IN2023_V05 Tasman Sea Bathymetry 10m - 210m Multi-resolution AusSeabed products

Brief description

This layer group describes multibeam echosounder data collected on RV Investigator voyage IN2023_V05 titled "Untangling the causes of change over 25 years in the southeast marine ecosystem". The voyage took place between June 26 and July 30, 2024, departing from Hobart (TAS) and arriving in Hobart (TAS).

The purpose of this voyage was to repeat fishery and ecosystem assessments conducted 25 years ago, to document changes and establish a new biological and environmental baseline to help answer three broad questions:
1. How and why have fish assemblages and species abundances changed in the southeast ecosystem, and can the causes be mitigated?
2. How does this affect the multiple-use management of the region, particularly conservation and biodiversity management of Australian Marine Parks and the hive of activity from fisheries, oil & gas, and renewable energy sectors?
3. What are the implications for marine spatial planning and adaptive management in the sectors that use the marine ecosystem?

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 Tasman Sea 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 11.4.7. 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.

A monthly Caris Mira AI license for the ‘Admiralty GAM’ function was purchased for use throughout the voyage. The Admiralty GAM, which is an automated cleaning function, was used to save time on data editing due to high volumes of EM710 data. The tool was found to be overly aggressive at times, editing out features, necessitating checking of all automated cleaning.

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.