High-resolution FALCON® airborne gravity gradient data adds values to seismic exploration in the Yakka Munga area of Canning Basin, West Australia

2014 ◽  
Author(s):  
David Moore ◽  
Mark Dransfield ◽  
Asbjorn Christensen ◽  
Xiong Li* ◽  
Tony Rudge
Keyword(s):  
High Resolution ◽  
Seismic Exploration ◽  
Airborne Gravity ◽  
Gravity Gradient ◽  
Canning Basin

Basin architecture from high-resolution gravity gradient, magnetic, and seismic data, King Sound, Canning Basin, Western Australia

AAPG Bulletin ◽  
2013 ◽  
Vol 97 (10) ◽  
pp. 1597-1620 ◽  
Author(s):  
Peter Kovac ◽  
Sharon Lowe ◽  
Tony Rudge ◽  
Carlos Cevallos ◽  
Jurriaan Feijth ◽  
...  
Keyword(s):  
High Resolution ◽  
Western Australia ◽  
Seismic Data ◽  
Gravity Gradient ◽  
Canning Basin

Interpreting the direction of the gravity gradient tensor eigenvectors: Their relation to curvature parameters of the gravity field

Geophysics ◽  
2016 ◽  
Vol 81 (3) ◽  
pp. G49-G57 ◽  
Author(s):  
Carlos Cevallos
Keyword(s):  
Equipotential Surface ◽  
Vertical Axis ◽  
Tidal Force ◽  
Airborne Gravity ◽  
Gravity Gradient ◽  
Gravity Gradiometer ◽  
Model Data ◽  
Gradient Tensor ◽  
Gravity Gradient Tensor ◽  
Canning Basin

Rotating the gravity gradient tensor about a vertical axis by an appropriate angle allows one to express its components as functions of the curvatures of the equipotential surface. The description permits the identification of the gravity gradient tensor as the Newtonian tidal tensor and part of the tidal potential. The identification improves the understanding and interpretation of gravity gradient data. With the use of the plunge of the eigenvector associated with the largest eigenvalue or plunge of the main tidal force, it is possible to estimate the location and depth of buried gravity sources; this is developed in model data and applied to FALCON airborne gravity gradiometer data from the Canning Basin, Australia.

Application of curvatures to airborne gravity gradient data in oil exploration

Geophysics ◽  
2013 ◽  
Vol 78 (4) ◽  
pp. G81-G88 ◽  
Author(s):  
Carlos Cevallos ◽  
Peter Kovac ◽  
Sharon J. Lowe
Keyword(s):  
Equipotential Surface ◽  
Shape Index ◽  
Airborne Gravity ◽  
Gravity Gradient ◽  
Gravity Gradiometer ◽  
Model Data ◽  
Canning Basin ◽  
Geologic Interpretation ◽  
The Mean ◽  
Differential Curvature

We apply equipotential surface curvatures to airborne gravity gradient data. The mean and differential curvature of the equipotential surface, the curvature of the gravity field line, the zero contour of the Gaussian curvature, and the shape index improve the understanding and geologic interpretation of gravity gradient data. Their use is illustrated in model data and applied to FALCON airborne gravity gradiometer data from the Canning Basin, Australia.

scholarly journals Application of curvatures and Poisson’s relation to airborne gravity gradient data in oil exploration

2013 ◽  
Vol 2013 (1) ◽  
pp. 1-4
Author(s):  
Carlos Cevallos ◽  
Peter Kovac ◽  
Sharon J. Lowe
Keyword(s):  
Airborne Gravity ◽  
Gravity Gradient ◽  
Oil Exploration

scholarly journals Unveiling the 3D undercover structure of a Precambrian intrusive complex by integrating airborne magnetic and gravity gradient data into 3D quasi-geology model building

2020 ◽  
Vol 8 (4) ◽  
pp. SS15-SS29 ◽  
Author(s):  
Jiajia Sun ◽  
Aline Tavares Melo ◽  
Jae Deok Kim ◽  
Xiaolong Wei
Keyword(s):  
High Resolution ◽  
Model Building ◽  
Country Rock ◽  
Joint Inversion ◽  
Sedimentary Cover ◽  
Geophysical Methods ◽  
Added Value ◽  
Gravity Gradient ◽  
Airborne Magnetic

