Exploration Geophysics Exploration Geophysics Society
Journal of the Australian Society of Exploration Geophysicists
RESEARCH ARTICLE

Regional and residual gravity anomaly separation using the singular spectrum analysis-based low pass filtering: a case study from Nagpur, Maharashtra, India

K. Satish Kumar 1 Rekapalli Rajesh 1 2 Rama Krishna Tiwari 1
+ Author Affiliations
- Author Affiliations

1 Council of Scientific and Industrial Research – National Geophysical Research Institute, Hyderabad 500 007, India.

2 Corresponding author. Email: rekapalli@gmail.com

Exploration Geophysics - https://doi.org/10.1071/EG16115
Submitted: 6 October 2016  Accepted: 12 April 2017   Published online: 13 June 2017

Abstract

We present here a singular spectrum analysis (SSA)-based low pass filtering algorithm for regional and residual gravity anomaly separation. The data adaptive decomposition in SSA frequency filtering algorithm facilitates reduction of the artefacts in the filtering of the non-linear and non-stationary gravity data. Initially, the method was tested on synthetic gravity data representing combined response of regional and residual components derived from the geological structures like infinite horizontal layers, intrusive dykes, deep-seated faults and volcanic intrusive bodies and compared with fast Fourier transform (FFT) wavenumber and wavelet-based filtering techniques. The results show that SSA-based filtered output exhibits a better match with pure synthetic data than the output generated from the FFT and wavelet filtering methods. The underlying method was then applied to two parallel gravity profiles of real data from the Umred coalfield, Nagpur, Maharashtra, India. Further, the SSA-based filtered regional anomaly was modelled using Geosoft GM-SYS software to construct the model of crustal structure of the study region. In essence, the modelling results suggest the following: (i) a basin-type graben structure with variable trap and sedimentary thicknesses and (ii) deep seated faults on either sides of the basin. These results correlate fairly well with known regional geology attesting the authenticity of the regional models generated from the two gravity profiles, which also agree well with each other. We, therefore, conclude that the SSA-based filtering technique is robust for regional gravity anomaly separation and could be effectively exploited for filtering other geophysical data.

Key words: gravity anomaly, regional and residual anomalies, SSA filtering.


References

Bhattacharyya, B. K., 1966, Continuous spectrum of the total-magnetic field anomaly due to a rectangular prismatic body: Geophysics, 31, 97–121
Continuous spectrum of the total-magnetic field anomaly due to a rectangular prismatic body:CrossRef |

Chamoli, A., Bansal, A. R., and Dimri, V. P., 2007, Wavelet and rescaled range approach for the Hurst coefficient for short and long time series: Computers & Geosciences, 33, 83–93
Wavelet and rescaled range approach for the Hurst coefficient for short and long time series:CrossRef |

Daubechies, I., 1992, Ten lectures on wavelets, CBMS-NSF conference series in applied mathematics: Society for Industrial and Applied Mathematics.

De, S., Ghosh, D., and Rao, K. J., 1982, Report on geophysical investigations for delineating Gondwana below traps in Umred trough in NW extension for Wardha valley coal field, Nagpur district, Maharashtra: Unpublished Report, Geological Survey of India.

DGM, 2009, Report on exploration for coal in Dahegaon-Makardhokada, Block-IV, Umred coal field district, Nagpur. Unpublished report.

Fedi, M., and Quarta, T., 1998, Wavelet analysis of the regional-residual and local separation of potential field anomalies: Geophysical Prospecting, 46, 507–525
Wavelet analysis of the regional-residual and local separation of potential field anomalies:CrossRef |

Geosoft, 2008, Oasis Montaj, GM-SYS version 7.0: gravity and magnetic modelling software user guide: Geosoft, Inc.

Ghil, M., Allen, M. R., Dettinger, M. D., Ide, K., Kondrashov, D., Mann, M. E., Robertson, A. W., Saunders, A., Tian, Y., Varadi, F., and Yiou, P., 2002, Advanced spectral methods for climatic time series: Reviews of Geophysics, 40, 3-1–3-41
Advanced spectral methods for climatic time series:CrossRef |

Golyandina, N., Nekrutkin, V. V., and Stepanov, D. V., 2003, Variants of the Caterpillar SSA-method for analysis of multidimensional time series [in Russian]. Availalable at: http://www.gistatgroup.com/cat/

Hahn, A., Kind, E. G., and Mishra, D. C., 1976, Depth estimation of magnetic sources by means of Fourier amplitude spectra: Geophysical Prospecting, 24, 287–306
Depth estimation of magnetic sources by means of Fourier amplitude spectra:CrossRef |

Hassani, H., Mahmoudvand, R., and Zokaei, M., 2011, Separability and window length in singular spectrum analysis: Comptes Rendus Mathematique, 349, 987–990
Separability and window length in singular spectrum analysis:CrossRef |

Hassani, H., Heravi, S., and Zhigljavsky, A., 2013, Forecasting UK industrial production with multivariate singular spectrum analysis: Journal of Forecasting, 32, 395–408
Forecasting UK industrial production with multivariate singular spectrum analysis:CrossRef |

Jogarao, M. V., Ghatak, S. K., and Rammohan, P. K., 1975, Progress report on reconnaissance gravity, magnetic and electrical resistivity surveys for coal in the Chandra-Wardha valley coal fields area, Chandrapur district, Maharashtra: Unpublished Report of the Geological Survey of India.

