<div>The Abbot Point to Hydrographers Passage bathymetry survey was acquired for the Australian Hydrographic Office (AHO) onboard the RV Escape during the period 6 Oct 2020 – 16 Mar 2021. This was a contracted survey conducted for the Australian Hydrographic Office by iXblue Pty Ltd as part of the Hydroscheme Industry Partnership Program. The survey area encompases a section of Two-Way Route from Abbot Point through Hydrographers Passage QLD. Bathymetry data was acquired using a Kongsberg EM 2040, and processed using QPS QINSy. The dataset was then exported as a 30m resolution, 32 bit floating point GeoTIFF grid of the survey area.</div><div>This dataset is not to be used for navigational purposes.</div>

Colour and greyscale images have been generated at several resolutions (pixel sizes 860m, 2km, 4km, 10km) and these are digital pictoral representations of the 30 arc second bathymetric point grid of the Australian region released in 1998 and a sub sampled version of the GEODATA NINE SECOND DEM, 1996 which is copyright, Commonwealth of Australia, AUSLIG. These images depict the continental margin morphology, and are suitable for use in diverse applications, such as resource management, oceanographic modelling and fisheries studies. The original gridded bathymetry model for the Australian continental margin was generated from 14,000,000 data points gathered from numerous data sources and compiled by Cameron Buchanan at the Australian Geological Survey Organisation, as part of the Continental Margins Program. The database is a 30-arc-second model that can display undersea features as small as 900 metres. The model has been compiled over several years from hundreds of marine surveys. It includes data acquired by industry and foreign agencies, and from over 200 days of modern deep-water seafloor swath-mapping surveys. In some areas not covered by marine surveys, it incorporates bathymetry data derived from satellite measurements. The raw ASCII data is available on CD Titled "Bathymetric 30 arc second grid of the Australian Region" (1998) from the AGSO sales centre. NOTE : This product does not contain topography.

A 3.30 minute movie, (based on the movie used in the 2007 Acreage Release Product CD - Geocat No. 65159), that has the viewer flying around Australia to 6 release areas: Gippsland Basin, Money Shoal Basin, Bonaparte Basin, Canning Basin, Browse Basin and Carnarvon Basin. The movie also stops at each release area to view, in detail, the: International/State seafloor boundaries; oil and gas fields; release areas; Basin/sub-basin outlines. Topographic markers are also shown, where possible. This movie has the addition of MUSIC.

The RV Franklin sailed from Brisbane on 17th January 2002 and returned to Cairns on 9th February, 2002. The cruise discovered that a zone of strong tidal currents at the northern end of the Great Barrier Reef prevents the southward advance of sediment that would otherwise bury the coral reefs. The Fly River, located in close proximity to the northern end of the Great Barrier Reef, discharges about 120 million tonnes/yr of sediment. This sediment does not penetrate as far south into the reef area as might be expected because, over glacial-interglacial cycles of sea level change, the southward-prograding deposits are eroded by tidal currents. Deployment of an instrumented current meter and suspended sediment measurement frame on the seabed, offshore from the Fly River Delta, recorded a net sediment advection southwards. Sediment transport was greatest following a northerly wind event, which caused high bottom stress and increased turbidity levels. Swath sonar mapping and underwater video equipment were used to map a series of channels up to 220 m deep extending from eastern Torres Strait across the northern end of the Great Barrier Reef. Channels in the north are clearly relict fluvial channels, exhibiting lateral accretion surfaces and incised channels that intersect and truncate underlying strata. Over-deepened channels in the south, however, appear to have formed by tidal current scour. They exhibit closed bathymetric contours at both ends and are floored with well-sorted carbonate gravely sand. Oceanographic observations indicate that the channels provide a conduit onto the shelf for up-welled Coral Sea water. The deepest channels form isolated depressions, and possibly were the sites of lakes during the last ice age. Preliminary modelling indicates that the strongest tidal currents occur when sea level is about 40m below present, suggesting that the channels are Pleistocene or older in age and of relict origin.

Please note: This product has been superseded by 50m Multibeam Dataset of Australia 2018. - This tile contains all multibeam data held by Geoscience Australia on August 2012 within the specified area. The data has been gridded to 50m resolution. Some deeper data has also been interpolated within the mapped area. The image provided can be viewed on the free software CARIS Easyview, available from the CARIS website: www.caris.com under Free Downloads.

Please note: This product has been superseded by 50m Multibeam Dataset of Australia 2018. - This tile contains all multibeam data held by Geoscience Australia on February 2012 within the specified area. The data has been gridded to 50m resolution. Some deeper data has also been interpolated within the mapped area. The image provided can be viewed on the free software CARIS Easyview, available from the CARIS website: www.caris.com under Free Downloads.

Please note: This product has been superseded by 50m Multibeam Dataset of Australia 2018. - This tile contains all multibeam data held by Geoscience Australia on August 2012 within the specified area. The data has been gridded to 50m resolution. Some deeper data has also been interpolated within the mapped area. The image provided can be viewed on the free software CARIS Easyview, available from the CARIS website: www.caris.com under Free Downloads.

Please note: This product has been superseded by 50m Multibeam Dataset of Australia 2018. - This tile contains all multibeam data held by Geoscience Australia on August 2012 within the specified area. The data has been gridded to 50m resolution. Some deeper data has also been interpolated within the mapped area. The image provided can be viewed on the free software CARIS Easyview, available from the CARIS website: www.caris.com under Free Downloads.

Please note: This product has been superseded by 50m Multibeam Dataset of Australia 2018. - This tile contains all multibeam data held by Geoscience Australia on August 2012 within the specified area. The data has been gridded to 50m resolution. Some deeper data has also been interpolated within the mapped area. The image provided can be viewed on the free software CARIS Easyview, available from the CARIS website: www.caris.com under Free Downloads.

Please note: This product has been superseded by 50m Multibeam Dataset of Australia 2018. - This tile contains all multibeam data held by Geoscience Australia on August 2012 within the specified area. The data has been gridded to 50m resolution. Some deeper data has also been interpolated within the mapped area. The image provided can be viewed on the free software CARIS Easyview, available from the CARIS website: www.caris.com under Free Downloads.