Bathymetry data was collected using a Simrad EK60 echosounder. The sample data have been corrected for the relative locations of GPS antenna, transducers and waterline. A sound-speed value of 1500 m/s was applied when calculating depth. The seafloor depth itself was defined firstly as the depth of the sounder-detected bottom minus 10m (contact Simrad for more information about their bottom-detection algorithm), and then modified manually where necessary to ensure that the line followed the seafloor as perceived by eye from the echogram. This is therefore a subjective process, and the true seafloor depth may vary from the perceived depth by several hundred metres in the worst cases. The greatest uncertainties are typically at greater depths, e.g. greater than 1000 m. This seafloor depth line therefore refers to the approximate depth (not range from transducer) of the seafloor less 10 m, i.e. 10 m should be added to the 'depth' values in the *.CSV file to give the 'true' seafloor depth. Depths greater than 5000 m are not available due to the 12 kHz data not being logged any deeper than this. These data are preliminary and subject to change. Bathymetry data was exported during the voyage by Belinda Ronai. Post voyage enquiries however should be directed to Toby Jarvis.

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.

Pre-processed satellite imagery [Mawson Station_Preprocessed_WV2_Shallow Water.tif] IMPORTANT: This data cannot be shared due to licensing conditions and is provided for archival purposes only. Worldview-2 Imagery was provided at Processing level 2A in GCS WG84. The following Pre-processing steps were applied: Radiometric Correction: Digital Numbers converted to TOA Reflectance Atmospheric Correction: Dark Object Subtraction Masking: Masking of Land and Ice features using classification of accompanying PAN imagery Shallow Water Masking: Deep water masked out by thresh-holding the green and yellow bands The pre-processed data is provided as an 8-band Geotiff in wg84 with pixels of 0.000018° Satellite-derived bathymetry grid [Mawson Station_SDB_wg84_alat.tiff] This bathymetry dataset was produced by applying the SMART-SDB model to Worldview 2 Multispectral Image acquired on 20170129 at 05:21:13Z. Singlebeam bathymetry data acquired in February 20191 using a CEESCOPE 200kHz SBES with CMAX SSS, with vertical and horizontal accuracy of 0.50m and 3.00m respectively, was used for both calibration and validation of the SMART-SDB model. Derived data was smoothed using a low pass filter, and manually cleaned for erroneous returns (however some may still exist). A description of the methods is available in the attached reports. Projection: GCS WG84 Tidal datum: ALAT (approximate lowest astronomical tide) Format: geotiff, ASCI xyz Depths Derived from Satellite Imagery. For SA awareness only. Not for Navigation. Vertical Accuracy is un-assessable and should be considered worse than ZOC C. Undetected features significant to surface navigation may exist. Bathymetry map (Mawson Station SDB Chart_OFFICIAL.pdf) This map shows the hydrographic chart from Mawson Station overlayed with the new satellite-derived bathymetry data. Python Scripts and Guide These scripts were developed to automate extraction of satellite-derived bathymetry from the Worldview-2 imagery. Details of the scripts and how to apply them are outlined in the guide: Antarctica SDB Project How To.docx Final report [AASP4392_Antarctica SDB Project_FINAL_REPORT.docx] This report “Potential of Satellite-Derived Bathymetry mapping in Antarctica using high-resolution multispectral imagery” outlines the objectives, methods, results and conclusions for the satellite-derived bathymetry project (AASP4392). It has not been peer-reviewed. 1 An Australian Hydrographic Service survey acquired singlebeam bathymetry data using a CEESCOPE 200kHz SBES with CMAX SSS, with vertical and horizontal accuracy of 0.50m and 3.00m respectively, in the nearshore waters of Holmes Bay near Mawson station in February 2019. This survey is part of Australian Antarctic Project (AAP) 5093: Hydrographic Surveying and Seabed Characterisation (CI: Ursula Harris) The data was extracted from the Australian Hydrographic Office database (20190208 Hydrographic survey) and is available at: O'Brien, P.E. (2011) Coastal seabed mapping survey, Vestfold Hills, Antarctica, February-March 2010, Ver. 2, Australian Antarctic Data Centre https://data.aad.gov.au/metadata/records/Davis_multibeam_grids)

