auSEABED
- Surficial Sediments of the 
Australian Seabed

Contact information:

For contributing or obtaining auSEABED data, please contact Dr. John You
The University of Sydney Institute of Marine Science (USIMS) 
Edgeworth David Building F05, Room 5008, University of Sydney, NSW 2006

Phone: (02) 93512003, Fax: (02) 93510184, E-mail: you@geosci.usyd.edu.au


Note: These web pages were constructed in 2002, and are published pending new 2005 release of auSEABED.



INTRODUCTION

The auSEABED was created by Dr. Chris Jenkins, a former staff member of School of Geoscience, to describe the materials of the Australian Maritime Region - in all, an area comprising 1/12 of the earth's globe. Because of Australia's relatively small population base and inadequate funding for at-sea science, maximum use of existing data had to be made to achieve a workable mapping. This motivated research into the use of datasets that were diverse in their methods, navigation, technologies, aims, standards,  formats - and whether numeric or linguistic. The research resulted in a data mining system designed especially for the seabed.
These web pages describe the digital GIS coverages that are now available for the seabed materials of the Australian maritime areas.


SPATIAL DATA DISTRIBUTION
 
At last count over 275,000 attributed sample sites comprised auSEABED. The distribution - geographic and by attribute - is not uniform, and it is clear from statistics where effort has been concentrated to now, and where major requirements are. Inshore (coastal) zone mapping is the most glaring shortcoming: it is tedious for reasons of the fractal complexity of coastlines, navigation hazards and the need for small-boat operations. Geographically, the most under-mapped regions of shallow depth are the Great Australian Bight, Gulf of Carpentaria and within the complex Great Barrier Reef.
Click to enlarge

Geographic distribution of attributed numeric (black) and 
descriptive (grey) data sites.

Attribute distributions in the data by depth zones. 
About 85% of the data are as word-based (linguistic)
descriptions.

A major feature of compiling auSEABED has been the generosity of many people and institutions in contributing data. The full list is provided at Data Contributors. To these people and institutions, their far-sighted attitudes and cooperative spirit are deeply appreciated. These same people have also provided valuable technical advice on data handling requirements and suitable forms of output.

The mean distances between sample sites is quite variable by region and attribute - as shown below. The average closest approach of sites with basic grainsize / carbonate information within the water depth bracket 5- 100m is about ##(TBA) km. A key feature of auSEABED is that as more datasets are added over the years, coverage and resolution steadily increase. Current rates of newly added data are ~300 sites / month, with priority to the inshore zones. The data come from many sources: research (geoscience, oceanography and biology), defence, fisheries and habitat protection, contaminant monitoring, subsea pipeline / cable / anchoring projects, offshore minerals / oil-gas exploration, and testing new technologies. 


OUTPUTS

Catalog of griddings
Catalog of point datasets
Associated grids
Griddings

The primary data delivery from auSEABED is via griddings, which have been compiled at a variety of resolutions and with various selections of data. We generate the grids in ArcView / Spatial Analyst using a straightforward Nearest Neighbour method so that areas far from sites with data are left ungridded (ie. unmapped till expeditions go there). Gridcell sizes and search radii are adjustable per project, but initially we supply generalized grids at 0.1 degr (~10km) resolution on 0.2 degr search radius. Most grids are generated as the mean of values within the search area. ARCview (Spatial Analyst) legends accompany the grids. Catalog of griddings

Point data

Some classification-type data cannot be delivered as grids because the values are non-numeric. ASCII, delimited point dataset tables are provided instead. The display of string (coded) values can be problematic in GIS, so an ARCView legend is provided to accompany each dataset.Catalog of point datasets

Visualizations

Once the data is acquired and processed using dbSEABED which integrates the data from multitudes of the seafloor surveys into single, unified mapping of the materials making the ocean floor, then visualization using GIS (Geographic Information System) and other software applications is possible, indeed easy. The outputs of the dbSEABED processing are designed to be importable into any GIS and/or RDB (Relational DataBase) and are also suited for use in mathematical packages such as Surfer, Matlab.

