Scientists reveal why Antarctica was covered in ice millions of years before the Arctic

On July 2, 2026, researchers from the University of Southampton published a groundbreaking study in Science explaining why Antarctica became engulfed by ice millions of years before the Arctic. This research resolves a long-standing climate science puzzle regarding the formation of a vast ice sheet during a period when Earth was approximately 5°C warmer than today.

Geological Processes Behind Antarctic Glaciation

The study indicates that geological changes initiated during the Jurassic Period (201-143 million years ago) were pivotal. As Antarctica and Africa began to separate, powerful geological forces uplifted East Antarctica's land surface over 100 million years, creating the necessary elevation for snow and ice accumulation.

Lead author Thomas Gernon, a professor of Earth science at the University of Southampton, emphasized, "Antarctica's land surface was gradually lifted to the point where ice could gain a permanent foothold, even while the surrounding polar oceans and global temperatures remained surprisingly warm." This uplift initiated the formation of the East Antarctic Ice Sheet around 34 million years ago.

The Role of Mantle Waves in Ice Formation

Researchers employed computational models to simulate the evolution of East Antarctica's surface over the last 100 million years. These simulations revealed that a phenomenon known as mantle waves played a critical role in raising the land surface. Mantle waves occur when tectonic plates separate, causing geological uplift.

The simulations showed that by approximately 45 million years ago, much of East Antarctica had risen above the crucial elevation of about 2 km, which was necessary for the formation and expansion of mountain glaciers, ultimately leading to the creation of the East Antarctic Ice Sheet.

Implications of the Research on Climate Understanding

This research offers insights into the historical asymmetry of polar ice formation. While Antarctica became glaciated around 34 million years ago, significant ice sheets in the Northern Hemisphere did not form until about 5 million years ago. The study challenges the notion that declining levels of carbon dioxide (CO2) were the sole trigger for Antarctic glaciation, as ice sheets began to form in a relatively mild climate.

Dr. Thea Hincks, a senior research fellow at the University of Southampton and co-lead of the study, noted, "We found that our models can realistically capture the evolution of the two-kilometer-high coastal escarpment, elevated plateau, and inland mountains, eventually seeding the East Antarctic Ice Sheet." This research underscores the importance of geological factors in understanding climate change.

• Formation of the East Antarctic Ice Sheet: 34 million years ago
• Jurassic Period: 201-143 million years ago
• Critical elevation for glacier formation: 2 km
• Global sea level increase potential if ice melts: 52 meters (171 feet)