This metadata record is a modified child record of an original parent record originating from custodians of data associated with Geoscience Australia (The identifier of the parent record is ANZCW0703009248, and can be found on the Australian Spatial Data Directory website - see the URL given below). Taken from the report: A bathymetric grid of the Heard Island-Kerguelen Plateau Region (Longitudes 68 degrees E - 80 degrees E, Latitudes 48 degrees S - 56 degrees S) is produced. In doing so, the individual datasets used have been closely examined and any deficiencies noted for further follow up or have been rectified immediately and the changes documented. These datasets include modern multibeam data, coastline data obtained from the World Vector Shoreline, echosounder data from research, fishing and Customs vessels and satellite derived bathymetric data. A hierarchical system was employed whereby the best and most extensive datasets were gridded first and applied as a mask to the next best dataset. A new masking grid would be formed from these datasets to pass non-overlapping data in the next best dataset. This procedure was employed until finally the satellite data were masked. All the various levels of masked data were then brought together by the gridding algorithm (Intrepid - Desmond Fitzgerald Associates) and an ERMapper format grid produced. A grid cell size of 0.005 degrees (nominal 500m) was used with many iterations of minimum curvature gridding and several passes of smoothing. The final grid is available in ERMapper, ArcInfo and ASCII xyz formats.

Readme - Bathymetry Files Data for BROKE-WEST 2006 1) Zipped folder contains .csv files created from each acoustics ev file for Transects 1 to 11. 2) These files contain subsections of each transect of variable length (usually between 50 and 100 km). 3) No data exists for files; Transect01_01 and 01_02 as the sea floor was greater than 5000m deep in these areas and was below the range set for the sounder. 4) Each file contains 11 columns of data; Ping_date, Ping_time, Ping_milliseconds, Latitude, Longitude, Position_status, Depth, Line_Status, Ping_status, Altitude, GPS_UTC time. 5) For practical purposes, the columns of interest will be Ping_date, Ping_time, Latitude, Longitude and Depth. Other columns are ancillary acoustics information and can be ignored. Line status should be 1 (meaning good) as sea floor was only picked when it could be easily defined. If the sea floor could not be visually defined or was deemed to uncertain, it was not picked in the echogram. Hence sea floor may not be totally contiguous. 6) Depth of the sea floor was only defined for those areas deemed to be 'on transect', i.e. straight transects for acoustics survey purposes. Deviations from the transect, i.e. to pick up moorings, conduct target or routine trawls or visit nice looking bergs were deemed 'off transect' and were excluded from the analysis. 7) Sea floor depth was primarly defined for the purposes of the acoustics analysis, i.e. exclusion from the echograms. Hence the values in the files are for the 'sea floor exclusion line' that is set above the true sea floor in order to exclude noise from the analysis. This means the sea floor depths in these files are likely to be an underestimate of the true depth. The uncertainty is likely to be of the order of 2 to 10m. 8) Another source of error is that depth was calculated with values of absorption coefficient and sound speed set to default values derived from pre-cruise hydrographic data. One value for each parameter was applied to the whole data set. These values were; 0.028 dB/m (120 KhZ), 0.010 dB/m (38kHz), 0.041 dB/m (200 kHz), 0.0017 dB/m (12kHz - bathy sounder) for absorption coefficient and 1456 m/s for sound speed. 9) These values will be recalculated from the oceanographic data derived during the voyage and applied to the data set during post-processing (forthcoming analyses for May-June 2006). Revision of these parameters may cause a slight shift in the calculated depths, although this is likely to be small. 10) Reprocessing of the data may also result in more accurate bottom detection. This data should be available post June 2006 and will be sent to interested parties as soon as it is completed. 11) Dataset was created by Esmee van Wijk.

