Bicubic spline smoothing of two-dimensional geophysical data

A method for the generation of bicubic spline functions is presented in this paper. From this method it becomes apparent that these functions derive their potential strength in accurate and reliable representation of two‐dimensional data by maintaining continuity of the variable and its slope and curvature throughout the area of observation. The results obtained by computing horizontal and vertical derivatives with model and field data illustrate the exceptional accuracy achieved with spline functions. The piecewise cubic polynomial functions expressing observed data analytically in space are used to estimate amplitude and phase spectra of magnetic anomalies. At relatively long wavelengths the amplitude spectrum thus calculated displays remarkable similarity with the true spectrum and is found to be superior to that obtained with two‐dimensional Fourier series expansion. A cubic spline method is also presented for computing values of an observed variable at equispaced points along two orthogonal directions with the help of irregularly distributed data. The interpolation technique applied to field data shows high resolution by maintaining the separation of neighboring anomalies and the small‐scale features. The shapes, peaks, and troughs of both large and small amplitude anomalies are faithfully reproduced. The gradients of the magnetic field do not undergo any appreciable distortion. It can thus be concluded that cubic splines are a reliable and accurate method of interpolation.

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Velocity Filters For Multiple Interferences In Two Dimensional Geophysical Data

10.1109/igarss.1990.688499 ◽

2005 ◽

Author(s):

Chih-Ming Chen ◽

M. Simaan

Keyword(s):

Geophysical Data ◽

Two Dimensional

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Advances in geophysical data processing: A research annual, vol. 2, two-dimensional t ransforms

Computers & Geosciences ◽

10.1016/0098-3004(86)90033-6 ◽

1986 ◽

Vol 12 (6) ◽

pp. 819-820

Author(s):

Brian Pim

Keyword(s):

Data Processing ◽

Geophysical Data ◽

Two Dimensional

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A geophysical interpretation of the geology of Conception Bay, Newfoundland

Canadian Journal of Earth Sciences ◽

10.1139/e83-128 ◽

1983 ◽

Vol 20 (9) ◽

pp. 1421-1433 ◽

Cited By ~ 5

Author(s):

H. G. Miller

Keyword(s):

Magnetic Susceptibility ◽

Volcanic Rocks ◽

Magnetic Anomalies ◽

Vertical Movement ◽

Geophysical Data ◽

Two Dimensional ◽

Geophysical Interpretation ◽

Gravity And Magnetic ◽

Conception Bay ◽

Avalon Peninsula

Geophysical data from Conception Bay and the adjacent peninsulas of the Avalon Peninsula, Newfoundland are presented and quantitatively interpreted using two-dimensional models to interpret the geology beneath the bay. The portion of the bay underlain by mafic volcanic rocks is determined and the maximum extent of the Cambro-Ordovician rocks containing the Wabana hematite deposit is delineated. All gravity and magnetic anomalies in the area are explained in terms of density and magnetic susceptibility variations confined to the upper 12 km of the crust. The geophysical models indicate that mafic volcanics underlie a significant portion of the study area and are more extensive than indicated by the surface outcrop on land. The models also indicate significant vertical movement on the Topsail Fault and on the extension of a fault passing out into the bay near Holyrood. The Cambro-Ordovician sediments are confined to the southern portion of the block bounded by these faults. The geophysical data are unable to detect the presence of the mafic volcanics east of the Topsail Fault in the study area.

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