This record describes multibeam echosounder data collected on RV Investigator voyage IN2025_V05, 'Eruption, destruction and seafloor ecosystem recovery – Tonga 2022 eruption of the century', which departed Hobart on 10 Aug and ended in Brisbane on 01 Oct 2025 (local). The voyage’s first leg transited from Hobart to Nuku’alofa (10–19 Aug 2025), where science participants boarded. A mid-voyage transfer occurred on 05 Sep, and all science personnel disembarked in Nuku’alofa on 23 Sep before the final transit to Brisbane (23 Sep–1 Oct 2025). The Kongsberg EM712 multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter data. The EM712 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 *.kmall raw format for bathymetry and backscatter and *.kmwcd format for watercolumn backscatter at CSIRO. There are 131 files totalling 17.8 GB of raw data and 131 files totalling 92.9 GB of watercolumn data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.kmall format are corrected for motion and position. GPS tide was computed using the EGM2008 model and applied to the processed data. Processed data has had outliers removed. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2025_V05, 'Eruption, destruction and seafloor ecosystem recovery – Tonga 2022 eruption of the century', which departed Hobart on 10 Aug and ended in Brisbane on 01 Oct 2025 (local). The voyage’s first leg transited from Hobart to Nuku’alofa (10–19 Aug 2025), where science participants boarded. A mid-voyage transfer occurred on 05 Sep, and all science personnel disembarked in Nuku’alofa on 23 Sep before the final transit to Brisbane (23 Sep–1 Oct 2025). The EM124 provides a 1 degree by 1 degree angular resolution. The echosounder's nominal frequency is 12 kHz. Data are stored in *.kmall raw format for bathymetry and backscatter and *.kmwcd format for watercolumn backscatter at CSIRO. There are 1044 files totalling 140 GB of raw data and 1044 files totalling 186 GB of watercolumn data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.kmall format are corrected for motion and position. GPS tide was computed using the EGM2008 model and applied to the processed data. Processed data has had outliers removed. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report.

This record describes sub bottom profiler data collected on RV Investigator voyage IN2025_V05, 'Eruption, destruction and seafloor ecosystem recovery – Tonga 2022 eruption of the century', which departed Hobart on 10 Aug and ended in Brisbane on 01 Oct 2025 (local). The voyage’s first leg transited from Hobart to Nuku’alofa (10–19 Aug 2025), where science participants boarded. A mid-voyage transfer occurred on 05 Sep, and all science personnel disembarked in Nuku’alofa on 23 Sep before the final transit to Brisbane (23 Sep–1 Oct 2025). The Kongsberg SBP29 (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 9 kHz. The SBP29 was logged continuously for the extent of the voyage. Data are stored in *.raw (2002 files 22 GB) raw and *.seg (1991 files 21.9 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 multibeam echosounder data collected on IN2025_V05, 'Eruption, destruction and seafloor ecosystem recovery – Tonga 2022 eruption of the century', which departed Hobart on 10 Aug and ended in Brisbane on 01 Oct 2025 (local). The voyage’s first leg transited from Hobart to Nuku’alofa (10–19 Aug 2025), where science participants boarded. A mid-voyage transfer occurred on 05 Sep, and all science personnel disembarked in Nuku’alofa on 23 Sep before the final transit to Brisbane (23 Sep–1 Oct 2025). The EM2040MK2 provides a 0.4 degree by 0.7 degree angular resolution. The echosounder's nominal frequency is 400 kHz (with a range of 200-700 kHz) and it operated in dual swath mode. Data are stored in *.kmall raw format for bathymetry and backscatter and *.kmwcd format for watercolumn backscatter at CSIRO. There are 71 files totalling 26 GB of raw data and 71 files totalling 203 GB of watercolumn data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.kmall format are corrected for motion and position. GPS tide was computed using the EGM2008 model and applied to the processed data. Processed data has had outliers removed. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report.

