Oct 16, 2024 · The geoid (illustrated in Figure 1) represents the equipotential surface of the Earth's gravity field, which is shaped by the inhomogeneous mass and density distribution in the interior, as well as the variable surface topography.

Gravity measurements are typically given with respect to a certain reference, which can but does not have to be an equipotential surface. An important example of an equipotential surface is

A ball will not be accelerated left or right by the force of gravity if it is resting on a flat, horizontal surface, because it is an equipotential surface. For the gravity of Earth, the corresponding geopotential isosurface (the equigeopotential) that best fits mean sea level is called the geoid.

The magnitude of the gravitational potential, U(r) is a constant on each of these surfaces: therefore, these surfaces are referred to as equipotential surfaces. Spherical surfaces at greater distances have lower values because (U decreases proportional to 1 / r).

Sep 7, 2020 · The geoid is the equipotential surface of the Earth’s gravity field, which best approximates the mean sea level at rest. Its determination requires (i) knowledge of the Earth’s gravity potential and (ii) a way of geometrically representing the geoidal surface, which is done via its deviations – called geoid undulations N – from the ...

Jul 19, 2024 · Revision notes on Gravitational Equipotential Surfaces (HL) for the HL IB Physics syllabus, written by the Physics experts at Save My Exams.

They are known as equipotential surfaces. Mean Sea Level itself is not an equipotential surface at all, of course. Forces other than gravity affect it, forces such as temperature, salinity, currents, wind, and so forth. The geoid, on the other hand, is defined by gravity alone.

Jun 29, 2021 · Any surface along with the potential is constant, so it is referred as an equipotential surface. Sea level, for example, is an equipotential surface, even though the actual force of gravity varies along the sea surface by more than (0.5%) between the equator and either of the poles.

Gravitational acceleration is the gradient of the potential: So, @U =constant on such an equipotential surface @z (gravity is constant at a given value of R). The actual Earth is not homogeneous. Earth has mass anomalies, U is not constant at a given R, and @U 6=constant, @z so gravity varies along an equipotential surface for the Earth.

Aug 27, 2001 · The geoid is the equipotential surface of the Earth's gravity field that coincides with average sea level. Variations in geoid height relative to a reference ellipsoid represent undulations varying by more or less 100 m.