NASA releases new 3D model of Earth's geoid, the true shape gravity gives the oceans
NASA released a 3D model on July 15 showing Earth's geoid, the shape oceans take under gravity alone. Heights run +85m near Iceland to -106m over southern India, exaggerated 10,000x. Built on a billion-plus readings over 15 years by GRACE and GOCE, the surface GPS elevation is me
NASA's Scientific Visualization Studio released a new 3D model on July 15 mapping Earth's geoid, the surface the world's oceans would settle into if shaped by gravity alone, with no tides, currents, or wind involved. The real variation is small: heights range from +85 meters near Iceland to -106 meters over southern India. To make that visible at all, NASA's visualization exaggerates the differences by a factor of 10,000. The underlying data is GOCO06s, a satellite-only gravity field model built from more than a billion observations collected over 15 years by two missions, NASA's GRACE and ESA's GOCE. This is not just an illustration for its own sake. The geoid is the reference surface used to define what counts as sea level in the first place, which means it underpins GPS-based elevation measurements, coastal and topographic mapping, and long-term monitoring of sea-level change and glacier mass loss. Small revisions to gravity field models like this one can shift elevation data used well beyond geodesy research. Source: NASA Scientific Visualization Studio.