Marine Vertical Gravity Gradients Reveal the Global Distribution and Tectonic Significance of “Seesaw” Ridge Propagation

2021 ◽  
Vol 126 (2) ◽  
Author(s):  
Hugh Harper ◽  
Brook Tozer ◽  
David T. Sandwell ◽  
Richard N. Hey
Keyword(s):  
Global Distribution ◽  
Gravity Gradients ◽  
Tectonic Significance ◽  
Vertical Gravity ◽  
Ridge Propagation

Reduction to the pole of the North American magnetic anomalies

Geophysics ◽  
1990 ◽  
Vol 55 (2) ◽  
pp. 218-225 ◽  
Author(s):  
J. Arkani‐Hamed ◽  
W. E. S. Urquhart
Keyword(s):  
North America ◽  
Gravity Anomalies ◽  
Magnetic Anomalies ◽  
Gravity Gradient ◽  
Plate Boundaries ◽  
Gravity Gradients ◽  
The North ◽  
Vertical Gravity Gradient ◽  
Regional Tectonic ◽  
Vertical Gravity

Magnetic anomalies of North America are reduced to the pole using a generalized technique which takes into account the variations in the directions of the core field and the magnetization of the crust over North America. The reduced‐to‐the‐pole magnetic anomalies show good correlations with a number of regional tectonic features, such as the Mid‐Continental rift and the collision zones along plate boundaries, which are also apparent in the vertical gravity gradient map of North America. The magnetic anomalies do not, however, show consistent correlation with the vertical gravity gradients, suggesting that magnetic and gravity anomalies do not necessarily arise from common sources.

scholarly journals 3‐D Modeling of Vertical Gravity Gradients and the Delimitation of Tectonic Boundaries: The Caribbean Oceanic Domain as a Case Study

2019 ◽  
Vol 20 (11) ◽  
pp. 5371-5393 ◽  
Author(s):  
Ángela María Gómez‐García ◽  
Christian Meeßen ◽  
Magdalena Scheck‐Wenderoth ◽  
Gaspar Monsalve ◽  
Judith Bott ◽  
...  
Keyword(s):  
Gravity Gradients ◽  
The Caribbean ◽  
Vertical Gravity ◽  
Tectonic Boundaries ◽  
Oceanic Domain

On the determination of vertical gravity gradients by corner-cube absolute gravimeters

Metrologia ◽  
2019 ◽  
Vol 56 (5) ◽  
pp. 055006 ◽  
Author(s):  
Vojtech Pálinkáš ◽  
Petr Křen ◽  
Miloš Vaľko ◽  
Pavel Mašika
Keyword(s):  
Gravity Gradients ◽  
Corner Cube ◽  
Vertical Gravity

The role of near topography and building effects in vertical gravity gradients approximation

First Break ◽  
2014 ◽  
Vol 32 (2004) ◽  
Author(s):  
P. Zahorec ◽  
J. Papčo ◽  
M. Mikolaj ◽  
R. Pašteka ◽  
V. Szalaiová
Keyword(s):  
Gravity Gradients ◽  
Building Effects ◽  
Vertical Gravity

THE VERTICAL GRAVITY GRADIENT IN BOREHOLE EXPLORATION

Geophysics ◽  
1963 ◽  
Vol 28 (6) ◽  
pp. 1072-1073 ◽  
Author(s):  
Stephen Thyssen‐Bornemisza
Keyword(s):  
Point Mass ◽  
Gravity Gradient ◽  
Gravity Gradients ◽  
Vertical Derivative ◽  
Rock Formations ◽  
Vertical Gravity Gradient ◽  
Vertical Gravity ◽  
First Vertical Derivative

In past years vertical gravity‐gradient observations have been repeatedly suggested for the determination of in‐situ densities of rock formations penetrated by a borehole (Smith, 1950; Hammer, 1963). However, calculations made for a point mass to one side of a borehole show that the first vertical derivative of gravity, g, is influenced by this mass to a much greater degree than g itself, or the second vertical derivative. This should be borne in mind if attempts are made to measure vertical gravity gradients in a borehole.

A RAPID METHOD FOR MEASURING THE PROFILE COMPONENTS OF HORIZONTAL AND VERTICAL GRAVITY GRADIENTS

Geophysics ◽  
1943 ◽  
Vol 8 (2) ◽  
pp. 119-133 ◽  
Author(s):  
C. A. Heiland
Keyword(s):  
Thermal Conditions ◽  
Observation Time ◽  
Resolving Power ◽  
Gravity Gradient ◽  
Maximum Effect ◽  
Gravity Gradients ◽  
Optical Sensitivity ◽  
Vertical Gravity Gradient ◽  
Terrain Corrections ◽  
Vertical Gravity

The trend in gravity exploration in the past years indicates the rather remarkable fact that a method of low resolving power (the gravity meter) has replaced one of higher resolving power (the torsion balance). This is entirely due to the superior speed of the former and suggests an instrument and procedure in which observation time is reduced by (1) reduction in number of quantities measured; (2) use of a reference direction near that of the maximum effect; (3) elimination of the torsionless position as unknown; (4) reduction in period, with compensating increase in optical sensitivity; (5) stabilization of thermal conditions. These objectives are attained by (1) measuring the profile components of gradients and curvature values, preferably at right angles to the assumed strike; whereby, for an ideal two‐dimensional feature, also the vertical gravity gradient is obtained, and the vertical and horizontal gravity components may be calculated by integration; (2) by holding the torsionless position constant with temperature control; (3) by decreasing the period and observation time to 3–4 minutes, and (4) by using a beam arrangement which will give the gradient in only one azimuth, and the profile gradient of the horizontal gravity component in a second azimuth if desired. Latitude and terrain corrections are also somewhat simplified by the proposed procedure.

In situ verification of refined predicted vertical gravity gradients on Etna

2020 ◽  
Author(s):  
Peter Vajda ◽  
Pavol Zahorec ◽  
Juraj Papčo ◽  
Massimo Cantarero ◽  
Filippo Greco ◽  
...  
Keyword(s):  
High Resolution ◽  
Monitoring Network ◽  
Ground Control ◽  
Gravity Gradients ◽  
North East ◽  
The North ◽  
In Situ Observations ◽  
Vertical Gravity ◽  
Modelling Effort

<p>In situ values of vertical gradients of gravity (VGGs) are often needed when compiling residual spatiotemporal gravity changes that are interpreted in volcanic areas with the objective of drawing inferences about sources of volcanic unrest or pending eruptions. VGG values are seldom acquired by in situ observations. Their availability in 4D volcano-microgravimetric surveys and studies can be mediated by predicting the VGGs based on high resolution high accuracy DEMs and modelling the topographic component (constituent) of the VGG. Based on a modelling effort and in situ verification of VGG predicted on Etna in the summit craters area, on the north-east rift and on benchmarks of the monitoring network covering the volcano in a wider context, we learned that the VGG prediction can be improved by using drone-borne photogrammetry with GNSS ground control to produce a finer DEM in the closest vicinity of the VGG point (benchmark or field point) with resolution higher than the available high-resolution LiDAR-derived DEM, and using detailed modeling of gravity effect (on VGG) of anthropogenic objects such as walls and buildings adjacent to the VGG points. In this poster we present the methods used in the refined VGG prediction and the results of the verification of VGGs predicted on Etna.</p>

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