Surficial Sediments  of the Australian Seabed Australian iSEABED     This site allows interactive viewing of maps showing the character of the Australian seabed             Jenkins, C.J. and Kettner, A. 2003. Australian iSEABED. The University of Colorado, Boulder, CO. [Web document: "www://instaar.colorado.edu/~jenkinsc/dbseabed/auseabed/interactive/index.htm", published 17 March 2003].

INTRODUCTION     What it shows     How to interact with the mappings     How it was compiled DATA SOURCES     The Contributors of Data TECHNICAL DETAILS COPYRIGHT CAVEAT INTERACTIVE MAPPING See also: Mississippi Delta interactive

iSEABED is an instrument for interactive viewing of the seabed: its geological character, composition and physical properties.
Griddings compiled in ArcView are combined with other topical datasets such as bathymetry, coastline and reef outlines, to provide a customizable, zoomable, theme-adjustable interactive map-creator.

Users of Australian iSEABED may:

Compose a regional scale map for printing or display in a document

Examine where data exists - and where the vacancies lie and further scientific work is required.

Query the maps for seabed properties like grainsize, strength, composition at any point.

Find where auSEABED has data that may be obtained for use in more detailed research.

The large data files that underlie the griddings cannot be downloaded through this site. However:

• Point datasets may be ordered from INSTAAR for the purposes of research and occasionally, for private, commercial and policy purposes.

    The restrictions on point datasets come about because auSEABED is able to use but not distribute certain non-public data that belong to other institutions.
• Gridded datasets may be ordered from INSTAAR, customized for resolution, projection/geoid, the plotted themes and layouts.

• Water depth (bathymetry contours)
• The grainsize^*, in terms of central grainsize (Mean) and grainsize sorting (Standard Deviation).
• The major size fractions Gravel, Sand, Mud (which are mobile under currents) and Rock.
• Carbonate content, a very good indicator of how much is made of dead organism's skeletons.
• Porosity showing how consolidated the seabed is, through the amount of space (porespace) between grains.
• Seafloor erodability expressed as the Critical Shear Stress^** of the mobile sediments; that is, not including rock or hard coral reef areas.

Visit the page "How to use an iSEABED display".

You may compose a map by selecting certain data themes, then print or copy that map. We request that users attach a copyright note for the University of Colorado to all reproductions made in paper and digital reports, charts, posters, books and articles and reference the maps as follows:

• Jenkins, C.J., Kettner, A.,Williams, S.J., Polloni, C.F., Reid, J.A., Currence, J.M. 2002. Northern Gulf of Mexico iSEABED. The University of Colorado, Boulder, CO. [Web document: "www://instaar.colorado.edu/~jenkinsc/dbseabed/usseabed/interactive/index.htm", published 18 November 2002].

In the interactive mapping, most of the layers are based on the EXTRACTED and PARSED data. However for Porosity and Critical Shear Stress, which are only rarely measured directly in the field, the map values are based mostly on CALCULATION.

A full list is provided at auCONTRIBUTORS. For any one area the exact sources of data can be supplied by INSTAAR.

If you wish to publish a map with references to the original scientific work, contact us; we will forward the appropriate listing.

The projection is Geographic (Unprojected Latitude / Longitude) in WGS84 spheroid. The location of displayed sites is rounded to 0.001 degrees (~100m precision).

Units
Water Depths and the SubottomTop, SubbottomBot values of burial depth are in metres.
Water depths are mostly uncorrected for tide and sonar sound speed profiles. They are not sufficiently accurate to use in the compilation of a bathymetry.

Reading the table data

Point sets

Grid sets

Source of information
EXT and PRS denote Extracted and Parsed forms of output from dbSEABED. Basically these are information sourced from
(i) numeric analytical data, (ii) word-based descriptive data. (For Detailed Explanation: HitHere).

The letters that follow them denote the sources of data that Extraction and Parsing have worked on.
For example the entries "EXT:T C G" and "PRS:L P" tell us that the data come from:
(i) Extraction of Grainsize Compositional and Geotechnical data and
(ii) Parsing of Lithology and GrainPetrology data.
 
 

Null default values
These are used to denote when "No Data" is available. In dbSEABED for thematic data it is "-99".

TEXT Copyright  © 2002 INSTAAR The University of Colorado

JPG

The data and images that may be obtained interactively from this site are provided for research and educational purposes only. If another purpose is intended - including but not limited to survey, navigation, commerce and/or engineering - then you must obtain from INSTAAR of the University of Colorado (email), written permission to use the data. This must be done before using the data and/or images. Without such permission, the data and images are not warranted fit for purpose.

Why the caveat ?
The data of auSEABED are accurate, and useful in many applications. However, fitness of purpose for a particular task involves obtaining the appropriate gridcell size, density of supporting data, data timeliness and correct grid theme. To obtain data which is fit for purpose in commerce, engineering and at-sea operations, apply to INSTAAR.

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Date: 16 Mar 2003
Copyright: INSTAAR, UnivColorado