XPost: sci.archaeology
https://www.wionews.com/science/study-suggests-first-people-reached-north-america-via-sea-ice-highway-around-24000-years-ago-670564
...
Research presented on December 15 at the American
Geophysical Union Annual Meeting (AGU23) suggests
that sea ice may have been one way for people to
move thousands of years ago.
While the idea that early Americans may have
travelled along the Pacific Coast isn’t new,
the conditions were not exactly favourable. In
2020, researchers noted that freshwater from
melting glaciers at the time may have created
a strong current which would make it difficult
for people to travel along the coast.
In line with this, Summer Praetorius the United
States Geological Survey (USGS) and her team
tried to study climate proxies in ocean sediment
from the coast. Archaeologists have previously
found evidence of coastal settlements as early
as 14,000 years ago.
Praetorious’ team found that ocean currents were
twice the strength they are today at the height
of the last glacial maximum around 20,000 years
ago due to glacial winds and lower sea levels,
conditions which would have made travelling by
boat nearly impossible.
Therefore, Praetorius suggests that since people
back then who were adapted to the cold, would
“rather than having to paddle against this
horrible glacial current, maybe they were using
the sea ice as a platform.” Similar to how people
living in the Arctic travel along sea ice on dog
sleds and snowmobiles.
Early Americans could have used the ‘sea ice
highway’ to get around and hunt marine mammals,
slowly making their way into North America in
the process, said Praetorius.
...
https://agu.confex.com/agu/fm23/meetingapp.cgi/Paper/1323023
PP51A-05 Did a “Sea-ice Highway” facilitate early
human migration from Beringia into North America
along the coastal route?
Abstract
Mounting evidence from archaeological sites in
the Americas suggests humans had arrived in North
America by at least 16 ka, and possibly as early
the last glacial maximum (LGM; 26.5-19 ka). This
time window would require populations stemming
from Beringia or Northeast Asia arrived via the
Pacific coast, as the interior route was blocked
by the merged Laurentide and Cordilleran ice
sheets between ~26 and 14 ka. However,
environmental conditions along the Cordilleran
coastal corridor would have been challenging
during the late Pleistocene, and it remains
unclear whether the coastal route was passable
throughout this period, or if there were times
when movement was blocked by marine-terminating
glaciers, strong ocean currents, and/or prolonged
sea ice conditions. Here we assemble multi-proxy
paleoceanographic data with model simulations to
shed light on the ocean and climate conditions in
the North Pacific during the late Pleistocene to
assess viable time periods in which humans could
have traversed the Cordilleran coastal corridor.
We find that the cyclonic currents along the
Alaskan margin would have been strengthened
during the LGM and times of enhanced meltwater
input, making southward transit by boat more
difficult. We infer that the Cordilleran
ice-surge episodes (“Siku events”) would have
been particularly challenging for coastal
migration due to regional cooling, abundant
icebergs, and strong coastal currents, possibly
creating episodic (1-2 kyr) barriers to southward
transit. Given the prevalence of seasonal sea
ice throughout the LGM and early deglacial period,
we suggest that stable winter sea ice may have
acted as a platform that facilitated early
coastal migrations into the Americas. Viable
time periods for this scenario would likely have
occurred intermittently between the Siku events
when intermediate sea-ice conditions prevailed
and unglaciated coastal refugia were available
along the Alaskan margin. We identify 24.5-22 ka
and 16.4-14.8 ka as the most likely time periods
to accommodate early migration along the Alaskan
coast, possibly aided by movement and
subsistence on a “Sea-ice Highway.”
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