Potential-field Data Covering the Capel and Faust Basins, Australia's Remote Offshore Eastern Frontier  

Authors / CoAuthors

Hackney, R.

Abstract

Record documenting sources of gravity and magnetic data covering the Capel and Faust basins (Lord Howe Rise) and the processes applied to level the data.

Product Type

document

eCat Id

70711

Contact for the resource

Keywords

• GA PublicationRecord

( Theme )

• continental margins

( Theme )

• data

( Theme )

• gravity

( Theme )

• magnetics

( Theme )

• marine survey

( Theme )

• marine

Australian and New Zealand Standard Research Classification (ANZSRC)

• Earth Sciences

• Published_External

Publication Date

2010-01-01T00:00:00

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

notPlanned

Topic Category

geoscientificInformation

Series Information

Record 2010/034

Lineage

The source data used to generate a levelled dataset for the Capel and Faust basins includes: 1) a dataset of gravity and magnetic data for the Australian region sourced internally from Geoscience Australia holdings of ship-track data and levelled by Desmond Fitzgerald and Associates Pty Ltd (now Intrepid Geophysics) in the late 1990s under contract to the Australian Geological Survey Organisation (now Geoscience Australia); 2) gravity and magnetic data from Geoscience Australia seismic survey GA-302 (2006/2007); and 3) gravity and magnetic data from Geoscience Australia marine survey GA-2436 (2007). The data for the GA-302 and GA-2436 surveys were provided to Geoscience Australia in mid-2008 by Fugro Robertson LCT Gravity and Magnetics Division (Job Numbers 4640 and 4731), the contractor used by Geoscience Australia to process gravity and magnetic data from these surveys. The processing steps applied to this dataset include: 1) re-computation of free-air gravity anomalies to ensure consistent computation of gravity anomalies between the different datasets; 2) splitting ship-tracks into relatively straight line segments to avoid multiple cross-overs between any pair of lines; 3) line filtering of the previously-levelled Australia-wide dataset to reduce noise and improve cross-over computations; 4) merge the individual datasets into a single master dataset for levelling; 5) editing to remove lines or line segments with spurious data - lines that were too short or too close to other line segments were also removed in order to improve levelling results; 6) line levelling - gravity data were levelled using a polynomial levelling technique referenced to a satellite radar altimetry-derived dataset, magnetic data were loop levelled (minmising misclosures around closed loops formed by ship tracks); 7) computation of simple Bouguer gravity anomalies (ie. without terrain corrections) using a spherical-cap Bouguer correction and a density contrast between water and sediment of 970 kilograms per cubic metre and water depths interpolated at each data point from the 2009 Bathymetry and Topography Grid of Australia. The data processing and levelling were conducted using the INTREPID software from Intrepid Geophysics (versions 4.2.756 and 4.2.1782). The resulting gravity and magnetic data for the Capel and Faust basins are contained in INTREPID vector databases and are also available in an ascii column-based file exported from INTREPID.

Parent Information

Extents

[-31.0, -24.0, 157.0, 165.0]

Reference System

Spatial Resolution

Service Information

Associations

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Source Information

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