Mapping the disruption of source magnetization depth estimates by near-surface magnetisations

<div>Near-surface magnetizations are ubiquitous across many areas of Australia and complicate reliable estimation of depth to deeper magnetizations. We have selected four test areas in which we use equivalent source dipoles to represent and quantify the near-surface magnetizations. We present a synthetic modelling study that demonstrates that field variations from the near-surface magnetizations substantially degrade estimation of depth to a magnetization 500 metres below the modelled sensor elevation and that these problems persist even for anomalies with significantly higher amplitudes. However, preferential attenuation of the fields from near surface magnetizations by upward continuation proved quite effective in improving estimation of depth to those magnetizations.</div>

This Abstract was submitted/presented at the 2023 Australasian Exploration Geoscience Conference (AEGC) 13-18 March ( https://2023.aegc.com.au/)

Simple

Identification info

Date (Creation)
2022-12-02T05:00:00
Date (Publication)
2023-07-19T21:59:29
Citation identifier
Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/147451

Cited responsible party
Role Organisation / Individual Name Details
Publisher

Commonwealth of Australia (Geoscience Australia)

 Voice
Author

Foss, C.

 External Contact
Author

Hope, J.

 Internal Contact
Name

Australasian Exploration Geoscience Conference (AEGC), Brisbane, 13-18 March 2023

Issue identification

4th AEGC conference

Purpose

This abstract discusses the results of synthetic modelling to test the effect of near-surface or surface magnetic bodies on obtaining depth to top of magnetic sources for deeper bodies of interest. We have developed an equivalent source dipole model to help quantify magnetic field variations due to near-surface magnetizations. We have inverted measured magnetic field variations over near-surface magnetizations to which we have added synthetic model magnetic fields and show that the magnetic fields due to the near-surface magnetizations significantly degrade estimation of depth to those lower magnetizations. However, upward continuation appears to provide an effective means to attenuate the fields from the near-surface magnetizations and improve estimation of depth to deeper magnetizations.

Status
Completed
Point of contact
Role Organisation / Individual Name Details
Resource provider

Minerals, Energy and Groundwater Division

 External Contact
Point of contact

Commonwealth of Australia (Geoscience Australia)

 Voice
Point of contact

Hope, J.

 Internal Contact
Spatial representation type
Topic category
  • Geoscientific information

Extent

N
S
E
W


Maintenance and update frequency
As needed

Resource format

Title

Product data repository: Various Formats

Website

Data Store directory containing the digital product files

Data Store directory containing one or more files, possibly in a variety of formats, accessible to Geoscience Australia staff only for internal purposes

Project

  • EFTF – Exploring for the Future

Project

  • Australia’s Resources Framework

Project

  • Darling-Curnamona-Delamerian

Keywords

  • near-surface

Keywords

  • Magnetics

Keywords

  • depth estimates

theme.ANZRC Fields of Research.rdf

  • Applied geophysics

  • Magnetism and palaeomagnetism

Keywords

  • Published_External

Resource constraints

Title

Creative Commons Attribution 4.0 International Licence

Alternate title

CC-BY

Edition

4.0

Website

https://creativecommons.org/licenses/by/4.0/

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Any
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© Commonwealth of Australia (Geoscience) 2022

Resource constraints

Title

Australian Government Security Classification System

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified
Classification system

Australian Government Security Classification System

Language
English
Character encoding
UTF8

Distribution Information

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Role Organisation / Individual Name Details
Distributor

Commonwealth of Australia (Geoscience Australia)

 Voice facsimile
OnLine resource

Link to Conference Page

Link to Conference Page

Distribution format

OnLine resource

Link to Conference Paper (Zenodo)

Link to Conference Paper (Zenodo)

Distribution format

OnLine resource

Link to Dropbox (full-paper_145.pdf)

Link to Dropbox (full-paper_145.pdf)

Distribution format

OnLine resource

Download Poster (pptx) [5.5 MB]

Download Poster (pptx) [5.5 MB]

Distribution format

Resource lineage

Statement

<div>Extended abstract submitted for Australasian Exploration Geoscience Conference, Brisbane 2023 for a poster presentation. </div><div><br></div><div>This work forms part of the magnetic depth estimation collaboration between CSIRO and Geoscience Australia, as part of the Australian Resources Framework project in Geoscience Australia's Exploring for the Future program. Depth estimates derived from this collaboration are intended to be stored in Geoscience Australia's Estimates of Geological and Geophysical Surfaces database, the national repository of depth estimate data points.</div>

Metadata constraints

Title

Australian Government Security Classification System

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified

Metadata

Metadata identifier
urn:uuid/6c40fa67-3d1e-4908-a2e6-84d549f886a5

Title

GeoNetwork UUID

Language
English
Character encoding
UTF8
Contact
Role Organisation / Individual Name Details
Point of contact

Commonwealth of Australia (Geoscience Australia)

 Voice
Point of contact

Hope, J.

 Internal Contact

Type of resource

Resource scope
Document
Name

Conference Abstract

Alternative metadata reference

Title

Geoscience Australia - short identifier for metadata record with

uuid

Citation identifier
eCatId/147451

Metadata linkage

https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search#/metadata/6c40fa67-3d1e-4908-a2e6-84d549f886a5

Date info (Creation)
2023-02-24T00:53:23
Date info (Revision)
2023-02-24T00:53:23

Metadata standard

Title

AU/NZS ISO 19115-1:2014

Metadata standard

Title

ISO 19115-1:2014

Metadata standard

Title

ISO 19115-3

Title

Geoscience Australia Community Metadata Profile of ISO 19115-1:2014

Edition

Version 2.0, September 2018

Citation identifier
https://pid.geoscience.gov.au/dataset/ga/122551

 
 

Spatial extent

N
S
E
W


Keywords

Australia’s Resources Framework Darling-Curnamona-Delamerian EFTF – Exploring for the Future
theme.ANZRC Fields of Research.rdf
Applied geophysics Magnetism and palaeomagnetism

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