Authors / CoAuthors
Bacchin, M.
Abstract
This grid represents gravity anomalies of the Australian region. The grid combines accurate onshore gravity measurements, with satellite data over the offshore region. The cell values represent simple Bouguer anomalies at a density of 2.67 tonnes per cubic metre onshore and free-air anomalies offshore. The grid cell size is 0.5 minutes of arc, which is equivalent to about 800 metres.
Product Type
dataset
eCat Id
67240
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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- Gravity Digital DataNon-standard scale
- ( Theme )
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- geophysics
- ( Theme )
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- gravity
- ( Theme )
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- National dataset
- ( Theme )
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- dataset
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Gravimetrics
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- Published_External
Publication Date
2009-01-01T00:00:00
Creation Date
Security Constraints
Legal Constraints
Status
Purpose
Maintenance Information
continual
Topic Category
geoscientificInformation
Series Information
Lineage
The gravity grid was derived from the complete onshore database as at May 2009 and marine gravity derived from satellite altimetry. A two-pass process was used to generate the grid from a composite file containing 1.4 Million land observations, 10.5 Million satellite values. For the satellite values refer to Sandwell, D.T. and W.H.F.Smith, Marine Gravity Anomaly from Geosat and ERS-1 Altimetry, J. Geophys. Research, 1997. The 0.5 minute grid is the finest mesh that is currently meaningful over the whole continent given that much of the data coverage is spaced at 4 or 11 km. The parameters of the grid are: Grid spacing: 0.5 minute = 0.0083333 degree (approx. 800 m) Projection: Rectangular in latitude and longitude Grid size: 8401 points longitude x 5276 points latitude Grid origin: 7 degrees 58.55 min south, 99 deg 57.35 min east (1,1) Scaling: Nil. Values are in decimal units (µms−² (micro metres per second squared)) Null value: -99999.0 Data accuracy: 5 units, maximum error 100 units onshore Data precision: 1 unit Gravity Datum: The gravity data as supplied are based on the AAGD07 datum. The gravity unit used is micrometres per second squared which is equivalent to 0.1 milligals. A filtered image was also created using a high-pass filter with a cutoff wavelength of 500 km. Images have a sunangle with illumination from the north east.
Parent Information
Extents
[-52, -8, 100, 170]
Reference System
Spatial Resolution
Service Information
Associations
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