This dataset contains bathymetry (water depth), ship's heading, ship's speed and position data collected during the Nella Dan Voyage 1 1985-86. This was a marine science voyage departing Hobart, visiting Heard Island, beset at Amundsen Bay and returning to Hobart. Data are available online via the Australian Antarctic Division Data Centre web page (or via the Related URL given below). For further information, see the Marine Science Support Voyage Report at the Related URL below.

This metadata record is a modified child record of an original parent record originating from custodians of data associated with Geoscience Australia (The identifier of the parent record is ANZCW0703006701, and can be found on the Australian Spatial Data Directory website - see the URL given below). A bathymetric grid of the Macquarie Island Region (Longitudes 151 E and 167 E, Latitudes 48 S and 62 S) was produced. In doing so, the individual datasets used were closely examined and any deficiencies noted for further follow up or were rectified immediately and the changes documented. These datasets include modern multibeam data, coastline data obtained from georeferenced SPOT imagery, hydrographic quality data, echosounder data from research and fishing vessels and satellite derived bathymetric data. A hierarchical system was employed whereby the best and most extensive datasets were gridded first and applied as a mask to the next best dataset. A new masking grid would be formed from these datasets to pass non-overlapping data in the next best dataset. This procedure was employed until finally the satellite data were masked. All the various levels of masked data were then brought together by the gridding algorithm (Intrepid and Desmond Fitzgerald Associates) and an ERMapper format grid produced. A grid cell size of 0.00225 (nominal 250m) was used with many iterations of minimum curvature gridding and several passes of smoothing. The final grid is available in geotiff, ArcInfo ascii and xyz text formats. A detailed report of the work completed is also available.

Taken from the accompanying report: Oceanographic measurements were collected aboard the Aurora Australis on cruise au0806 (voyage 6 2007/2008, 22nd March 2008 to 17th April 2008). This cruise completed the CASO oceanographic program begun on the CEAMARC cruise (au0803, voyage 3 2007/2008), with a full occupation of the SR3 transect between Antarctica and Tasmania. CASO program objectives were: 1. to measure changes in water mass properties and inventories throughout the full ocean depth between Australia and Antarctica along 140oE (the CLIVAR/WOCE repeat section SR3), as part of a multi-national International Polar Year program to obtain a circumpolar snapshot of the Southern Ocean in austral summer 2007-8; 2. to estimate the transport of mass, heat and other properties south of Australia, and to compare results to previous occupations of the SR3 line and other sections in the Australian sector; 3. to deploy moorings near the Adelie Depression (142-145oE) as part of a joint Australia-France-Italy program to monitor changes in the properties and flow of Adelie Land Bottom Water; 4. to identify mechanisms responsible for variability in ocean climate south of Australia. The CASO program (with a full occupation of the SR3 transect) was originally scheduled for a single cruise. The shipping schedule was re-arranged following an unexpected period in drydock, due to a problem with the ship's thrusters, and as a result the CASO program was split over the two cruises. Several of the southern stations occupied on the first cruise au0803 were repeated on the second cruise au0806, to minimise the impact on the data set of the time gap between the cruises. A total of 131 CTD vertical profile stations were taken on au0803, and 73 CTD station were taken on au0806, most to within 20 metres of the bottom. During the 2 cruises, over 2900 Niskin bottle water samples were collected for the measurement of salinity, dissolved oxygen, nutrients (phosphate, nitrate+nitrite and silicate), 18O, CFC's, dissolved inorganic carbon, alkalinity, 14C, dissolved organic carbon, density (i.e. analysis of the effect of water composition on water density), germanium/silica/boron isotopes, trace metals, neodymium, chlorophyll-a, cell counts, pigments, genetic analyses, and other biological parameters, using a 24 bottle rosette sampler. Full depth current profiles were collected by an LADCP attached to the CTD package, while upper water column current profile data were collected by a ship mounted ADCP. Data were also collected by the array of ship's underway sensors. This report describes the processing/calibration of the CTD data, and details the data quality. An offset correction is derived for the underway sea surface temperature and salinity data, by comparison with near surface CTD data. CTD station positions are shown in Figures 1 and 2, while CTD station information is summarised in Table 1. Mooring and drifter deployments/recoveries are summarised in Table 14. Mooring data from the Adelie Depression deployments are discussed in the mooring data reports Rosenberg (unpublished report, 2009) and Meijers (unpublished report, 2009). Further cruise itinerary/summary details can be found in the voyage leader reports (Australian Antarctic Division unpublished reports: Riddle, V3 2007/08 VL report; Rintoul, V6 2007/08 VL report). Hydrochemistry and CFC cruise reports are in Appendix 1 and Appendix 2. Details about the data are available in a readme file and a full report in the download file.

