IN2024_V04 East Australian Current Bathymetry 10m - 210m Multi-resolution AusSeabed products

Full description

This layer group describes multibeam echosounder data collected on RV Investigator voyage IN2024_V04 titled "Linking East Australian current dynamics and submarine canyon geomorphology to marine ecosystem hotspots". The voyage took place between June 7 and July 3, 2024, departing from Sydney (NSW) and arriving in Brisbane (QLD).

The purpose of this voyage was to conduct a geophysical, oceanographic and biological survey of seafloor canyons along the continental shelf off NSW Solitary Canyon (~30.1°S, within the Central Eastern Marine Park) and the Richmond Canyon (~28.4°S). This research sought to better understand coastal-ocean exchange processes that are key controllers of coastal ocean properties and are important to marine ecosystem functioning. The data collected will improve our understanding of coastal-open ocean interaction mediated by the East Australian Current and their influence on climate, leading to more reliable forecasts for coastal communities and improved management of east coast fisheries. A small survey dedicated to a suspected paleo-shoreline was conducted on the shelf near Solitary Canyon. This survey involved mapping an area of approx. 13 x 3.5 km using the EM710 and running a crossline with the SBP120. A shipwreck survey over the MV Noongah was performed off the NSW coast, including a comprehensive multibeam survey with the EM710 and drop camera footage. This survey was conducted as a piggyback project for Heritage NSW and The Sydney Project to confirm the identity of the wreck.

This dataset is published with the permission of CSIRO. Not to be used for navigational purposes.

The dataset contains bathymetry grids of 10m to 210m resolution of the East Australian Current produced from the processed EM122 and EM710 bathymetry data.
Lineage: Multibeam data was logged from the EM’s in Kongsberg’s proprietary *.all format and was converted to be
processed within CARIS HIPS and SIPS version 12.0.8. Data were imported into the HIPS project using EM
Height and the vessel file appropriate for either the EM122 or EM710. GPS tide was computed using the
EGM2008 model EGM_2008_1Min_Aust_WGS84.csar. TPU values were computed using Measured Sound
Velocity = 0.5 and Surface Sound Velocity = 0.2. The raw files were analysed for noise and cleaned manually.
The data was then gridded at the highest resolution possible and further inspected for outliers.

For certain areas of EM710 data, the real-time applied sound velocity did not fully correct for refraction
errors. For the dedicated mapping completed for the Paleo Shoreline, sound velocity was reapplied using the
SVX2 casts taken along the shelf, which improved the data quality. These lines are noted in the MBES
processing log.

The data was then gridded at multiple resolutions in python Caris batch script using a Depth filter Vs Resolution guideline derived from AusSeabed Multibeam guidelines v2 and further inspected for outliers. Final raster products are available in L3 folder of this collection. Final processed data were also exported per line as GSF and ASCII format and available in the L2 folder of this collection.