Petrel Sub-basin CO2 storage Seismic survey (GA0336/ Duke9144) (NLECI Program) - High resolution Bathymetry grids

Brief description

The Petrel Sub-basin CO2 storage 2D seismic survey GA-0336, was acquired by the MV Duke in the Bonaparte Bay, NW Australia for Geoscience Australia between the the 3rd of May to the 24th of June 2012. This survey was part of the Australian government's National Low emission Coal Initiative (NLECI).The purpose was to acquire geophysical data on shallow water (less than 120m water depth) in the Petrel sub-basin to support investigation for CO2 storage potential in the area. Multibeam bathymetry data was acquired by the vessel at the same time as the seismic data. This bathymetry dataset consist of the high resolution bathymetry grids (2m) of all the swath data acquired by the MV Duke.

This dataset is not to be used for navigational purposes.

Lineage

Maintenance and Update Frequency: asNeeded

Statement: The multibeam bathymetry was acquired by the following survey: - Survey Name: GA-0336 Petrel sub-basin CO2 Storage Seismic Survey 9144 - Vessel Name: MV Duke - Institution: Geoscience Australia - Country: Australia - Operator: Gardline CGGV Pte Ltd. - Multibeam system: Kongsberg EM2040 - Year of installation: 2011 - Nominal sonar frequency: 200-400 kHz 200 kHz used at Normal sector. - Number of beams: 400 beams/ping - Beamwidth across track: 0.5 degree - Beamwidth alon track: 1 degree - Pulse length: variable - Selectable depth range: 0.5m - 500m - Vessel speed: 7 - 8 knots - Start Date: 03/05/2012 - End Date: 24/06/2012 - Start Port: Darwin - End Port: Darwin The Petrel Sub-Basin Seismic survey, GA-0336 Duke 9144 was acquired by Geoscience Australia onboard the MV Duke from the 3rd of May to the 24th of June 2012. The Chief scientist was Dr. Chris Consoli. This dataset was acquired and partially processed onboard by Gardline CGGV 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 artifacts. 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-52S. 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 artifacts 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 artifacts 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 in ASCII XYZ as well as geotif formats of 2m resolution. 10- Using CARIS Base editor 4.0 the grids were exported as ESRI ASCII grid, then imported into ARC catalogue/info to create a raster file for the entire survey.