Authors / CoAuthors
Li, J.
Abstract
This dataset provides the spatially continuous data of seabed gravel (sediment fraction >2000 µm), mud (sediment fraction < 63 µm) and sand content (sediment fraction 63-2000 µm) expressed as a weight percentage ranging from 0 to 100%, presented in 0.0025 decimal degree (dd) resolution raster grids format and ascii text file. The dataset covers the Petrel sub-basin in the Australian continental EEZ. This dataset supersedes previous predictions of sediment gravel, mud and sand content for the basin with demonstrated improvements in accuracy. Accuracy of predictions varies based on density of underlying data and level of seabed complexity. Artefacts occur in this dataset as a result of insufficient samples in relevant regions. This dataset is intended for use at the basin scale. The dataset may not be appropriate for use at smaller scales in areas where sample density is insufficient to detect local variation in sediment properties. To obtain the most accurate interpretation of sediment distribution in these areas, it is recommended that additional samples be collected and interpolations updated.
Product Type
dataset
eCat Id
75121
Contact for the resource
Custodian
Owner
Custodian
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
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- GIS DatasetRegional
- ( Theme )
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- GIS
- ( Theme )
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- environmental
- ( Theme )
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- seabed
- ( Theme )
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- sedimentology
- ( Theme )
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- marine
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Environmental Science and Management
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- Published_External
Publication Date
2012-01-01T00:00:00
Creation Date
Security Constraints
Legal Constraints
Status
Purpose
Maintenance Information
notPlanned
Topic Category
environment
Series Information
Lineage
Sediment samples were exported from Geoscience Australia's Marine Sediments database (MARS), an Oracle database developed by Geoscience Australia in line with ANZLIC data standards. A subset of this data was selected for use in predicting spatial distribution of gravel, mud and sand content based on a set of data quality control criteria (see Li et al. 2010 and 2012). Predicting the spatial distribution of gravel, mud and sand content at a 0.0025 decimal degree resolution was undertaken using a combined method of random forest and ordinary kriging (see Li et al. 2010, 2011 and 2012). The spatial interpolation method used was experimentally selected from over 40 methods/sub-methods based on assessment of predictive errors (Li et al. 2010, 2011 and 2012) and was refined for gravel, mud and sand respectively based on further experimental testing during Nov and Dec 2012. The predictions in raster grids and ascii text file were generated in R. Final file is in WGS 84 coordinate system with a 0.0025 dd spatial resolution. File sizes are approximately 23 MB (raster grids) and 136 MB (ascii text) for each sediment type (i.e., gravel, mud and sand), with data dimensions of 2356 (row) x 2400 (column) and 5654400 (cells).
Parent Information
Extents
[-15.579891, -9.584891, 125.2522, 131.7497]
Reference System
Spatial Resolution
Service Information
Associations
Source Information
see abstract