Ancient Breakup of Gondwana May Explain Why Antarctica Became Covered in Ice

A new scientific study reveals that tectonic uplift triggered by the breakup of the Gondwana supercontinent more than 100 million years ago created the conditions that allowed Antarctica to become the ice-covered continent we see today.  

Antarctica was not always the frozen wilderness it is now. Hundreds of millions of years ago, it formed part of the Gondwana supercontinent, situated in a very different climate zone characterised by warm, humid conditions and dense tropical vegetation. Yet roughly 34 million years ago, glaciers began forming across East Antarctica, eventually expanding into the massive ice sheet that now covers nearly the entire continent. A new study published in the journal Science proposes a surprising explanation for this dramatic transformation: the geological aftershocks of Gondwana's breakup, more than 100 million years earlier, may have slowly lifted the continent's interior high enough for ice to take hold.

 

The research, led by Dr Thomas Gernon, an Earth scientist at the University of Southampton, draws on a striking parallel between East Antarctica and southern Africa. Both regions were once joined within Gondwana, and both share remarkably similar landscapes — steep escarpments leading up to vast, high-elevation plateaus. In southern Africa, these features are known to have formed from "mantle waves" — broad, slow upwellings of hot rock deep within the Earth — triggered by tectonic rifting as the supercontinent began splitting apart during the Jurassic period. Gernon noticed that the same process may have occurred beneath Antarctica, particularly in the region of the Gamburtsev Subglacial Mountains — a massive range buried entirely beneath the ice, long suspected to be the birthplace of the East Antarctic Ice Sheet.

 

Using computer models, the team demonstrated that these tectonic forces could have uplifted large portions of East Antarctica over tens of millions of years, raising the interior landscape to a critical elevation where snow and ice could survive year-round. Once that threshold was crossed, a powerful feedback loop kicked in: the reflective ice cooled the land surface, which encouraged even more ice to accumulate, eventually building the colossal ice sheet that exists today. The modelling suggests this process may have begun as early as 40 million years ago — earlier than many previous estimates — and explains why Antarctica developed a permanent ice cap before the Arctic did. "It's kind of inspiring to think that a tectonic chain reaction 100 million years ago could have an impact more recently," Gernon remarked. The findings also highlight how deeply Earth's present climate is connected to its geological past, with events hundreds of millions of years ago continuing to shape the planet we inhabit today.