scholarly journals Procedures for calculating terrain corrections for gravity measurements

1970 ◽  
Author(s):  
R A Stacey ◽  
L E Stephens
Keyword(s):  
Gravity Measurements ◽  
Terrain Corrections

scholarly journals Thickness and Basal Configuration of Lower Blue Glacier, Washington, Determined by Gravimetry

1965 ◽  
Vol 5 (41) ◽  
pp. 637-650 ◽  
Author(s):  
Charles E. Corbató
Keyword(s):  
Gravity Field ◽  
Three Dimensional ◽  
Successive Approximations ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Gravity Measurements ◽  
Computational Errors ◽  
Terrain Corrections ◽  
Seismic Reflections ◽  
Regional Gravity

AbstractGravity measurements at 146 stations on lower Blue Glacier were used to determine the subglacial bedrock configuration. The gravity values, station elevations and density contrast were carefully measured, and terrain corrections thoroughly evaluated to insure accuracy of the Bottguer anomalies. A series of successive approximations results in evaluation of the regional gravity field and a three-dimensional model of the glacier whose gravimetric effects fit the range of the observational and computational errors. Comparison with bore holes and seismic reflections indicates no significant errors in the model and accuracies of 5–10 per cent in the calculated thicknesses of the glacier.

Developing an autonomous unmanned aerial system to estimate field terrain corrections for gravity measurements

2018 ◽  
Vol 37 (8) ◽  
pp. 584-591 ◽  
Author(s):  
Leon Kaub ◽  
Christopher Seruge ◽  
Shaurya D. Chopra ◽  
Jonathan M. G. Glen ◽  
Mircea Teodorescu
Keyword(s):  
Unmanned Aerial System ◽  
Gravity Measurements ◽  
Terrain Corrections

Gravity terrain corrections calculated using digital elevation models

Geophysics ◽  
1990 ◽  
Vol 55 (1) ◽  
pp. 102-106 ◽  
Author(s):  
Allen H. Cogbill
Keyword(s):  
High Precision ◽  
The Other ◽  
Mountainous Areas ◽  
Data Set ◽  
Gravity Station ◽  
Digital Terrain ◽  
Terrain Effects ◽  
Digital Elevation ◽  
Gravity Measurements ◽  
Terrain Corrections

Corrections for terrain effects are required for virtually all gravity measurements acquired in mountainous areas, as well as for high‐precision surveys, even in areas of low relief. Terrain corrections are normally divided into two parts, one part being the correction for terrain relatively close to the gravity station (the “inner‐zone” correction) and the other part being the correction for more distant, say, >2 km, terrain. The latter correction is normally calculated using a machine procedure that accesses a digital‐terrain data set. The corrections for terrain very close to the gravity station are done manually using Hammer’s (1939) procedures or a similar method, are guessed in the field, or simply are neglected. Occasionally, special correction procedures are used for the inner‐zone terrain corrections (e.g., LaFehr et al., 1988); but such instances are uncommon.

scholarly journals Inner zone terrain correction calculation using interpolated heights

2015 ◽  
Vol 45 (3) ◽  
pp. 219-235 ◽  
Author(s):  
Pavol Zahorec
Keyword(s):  
Gravity Data ◽  
Real Data ◽  
Test Area ◽  
Gravity Measurements ◽  
Topography Model ◽  
Terrain Corrections ◽  
Elevation Model ◽  
Regional Gravity ◽  
Synthetic Models ◽  
Simple Statistical Analysis

Abstract The discrepancy between real heights of gravity points and the elevation model has a significant impact on the terrain corrections calculation especially within the inner zone. The concept of interpolated heights of calculation points used instead of measured ones within the specified inner zone can considerably decrease the resulting errors. The choice of appropriate radius of the inner zone for use of interpolated heights is analysed on synthetic topography model as well as real data. The tests with synthetic models showed the appropriate radius of this zone is proportional to the deformation wavelength of the model. Simple statistical analysis of a particular elevation model can give an estimate of the appropriate radius for the calculation using interpolated heights. A concept with interpolated heights in the zone 0–250 m is used in actual practice in Slovakia. The analysis of regional gravity data from the Tatry Mountains test area indicates the searched radius should be about 100 m. Detailed gravity measurements from different areas showed the searched radius does not play so important role but the use of interpolated heights instead of measured ones is still relevant. The more reasonable method instead of using interpolated heights is also presented when calculating the topographic effect.

