1887
Volume 12 Number 5
  • ISSN: 1569-4445
  • E-ISSN: 1873-0604

Abstract

ABSTRACT

We propose an effective technique, based on eigenvalues of the curvature gradient tensor matrix (CGTM), to determine edges and depths of shallow subsurface cavities. The new technique is similar to the tilt angle and tilt‐depth methods in edge detection and depth estimation, respectively. Our improvement to this method is that the vertical derivative of the tilt angle is replaced by an eigenvalue of the CGTM. Zero contours of eigenvalues of the CGTM can be used to outline the edges of causative sources, and the characteristic is similar to the vertical derivative of gravity field. Therefore, we use the smaller of the two eigenvalues to replace the vertical derivative in the numerator of the tilt angle, and this results in an improved edge detection method. In addition, we deduce a new depth estimation method using the point mass model parameters which can be used to estimate the centre depths of shallow causative sources. The new method is tested on a synthetic model with and without noise. It demonstrates that the new method is simple, robust and accurate. Finally, we apply the method on the measured gravity data of a mining subsidence area from Liaoyuan, Northeast of China. The results show a good correspondence with the inversion results of electrical resistivity tomography (ERT) data. Such results can serve as preliminary depth estimates and location of near surface cavities.

Loading

Article metrics loading...

/content/journals/10.3997/1873-0604.2014021
2013-12-01
2024-04-25
Loading full text...

Full text loading...

References

  1. AbdelrahmanE.M., El‐ArabyH.M., El‐ArabyT.M. and Abo‐EzzE.R.2001. Three least‐squares minimization approaches to depth, shape, and amplitude coefficient determination from gravity data. Geophysics66, 1105–1109.
    [Google Scholar]
  2. BastaniM. and PedersenL. B.2001. Automatic interpretation of magnetic dike parameters using the analytical signal technique. Geophysics66, 551–561.
    [Google Scholar]
  3. BlakelyR.1995. Potential Theory in Gravity and Magnetic Applications. Cambridge University Press, Cambridge, 300–310.
    [Google Scholar]
  4. CooperG.R.J.2012. A gradient‐ratio method for the semi‐automatic interpretation of gravity map data sets. Geophysical Prospecting60, 995–1000.
    [Google Scholar]
  5. ElawadiE., SalemA. and UshijimaK.2001. Detection of cavities and tunnels from gravity data using a neural network. Exploration Geophysics32, 204–208.
    [Google Scholar]
  6. FairheadJ.D., SalemA., CasconeL., HammillM., MastertonS. and SamsonE.2011. New developments of the magnetic tilt‐depth method to improve structural mapping of sedimentary basins. Geophysical Prospecting59, 1072–1086.
    [Google Scholar]
  7. FediM. and RapollaA.1999. 3‐D inversion of gravity and magnetic data with depth resolution. Geophysics64, 452–460.
    [Google Scholar]
  8. HajianA., ZomorrodianH., StylesP., GrecoF. and LucasC.2012. Depth estimation of cavities from microgravity data using a new approach: the local linear model tree (LOLIMOT). Near Surface Geophysics10, 221–234.
    [Google Scholar]
  9. HansenR.O. and deRidderE.2006. Linear feature analysis for aeromag‐netic data. Geophysics71, L61–L67.
    [Google Scholar]
  10. HoodP. and McClureD.J.1965. Gradient measurements in ground magnetic prospecting. Geophysics30, 403–410.
    [Google Scholar]
  11. KeatingP.2009. Improved use of local wavenumber in potential filed interpretation. Geophysics74, 75–85.
    [Google Scholar]
  12. LiY. and OldenburgD.W.1996. 3‐D inversion of magnetic data. Geophysics61, 394–408.
    [Google Scholar]
  13. MickusK.L. and HinojosaJ.H.2001. The complete gravity gradient tensor derived from the vertical component of gravity: a Fourier transform technique. Journal of Applied Geophysics46, 159–174.
    [Google Scholar]
  14. NabighianM.N.1972. The analytic signal of two dimensional magnetic bodies with polygonal cross‐section. Its properties and use of automated anomaly interpretation. Geophysics37, 507–517.
    [Google Scholar]
  15. NettletonL.L.1942. Gravity and magnetic calculation. Geophysics7, 293–310.
    [Google Scholar]
  16. OruçB. and KeskinsezerA.2008. Structural Setting of the Northeastern Biga Peninsula (Turkey) from Tilt Derivatives of Gravity Gradient Tensors and Magnitude of Horizontal Gravity Components. Pure and Applied Geophysics165, 1913–1927.
    [Google Scholar]
  17. OruçB., SertcelikI., KafadarO. and SelimH.H.2013. Structural interpretation of the Erzurum Basin, eastern Turkey, using curvature gravity gradient tensor and gravity inversion of basement relief. Journal of Applied Geophysics88, 105–113.
    [Google Scholar]
  18. PhillipsJ.D., HansenR.O. and BlakelyR.J.2007. The use of curvature in potential‐field interpretation. Exploration Geophysics38, 111–119.
    [Google Scholar]
  19. RoestW.R., VerhoefJ. and PikingtonM.1992. Magnetic interpretation using the 3_D analytic signal. Geophysics57, 116–125.
    [Google Scholar]
  20. SalemA., ElawadiE. and UshijimaK.2003. Depth determination from residual gravity anomaly data using a simple formula. Computers & Geosciences29, 801–804.
    [Google Scholar]
  21. SalemA., WillamsS., FairheadJ.D., RavatD. and SmithR.2007. Tilt depth method: A simple depth estimation method using first order magnetic derivatives. The Leading Edge26, 1502–1506.
    [Google Scholar]
  22. SalemA., WilliamsS., SamsonE., FairheadD., RavatD. and BlakelyR.J.2010. Sedimentary basins reconnaissance using the magnetic Tilt‐ Depth method. Exploration Geophysics41, 198–209.
    [Google Scholar]
  23. StavrevP. and ReidA.2010. Euler deconvolution of gravity anomalies from thick contact/fault structures with extended negative structural index. Geophysics75, I51–I58.
    [Google Scholar]
  24. ThompsonD.T.1982. EULDPH: A new technique for making computer assisted depth estimates from magnetic data. Geophysics47, 31–37.
    [Google Scholar]
  25. ThurstonJ.B. and SmithR.S.1997. Automatic conversion of magnetic data to depth, dip, and susceptibility constrast using the SPI (TM) method. Geophysics62, 807–813.
    [Google Scholar]
  26. VerduzcoB., FairheadJ.D. and GreenC.M.2004. The meter reader – new insights into magnetic derivatives for structural mapping. The Leading Edge23, 116–119.
    [Google Scholar]
  27. WangW.Y., ZhangG.C. and LiangJ.S.2010. Spatial variation law of vertical derivative zero points for potential field data. Applied Geophysics7, 197–209.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.3997/1873-0604.2014021
Loading
/content/journals/10.3997/1873-0604.2014021
Loading

Data & Media loading...

  • Article Type: Research Article

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error