This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2025_V05, 'Eruption, destruction and seafloor ecosystem recovery – Tonga 2022 eruption of the century', which departed Hobart on 10 Aug and ended in Brisbane on 01 Oct 2025 (local). The voyage’s first leg transited from Hobart to Nuku’alofa (10–19 Aug 2025), where science participants boarded. A mid-voyage transfer occurred on 05 Sep, and all science personnel disembarked in Nuku’alofa on 23 Sep before the final transit to Brisbane (23 Sep–1 Oct 2025). The Simrad EK80 split beam echosounders for 18, 38, 70 120 and 200 were used to acquire acoustic backscatter data to a range of 1500 m. All frequencies were logged mostly continuously for the extent of the voyage, with the exception of short periods of focused seabed mapping or other sampling operations. Data are stored in *.raw and *.idx format at CSIRO. There are 6540 files totalling 156 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 gravity data collected on RV Investigator voyage IN2025_V05, 'Eruption, destruction and seafloor ecosystem recovery – Tonga 2022 eruption of the century', which departed Hobart on 10 Aug and ended in Brisbane on 01 Oct 2025 (local). The voyage’s first leg transited from Hobart to Nuku’alofa (10–19 Aug 2025), where science participants boarded. A mid-voyage transfer occurred on 05 Sep, and all science personnel disembarked in Nuku’alofa on 23 Sep before the final transit to Brisbane (23 Sep–1 Oct 2025). The gravity meter instrument is a MicroG Lacoste Air-Sea II. Data are stored in .ENV and .DAT data files at CSIRO. There are 52 files totalling 852 MB of raw data in this dataset. Wharf ties were undertaken at Hobart (PW4) and in Brisbane (Grain Corp, Multiuser Terminal) using a Scintrex Autograv CG-5. Wharf tie data can be found in GravityTie_in2025_v05_Hobart_20250807.TXT & GravityTie_in2025_v05_Brisbane_20251001.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 XBT data collected on RV Investigator voyage IN2025_V05, 'Eruption, destruction and seafloor ecosystem recovery – Tonga 2022 eruption of the century', which departed Hobart on 10 Aug and ended in Brisbane on 01 Oct 2025 (local). The voyage’s first leg transited from Hobart to Nuku’alofa (10–19 Aug 2025), where science participants boarded. A mid-voyage transfer occurred on 05 Sep, and all science personnel disembarked in Nuku’alofa on 23 Sep before the final transit to Brisbane (23 Sep–1 Oct 2025). A total of 17 XBT casts were conducted over the duration of this voyage. 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 Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2025_V05, titled: "Eruption, destruction, and seafloor ecosystem recovery – Tonga's 2022 eruption of the century." The voyage took place between August 10, 2025 and October 01, 2025 (AEST), departing from Hobart and returning to Brisbane. 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 End of Voyage (EOV) data archive from the Marine National Facility (MNF) RV Investigator voyage IN2025_V05, titled "Eruption, destruction, and seafloor ecosystem recovery – Tonga's 2022 eruption of the century." The voyage took place between August 10, 2025 and October 01, 2025 (AEST), departing from Hobart and returning to Brisbane. For further information please refer to the voyage documentation links. Instruments used and data collected include: Regular measurements: Lowered ADCP (LADCP), Acoustic Doppler Current Profiler (ADCP; 38, 75, 150 KHz ), Greenhouse Gas Analysers (Picarro), Cloud Condensation Nuclei counter (CCN), Condensation Particle Counters (CPC), Disdrometer, Radon sensor, Black Carbon sensor (Aethalometer), CTD, Hydrochemistry, Fisheries Echosounder (EK80), Multibeam Echosounder (EM712, EM124, EM2040), Sub-bottom Profiler (SBP29), GPS Positioning System, Doppler Velocity Log, Thermosalinographs (TSG), Fluorometer, Oxygen Optode, Infrared Sea Surface Temperature Autonomous Radiometer (ISAR), pCO2, Gravimeter, Ozone Sensor, Nephelometer, Atmospheric Temperature, Humidity, Pressure, Wind and Rain sensors, Photosynthetically Active Radiation (PAR) sensor, Precision Infrared Radiometer (PIR), Precision Spectral Pyranometer (PSP), Starboard and Portside Radiometers, Air Sampler, Ultra Short BaseLine Underwater Positioning System (USBL), Expendable Bathythermographs (XBTs). Voyage-specific measurements: Deep Towed Camera (DTC), Micro Rain Radar (MRR), Miniature Autonomous Plume Recorder (MAPR), Optical Backscatter sensor, Oxidation-Reduction Potential (ORP) meter, Box corer, Multi-corer, Piston Corer, Rock Dredge, NIWA epibenthic sled (mini-Sherman), Seismic, Video, Wildlife Observations (seabirds, cetaceans and seals). The archive for the IN2025_V05 EOV raw data is curated by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart, with a permanent archive at the CSIRO Data Access Portal (https://data.csiro.au/), providing access to voyage participants and processors of the data collected on the voyage. All voyage documentation is available electronically to MNF support via the local network. Applications to access voyage documentation by non-CSIRO participants can be made via data-requests-hf@csiro.au All processed data from this voyage are made publicly available through the MNF Data Trawler (in the related links)