An interpretation of gravity measurements on the west coast of Canada

1969 ◽  
Vol 6 (3) ◽  
pp. 463-474 ◽  
Author(s):  
R. A. Stacey ◽  
L. E. Stephens
Keyword(s):  
Gravity Field ◽  
Bouguer Anomaly ◽  
Vancouver Island ◽  
Coast Mountains ◽  
Bouguer Anomalies ◽  
Queen Charlotte Islands ◽  
Gravity Measurements ◽  
Terrain Corrections ◽  
Tectonic Belt ◽  
Local Anomalies

The survey area lies close to the continental margin and includes parts of the Insular Tectonic Belt and the Coast Mountains igneous and metamorphic complex, which are part of the Cordilleran (geological) Region. In an endeavor to clarify the structure of the Insular Tectonic Belt and the Coast Mountains complex, gravity measurements have been made using Worden or LaCoste and Romberg meters at 12–15 km intervals throughout the Queen Charlotte Islands, Vancouver Island, and the coastal areas of the British Columbia mainland. Measurements have been made at the same interval using a LaCoste and Romberg underwater gravity meter wherever the depth of water is less than 300 fathoms (< 540 m) along the fiords of the mainland coast and over the continental shelf. The observed gravity values have been reduced to Bouguer anomalies and terrain corrections have been calculated using either Bible's tables or a computer system based on the attraction of the rectangular prismatic block.The major features of gravity field are: (1) a positive Bouguer anomaly along the western edge of the area, which is associated with the change from continental to oceanic crust, and (2) a negative anomaly along the Coast Mountains, which is attributed to the thickening of the continental crust below these mountains. On the eastern side of the Queen Charlotte Islands, Hecate Strait, Queen Charlotte Sound, and Vancouver Island, the average Bouguer anomaly is approximately zero, with local anomalies superimposed on a fairly flat gravity field. Several of these local anomalies are related to density variations in the surface rocks.

Terrain corrections for borehole gravity measurements

Geophysics ◽  
1979 ◽  
Vol 44 (9) ◽  
pp. 1584-1587 ◽  
Author(s):  
Larry A. Beyer
Keyword(s):  
Density Profiles ◽  
Gravity Measurements ◽  
Vertical Density ◽  
Terrain Corrections ◽  
Made In

This note presents examples of terrain corrections calculated for borehole gravity surveys made in a variety of topographic settings. The effect of terrain corrections on vertical density profiles calculated from borehole gravity measurements also is shown.

scholarly journals High-precision local gravity survey along planned motorway tunnel in the Slovak Karst

2019 ◽  
Vol 49 (2) ◽  
pp. 207-227 ◽  
Author(s):  
Pavol Zahorec ◽  
Juraj Papčo ◽  
Peter Vajda ◽  
Stanislav Szabó
Keyword(s):  
Laser Scanning ◽  
Gravity Data ◽  
Digital Terrain Model ◽  
Gravity Survey ◽  
Railway Tunnel ◽  
Bouguer Anomalies ◽  
Terrain Model ◽  
Gravity Measurements ◽  
Terrain Corrections ◽  
The Difference

Abstract Results from a detailed gravity survey realized along the planned highway tunnel in the karstic area of Slovak Karst in the eastern Slovakia are presented. Detailed gravity profiles crossed an area of rugged topography, therefore the terrain corrections played a crucial role in the gravity data processing. The airborne laser scanning technique (LiDAR) was used in order to compile a high-resolution digital terrain model (DTM) of the surrounding area and to calculate terrain corrections properly. The difference between the Bouguer anomalies calculated with an available nationwide DTM and those with new LiDAR-based model can be significant in some places as it is presented in the paper. A new method for Bouguer correction density analysis based on surface data is presented. Special underground gravity measurements in the existing nearby railway tunnel were also conducted in order to determine the mean density of the topographic rocks. The Bouguer anomalies were used to interpret lithological contacts and tectonic/karstic discontinuities.

scholarly journals Thickness and Basal Configuration of Lower Blue Glacier, Washington, Determined by Gravimetry

1965 ◽  
Vol 5 (41) ◽  
pp. 637-650 ◽  
Author(s):  
Charles E. Corbató
Keyword(s):  
Gravity Field ◽  
Three Dimensional ◽  
Successive Approximations ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Gravity Measurements ◽  
Computational Errors ◽  
Terrain Corrections ◽  
Seismic Reflections ◽  
Regional Gravity

AbstractGravity measurements at 146 stations on lower Blue Glacier were used to determine the subglacial bedrock configuration. The gravity values, station elevations and density contrast were carefully measured, and terrain corrections thoroughly evaluated to insure accuracy of the Bottguer anomalies. A series of successive approximations results in evaluation of the regional gravity field and a three-dimensional model of the glacier whose gravimetric effects fit the range of the observational and computational errors. Comparison with bore holes and seismic reflections indicates no significant errors in the model and accuracies of 5–10 per cent in the calculated thicknesses of the glacier.

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