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### Does gravity vary across the Earth's surface Gravitational Anomalies on Earth.

Answer: Yes, but the variations are very small.

On the one hand we have the effect of earth rotation. The centrifugal force is greatest at the equator, and "pushes things out." For this reason, at the equator you weigh a little less than at the poles (0.03% to 0.05% less). gravity is also weaker at high altitudes, further away from the center of the planet.

On the other hand, the Earth is not a perfect sphere, it is flattened at the poles. So there is more land below you at the equator than at the poles. This produces the opposite effect to the one mentioned above, it makes gravity at the equator a little stronger than at the poles.

Then we have the height and composition of the Earth's crust. At the top of a large rocky mountain range like the Himalayas, gravity is slightly stronger than on a plain at sea level on sedimentary material.

## Gravitational anomalies

Gravitational anomalies in geophysics - deviations of the magnitude of the gravitational field from the calculated one based on a mathematical model. The gravitational potential of the Earth's surface, or geoid, is usually described on the basis of mathematical theories using harmonic functions. These deviations can be caused by various factors, among others:

• The Earth is not homogeneous, its density differs in different areas.
• The Earth is not an ideal sphere, and the formula uses the average value of its radius.
• The calculated value g takes into account only gravity and does not take into account centrifugal force caused by the Earth's rotation.
• As the body rises above the surface of the Earth, the value of g decreases.
• The Earth is affected by the gravitational fields of other cosmic bodies, in particular the tidal forces of the Sun and the Moon.