This record describes multibeam echosounder data collected on RV Investigator voyage IN2023_V01, titled "Antarctic Bottom Water Production in the past: Records from marine sediments, Cape Darnley, East Antarctica". The voyage took place between 25th January, 2023 and 2nd March, 2023 departing from Henderson's (WA) and arriving in Hobart (TAS). The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter between Fremantle to Antarctica and Albany to Hobart. The EM710 MKII provides a 0.5° by 1° transmit and receive angular resolution respectively. The echosounder's nominal frequency range is from 40 to 100 kHz. Data are stored in *.all raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. There are 102 files totalling 26.3 GB of raw data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format are corrected for motion and position. Bathymetry data contained in *.all format are corrected for motion and position. GPS tide was computed using the EGM2008 model and applied to the processed data. Processed data had outliers removed. Processed line data are available in *.gsf and ascii format, and processed bathymetry and backscatter grids in geotiff format. Additional information regarding this dataset, including information on processing streams, is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2023_V01, titled "Antarctic Bottom Water Production in the past: Records from marine sediments, Cape Darnley, East Antarctica". The voyage took place between 25th January, 2023 and 2nd March, 2023 departing from Henderson's (WA) and arriving in Hobart (TAS). The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter between Fremantle to Antarctica and Albany to Hobart. The EM122 provides a 1 degree by 1 degree angular resolution. The echosounder's nominal frequency is 12 kHz. Data are stored in *.all raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. There are 1,395 files totalling 60 GB of raw data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format are corrected for motion and position. Bathymetry data contained in *.all format are corrected for motion and position. GPS tide was computed using the EGM2008 model and applied to the processed data. Processed data had outliers removed. Processed line data are available in *.gsf and ascii format, and processed bathymetry and backscatter grids in geotiff format. Additional information regarding this dataset, including information on processing streams, is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2023_V01, titled "Antarctic Bottom Water Production in the past: Records from marine sediments, Cape Darnley, East Antarctica". The voyage took place between 25th January, 2023 and 2nd March, 2023 departing from Henderson's (WA) and arriving in Hobart (TAS). The Simrad EK60 split beam echosounders for18kHz and Simrad EK80 split beam echosounders for 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a range of 1,500m, between Fremantle and Antarctica (one-way) and then from Albany to Hobart. All frequencies were logged continuously for the extent of the voyage. The 75kHz and 120kHz frequencies were set to passive for shallow areas where EM710 was used. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 1,143 lines totalling 106 GB of raw data in this dataset. No post processing has been conducted on this data. Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes sub bottom profiler data collected on RV Investigator voyage IN2023_V01, titled "Antarctic Bottom Water Production in the past: Records from marine sediments, Cape Darnley, East Antarctica". The voyage took place between 25th January, 2023 and 2nd March, 2023 departing from Henderson's (WA) and arriving in Hobart (TAS). The Kongsberg SBP120 (sub bottom profiler) was used to acquire data containing the specular reflections at different sediment interfaces below the seafloor. The SBP120 provides a 3° by 3° angular resolution. The echosounder's frequency sweep range is from 2.5 to 7 kHz. The SBP120 was logged continuously for the extent of the voyage. Data are stored in *.raw (2,284 files 41.4 GB) raw and *.seg (1,078 files 20.8 GB) segy formats at CSIRO. The segy format data had a real time processing stream applied, which applies gain, a gain correction, matched filter with replica shaping, an attribute calculation for instantaneous amplitude and time variable gain. Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request

This record describes gravity data collected on RV Investigator voyage IN2023_V01, titled "Antarctic Bottom Water Production in the past: Records from marine sediments, Cape Darnley, East Antarctica". The voyage took place between 25th January, 2023 and 2nd March, 2023 departing from Henderson's (WA) and arriving in Hobart (TAS). The gravity meter instrument is a MicroG Lacoste Air-Sea II. Data are stored in .ENV and .DAT data files at CSIRO. There are 74 files totalling 582 MB of raw data in this dataset. Wharf ties were undertaken at Henderson_AMC Wharf and Hobart Wharf using a Scintrex Autograv CG-5. Wharf tie data can be found in gravity_data folder\Hobart_wharf_tie_2023_03_02.txt & Henderson_AMC_wharf_tie_2023_01_24.txt, which is stored with the raw data. No processing has been conducted on this data. Additional information regarding this dataset is contained in the GSM data acquisition and processing report.

This record describes magnetometer data collected on RV Investigator voyage IN2023_V01, titled "Antarctic Bottom Water Production in the past: Records from marine sediments, Cape Darnley, East Antarctica". The voyage took place between 25th January, 2023 and 2nd March, 2023 departing from Henderson's (WA) and arriving in Hobart (TAS). The SeaSPY2 magnetometer uses an omnidirectional Overhauser sensor that requires no realignment or recalibration and has no heading error. The instrument has an absolute accuracy of 0.1 nT, sensor sensitivity of 0.01 nT and resolution of 0.001 nT. Data are stored in .CSV and .MMS data files at CSIRO. 15 final files for 150 MB were exported as .csv files in this dataset. No processing has been conducted on this data. A total of 3,909 track kilometre's of magnetometer data was collected. The magnetometer was towed ~300 m astern of the ship and a layback value of 361 was applied to the magnetometer data. This was the total distance behind the ship's positioning reference point. Additional information regarding this dataset is contained in the GSM data acquisition and processing report.

