This record describes multibeam echosounder data collected on RV Investigator voyage IN2023_V02, titled "Gigantic submarine landslide offshore western Tasmania: risk mitigation for shelf derived tsunami in Australia", which departed Hobart on March 24 and returned to Hobart on April 30, 2023.
The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter during the voyage to the SW of Tasmania (Hobart 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 938 files totalling 39.5 GB of raw bathymetry/backscatter data and 937 (.wcd) files totaling 56.7 GB of watercolumn data in this dataset.
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Sound velocity profiles were applied to this data during data acquisition. 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. In some cases of bad navigation due to runoff issues with the POSMV, the Seapath navigation (Nav source 3) was applied instead. These lines are noted in the multibeam processing log (in2023_v02_MBES_processing_log.xlsx).
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.
