This record describes multibeam echosounder data collected on RV Investigator voyage IN2019_V04, 'Hotspot dynamics in the Coral Sea: connections between the Australian plate and deep Earth', which departed Cairns on the 7th August 2019 and returned to Brisbane on the 3rd September 2019. The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter on the continental shelf and continental slope to a depth of ~1000m, off Cairns and Brisbane. 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 27 files totalling 5.12 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. Tide corrections were not applied to the processed data. Processed data has 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 further 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 XBT data collected on RV Investigator voyage IN2019_V04, which departed Hobart on the 11 April 2019 and returned to Hobart on the 23 April 2019. A total of 2 XBT casts were conducted over the duration of this voyage. Both were undertaken in quick succession in the same location. 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 sub bottom profiler data collected on RV Investigator voyage IN2019_V04, 'Hotspot dynamics in the Coral Sea: connections between the Australian plate and deep Earth' which departed Cairns on the 7th August 2019 and returned to Brisbane on the 3rd September 2019. The Kongsberg SBP120 (sub bottom profiler) was used to acquire data, containing the specular reflections at different sediment interfaces below the seafloor, in the Coral Sea within the EEZ of Australia, Papua New Guinea, Solomon Islands and New Caledonia 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 whilst underway during the voyage. Data are stored in *.raw (859 files 19.3 GB) raw and *.seg (868 files 19.7 GB) segy formats at CSIRO. There are additional *.seg files due to line splitting that was required. The segy format data had a real time processing stream applied, which applies gain, a gain correction, matched filter with replica shaping and time variable gain. Instantaneous amplitude was not applied in the processing stream. 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 IN2019_V04, 'Hotspot dynamics in the Coral Sea: connections between the Australian plate and deep Earth' which departed Cairns on the 7th August 2019 and returned to Brisbane on the 3rd September 2019. The gravity meter instrument is a MicroG Lacoste Air-Sea II and was run continuously during the voyage in the Coral Sea, within the EEZ of Australia, Papua New Guinea, Solomon Islands and New Caledonia. Data are stored in .ENV and .DAT data files at CSIRO. There are 57 files totalling 463 MB of raw data in this dataset. Wharf ties were undertaken at the start and end of the voyage using a Scintrex Autograv CG-5. Reference station number 2008909952 was used in Cairns (located at Cairns airport) and station number 2016909147 was used in Brisbane (located at Northshore Riverside Park). Wharf tie data can be found in "Cairns_wharf_gravity_tie_in2019_v04.TXT" and "Brisbane_wharf_gravity_tie_post_in2019_v04.TXT", which are stored with the raw data folder. 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 multibeam echosounder data collected on RV Investigator voyage IN2019_V04, 'Hotspot dynamics in the Coral Sea: connections between the Australian plate and deep Earth', which departed Cairns on the 7th August 2019 and returned to Brisbane on the 3rd September 2019. The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter in the Coral Sea, within the EEZ of Australia, Papua New Guinea, Solomon Islands and New Caledonia. 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 977 files totalling 49.2 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. Tide corrections were not 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 IN2019_V04, 'Hotspot dynamics in the Coral Sea: connections between the Australian plate and deep Earth', which departed Cairns on the 7th August 2019 and returned to Brisbane on the 3rd September 2019. The Simrad EK60 split beam echosounders 18, 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a range of 1500 m in the Coral Sea, within the EEZ of Australia, Papua New Guinea, Solomon Islands and New Caledonia. All frequencies were logged continuously for the extent of the voyage. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 766 files totalling 73.9 GB of raw data in this dataset. No 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 the Acoustic Doppler Current Profiler (ADCP) data collected from the Marine National Facility RV Investigator voyage IN2019_V04, titled "Hotspot dynamics in the Coral Sea: connections between the Australian plate and deep Earth." The voyage took place from Cairns (QLD) to Brisbane (QLD) between August 7 and September 3, 2019. Data was collected during in2019_v04 for the duration of the voyage. Data was collected using UHDAS and post-processed using CODAS. Both the RDI Ocean Surveyor 150kHz ADCP and the RDI Ocean Surveyor 75kHz ADCP were run in narrowband mode for the duration of the voyage. Internal triggering was used. The drop keel was at 2m below the waterline for the duration of the voyage. See the voyage computing and electronics report for more details regarding data acquisition. This dataset was processed and then archived within the CSIRO Oceans and Atmosphere (O&A) Information and Data Centre (IDC) in Hobart.

This record describes the Underway (UWY) data collected from the Marine National Facility (MNF) RV Investigator Voyage IN2019_V04, titled: "Hotspot dynamics in the Coral Sea: connections between the Australian plate and deep Earth." The voyage took place between August 7 and September 3, 2019 departing from Cairns (QLD) and arriving in Brisbane (QLD). 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 where they are publicly available at the "Ships of Opportunity" Thredds server (http://thredds.aodn.org.au/thredds/catalog/IMOS/SOOP/SOOP-ASF/VLMJ_Investigator/catalog.html) for research. From there, they are downloaded by NOAA for their In Situ Quality Monitoring web site (iQUAM2) and made available for satellite SST validation. The SBE 38 SST data are used within the Australian Bureau of Meteorology for real-time satellite SST validation and ingested into real-time SST analyses which are then used as the boundary condition for Numerical Weather Prediction models. The meteorological and SST data are uploaded onto the Global Telecommunications System (GTS) for global dissemination to Meteorological Agencies, and separately supplied to the SAMOS (http://samos.coaps.fsu.edu/html/) Project for air-sea flux research. The real-time SBE 38 SST data are currently (2017) used in the following data products (accessed via the GTS): • International Comprehensive Ocean-Atmosphere Data Set (ICOADS R3.0) (http://icoads.noaa.gov/) • NOAA NCEI Extended Reconstructed Sea Surface Temperature version 4 (ERSST.v4) (https://www.ncdc.noaa.gov/data-access/marineocean-data/extended-reconstructed-sea-surface-temperature-ersst-v4) • Hadley Centre SST Data Set (HadSST3) (http://www.metoffice.gov.uk/hadobs/hadsst3/) • Global Ocean Surface Underway Data (GOSUD) Project (http://www.gosud.org/) • Bureau of Meteorology daily and weekly SST analyses (http://www.bom.gov.au/marine/sst.shtml) • NOAA NCEI “Reynolds” daily global OISST analysis (https://www.ncdc.noaa.gov/oisst) • NASA JPL “MUR” 1 km daily global SST analysis (https://mur.jpl.nasa.gov/) • UK Met Office “OSTIA” daily global SST analysis (http://ghrsst-pp.metoffice.com/pages/latest_analysis/ostia.html) • CMC daily global SST analysis • Ourocean “G1SST” global daily 1 km SST analysis (https://ourocean.jpl.nasa.gov/SST) As part of the underway data gathering system, other datasets are produced (e.g., pCO2, ISAR SST) which are processed separately and have their own metadata records. Data are recorded at 5 second intervals. Near real-time data are available via the link "Visualisation tool for Underway Data." This dataset will be processed and archived within the CSIRO Oceans & Atmosphere (O&A) Information and Data Centre (IDC) in Hobart (TAS). Data are available at time intervals of 5 sec (NetCDF format), 10 sec and 5 min (ASCII format). Additional information regarding this dataset is contained in the Voyage Summary and/or the Data Processing Report for this voyage.