Humans were able to move south in North America through a frozen sea

2023-12-15 14:28:19

MADRID, 15 Dic. (EUROPA PRESS) –

Paleoclimatic reconstructions of the Pacific Northwest They hint that sea ice may have been an early way for humans from Asia to travel further south into North America.

One of the hottest debates in archeology is how and when humans first arrived in North America. Archaeologists have traditionally argued that people walked through an ice-free corridor that briefly opened between ice sheets about 13,000 years ago.

But a growing number of archaeological and genetic finds (including human footprints in New Mexico dating back about 23,000 years) suggests that people arrived on the continent much earlier.

Summer Praetorius of the US Geological Survey and her colleagues observed climate indicators in the area’s ocean sediments. Most of the data comes from tiny fossilized plankton, whose abundance and chemistry help reconstruct ocean temperatures, salinity, and ice cover. The results have been presented at the autumn meeting of the American Geophysicial Union (AGU).

Praetorious’ team used climate models and found that ocean currents were more than twice as strong as today during the height of the Last Glacial Maximum about 20,000 years ago due to glacial winds and lower sea levels. While not impossible, paddling against these conditions would have made boat travel very difficult, Praetorius said. it’s a statement.

However, records also showed that much of the area was home to winter sea ice until about 15,000 years ago. As a people adapted to the cold, “instead of having to row against this horrible glacial current, Maybe they were using the sea ice as a platform,” Praetorius said.

While proving that people used sea ice to travel will be difficult given that most archaeological sites are underwater, the theory provides a new framework for understanding how humans could have reached North America without a land bridge or an easy trip across the ocean.

And the sea ice highway It is not exclusive of other subsequent human migrations, says Praetorius. The team’s models show that the Alaska Current had calmed down by 14,000 years ago, making it easier for people to travel by boat along the coast.