By Will Dunham
A team of researchers has solved the long-standing mystery of why the South Pole froze over before the North Pole. The scientists found that a powerful geological process drove the renewed uplift of a mountain range in eastern Antarctica, eventually passing an elevation threshold crucial for letting mountain glaciers form and expand, and for permanent ice to take hold.
Geological Process
The geological process, known as mantle waves, involves slow-moving disturbances deep within the Earth that are triggered during continental breakup. These waves can remove dense rock from the underside of tectonic plates, making the continents lighter and causing them to rise, ultimately forming high ground such as plateaus and mountain ranges.
When these mantle waves moved under Antarctica, they caused the formation of a large plateau topped by the Gamburtsev Mountains, a range in the central part of eastern Antarctica. While these mountains reach up to about 11,120 feet tall, the range is now buried under the world’s largest ice sheet.
Climate and Topography
The researchers said that the erosion and uplift caused by mantle waves gradually pushed the landscape to elevations high enough for ice to stabilize, even at a time of a warm global climate. The study’s simulations indicated that by around 45 million years ago, large areas of the eastern Antarctic landscape had ascended above the elevation threshold for facilitating permanent ice.
The situation differed in the Arctic, where glaciers waxed and waned over the past 50 million years but large ice sheets did not stabilize until less than 10 million years ago. There is no actual land at the North Pole, which means there was no terrain to reach the elevation threshold earlier to foster permanent ice.
Original reporting: Appleton, WI News Feed (HLL/CB) — read the source article.
