VẬT lý địa CHẤN grav

Satellite-derived marine free-air gravity field, merged with terrestrial gravity field, published by Sandwell and Smith 2001, courtesy of the NOAA-NGDC... Perspective view of a 3D model

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Figure captions

Figure 1 Satellite-derived marine free-air gravity field, merged with terrestrial gravity field, published by Sandwell and Smith (2001), courtesy of the NOAA-NGDC

Figure 2 Perspective view of a 3D model representing the base of aquifer sediments in the Albuquerque and neighboring basins Gravity modeling, which focused on separating the effects

of the aquifer thickness from the underlying sedimentary package plus Precambrian basement, used the iterative technique of Jachens and Moring (1990) constrained by drill hole information The model was combined with faults synthesized from geophysical interpretations and geologic mapping to give a 3D surface that ultimately served as the lower limit of a regional ground-water flow model for the entire basin area From Grauch et al (2002)

Figure 3 Gzz, the partial derivative with respect to the Z axis, of the vertical force of gravity Left: Gzz derived from conventional Bouguer gravity Center: Gzz as measured with FTG survey Right: “Best estimate” of Gzz where all tensor components have been incorporated in data enhancement procedures

Figure 4 Prestack depth-migration profile along line B through K-2 Field Top: Kirchhoff migration Center: Kirchhoff migration with base of salt horizon shown in yellow, as determined

by FTG inversion Bottom: Wave-equation prestack depth-migration which also shows the presence of a salt keel Yellow horizon shows the FTG inversion result

Figure 5 Vertical gravity gradient, Gzz, from the Ekati survey The image below shows an enlarged section of a south-east part of the image above Two dykes separated at just over 300 m are resolved on the lower image, in which the white bar has a horizontal dimension of 300 m

Figure 6 Vertical gravity, Gz, from the Ekati survey

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