Bass Basin GIS project : an output of the Western Tasmanian Regional Minerals Program - bathymetry contours

Note: This metadata describes the dataset in accordance with the ANZLIC (Australia New Zealand Land Information Council) Core Metadata Guidelines Version 2.

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Dataset citation

ANZLIC unique identifier: ANZCW0703004762

Title: Bass Basin GIS project : an output of the Western Tasmanian Regional Minerals Program - bathymetry contours

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Custodian

Custodian: Geoscience Australia

Jurisdiction: Australia

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The contours of bathymetry of the Bass Basin region is a dataset that contains digital bathometric information in the form of contours. The contours were generated from Geoscience Australia's Bathymetry data. Contours occur ever 500 meters from abyssal depths to 100 meters, at which time they are at 25 meters intervals to 50 meters of depth.

ANZLIC search words:

MARINE Geology and Geophysics Research

Spatial domain:

locality map

Geographic extent name: BASS STRAIT - BASS STRAIT - Ocean and Sea Regions - Australia

Geographic extent polygon: 143 -37, 149 -37, 149 -43, 143 -43, 143 -37,

Note: The format for each Geographic extent name is: Name - Identifier - Category - Jurisdiction (as appropriate) See GEN Register

Geographic bounding box:: North bounding latitude: -37 °; South bounding latitude: -43 °; East bounding longitude: 149 °; West bounding longitude: 143 °

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Data currency

Beginning date: 2002-02-10

Ending date: 2002-06-10

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Dataset status

Progress: Complete

Maintenance and update frequency: Not Known

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Access

Stored data format:: DIGITAL - shp ArcView shape file ArcView Geographic WGS84

Available format type:: DIGITAL - shp ArcView shape file ArcView Geographic WGS84

Access constraints:

No restrictions

Free Data Download

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Data quality

Lineage:

The contour data was created using ER Mapper (V6.21) contouring feature. Contours were derived from Geoscience Australia's bathymetry grid of Australia. Once created they were export as an AutoCAD dxf file with depth values and then imported into ArcView (V3.2), where they were saved as a shapefile. Cleaning of the line data was done manually. Data was then checked by scientific staff for accuracy.

Positional accuracy:

Nominal Scale of usage 1:5 000 000

Positional accuracy in the underlying data varies from < 10m to excess of 2 km, due to the variety of vintages used in the source database. Additionally there was smoothing (3 by 3 kernal filter) to the source data to smooth out the contours, adding a larger degree of error.

Attribute accuracy:

Variable due to the source data, as for many surveys a nominal speed of sound of 1500 m/s was used in the conversion of acoustic travel time to depth, while other surveys used 1463 m/s. For many surveys the speed of sound used was not documented. In some areas the source data were taken from interpreted contour strings. Overall accuracy of the depth soundings is expected to be better than 5%.

Logical Consistency:

In creation of the underlying grid from which the contours were made, certain data were adjusted or omitted to remove artefacts resulting from cross-over errors. The grid is therefore internally consistent.

Completeness:

Complete for bathymetry values. Spatial and attribute accuracy is performed visually.

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