By way of demonstration, several examples are shown below. Generally generation of the visualization is left to clients of auSEABED, for example in the making of multitheme GIS compilations between benthic biological communities and substrate type. However, auSEABED project explores visualization methods and can advise on methods that have proven successful.


Multidata GIS map composition
Hydrographic (NIMA) chart type outputs
Multi-theme habitat mapping

Input To Models

A primary goal of dbSEABED is to provide inputs of important seabed parameters to the community of ocean modellers, including wave damping, nutrient budgets, sediment erosion, object burial, acoustic propagation and backscatter, stratigraphy and carbon cycle. This is done mostly through grids of seabed properties in areas of concern (see Florida griddings). As demonstrations of the capabilities, a number of modelling products are illustrated here.



A. Communication distances, Southern Right Whales 
of Great Australian Bight. With a knowledge of the bottom
materials, bathymetry and water column layering 
plus of whale propagation and hearing characteristics, 
the likelihood of a whale call can be modelled, in this case with 
the BAe Systems application "INSTANT".
(Project by James Hohnen (Sydney University) 2000; software kindly supplied by 
BAE Systems, Dorchester).


B. Benthic impact of a week's winter storminess in Bass Strait
a. A maximum of wind effects on wave heights; wave 
periods also available.
b. Bottom water velocity distribution, given the
characteristics of wind and bathymetry.
c. Excess velocity ofer the threshold for sediment motion.
(Project by Tanya Schindler (Sydney University), 1999; 
wave climate kindly supplied by WNI, Perth)


REFERENCES
 
(Printed)
Ferns, L. 1999. Environmental inventory of Victoria's marine ecosystems : Stage 4 (Vol. 1) : Final report.
    Dept. of Natural Resources and Environment, August 1999
Harris, P.T., Porter-Smith, R. Anderson, O., Coleman, R., and Greenslade, D. (2000)
    GEOMAT - Modelling of Continental Shelf Sediment Mobility in Support of Australia's Regional Marine Planning Process,
    AGSO Record No. 2000/41, 64 pp.
Hohnen, J.G. 2000. Propagation of Southern Right Whale Song in the Great Australian Bight. [B.Sc. Hons. Thesis].
    School of Geosciences, The University of Sydney, 89p.
Jenkins, C.J. 1997. Building a national scale offshore soils database from both word-based and numeric datasets.
    Sea Technology, Dec 1997.
Jenkins, C.J. & Rawson, G.A. 1994. A GIS of the Australian Seabed.
    GIS User, 9, 33-35.
Jenkins, C.J. 1995. Applications of the AUSEABED Marine GIS/Database in Engineering and Naval Acoustics.
    Second National Forum on GIS in the Geosciences, Aust. Geol. Surv. Orgnzn, Mar 1995.
Ward T.J., R.A. Kenchington, D. Faith and C.R. Margules  1998
    Marine BioRap Guidelines: Rapid Assessment of Marine Biological Diversity. CSIRO Australia, Perth. 52 pp.

(Electronic)
AGSO, 1997. Ocean Rescue 2000 (OR2000): A National Representative System of Marine Protected Areas for Australia.
    Commonwealth Technical Consortium Regionalisation Products (Component 2). [Ed. C. Parvey].
    "http://www.ea.gov.au/coasts/mpa/nrsmpa/or2000/"
Butler, CDR C.L. 2000. dbSEABED Database Project – A GIS/ Database with Multiple Applications.
    Office of Naval Research International Field Office, Ocean, Atmosphere and Space Technology Newsletter 00-03.
    "http://www.ehis.navy.mil/onrnews/metoc/metoc-00-03.pdf" (June 2002 download)
Department of Natural Resources and Environment, Victoria, 1999.
    Rock Interpolation - Victorian Open Waters (ROCK). Victorian Spatial Data Directory.
NSW Marine Park Assessment Authority, 2001. Byron Bay Marine Park Assessment Report, Appendix 1.
    "http://www.mpa.nsw.gov.au/byron/assessment-report/append/app1.htm#P270_41886" (June 2002 download).

Acknowledgements

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Date: 7 June 2005
Copyright: USIMS, 2005.