Magnetic multipoles: forward modelling the gradient tensor, and hybrid global/linearised inversion

Heath Philip; Greenhalgh Stewart; Direen Nicholas

doi:10.1071/ASEG2006ab064

ISSN: 2202-0586
E-ISSN:

oa Magnetic multipoles: forward modelling the gradient tensor, and hybrid global/linearised inversion
Authors Heath Philip^a, Greenhalgh Stewart^b and Direen Nicholas^c
View Affiliations Hide Affiliations

^a CRC LEMEThe University of Adelaide, North Temce Campus Adelaide, SA, 5005, [email protected] ^b Department of PhysicsThe University of Adelaide, North Temce Campus Adelaide, SA, 5005, [email protected] ^c School of Earth and Environmental SciencesThe University of Adelaide, North Temce Campus Adelaide, SA, 5005, [email protected]
Publisher: Australian Society of Exploration Geophysicists
Source: ASEG Extended Abstracts, Volume 2006, Issue ASEG2006 - 18th Geophysical Conference, Dec 2006, p. 1 - 5
DOI: https://doi.org/10.1071/ASEG2006ab064
- Published online: 01 Dec 2006

Abstract

With magnetic gradiometry emerging as a new tool for geophysical exploration, the mathematical modelling of gradient fields is necessary for interpretation of field measurements. Magnetic multipoles may be useful for the modelling of complex geological sources, and so formulae for their field responses are presented here in Cartesian form. The formulae required for the forward modelling of the magnetic gradient tensor can be expressed as a set of linear equations. This fact is exploited to create a hybrid global and local inversion technique whereby simulated multipoles must satisfy the gradient tensor measurements for more than a single measurement.

The inversion process yields subsurface images showing the variation of multipole moment components, as each component is calculated to satisfy measured components of the magnetic gradient tensor. The images exhibit high probability (or small variance) if a multipole is found. The inversion routine is quick, and can be applied automatically to data as it is being collected, or applied to an already complete data set.

Article metrics loading...

/content/journals/10.1071/ASEG2006ab064

2006-12-01

2026-01-13

From This Site

/content/journals/10.1071/ASEG2006ab064

dcterms_title,dcterms_subject,pub_keyword

-contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution

10

5

Full text loading...

References

Andrew, J. A., Edwards, D. M., Graf, R. J., and Wold, R. J., 1991, Empirical observations relating near-surface magnetic anomalies to high-frequency seismic data and Landsat data in eastern Sheridan County, Montana: Geophysics, 56, ESISTO.
Bellott, A., Corpel, J., and Millon, R., 1991, Contribution of magnetic modelling to the discovery of a hidden massive sulfide body at Hajar, Morocco: Geophysics, 56, 983-991.
Blakely, R., 1996, Potential theory in gravity and magnetic applications: Cambridge University Press.
Carlson, N. R and Zonge, K. L., 2003, Minerals exploration methods modified for environmental targets: Exploration Geophysics, 34, 114-119.
Cowan, E. W., 1968, Basic Electromagnetism: Academic Press Inc.
Doll, W. E., Gamey, T. J., Beard, L. P., and Bell, D. T., 2006, Airborne vertical gradient for near-surface applications: The Leading Edge, 25, 50-53.
Gamey, T. J., Doll, W. E., Beard, L. P., and Bell, D. T., 2002, Airborne vertical magnetic gradient for UXO detection, Proceedings of SAGEEP 2002.
Grauch, V. J. S. and Millegan, P. S., 1998, Mapping intrabasinal faults from high-resolution aeromagnetic data: The Leading Edge, 17, 53-55.
Gunn, P., 1998, Aeromagnetics locates prospective areas and prospects: The Leading Edge, 17, 67-69.
Halliday, D., Resnick, R., and Walker, J., 1997, Fundamentals of Physics: John Wiley & Sons, Inc.
Heath, P. J., Heinson, G., and Greenhalgh, S. A., 2003, Some comments on potential field tensor data: Exploration Geophysics, 34, 57-62.
Schmidt, P., Clark, D., Leslie, K., Bick, M., Tilbrook, D., and Foley, C, 2004, GETMAG a SQUID magnetic tensor gradiometer for mineral and oil exploration: Exploration Geophysics, 35, 297-305.
Schmidt, P. W. and Clark, D. A., 2000, Advantages of measuring the magnetic gradient tensor: Preview, 85, 26-30.
Schmidt, P. W. and Clark, D. A., 2006, The magnetic gradient tensor: Its properties and uses in source characterization: The Leading Edge, 25, 75-78.
Telford, W. M., Geldart, L. P., and Sherrif, R. E., 1996, Applied Geophysics: Cambridge University Press.
Tsokas, G. N., Stampolidis, A., Angelopoulos, A. D., and Kilias, S., 1998, Analysis of potential field anomalies in Lavrion mining area, Greece: Geophysics, 63, 1965-1970.

/content/journals/10.1071/ASEG2006ab064

Article Type: Research Article

Keyword(s): Forward modelling; Inversion; Multipoles

Most Cited This Month Most Cited RSS feed

- Inversion of data from electrical imaging surveys in water-covered areas
  
  Authors M. H. Loke and J. W. Lane
- Inversion of Magnetic Data from Remanent and Induced Sources
  
  Authors Robert G. Elllis, Barrry de Wet and Ian N. Macleod
- A comparison of smooth and blocky inversion methods in 2-D electrical imaging surveys
  
  Authors M. H. Loke, Ian Acworth and Torleif Dahlin
- Designing matched bandpass and azimuthal filters for the separation of potential-field anomalies by source region and source type
  
  Authors Jeffrey D. Phillips
- Bad Colour Maps Hide Big Features and Create False Anomalies
  
  Authors Peter Kovesi
- Practical 3D EM inversion – the P223F software suite
  
  Authors Art Raiche, Fred Sugeng and Glenn Wilson
- Estimating Noise Levels in AEM Data
  
  Authors Andy Green and Richard Lane
- Target delineation using Full Tensor Gravity Gradiometry data
  
  Authors Colm A. Murphy and James Brewster
- Transdimensional Monte Carlo Inversion of AEM Data
  
  Authors Ross C Brodie and Malcolm Sambridge
- The geotech VTEM time domain helicopter em system
  
  Authors Ken Witherly, Richard Irvine and Edward Morrison
More Less

oa Magnetic multipoles: forward modelling the gradient tensor, and hybrid global/linearised inversion

Abstract

Most Read This Month

Most Cited This Month Most Cited RSS feed