On: “Direct Interpretation of Two‐Dimensional Structural Faults From Gravity Data,” by Mrinal K. Paul, Sukumar Datta and Buddhadeb Banerjee (GEOPHYSICS, October 1966, p. 940–948)

Geophysics ◽  
1973 ◽  
Vol 38 (5) ◽  
pp. 981-981
Author(s):  
S. K. Choudhury ◽  
R. Amaravadi
Keyword(s):  
Gravity Data ◽  
Two Dimensional ◽  
Correct Equation ◽  
Upward Continuation ◽  
Direct Interpretation ◽  
Gravity Profile

In their paper, Paul et al. have outlined a useful method by which the parameters of a two‐dimensional fault can be directly determined from the gravity data. The upward continuation of the gravity profile over the fault plays a very important role in this method. The necessary coefficients for the upward continuation and the theory involved in their determination form the appendix of the paper. The equation (9) in the appendix is incorrect since for any positive integral values of m and n, the coefficients Q(m, n) become quite large and negative, which will never satisfy the relation (10). The correct equation (9) should be [Formula: see text]

DIRECT INTERPRETATION OF TWO‐DIMENSIONAL STRUCTURAL FAULTS FROM GRAVITY DATA

Geophysics ◽  
1966 ◽  
Vol 31 (5) ◽  
pp. 940-948 ◽  
Author(s):  
Mrinal K. Paul ◽  
Sukumar Datta ◽  
Buddhadeb Banerjee
Keyword(s):  
Horizontal Plane ◽  
Gravity Data ◽  
Direct Determination ◽  
Two Dimensional ◽  
Upward Continuation ◽  
Direct Interpretation ◽  
Dimensional Gravity ◽  
Gravity Profile

Some methods of direct determination of the parameters of a two‐dimensional structural fault with horizontal plane faces, from the gravity profile caused by it, have been formulated in this paper. The upward continuation of the two‐dimensional gravity profile plays an important role in these methods. The determinations by these methods are unique for structures of the same type in the sense that no structure of the same type other than that arrived at by the proposed methods can give rise to the observed anomaly. The necessary coefficients for upward continuation of two‐dimensional gravity data and the theory involved in their determinations form the appendix of this paper.

To: “Direct Interpretation of Two‐Dimensional Structural Faults from Gravity Data” (by Mrinal K. Paul, Sukumar Datta and Buddhadeb Banerjee, GEOPHYSICS, October 1966, p. 940–948)

Geophysics ◽  
1974 ◽  
Vol 39 (3) ◽  
pp. 364-364
Keyword(s):  
Gravity Data ◽  
Two Dimensional ◽  
Direct Interpretation

In the Discussion on “Direct Interpretation of Two‐Dimensional Structural Faults from Gravity Data” (by Mrinal K. Paul, Sukumar Datta and Buddhadeb Banerjee, Geophysics, October 1966, p. 940–948) by S. K. Choudhury and R. Amaravadi, Geophysics, v. 38, no. 5, p. 981, the last term of the equation should be corrected as: [Formula: see text]The term 9/4 in the numerator was incorrectly printed as 2/4.

scholarly journals Gravity Measurements in Permafrost Terrain Containing Massive Ground Ice

1983 ◽  
Vol 4 ◽  
pp. 133-140 ◽  
Author(s):  
K. Kawasaki ◽  
T. E. Osterkamp ◽  
R.W. Jurick ◽  
J. Kienle
Keyword(s):  
Limit Of Detection ◽  
Gravity Data ◽  
Soil Layer ◽  
Road Construction ◽  
Ground Truth ◽  
Ground Ice ◽  
Ground Truth Data ◽  
Gravity Measurements ◽  
Ice Content ◽  
Gravity Profile

