Climate change is making Earth more spherical

New research indicates that Earth is becoming increasingly spherical due to the melting of polar ice caps. While the planet is naturally an oblate spheroid—flattened at the poles and bulging at the equator—the solid part of the Earth is rounding out at an accelerated pace.

A study published in the journal JGR Solid Earth utilized Global Navigation Satellite System (GNSS) measurements to track these shifts. Findings show that between 2011 and 2015, the poles rose while the equatorial bulge decreased by approximately one millimeter per year. This rate of change is significantly higher than the 0.5 millimeters per year observed between 1997 and 2000.

To overcome the lack of GNSS stations near the poles and in remote oceans, Christoforos Kotsakis, a professor of geodesy at Aristotle University of Thessaloniki, developed a new method for analyzing GNSS data. Monitoring these morphological changes helps scientists more accurately determine the consequences of ice loss in Greenland and Antarctica.