This record describes XBT data collected on RV Investigator voyage IN2023_V01, titled "Antarctic Bottom Water Production in the past: Records from marine sediments, Cape Darnley, East Antarctica". The voyage took place between 25th January, 2023 and 2nd March, 2023 departing from Henderson's (WA) and arriving in Hobart (TAS). A total of 10 XBT casts were conducted over the duration of this voyage. Four XBT's failed due to cold shock in Antarctic waters, 6 were used for Caris processing of multibeam datasets. Data are stored in netCDF files at CSIRO. Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes the Acoustic Doppler Current Profiler (ADCP) data collected from the Marine National Facility RV Investigator voyage IN2023_V01, titled: "Antarctic Bottom Water production in the past: Records from marine sediments, Cape Darnley, East Antarctica." The voyage took place between January 25, 2023 and March 2, 2023 (AEST), departing from Fremantle and returning to Hobart. This voyage had two main scientific objectives. First, to understand past changes in Antarctic Bottom Water (AABW) production using long sediment cores from the continental slope over multiple warm periods during the Pleistocene. Second, to develop an improved bathymetry model to support oceanographic modelling of AABW pathways. Sediment core records of previous warmer interglacial will provide an analogue for understanding the impact of any future changes in bottom water production associated with a warming climate. This report describes the production of quality-controlled ADCP data from RV Investigator voyage IN2023_V01. The OS150 unit was run for the majority part of the voyage whilst the OS75 was run for parts of the voyage. The OS75 showed unusual behaviour where the data depth was half the expected value at around 350m with low data quality. On-board investigation discovered that beams 1 and 2 of the OS75 unit were severely degraded and the fault was attributed to the likely failure of the ceramic arrays. ADCP data were collected using the University of Hawaii Data Acquisition System (UHDAS) and post-processed using the Common Ocean Data Access System (CODAS). Documentation for these systems can be found in (Hummon, 2009-2021). Both the RDI Ocean Surveyor 150kHz ADCP and the RDI Ocean Surveyor 75kHz ADCP were run in narrowband mode. Internal triggering was used. The drop keel (port) extension was set at below the waterline as detailed: 2m from the voyage start until 11-Feb-2023 09:20:05 UTC, 0m (Zero) from 11-Feb-2023 09:21:30 to 21-Feb-2023 23:24:15 UTC and 2m from 21-Feb-2023 23:25:05UTC to the end of the voyage. There were several gaps in the OS75 ADCP data due to the investigation on board related to the fault discussed above and the reduction in the usual data quality resulted in extra processing effort being required. Apart from the usual data cleaning, there were no significant ADCP processing-related issues in relation to the OS150 data. To access the full voyage plan and other reports and data associated with this voyage, please see the contact information at the end of this report. This dataset was processed (quality-controlled), and then archived by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC).

This record describes Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2023_V01, titled: "Canyons: Antarctic Bottom Water Production in the past: Records from marine sediments, Cape Darnley, East Antarctica." The voyage took place between January 25 and March 2, 2023, departing from Henderson (WA) and returning to Hobart. Hydrology samples were collected from Niskin bottles sampled at various depths during Conductivity-Temperature-Depth (CTD) deployments. Parameters analysed were salinity, dissolved oxygen, phosphate, silicate, nitrate plus nitrite and ammonium. This dataset has been processed (quality-controlled), and archived at the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset is contained in the Voyage Report and Data Processing Report.

This record describes the Underway (UWY) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2023_V01, titled: "Canyons: Antarctic Bottom Water Production in the past: Records from marine sediments, Cape Darnley, East Antarctica." The voyage took place between January 25 and March 2, 2023, departing from Henderson (WA) and returning to Hobart. Standard Underway data is continuously recorded, consisting of: (1) Navigation data (NAV): Latitude, Longitude, Speed, Heading, Course Over Ground, Gyros, and Doppler Log (dual GPS instrument). (2) Thermosalinograph (TSG): Water Salinity, Flow-Rate, Temperature, Fluorescence, pCO2 and Optode/Oxygen. (3) Atmospheric (MET): Humidity, Wind Speed and Direction (vane and ultrasonic), Radiometer/Sea Surface Temperature, Pyranometer/Solar Radiation, Photosynthetically Active Radiation (PAR), Air Temperature, Air Pressure, Rain, Ozone and Trace Gases (port and starboard instruments). The quality-controlled RV Investigator underway meteorological and SST data are supplied to the IMOS AODN and other global data repositories and distributors, and made available for satellite SST validation by the Australian Bureau of Meteorology (BoM). Near real-time, unprocessed data are available via the link "Visualisation tool for Underway Data." This dataset has been processed (quality-controlled), and archived by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC). Data are available at time intervals of 5 sec (NetCDF format), 5 sec, 10 sec, 1 min and 5 min (ASCII format). Note: not all variables are quality controlled; please check for existing QC flags in the datasets. Additional information regarding this dataset is contained in the Voyage Summary and/or the Data Processing Reports for this voyage.