English: Earth's Gravity according to the Preliminary Reference Earth Model (PREM). The acceleration has its maximum at 3480 km and a value of 10.68 m/s²
The other curves show:
An approximated Earth, where the density decreases linearly from center to surface. In this model, the density at the center is the same as in the PREM, but the surface density is chosen in such a way that the mass of the resulting sphere equals the mass of the Earth.
An idealized Earth with constant density (naturally, Earth's average density was used for this).
La gravité est nulle au centre du globe. Elle passe par un maximum de 10,68 m/s² au rayon 3480 km. Elle est de 9,81 m/s² en surface (rayon 6400 km). Elle décroit depuis la surface de la Terre en s'éloignant vers l'espace.
Les autres courbes du diagramme montrent, à titre de comparaison, des approches simplifiées :
Un modèle où la densité diminuerait linéairement du centre à la surface. Dans ce modèle, la densité au centre est la même que dans le PREM, mais la densité en surface est choisie de manière à ce que la masse de la sphère résultante soit égale à la masse réelle de la Terre.
Un modèle utilisant une densité moyenne constante.
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Dziewonski, A.M. (1981). "Preliminary reference Earth model". Physics of the Earth and Planetary Interiors25: 297–356.
The source data of the chart is in the SVG image file in a clearly readable format. You see the original numbers inside of the SVG file in the form of a list such as this:
...
1995 10.06
1996 11.75
1997 12.45
...
Content of SVG
To view the data download the SVG file itself. To do so right-click this link, and then choose the option to save: File:EarthGravityPREM.svg. Launch any text editor. Open the downloaded SVG file with the text editor (usually; file menu, open). To see the list of data, search for the phrase id="graph1".
Edit SVG
Please, do not use a special SVG editor such as Inkscape; the readability of the database would be destroyed. You can edit the SVG file with any text editor, for example; en: List of text editors. You can view the edited SVG file in various web browsers. As of 2011, all major desktop browsers, and many minor ones, have some level of SVG support. See: en: Scalable Vector Graphics#Support for SVG in web browsers. When satisfied with your edits, upload the edited SVG file with the link labeled "Upload a new version of this file".