Antarctica became covered in ice around 34 million years ago, while the Arctic region remained largely ice-free for another 25 million years. This significant difference in timing has puzzled scientists, especially given the dramatic fall in atmospheric carbon dioxide levels during that period. A recent study published in Science provides insights into the geological forces at play beneath the ice sheets.
Understanding Antarctica's Ice Formation
The formation of the East Antarctic Ice Sheet is a key mystery. During the Eocene-Oligocene transition, atmospheric conditions changed, but Antarctica's glaciers began forming earlier than those in the Arctic. According to researchers, the Earth’s cooling was not the only factor; geological processes contributed significantly.
In their research, scientists found that around 170 million years ago, the breakup of the supercontinent Gondwana initiated a series of geological changes. As Antarctica drifted towards the South Pole, hot mantle material rose beneath the continent, causing instability and geological phenomena known as mantle waves.
The Role of Mantle Waves in Ice Sheet Formation
These mantle waves can lead to volcanic eruptions and uplift land far from the original rift zones. Research indicates that these waves played a critical role in shaping East Antarctica's landscape. The uplift caused by mantle waves created a plateau, which facilitated the retention of snow and ice.