Mineral exploration under a thick sedimentary cover naturally relies on geophysical methods. We have used high-resolution airborne magnetic and gravity gradient data over northeast Iowa to characterize the geology of the concealed Precambrian rocks and evaluate the prospectivity of mineral deposits. Previous researchers have interpreted the magnetic and gravity gradient data in the form of a 2D geologic map of the Precambrian basement rocks, which provides important geophysical constraints on the geologic history and mineral potentials over the Decorah area located in the northeast of Iowa. However, their interpretations are based on 2D data maps and are limited to the two horizontal dimensions. To fully tap into the rich information contained in the high-resolution airborne geophysical data, and to further our understanding of the undercover geology, we have performed separate and joint inversions of magnetic and gravity gradient data to obtain 3D density contrast models and 3D susceptibility models, based on which we carried out geology differentiation. Based on separately inverted physical property values, we have identified 10 geologic units and their spatial distributions in 3D which are all summarized in a 3D quasi-geology model. The extension of 2D geologic interpretation to 3D allows for the discovery of four previously unidentified geologic units, a more detailed classification of the Yavapai country rock, and the identification of the highly anomalous core of the mafic intrusions. Joint inversion allows for the classification of a few geologic units further into several subclasses. We have demonstrated the added value of the construction of a 3D quasi-geology model based on 3D separate and joint inversions.

scholarly journals Bathymetry of Northwest Greenland Using “Ocean Melting Greenland” (OMG) High-Resolution Airborne Gravity and Other Data

2019 ◽  
Vol 11 (2) ◽  
pp. 131 ◽  
Author(s):  
Lu An ◽  
Eric Rignot ◽  
Romain Millan ◽  
Kirsty Tinto ◽  
Josh Willis
Keyword(s):  
High Resolution ◽  
Continental Shelf ◽  
Gravity Data ◽  
Three Dimensional ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Three Dimensions ◽  
Airborne Gravity ◽  
Lack Of Information ◽  
Sea Bed

Marine-terminating glaciers dominate the evolution of the Greenland Ice Sheet (GrIS) and its contribution to sea-level rise. Widespread glacier acceleration has been linked to the warming of ocean waters around the periphery of Greenland but a lack of information on the bathymetry of the continental shelf and glacial fjords has limited our ability to understand how subsurface, warm, salty ocean waters of Atlantic origin (AW) reach the glaciers and melt them from below. Here, we employ high-resolution, airborne gravity data (AIRGrav) in combination with multibeam echo sounding (MBES) data, to infer the bathymetry of the coastal areas of Northwest Greenland for NASA’s Ocean Melting Greenland (OMG) mission. High-resolution, AIRGrav data acquired on a 2 km spacing, 150 m ground clearance, with 1.5 mGal crossover error, is inverted in three dimensions to map the bathymetry. To constrain the inversion away from MBES data, we compare two methods: one based on the Direct Current (DC) shift of the gravity field (absolute minus observed gravity) and another based on the density of the bedrock. We evaluate and compare the two methods in areas with complete MBES coverage. We find the lowest standard error in bed elevation (±60 m) using the DC shift method. When applied to the entire coast of Northwest Greenland, the three-dimensional inversion reveals a complex network of connected sea bed channels, not known previously, that provide natural and varied pathways for AW to reach the glaciers across the continental shelf. The study demonstrates that the gravity approach offers an efficient and practical alternative to extensive ship mapping in ice-filled waters to obtain information critical to understanding and modeling ice-ocean interaction along ice sheet margins.

scholarly journals High-resolution coherency functionals for velocity analysis: An application for subbasalt seismic exploration

Geophysics ◽  
2013 ◽  
Vol 78 (5) ◽  
pp. U53-U63 ◽  
Author(s):  
Andrea Tognarelli ◽  
Eusebio Stucchi ◽  
Alessia Ravasio ◽  
Alfredo Mazzotti
Keyword(s):  
High Resolution ◽  
Seismic Data ◽  
Field Data ◽  
Signal To Noise Ratio ◽  
Synthetic Seismograms ◽  
Seismic Exploration ◽  
Velocity Analysis ◽  
Signal To Noise ◽  
Geologic Setting ◽  
Analytic Signals

We tested the properties of three different coherency functionals for the velocity analysis of seismic data relative to subbasalt exploration. We evaluated the performance of the standard semblance algorithm and two high-resolution coherency functionals based on the use of analytic signals and of the covariance estimation along hyperbolic traveltime trajectories. Approximate knowledge of the wavelet was exploited to design appropriate filters that matched the primary reflections, thereby further improving the ability of the functionals to highlight the events of interest. The tests were carried out on two synthetic seismograms computed on models reproducing the geologic setting of basaltic intrusions and on common midpoint gathers from a 3D survey. Synthetic and field data had a very low signal-to-noise ratio, strong multiple contamination, and weak primary subbasalt signals. The results revealed that high-resolution coherency functionals were more suitable than semblance algorithms to detect primary signals and to distinguish them from multiples and other interfering events. This early discrimination between primaries and multiples could help to target specific signal enhancement and demultiple operations.

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