Gravity measurements were made with a very sensitive gravimeter in permafrost terrain containing massive ground ice and other segregated ice. Measurements were first taken along a line over undisturbed terrain where a road cut was to be made; a second gravity profile parallel to the first profile but laterally displaced from it by about 36 m was subsequently made along the edge of the roadbed after road construction. Data from pre-construction borings and a profile of subsurface soil and ice conditions, synthesized from information obtained during cutting, were used for ground-truth information and compared with the gravity measurements. The horizontal dimensions and locations of the deposits of ground ice embedded in the soil layer correlated reasonably well with the dimensions and locations of the lows in the gravity profile. However, the second profile, taken along the roadbed, also showed significant variation even after the usual types of gravity corrections were applied, suggesting that there are significant horizontal variations in the density of the topmost layers of the underlying bedrock (schist) through which the cut was made. The density contrast of the undisturbed ice-rich soil as a function of distance along the first pro-file was estimated assuming the contrast was produced by infinitely long, transverse, rectangular blocks of given dimensions but unknown density. A set of equations dependent (to a first approximation) only on the unknown block densities was constructed from the corrected gravity data and solved by the Gauss-Seidel method. The maximum contrast for one block was found to be about 0.4 Mg m3 which gives a volumetric ice content of about 80% for the block, if the mean den-sity for all the blocks is taken to be 1.45 Mgg m3 A third gravity profile was made over an artificially-constructed ice mass with dimensions of 34 × 0.69 × 3.2 m buried at a depth of 1.2 m. This profile did not show conclusively the presence of the ice mass, partly because the anomaly it produces is close to the nominal limit of detection of the gravimeter. It is concluded that large massive ground ice can be detected by means of its gravitational field using sensitive commercially-available gravimeters in conjunction with some ground-truth data. However, the application of such gravimeters to routine pre-construction investigations and terrain reconnaissance for ground ice is limited by their sensitivity and by the requirement for a stable measuring platform. At present, the gravity method and possibly impulse radar are the only non-contacting remote methods for obtaining an estimate of the excess ice in permafrost.

Inversion of gravity data for two-dimensional density distributions

1974 ◽  
Vol 79 (14) ◽  
pp. 2017-2021 ◽  
Author(s):  
L. W. Braile ◽  
G. R. Keller ◽  
W. J. Peeples
Keyword(s):  
Gravity Data ◽  
Two Dimensional ◽  
Density Distributions

scholarly journals Identification of local sesars of tejakula buleleng bali with anomaly gravity data using second vertical derivative method

2020 ◽  
Vol 3 (1) ◽  
pp. 18-25
Author(s):  
Komang Ngurah Suarbawa ◽  
I Gusti Agung Putra Adnyana ◽  
Elvin Riyono
Keyword(s):  
Gravity Anomaly ◽  
Gravity Data ◽  
Three Dimensional ◽  
Fault Model ◽  
Two Dimensional ◽  
Upward Trend ◽  
Gravity Method ◽  
Vertical Derivative ◽  
Subsurface Structures ◽  
Derivative Method

Research has been carried out related to subsurface structures in the Tejakula Buleleng Bali area and its surroundings using the gravity method. This study aims to identify the local Tejakula fault. The data used in this study is gravity anomaly data obtained from observations of Geodetic Satellite (GEOSAT). The method used in interpreting the type of disturbance uses the Second Vertical Derivative method, which then produces two-dimensional (2D) and three-dimensional (3D) fault model interpretations. Based on the results obtained in the study, the condition of the bouguer gravity anomaly value in the Tejakula area and its surroundings at the research location is in the range of 65 mGal to 185 mGal. Meanwhile, based on the Second Vertical Derivative method in determining the type of fault, the Tejakula Fault can be categorized as a mandatory fault with an upward trend.

On: “Inversion of gravity profiles by use of a Backus‐Gilbert approach” by William R. Green (GEOPHYSICS, October 1975, p. 763–772).

Geophysics ◽  
1976 ◽  
Vol 41 (4) ◽  
pp. 777-777
Author(s):  
Ramesh Chander
Keyword(s):  
Gravity Anomaly ◽  
Total Mass ◽  
Gravity Data ◽  
Unit Length ◽  
Three Dimensional ◽  
Density Model ◽  
Dimensional Case ◽  
Two Dimensional ◽  
Mass Excess ◽  
Seminal Paper

An important possible constraint on a density model obtained from inversion of gravity data has been overlooked in the seminal paper by Green. The computed density model should be such that the corresponding total mass excess or deficit per unit length in a two‐dimensional case, or total mass excess or deficit in a three‐dimensional case, should be comparable to the value obtained by applying Gauss’s theorem to the observed gravity anomaly data (Grant and West, 1965, p. 227–28 and p. 232).

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