Ice Bridges and Early Travel in North America

The question of how and when humans arrived in North America has fueled heated debates in archaeology. While the traditional theory posits a land bridge migration around 13,000 years ago, recent discoveries, including 23,000-year-old footprints in New Mexico, have reignited the discussion. A new study, presented at the American Geophysical Union Annual Meeting, proposes sea ice as a potential route for ancient human migration.

Traditional Land Bridge Theory

• Land Bridge Migration: Historically, it was believed that Stone Age hunters migrated from eastern Siberia to western Alaska across a land bridge around 13,000 years ago.
• Ice-Free Corridor: The hunters then traversed an ice-free corridor that briefly opened between ice sheets.

Sea Ice as a Pathway

Challenging Coastal Conditions:

• Previous Challenges: In 2020, researchers suggested that melting glacier freshwater created strong currents, making coastal travel difficult for early Americans.
• Study by Praetorius: Summer Praetorius and her team aimed to study climate proxies in ocean sediment to understand ancient conditions.

Research Findings

Ocean Current Strength

• Last Glacial Maximum (20,000 years ago): Praetorius’ team found that ocean currents were twice as strong as today due to glacial winds and lower sea levels.
• Barrier to Boat Travel: Strong currents would have made boat travel nearly impossible along the coast.

Sea Ice Platform

• Alternative Travel Method: Praetorius proposes that people adapted to the cold might have used sea ice as a platform instead of paddling against the strong glacial current.
• Similar to Arctic Travel: Analogous to how Arctic residents use sea ice for travel using dog sleds or snowmobiles.

Implications for Human Migration

• Sea Ice Highway: Early Americans could have utilized a ‘sea ice highway’ to navigate and hunt marine mammals, gradually moving into North America.
• Difficult to Prove: Proving this theory is challenging as many archaeological sites are underwater, but it offers a new framework for understanding ancient migration.

Compatibility with Other Migrations

• Not Exclusive: Praetorius notes that the sea ice highway theory does not exclude other human migrations. Models suggest that the Alaskan current calmed down by 14,000 years ago, enabling boat travel along the coast.

Month: Current Affairs - December, 2023

Category: Science & Technology Current Affairs