Bremer Basin - Bathymetry Images  

Authors / CoAuthors

Mitchell, C. | Buchanan, C. | Kroh, F.

Abstract

These colour and greyscale images are a digital pictorial representation of the 250 decimal degree bathymetric grid of the Australian region. This image is a dirivitive of the origional 30 arc second grid of Australia. There have been recent swath mapping additions to the origional in bathymetric data that have vastly improve the quality of the data and these images contain that information, they are however a work in progress and official higher resolotion datasets are expected in the near future. 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 (as seen in the images). 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.

Product Type

nonGeographicDataset

eCat Id

66082

Contact for the resource

Keywords

• Marine MapBathymetry Map

( Theme )

• marine

Australian and New Zealand Standard Research Classification (ANZSRC)

• Marine Geoscience

• Published_Internal

Publication Date

2008-06-11T00:00:00

Creation Date

Security Constraints

Australian Government Security ClassificationSystem    

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence    

Access - restricted

Use - license

Status

Purpose

Maintenance Information

notPlanned

Topic Category

geoscientificInformation

Series Information

Lineage

These images are generated using ERMAPPER from the 250 decimal degree Australian Bathymetric Grid. For the colour image the bathymetric and DEM data were merged and coloured using a Custom colour scheme. This image was also gradient filtering (north South and East West) and illuminated from the SW to enhance topographic features.The grid was then converted into a georefernced 8bit Tif image suitable for Arcinfo/Arcview. The one band greyscale image was developed by merging the bathymetric and DEM data histogram equlised A one band greyscale image has been developed of the above as well. The original gridded bathymetry model for the Australian continental margin was generated from Bathymetry data collected from various agencies and compiled and extrapolated by an algorithm developed by C. Buchanan. The number of values corresponds to a grid of 2940 by 2160 two-byte binary integer values representing all the one minute intersection points between 90 00' - 440 59' south, and 1080 00' - 1560 59' east. The geographical coordinates and water depths only were used. Compiled data were then read and applied to the model (the grid) using a nearest point (distance weighted) method. The nearest point was used because resampling of the dataset to a lower resolution would not require reintegration of raw data by the iteration process. Resampling to a higher resolution could be achieved by reintegration using the same algorithm and the result would be a more detailed model. More recently swath mapping data from Geoscience Australia Survey 265 in the south-west of Australia has added to the dataset.

Parent Information

Extents

[-37.3461, -33.0475, 116.346, 122.1068]

Reference System

Spatial Resolution

Service Information

Associations

Downloads and Links

Source Information

Source data not available.