Global maps of the Geoid height, which is the difference of an imaginary sea-level surface that in fact has a wavy surface over all of the Earth, to a perfect ellipsoid. This wavy surface exists because the Earth’s mass is not spread out evenly. Mountain ranges, ocean trenches, and even hidden density differences deep underground pull on gravity slightly more or less from place to place. As a result, sea level actually dips and bulges by up to about 100 meters depending on location, even though these variations are far too gradual to notice standing on a beach. The geoid is important because it serves as the true physical reference for measuring elevation and depth, rather than the simplified mathematical ellipsoid normally used for maps and GPS.
The rendered data is based on EGM2008 (Pavlis et al., 2012) and plotted using an equal-area Mollweide map projection to preserve the relative sizes of land- and ocean areas (other projections are included in the download package). The Scientific colour map ‘vik‘ is used to represent data accurately and to all readers.
- Creator: Fabio Crameri
- This version: 19.09.2021
- License: Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
- Specific citation: This graphic by Fabio Crameri is available via the open-access s-Ink repository.
- Related references: Nikolaos K. Pavlis, Simon A. Holmes, Steve C. Kenyon, John K. Factor; 2012, EGM2008: The development and evaluation of the Earth Gravitational Model 2008 (EGM2008) -Journal of Geophysical Research: Solid Earth (1978-2012) Volume 117, Issue B4, April 2012. https://doi.org/10.1029/2011JB008916
- Alternative map projections
- Alternative colour maps
- Transparent background
- Light & dark background versions
- Perceptually uniform
- Colour-vision deficiency friendly
- Readable in black&white
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