Gravity anomaly | physics | Britannica (original) (raw)

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deep-sea trenches

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  In deep-sea trench: Origin of deep-sea trenches
  These negative gravity anomalies are interpreted to mean that the segments of the lithosphere (that is, the crust and upper mantle comprising the rigid, outermost shell of the Earth) that underlie trenches are being forced down against buoyant isostatic forces.
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Earth

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  In geoid
  …in Earth and the resultant gravity anomalies, the geoid is not a simple mathematical surface. It consequently is not a suitable reference surface for a geometric figure of Earth. As reference figures of Earth, but not for its topography, simple geometric forms are used that approximate the geoid. For many…
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  In gravity: Gravimetric surveys and geophysics
  …factors imply a variation of gravity with latitude that can be calculated for an assumed shape for Earth. The third factor, which is the decrease in gravity with elevation, due to increased distance from the centre of Earth, amounts to −0.3086 milligal per metre. This value, however, assumes that material…
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ocean basins

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  In ocean basin: Exploration of the ocean basins
  …shows a linear pattern of gravity anomalies that cut obliquely across the grain of the topography. These anomalies are most pronounced in the Pacific basin; they are apparently about 100 km (about 60 miles) across and some 1,000 km (about 600 miles) long. They have an amplitude of approximately 10…
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