A database containing sounding data around Macquarie Island. Track line data for each data source is included.

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)

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).

Metadata record for data from ASAC Project 933 See the link below for public details on this project. Australian Antarctic and Southern Ocean Profiling Project (AASOPP) was the outcome of a government decision in 1999 that it would carry out the necessary work to place Australia in a position to be able to prepare a submission defining the outer limit the 'extended Continental Shelf' (ECS) off the Australian Antarctic Territory (AAT). The ECS is the area of seabed/subsoil jurisdiction extending beyond the 200 nautical mile Exclusive Economic Zone, and is defined by Article 76 of the United Nations Convention on the Law of the Sea. AASOPP was set up in 2000, under the management of the Department of Finance and Administration and in consultation with the Australian Antarctic Division, to undertake the acquisition and interpretation of the data that would underpin a UN submission. Technical aspects of the work were largely the responsibility of the Australian Geological Survey Organisation and the Australian Surveying and Land Information Group (later Geoscience Australia). Marine geophysical surveys were conducted in 2001/2 and 2002/3 by the primary contractors, FUGRO Geoteam supervised by AGSO (Geoscience Australia) using the vessels Geoarctic and Polar Duke (survey numbers GA227, GA228 and GA229). Data collected were seismic reflection, sonobuoy seismic refraction, magnetic and gravity profiles. Data processing was supervised by Geoscience Australia where they are archived. Seismic data were lodged with the SCAR Seismic Data Library. Law of the Sea interpretations were lodged as part of the Australian submission to the United Nations by November, 2004 with a request not to examine the Antarctic case until requested.

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.

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)

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.

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 contains temperature data obtained from XBTs (expendable bathythermographs) deployed during a cruise between Sydney and Noumea (New Caledonia).