Geophysical Globe: Geoid

Geoid height globe of the EIGEN-6C4 model by Foerste et al.

"The Geoid" is a theoretical surface which represents the shape that the ocean surface would have due to the earths gravitational field, and its extension onto land, relative to a reference ellipsoid.

It provides geophysicists with information about the density structure of the earth - where there is a high density anomaly, gravity is slightly stronger and pulls the water towards it which creates a bulge at the surface - a "geoid high". Geoid topography is generally in the range of ±100m.

The model here has a vertical exaggeration of approximately 12,000. A step of ~1 mm has been added at the coastline to aid visual interpretation of location in areas with extensive continental shelves. No other source of topography has been added - the resemblance to actual surface topography reflects that mountains are much more dense than the air around them!

The underlying data, along with many other global determinations of the geoid / gravity can be found at the excellent website from ICGEM at GFZ Potsdam (http://icgem.gfz-potsdam.de/tom_longtime). The colour image of the EIGEN 6C4 model was generated on this website (http://icgem.gfz-potsdam.de/vis3d/longtime?modelid=7fd8fe44aa1518cd79ca84300aef4b41ddb2364aef9e82b7cdaabdb60a9053f)

Print Settings

Print the upper and lower halves separately and glue together with a bit of superglue. Full file only included for reference and not expected to be printed.

How I designed this

The detailed methodology for creating the globes in my geophysical globe series is available here: https://github.com/jeffwinterbourne/3D_globes/