{"id":35398,"date":"2026-09-02T17:55:53","date_gmt":"2026-09-02T21:55:53","guid":{"rendered":"https:\/\/www.ecoportal.net\/en\/?p=35398"},"modified":"2026-09-02T17:55:53","modified_gmt":"2026-09-02T21:55:53","slug":"antarctica-ice-sheet-formation-arctic","status":"publish","type":"post","link":"https:\/\/www.ecoportal.net\/en\/antarctica-ice-sheet-formation-arctic\/35398\/","title":{"rendered":"Antarctica froze millions of years before the Arctic and deep Earth may have quietly “set the stage” for it all by slowly lifting a hidden mountain range to ice-sustaining heights"},"content":{"rendered":"

Antarctica was blanketed in a massive ice sheet roughly 34 million years ago \u2014 while the Arctic remained largely ice-free until just five million years ago. That’s a 30-million-year gap, and it has puzzled climate scientists for decades.<\/p>\n

The world back then was around 9\u00b0F warmer than today<\/strong>. Yet one pole was already freezing over. A new study published in Science<\/em> suggests the answer may lie not in the atmosphere, but in something far less visible \u2014 hidden deep beneath Antarctica’s surface.<\/p>\n

A 30-million-year head start on ice<\/h2>\n

Antarctica’s ice sheet began forming around 34 million years ago. Northern Hemisphere ice sheets didn’t arrive until the past five million years or so<\/strong>. That asymmetry is striking, and it has long resisted easy explanation.<\/p>\n

Falling CO2 levels are the standard candidate. As atmospheric carbon dioxide declined, global temperatures dropped, and glaciation followed. But there’s a problem: if CO2 were the only driver, both poles should have responded more symmetrically. They didn’t. Antarctica got a massive head start, and paleoclimatologists have spent decades trying to figure out why.<\/p>\n

Waves beneath the crust: the hidden engine of uplift<\/h2>\n

The new study, led by the University of Southampton and published in Science<\/em>, points to a geological mechanism only recently identified: mantle waves<\/strong>.<\/p>\n

These are slow-moving disturbances traveling through the mantle \u2014 the layer beneath Earth’s crust \u2014 after tectonic plates begin to pull apart. The same research team previously linked mantle waves to diamond-bearing volcanic eruptions and puzzling episodes of continental uplift. To trace their role in Antarctica, researchers built computational models reconstructing 100 million years of landscape evolution in East Antarctica.<\/p>\n

The story starts in the Jurassic Period, between 201 and 143 million years ago<\/strong>, when Antarctica and Africa began separating. As that rift opened, mantle waves propagated beneath East Antarctica \u2014 and over tens of millions of years, gradually pushed the land upward, building a coastal escarpment, a high plateau, and the inland Gamburtsev Mountains.<\/p>\n

How mountains made ice possible in a warm world<\/h2>\n

Elevation is a quiet but powerful climate lever. Air temperature drops by up to 1.8\u00b0C for every 100 meters of altitude gained, which means even modest uplift can determine whether summer snow survives or melts away entirely<\/strong>.<\/p>\n

Before 50 million years ago, most of the Gamburtsev Mountains<\/a> sat below 1.5 km. By 34 million years ago, nearly half the range had risen above 2 km. That threshold matters. At those heights, even in a warmer world, snow could persist year-round and gradually accumulate. By around 45 million years ago, the models suggest, large parts of East Antarctica had already crossed that mark \u2014 mountain glaciers began forming, then merging, eventually seeding the East Antarctic Ice Sheet, now the largest on Earth. It holds enough frozen water to raise global sea levels by roughly 52 meters if it were to melt completely.<\/p>\n

Ice that cools itself: feedbacks that locked in the freeze<\/h2>\n

Once the ice sheet started growing, it didn’t need much outside help to keep going<\/strong>. Ice is bright. Its surface reflects sunlight back into space rather than absorbing it \u2014 a process called the ice-albedo effect<\/strong> \u2014 and researchers estimate this reflection reduced global temperatures by about 1.8\u00b0C on its own.<\/p>\n

A second feedback reinforced the cooling. Cold air holds less water vapor, and water vapor normally acts as an insulating layer around the planet. As Antarctica chilled, the atmosphere dried out, that insulation weakened, and temperatures dropped further still.<\/p>\n

Together, these feedbacks drove ice from the inland mountains outward toward the coast. The Arctic, meanwhile, sat at lower elevations<\/a>. Even as global cooling progressed, Northern Hemisphere landmasses lacked the geological precondition \u2014 the height \u2014 needed for large ice sheets to take hold<\/strong>. That wouldn’t change for another 30 million years.<\/p>\n

Rethinking what triggers an ice age<\/h2>\n

The findings suggest that climate forcing alone may not be enough to initiate glaciation. Declining CO2 can push the system toward cold, but without terrain raised to the right elevation, permanent ice may never gain a foothold. Earth’s interior, it turns out, may quietly prepare landscapes for major climate transitions long before the atmosphere acts.<\/p>\n

That reframing matters. It’s not just when<\/em> CO2 falls \u2014 it’s whether the ground beneath the ice is already high enough<\/strong>. The research could inform how scientists identify future tipping points in the climate system, and how they interpret ancient ice ages on Earth and potentially other planets.<\/p>\n

The ice sheet that defines Antarctica today \u2014 one of the most consequential features of Earth’s climate \u2014 may owe its existence to waves of pressure moving silently through rock over millions of years, long before the first glacier ever formed. The atmosphere got the credit. The deep Earth may have done the groundwork.<\/p>\n

The full version of the international research is available here: Thomas M. Gernon et al. <\/em><\/span>Continental breakup\u2013driven uplift instigated East Antarctic Ice Sheet formation.<\/span>Science<\/i><\/span>393<\/b>,<\/span>eadz6758<\/span>(2026).<\/span>DOI:10.1126\/science.adz6758<\/a><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Antarctica was blanketed in a massive ice sheet roughly 34 million years ago \u2014 while the Arctic remained largely ice-free until just five million years ago. That’s a 30-million-year gap, and it has puzzled climate scientists for decades. The world back then was around 9\u00b0F warmer than today. Yet one pole was already freezing over. …