Pre-processed satellite imagery [Davis Station_Preprocessed_WV2_Shallow Water.tif] IMPORTANT: This data cannot be shared due to licensing conditions and is provided for archival purposes only. Worldview-2 Imagery was provided at Processing level 2A in UTM 44S projection. The following Pre-processing steps were applied: 1. Radiometric Correction: Digital Numbers converted to TOA Reflectance 2. Atmospheric Correction: Dark Object Subtraction 3. Masking: Masking of Land and Ice features using classification of accompanying PAN imagery 4. Shallow Water Masking: Deep water masked out by thresh-holding the green and yellow bands The pre-processed data is provided as an 8-band Geotiff in UTM 44s with pixels of 2 m. Satellite-derived bathymetry grid [Davis Station_SDB_utm44s_alat.tiff] This bathymetry dataset was produced by applying the SMART-SDB model to Worldview 2 Multispectral Image acquired on 20120118 at 04:52:17Z. Multibeam bathymetry data acquired in February-March 20101 using a Kongsberg EM 3002D MBES, with vertical and horizontal accuracy of 0.38m and 1.95m respectively, was used for both calibration and validation of the SMART-SDB model. Derived data was smoothed using a low pass filter, and manually cleaned for erroneous returns (however some may still exist). A description of the methods is available in the attached reports. Projection: UTM44S Tidal datum: ALAT (approximate lowest astronomical tide) Format: geotiff, ASCI xyz Depths Derived from Satellite Imagery. For SA awareness only. Not for Navigation. Vertical Accuracy is un-assessable and should be considered worse than ZOC C. Undetected features significant to surface navigation may exist. Bathymetry map (Davis Station SDB Chart_OFFICIAL.pdf) This map shows the hydrographic chart from Davis Station overlayed with the new satellite-derived bathymetry data. Python Scripts and Guide These scripts were developed to automate extraction of satellite-derived bathymetry from the Worldview-2 imagery. Details of the scripts and how to apply them are outlined in the guide: Antarctica SDB Project How To.docx Final report [AASP4392_Antarctica SDB Project_FINAL_REPORT.docx] This report outlines the objectives, methods, results and conclusions for the satellite-derived bathymetry project (AASP4392). It has not been peer-reviewed. 1 A collaborative Australian Hydrographic Service, Geoscience Australia and Australian Antarctic Division survey on the Howard Burton acquired multibeam bathymetry data using a Kongsberg EM 3002D MBES with vertical and horizontal accuracy of 0.38m and 1.95m respectively in the nearshore waters of the Vestfold Hills in February-March 2010. This survey is part of Australian Antarctic Project (AAP) 5093: Hydrographic Surveying and Seabed Characterisation (CI: Ursula Harris) The data was extracted from the Australian Hydrographic Office database (20100329 Hydrographic survey) and is available at: O'Brien, P.E. (2011) Coastal seabed mapping survey, Vestfold Hills, Antarctica, February-March 2010, Ver. 2, Australian Antarctic Data Centre https://data.aad.gov.au/metadata/records/Davis_multibeam_grids)

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.