Antarctica’s new river

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

Credits: Phys

• 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 Gondwana.
• After Gondwana’s 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.

Rio Grande River Location: North America. Origin: San Juan Mountains of Colorado, USA. Also known as Rio Bravo in Mexico, it flows into the Gulf of Mexico. As a border between the US and Mexico, it forms an entry point for illegal migrants.