NASA Unveils 3D Earth Geoid Built From 1 Billion Observations
Updated
Updated · Kursiv Media · Jul 31
NASA Unveils 3D Earth Geoid Built From 1 Billion Observations
3 articles · Updated · Kursiv Media · Jul 31
Summary
NASA’s new 3D Geoid model shows Earth’s gravity field as bulges and depressions rather than a perfect sphere, with the ocean-surface reference shape distorted by uneven mass inside the planet.
10,000-fold Vertical exaggeration makes the tiny differences visible; in reality they span only a few dozen meters, from about 85 meters above the reference level near Iceland to 106 meters below south of India.
15 years of satellite data underpin the model, which maps stronger pull over denser rock and weaker pull where mass is less concentrated.
The geoid serves as a baseline for tracking sea level, ice-sheet mass, groundwater and drought, with NASA estimating Antarctica lost about 135 gigatons of ice a year from 2002 to 2025 and Greenland about 264 gigatons.