Abstract

GEOMA T is a geological-oceanographic computer modelling project which aims to enhance our understanding of the processes controlling sediment mobilisation on the Australian continental shelf. This report describes tidal and surface ocean swell-wave models and their application to studies of shelf sediment mobilisation. The work has been carried out over the past 2 years by a team of collaborators from AGSO, the University of Tasmania, the Australian Bureau of Meteorology and Kort & Matrikelstyrelsen, Geodetic Division in Denmark. Our models predict that swell wave energy is sufficient to mobilise fine sand (0.1 mm diameter), on at least one occasion during the year March 1997 to February 1998, over 63.5% of the Australian continental shelf. The largest and most powerful waves were able to mobilise fine sand up to a water depth of 148 m in the Great Australian Bight. Tidal currents are capable of mobilising fine sand at least once per semi-lunar cycle (ie. -2 weeks) over about 56.4% of the shelf. Overlaying the wave and tide threshold exceedence maps demonstrates that there are areas on the shelf where one process dominates, some areas where tides and waves are of relatively equal importance and still other areas where neither process is significant. We defined 6 shelf regions of relative wave and tidal energy: zero (no-mobility); waves-only, wave-dominated, mixed, tide-dominated and tides-only. The relative distribution of these regions varies with grain size. Inclusion of estimated mean grain size is being undertaken at the present time and this will enhance the usefulness of the regionalisations. GEOMA T provides a predictive, process-based understanding of the shelf sedimentary system. It helps to explain the distribution patterns of surficial sediments and will probably be useful for mapping biological habitats and communities, although further work is needed to better define these relationships. GEOMA T provides a useful tool that will assist with marine environmental management in general, and with the National Ocean's Office regional marine planning process in particular. It has demonstrated applications to marine engineering projects where shelf sediment mobilisation is of concern and to regional studies of pollution dispersal and accumulation.
Google map showing geographic bounding box with values North bound -8.88189 East bound 163.192085 West bound 109.23348 South bound -47.193641
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Product Type/Sub Type

nonGeographicDataset

Constraints

Creative Commons Attribution 4.0 International Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

2000-01-01T00:00:00

Product Type

nonGeographicDataset

Topic Category

geoscientificInformation

GA Catalogue Number

34373 Product http://www.ga.gov.au/metadata-gateway/metadata/record/34373/

Keywords

GA Publication
Record
bathymetry
continental margins
marine
AU-EEZ
Earth Sciences

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Geographic Extent

North bound
-8.88189
East bound
163.192085
West bound
109.23348
South bound
-47.193641

Lineage

Unknown

Digital Transfer Options

onLine

Distributor

Role
distributor
Organisation Name
Commonwealth of Australia (Geoscience Australia)
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address

Source Description

Source data not available.

Metadata File Identifier

a05f7892-b3dc-7506-e044-00144fdd4fa6

Metadata Standard Name

ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata

Metadata Standard Version

1.1

METADATA SECURITY CLASSIFICATION

unclassified

Metadata Contact

Role
pointOfContact
Organisation Name
Commonwealth of Australia (Geoscience Australia)
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address
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