared for scientific use and further processing for hydrographic charting is ongoing. A new sea floor geomorphic map has been prepared using the multibeam data, preliminary video and sampling data. The project was a component of Australian Antarctic Science (AAS) Project 2201 - Natural Variability and Human Induced Change on Antarctic Nearshore Marine Benthic Communities. In 2011, Dr Phil O'Brien provided to the Australian Antarctic Data Centre the following interim data: 75 cm multibeam data in CARIS format; and a 4 metre resolution bathymetric grid and an image of the sea floor, both derived from the 75 cm multibeam data. This data was made available for download from this metadata record. In August 2013, Geoscience Australia released 2 metre resolution bathymetric and backscatter grids after further processing of the multibeam data. The bathymetry and backscatter data have now been fully processed checked and validated by Geoscience Australia and supersede the interim data. The interim data has been archived by the Australian Antarctic Data Centre. The 2 metre resolution grids and final report are available for download from the Geoscience Australia website.

This dataset consists of underway data, including bathymetric data, collected aboard Australian Antarctic Division research vessels between 1985 and 2012. The data are available in csv format and the raw SIMRAD format. In the csv files bathymetric data is in the WTR_DEPTH_M column. Some voyages will not have bathymetric data associated with them. The csv data may have been quality checked. Most of the underway data was quality checked ('dot zapped') up to and including voyage 4 2003/04. Data quality reports are available by searching at http://data.aad.gov.au/aadc/voyages/ Other than on Marine Science voyages, the Aurora Australis bathymetric data gathering procedures prior to about 2000 were not checked during the voyage. The echo sounder was turned on in Hobart and if it stopped working during the voyage, then there was no one to get it going again. Bathymetric data from these voyages that has been processed by the Royal Australian Navy is available via other metadata records linked to the parent record with ID AAD_voyage_soundings.