Gravitational Anomalies

Gravitational Anomalies

 

the difference between the observed force of gravity and its theoretical (normal) value at the same point, to which a correction is introduced allowing for the dependence of the force of gravity on the height of the observation point. Depending on the corrections introduced, several types of anomalies are distinguished. If the decrease in the force of gravity with height in free space is considered, with an average gradient taken over the entire earth of 0.3086 milligal/m (1 milligal = 10-3 cm/sec2), then the anomaly is called a gravitational anomaly in free air (or Faye anomaly); these anomalies are used in studying the earth’s figure in geodetic gravimetry. If, in addition, the attraction exerted by a uniform layer of mass between the level of the observation point and sea level is considered, the gravitational anomaly is called a Bouguer anomaly. Since Bouguer anomalies reflect the nonuniform density of rock in the earth’s topmost layer, they are employed in the solution of geological prospecting problems.

M. U. SAGITOV

References in periodicals archive ?
Bottom: Gravitational anomalies mapped by NASA's GRAIL orbiter, combined with a map highlighting wrinkle ridges (seen as orange lines), show that both features closely parallel the northern rim of Frigoris.
Cahill [8] introduced an additional dimensionless constant that coincides with the fine structure constant and determines the strength of a new 3-space self-interaction that can explain various gravitational anomalies, such as the 'borehole anomaly' and the 'dark matter anomaly' in the rotation speeds of spiral galaxies.
All these structures were deemed as "associated with gravity anomalies." These structures point to a clash between the existing model of Ceres' gravity and newly observed gravitational anomalies.
Independently of gravitational anomalies in space, theorists had forecast exotic new massive particles permeating the cosmos.
Gallentine does not mince words about the temperature swings of the moon and Mars, of gravitational anomalies, of the difficulties of demonstrating a case of life on Mars and differentiating it from chemical processes, and of the thrill of being the first to reach and to explore alien worlds, even remotely.
Because of lensing, light not only magnifies, but is forced to take different routes owing to gravitational anomalies bending light paths.
Though physical properties of the crust medium reflected by the crustal and gravitational anomalies are different, there is no comparability in the distribution patterns of both.
During the GRAIL mission, the twin probes have accomplished more than 100 tasks orbitting the Moon and measured gravitational anomalies, proving there are more erosion on the Moon's surface than it is thought.
The recommendations for using the automated fitting algorithms and software are developed on examples of modelling of (a) a gravitational field along regional seismic profiles, (b) configurations of intrusive massifs and ore objects, (c) airborne magnetic measurements along regional geotransects at different altitudes and recalculated gravitational anomalies on different levels, (d) separate ore bodies in an iron-ore deposit, and (e) gravitational and magnetic fields along geological cross-sections during large-scale geological mapping.
Caption: Buried craters, including Lambert R, seen just south of Lambert, create gravitational anomalies picked up by NASA's GRAIL spacecraft.
"Our work provides an intriguing link between two seemingly unrelated topics: gravitational anomalies and computational complexity.