Mantle waves helped freeze Antarctica 34 million years ago

New geophysical research suggests that mantle waves from deep within the Earth played a decisive role in the formation of Antarctica’s permanent ice sheet approximately 34 million years ago.

While previous theories focused on declining atmospheric CO2 levels and changes in ocean currents, computational modeling indicates that slow-moving waves in the Earth's mantle caused significant topographic shifts. These waves, triggered by the separation of tectonic plates, lifted parts of the Antarctic surface by hundreds of meters.

Specifically, the research shows that as the landscape rose above a critical elevation threshold of roughly two kilometers, air temperatures dropped sufficiently to allow snow to accumulate and persist through summer months. This process enabled the continent to develop a massive ice sheet even while global temperatures were significantly warmer than they are today.