Geoscience Australia conducted a marine seismic survey (GA-0352) over various areas of the Gippsland Basin, between 5th of April to the 24th of April 2015, by the Gardline CGG vessel MV Duke. This service includes all the bathymetry data collected during the survey, with the data also available as a free download from the Geoscience Australia website.
The aim of the survey was to acquire industry-standard precompetitive 2D seismic data, Multi-beam echo-sounder (MBES) and sub-bottom profiling (SBP) data to support an assessment of the CO2 storage potential of the basin. The survey, undertaken as part of the Department of Industry and Science's National CO2 Infrastructure Plan (NCIP), aimed to identify and characterise indicators of natural hydrocarbon or fluid seepage that may indicate compromised seal integrity in the region. The data collected during this survey will enhance sequence stratigraphic studies in the Gippsland Basin that provide constraints on the most suitable areas for storage of CO2 and help to identify potential CO2 storage reservoirs.
The Gippsland 2D Infill MSS 2015, GA-0352 was acquired by Geoscience Australia onboard the MV Duke from the 5th of April to the 24th of April 2015.
The Chief scientist onboard was Dr. Robert Langford.
This bathymetry dataset was acquired and processed onboard by Gardline CGG Pte Ltd and further processing was conducted in the office by Michele Spinoccia, using CARIS HIPS & SIPS ver 7.1.2.
1. First a vessel configuration file was created where the co-ordinates of the motion sensor and DGPS antenna and patch test offsets were recorded.
2. A new project was then created and the vessel configuration file was attached to the project file.
3. The raw swath sonar data, in raw.all format, for each line was then imported into the project and the vessel information assigned to the data.
4. The motion sensor, DGPS and heading data were then cleaned using a filter that averaged adjacent data to remove artefacts.
5. Different sound velocity profiles data for each block were attached to the corresponding raw swath sonar data files to correct the depths for changes in the speed of sound through the water column.
6. Then a new blank field area was defined that specified the geographic area of study and the co-ordinate system used. The co-ordinates for the study areas were WGS84 UTM-55S.
7. The data was cleaned by applying several filters that removed any remaining spikes in the bathymetry data using user defined threshold values. A visual inspection of the data for each line was then undertaken where artefacts and noisy data not removed by the filtering process were removed manually using Swath and subset editors modules of the Caris HIPS/SIPS software.
8. All the data for each bathymetric, motion sensor, DGPS, heading, tide and sound velocity profile data were merged to produce the final processed data file. A weighted grid of the processed data was then created for each Block.
In GA the tide was applied to the grid to correct for tidal variations and velocity corrections were performed to correct for different artefacts and mismatches.
9. The processed data was finally exported as grids soundings or false colored images for presentation and reporting and as final processed data in ASCII XYZ , CARIS csar and geotif formats of 1m resolution.
10-The CARIS csar were used by ESRI FME to create in ARC catalogue/info to create a raster file for the entire survey.