A new generation Magnetic Anomaly Grid Database of Australia (MAGDA) - use of independent data increases the accuracy of long wavelength components of continental-scale merges

Authors / CoAuthors

Milligan, P.R. | Franklin, R. | Ravat, D.

Abstract

A new Geoscience Australia Magnetic Anomaly Grid Database of Australia (MAGDA) has been developed. This database contains publicly available airborne magnetic grid data for on- and near-offshore Australia. Flight-line magnetic data for each survey have been optimally gridded and the grids matched in one inverse process. New composite grids at 250 m and 400 m grid spacing form the basis of the new fourth edition of the Magnetic Anomaly Map of Australia. Aeromagnetic traverses flown around Australia during 1990 and 1994 are used in both quality control of the grids they intersect, and also to constrain grid merging by forcing grid data, where intersected, to the level of the traverse data. Although matching and merging of many grids into a seamless compilation produces a pleasing result, without obvious short-wavelength artefacts, accurate long wavelength components of crustal origin are more difficult to obtain. Errors in the ?tilt? of individual surveys, due either to older instrumentation, errors in processing, or incomplete core-field removal, can lead to large long wavelength errors when hundreds of surveys are combined across thousands of kilometres. Quantification of the accuracy of long-wavelength components is only possible by comparison with independent datasets. A low-pass filtered composite grid of the Australian region has been compared with CHAMP satellite magnetic data, and shows a considerable improvement in the correlation of long wavelength components compared with the previous edition

Product Type

nonGeographicDataset

eCat Id

61714

Contact for the resource

Custodian

MNHD

Owner

Commonwealth of Australia (Geoscience Australia)

Custodian

Commonwealth of Australia (Geoscience Australia)
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia

Keywords

External PublicationArticle

( Theme )

geophysics

( Theme )

Australian and New Zealand Standard Research Classification (ANZSRC)

Earth Sciences

Published_External

Publication Date

2004-01-01T00:00:00

Creation Date

Security Constraints

Australian Government Security ClassificationSystem

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence

Access - license

Use - license

Status

Purpose

Maintenance Information

unknown

Topic Category

geoscientificInformation

Series Information

Lineage

This is an article for Preview, the newsletter of the Australian Society of Exploration Geophysicists. Geoscience Australia acknowledges the Australian Society of Exploration Geophysicists (ASEG) for permission to use this article on the Geoscience Australia website.

Parent Information

Extents

[-45.0, -10.0, 112.0, 155.0]

Reference System

Spatial Resolution

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