Antarcticas new river

Antarctica’s new river

Context: A recently discovered ancient river in Antarctica is providing new insights into the continent’s climatic history.

• This river system was buried under ice for millions of years and offers a unique window into the past.
• The river’s channels stretch over 680 miles (Similar to the Rio Grande River in the U.S.).
• Until 100 million years ago, Antarctica constituted the central part of the supercontinent Gondwanan.
• After Gondwanan breakup, Antarctica established itself as an independent continent.

West Antarctica

• Also known as Lesser Antarctica, it is located in the Western Hemisphere.
• It is separated from East Antarctica by the Transantarctic Mountains, covered by a massive ice sheet.
• This mountain range has been uplifting since the late Eocene as the steep shoulder of a continental rift, the West Antarctic Rift System.

Inferences from findings

• Evidence suggested that West Antarctica was a river delta or estuary 34 to 44 million years ago (Eocene).
• It suggests that Antarctica once had a milder climate, with conditions that could support flowing water.
• The existence of such a transcontinental river system shows that – unlike today – large parts of West Antarctica must have been located above sea level as extensive, flat coastal plains.
• Due to the low topography, West Antarctica was still ice-free at the end of the Eocene, while the mountainous regions of East Antarctica were already beginning to glaciate.
• Uplift and erosion of the Transantarctic Mountains have since produced erosion debris.
• The newly discovered river transported more than 1,500 km through the West Antarctic Rift System into the Amundsen Sea and deposited it as a swampy river delta.