Jogarao, M. V., Pathak, C. S., Ghosh, D., and Ghosh, D. C., 1984, Report on geophysical surveys to trace Gondwana below Deccan traps under project deep geology in Hinganghat area of Wardha valley, Chandrapur district, Maharashtra: Unpublished Report of the Geological Survey of India.

Kailasam, L. N., 1948, Report on electrical resistivity surveys of the Kamptee coal field area, Nagpur district, Maharashtra: Unpublished Report of the Geological Survey of India.

Kumar, D., Bastia, R., and Guha, D., 2004, Prospect hunting below Deccan basalt: imaging challenges and solutions: First Break, 22, 35–39
Prospect hunting below Deccan basalt: imaging challenges and solutions:CrossRef |

Mallat, S., 1989, A theory for multiresolution signal decomposition: the wavelet representation: IEEE Transactions on Pattern Analysis and Machine Intelligence, 11, 674–693
A theory for multiresolution signal decomposition: the wavelet representation:CrossRef |

Meyer, Y., 1995, Wavelets and operators (Vol. 1). Cambridge University Press.

Naidu, P. S., 1970, Statistical structure of aeromagnetic field: Geophysics, 35, 279–292
Statistical structure of aeromagnetic field:CrossRef |

Naskar, D. C., and Saha, D. K., 2015, Geophysical investigations for delineation of Gondwana sediments below Deccan trap beyond the western limit of Wardha Valley coalfields, Yeotmal and Wardha districts, Maharashtra: a comprehensive analysis of case studies: Journal of the Indian Geophysical Union, 19, 433–446

Padilha, A. L., Trivedi, N. B., Vitorello, I., and da Costa, J. M., 1992, Upper crustal structure of the northeast Parana Basin, Brazil, determined from integrated magnetotelluric and gravity measurements: Journal of Geophysical Research, 97, 3351–3365
Upper crustal structure of the northeast Parana Basin, Brazil, determined from integrated magnetotelluric and gravity measurements:CrossRef |

Prieto, C., Perkins, C., and Berkman, E., 1985, Columbia River basalt plateau – an integrated approach to interpretation of basalt-covered areas: Geophysics, 50, 2709–2719
Columbia River basalt plateau – an integrated approach to interpretation of basalt-covered areas:CrossRef |

Raja Rao, C., 1982, Coalfields of India: Geological Survey of India, Bulletin Series A, No. 45.

Rajesh, R., and Tiwari, R. K., 2015, A short note on the application of singular spectrum analysis for geophysical data processing: Journal of the Indian Geophysical Union, 19, 77–85

Rama Krishna, T. S., Ramarao, M. S. V., Bhaskar Rao, K. V. S., and Punekar, D. V., 1999a, Geophysics of the Mahrashtra Gondwana: GSI special publication, 47.

Rama Krishna, T. S., Ramarao, M. S. V., Bhaskar Rao, K. V. S., and Punekar, D. V., 1999b, Geophysics of the Mahrashtra Gondwana: GSI special publication, 49.

Rekapalli, R., and Tiwari, R. K., 2016, Singular spectral analysis based filtering of seismic signal using new Weighted Eigen Spectrogram: Journal of Applied Geophysics, 132, 33–37
Singular spectral analysis based filtering of seismic signal using new Weighted Eigen Spectrogram:CrossRef |

Rekapalli, R., Tiwari, R. K., Dhanam, K., and Seshunarayana, T., 2014, T-x frequency filtering of high resolution seismic reflection data using singular spectral analysis: Journal of Applied Geophysics, 105, 180–184
T-x frequency filtering of high resolution seismic reflection data using singular spectral analysis:CrossRef |

Sarma, S. V. S., Harinarayna, T., Virupakshi, G., Someswara Rao, M., Rao, M., Nagarajan, N., Sastry, T. S., and Rao, S. P. E., 2004, Magnetotelluric investigations in Deccan trap covered areas of Nagpur-Wardha region, India: Journal of Geophysics, XXV, 87–91

Skeels, D. C., 1967, What is residual gravity?: Geophysics, 32, 872–876
What is residual gravity?:CrossRef |

Spector, A., and Grant, F. S., 1970, Statistical models for interpreting aeromagnetic data: Geophysics, 35, 293–302
Statistical models for interpreting aeromagnetic data:CrossRef |

Stanley, W. D., Saad, A. R., and Ohofugi, W., 1985, Regional magnetotelluric surveys in hydrocarbon exploration, Parana Basin, Brazil: AAPG Bulletin, 69, 344–360

Talwani, M., and Heirtzler, J. R., 1964, Computation of magnetic anomalies caused by two dimensional bodies of arbitrary shape, in G. A. Parks, ed., Computers in the mineral industries, part 1: Stanford University Publications in the Geological Sciences, 9, 464–480.

Talwani, M., Worzel, J. L., and Landisman, M., 1959, Rapid gravity computations for two dimensional bodies with application to the Mendocino submarine fracture zone: Journal of Geophysical Research, 64, 49–59
Rapid gravity computations for two dimensional bodies with application to the Mendocino submarine fracture zone:CrossRef |

Won, I. J., and Bevis, M., 1987, Computing the gravitational and magnetic anomalies due to a polygon: algorithms and FORTRAN subroutines: Geophysics, 52, 232–238
Computing the gravitational and magnetic anomalies due to a polygon: algorithms and FORTRAN subroutines:CrossRef |



Export Citation