The Australian Antarctic Division identified areas that required hydrographic surveying. (See map available in the download at \Plans and Instructions\HPS Supplied Data\davis_plan_2019_2020 version 5.1.pdf and a shapefile of the identified areas at FSD\ArcGIS\Pink V2\AOI_Unproject_wgs84.shp) A team from the Maritime Geospatial Warfare Unit, of the Australian Hydrographic Service, was at Davis in early February 2020. Single beam and side scanning survey data was collected on the water, beach profiles collected and rock data. Single beam and side scanning survey data Areas A, D, F, H, I, J and K were ice free. Area J was further broken down into four areas, J1, J2, J3 and J4. Areas A, D and F were thoroughly surveyed with 10m mainline spacing with 20m X-line spacing. Areas I, J3 and J4 were surveyed but due to time constraints were surveyed at approximately 40m line spacing to provide 200% sea floor coverage with the SSS to detect any features dangerous to navigation with one shoal detected in area I which is mentioned in Section I. Area H was too shallow to survey at any other time except high tide and it was decided to focus on other areas as the survey of this area would not value add to the required results of the survey. Area J1, J2 and K were not surveyed due to time constraints. RTK corrections or access to the CORS network couldn't be made to the CEESCOPE survey system. Instead positioning during the survey was recorded exclusively with the NovaTel GNSS 850 Antenna. No post processing was conducted. The team wasn't able to determine why the CEESCOPE was unable to connect to the CORS network or Base Station to gain RTK corrections, despite considerable effort spent problem solving and conducting a number of trials. Tide data collected was applied to the data and all tidal information is explained in section F of the report. A map showing the surveyed areas can be found in the report. Raw data in caris format is available from the Australian Hydrographic Office (AHO). Sounding data, stored as a shapefile, is available as a download file. Beach profiles Sites were also surveyed with 5m line spacing to maximise seafloor coverage, at 5 beach locations, 4 in area A and 1 in Area F. ArcGIS projects and PDF documents displaying the depth data and significant rocks are included in the download. Please note the ArcGIS projects do not include the AHO chart, due to distribution restrictions on digital charts. It is included in the PDF documents. These documents refer to images taken from the survey boat and spreadsheets displaying gradients data. Rock data A shapefile recording conspicuous rocks as well as photographs is available for downloading. Bench mark positions were reclaimed using Trimble R10 and post processed with AUSPOS. Abbreviations used in the download directories ROS = Report of Survey, FSD = Final Survey Data A detailed report can be found at /ROS/ Projection……..…...…...………….….……..Universal Transverse Mercator (UTM) Zone 43 South Horizontal Datum……………………………World Geodetic System 1984 (WGS84) Vertical Datum…………………………….....Approximated Lowest Astronomical Tide (LAT) Sounding Depths.……………………………Metres (m) Survey Date………………..………………….6th - 18th Feb 2020 Bathymetric Accuracy Horizontal……………± 0.8m Bathymetric Accuracy Vertical………………±0.46m Sounding Density……………………………..2m Surface Chart Reference………………………………AUS 451, 602​ ITRF 2014 and GRS80 were utilised for static observations of bench marks and levelling to the tide pole for establishment of approximate LAT. Hypack v19.1.11.0 which was used to gather all bathymetric data does not have the option to use the ITRF datum and the WGS84 Datum was used.

Two components. The first component is an even log for all station and instrument deployements. The second component is a log where start and end bottom times need to be recorded for instruments for example the benthic trawl. There is one file for each of the logs. Both logs need to be ideally merged into one to have one data source of event information. The start and end bottom times need to ideally go into the event logging system on the ship. 1) Event log for stations and all instrument deployments Stations and instrument deployments were recorded (including failures) over the progress of the voyage to provide a summary of all work carried out over voyage and and assigned an Event ID number for referencing data associated with these events. Data_Format Data was initially recorded in the ship board PostgreSQL database. Data was exported as a comma delimited file 'events.csv' at the end of the voyage. Column 1 - Setcode (voyage identifier of the form 200708030 meaning year 2007-08, voyage 3) Column 2 - Voyage Code (text voyage identifier) Column 3 - Transect ID (transect identifier, no transects were identified this voyage) Column 4 - Station ID (Station identifier, blank for events not associated with a station, CEAMARC project stations are pre-pended with 'CEAMARC', CASo stations are pre-pended with 'CASO', sampling near icebergs for trace metals pre-pended with 'ICEBERG', woCE SR3 transect sampling pre-pended with 'SR3'). Column 5 - Event ID (unique ID across voyage for individual events) Column 6 - Event Type (usually the instrument deployed, self explanatory. One event type 'Plankton Water Sample' refers to mass water sampling undertaken for genomics work). Column 7 - User Reference (id used by individual scientists to reference their data for this event. If left blank they are using the auto assigned event id from this table). Column 8 - Start Timestamp (start timestamp of the event in UTC). Column 9 - Start Latitude (start latitude of the event from the ship gps) Column 10 - Start Longitude (start longitude of the event from the ship gps) Column 11 - Start Bottom Depth (bottom depth at the start time of the event in metres from EK60 sounder bathymetry export) Column 12 - End Timestamp (end timestamp of the event in UTC) Column 13 - End Latitude (end latitude of the event from the ship gps) Column 14 - End Longitude (end longitude of the event from the ship gps) Column 15 - Duration (duration of the event in hours) Column 16 - End Bottom Depth (bottom depth at the end time of the event in metres from EK60 sounder bathymetry export) Column 17 - Min bottom Depth (minimum bottom depth encountered over event period from EK60 sounder bathymetry export) Column 17 - Avg Bottom Depth (average bottom depth encountered over event period from EK60 sounder bathymetry export) Column 18 - Max Bottom Depth (maximum bottom depth encountered over event period from EK60 sounder bathymetry export) Column 19 - Author (person who entered event details into logging system) Column 20 - Notes (notes peculiar to the event, may be blank) 2) Log of instrument bottom times. Excel spreadsheet 'Trawl_log_18_Jan_08_final.xls' Column A - Station number, these are all CEAMARC station numbers, matching stations in the event log pre-pended by 'CEAMARC'. Column B - Event ID (matching event log, sometimes blank as this log an contain entries on intended events that did not get carried out for some reason or another) Column C - Trawl Name (labelled trawl name, actually event type as the log started off with just trawl start/end bottom times, but was expanded to encompass other event types like grabs etc.) Column D - Date of the event. Column E - Ship Speed (in knots from displays of gps speed). Column F - Time instrument hit the water in utc Column G - Time instrument reached the bottom in utc. Column H - Time instrument left the bottom (i.e. hauling started) in utc. Column I - Time instrument on the deck (ie out of the water) Column J - Depth in meters read of EK60 sounder display (could be any time during event). Column K - Comments pertaining to the event.

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.