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Geomorphic units of Australia's EEZ

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

Dataset citation

ANZLIC unique identifier: ANZCW0703008890

Title: Geomorphic units of Australia's EEZ


Custodian: Geoscience Australia

Jurisdiction: Australia



The dataset provides outlines for the maximum extent of Geomorphic Units of

Australia's Exclusive Economic Zone, including the offshore island

territories but not the Australian Antarctic Territory. The 14 Geomorphic

Unit classes represent areas of similar geomorphology across Australia's EEZ

and are intended to capture some of the small-scale benthic marine habitat

distributions. They were derived from a quantitative analysis of individual

geomorphic features on the Australian margin. The data were compiled in 2004

as part of the draft benthic marine bioregionalisation which is designed to

provide improved knowledge of Australia's seabed. The dataset includes the

names of units in the attribute table as well as the area and perimeter of

each class.

ANZLIC search words:

  • GEOSCIENCES Geomorphology Classification
  • MARINE Mapping

Spatial domain:

locality map

Geographic extent name: AUSTRALIA INCLUDING EXTERNAL TERRITORIES - AUSAAT - Australia - Australia

Geographic extent polygon: 90 -9, 175 -9, 175 -55, 90 -55, 90 -9,

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

Geographic bounding box:
North bounding latitude: -9 °
South bounding latitude: -55 °
East bounding longitude: 175 °
West bounding longitude: 90 °

Data currency

Beginning date: 2002-07-01

Ending date: Not Known

Dataset status

Progress: In Progress

Maintenance and update frequency: Not Known


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

Data quality


The Geomorphic Units were defined from a spatial analysis of the geomorphic

feature dataset as part of the development of the draft national benthic

marine bioregionalisation run by Geoscience Australia and National Oceans

Office to create a spatial inventory of large-scale benthic biogeographical

regions for Australia?s Exclusive Economic Zone. The objective of the

analysis was to define areas of like geomorphology across Australia?s EEZ

to highlight regions of similar benthic marine biodiversity at spatial

scales relevant for marine planning.

A quantitative analysis of individual geomorphic features (e.g., plateau,

sill, terrace) was first undertaken to objectively describe the spatial

distribution of seabed geomorphology. Two simple spatial metrics were used

to undertake this spatial clustering: Cohesion, which is a measure of the

physical connectedness of individual features (i.e., a shape measure); and

Connectance, which is a measure of the total number of physical joinings

between individual patches subject to a 1,000 km threshold distance. The

Geomorphic Units were generated using a Joining Tree algorithm, with

Complete Linkage and Euclidean Distance options on the Cohesion and

Connectance metrics. The final classifications were decided by visual

inspection of the joining tree to produce meaningful classes. The results

of this spatial analysis were also used to guide a subjective clustering

based on the presence and absence and relative spacing of smaller and more

numerous geomorphic features on the shelf and slope.

Positional accuracy:

Positional accuracy of the boundaries varies depending on the source data.

Due to the scale of the map, and quality of the bathymetric, reflectionand sediment data, the approximate accuracy of the boundaries is probably +/-10 km.

Attribute accuracy:

No attribute for data quality exists at this stage. This attribute will be

updated once a reliability map for the source data has been generated. The

reliability map will be based on the spatial distribution of soundings.

Logical Consistency:

The Geomorphic Units were derived from individual geomorphic features which

themselves were derived from Geoscience Australia?s 250 m bathymetry grid.

The bathymetric grid was examined visually for data consistency. In some

circumstances individual data were inconsistent in the grid. In these cases

the data were either left out or corrected.

Where appropriate, the boundaries and Primary Bathymetric Unit

classifications are consistent with United Nations Law of the Sea

boundaries and definitions.

Tests were also carried out on the data for completeness, correct spatial

representation, attribute accuracy, and logical consistency and correctness


Coverage: The Geomorphic Units cover all of the Exclusive Economic Zone. The

raw data that makes up the bathymetric grid upon which the units are based

is derived from numerous sources and has been obtained opportunistically

hence the actual data coverage is generally patchy and irregular. A data

density map for the bathymetry grid is not yet available.

Classification: The final Geomorphic Units represent unique groups of

individual geomorphic features which are internationally recognised

categories of seabed features (IHO, 2002). Further details of these terms

and documentation underlying their adoption by IHO may be found at the

following internet address:

Verification: Field verification was limited to reviewing published literature

of the individual geomorphic features and their combinations which make up

the Geomorphic Units.

Contact information

Contact organisation: Commonwealth of Australia (Geoscience Australia) (GA)
Contact position: Manager Client Services
Mail address: Cnr Jerrabomberra Ave and Hindmarsh Dr
Mail address: GPO Box 378
Locality: Canberra
State: ACT
Country: Australia
Postcode: 2601
Telephone: 02 6249 9966
Facsimile: 02 6249 9960
Electronic mail address:

Metadata information

Metadata date: 2013-03-08

Additional metadata

Metadata reference XHTML:

Metadata reference XML:

Nominal Scale 1 : 5000000


IHO, 2002.


Petroleum and Marine Division Project Data Officer

Authors:Heap, A.D. Harris, P.T. Hinde, A. Woods, M.