(ORDO NEWS) — The land bridge between Asia and America appeared much later than is commonly believed.
This conclusion was made by scientists from the University of California at Santa Cruz (USA), after reconstructing historical sea levels in the Bering Strait.
The last glacial maximum occurred 26,500 – 19 thousand years ago. Ice sheets covered a large area of ​​North America.
The sea level dropped sharply, and land called Beringia appeared on the surface – a land bridge that ran from Siberia to Alaska.
As the ice sheets melted, the Bering Strait flooded again. This happened 13 – 11 thousand years ago.
In a new study, scientists analyzed nitrogen isotopes from bottom sediments. The results were then combined with computer sea level models.
This made it possible to determine in what periods over the past 46 thousand years Beringia was under water.
The results of scientific work showed that the Bering Bridge arose 35,700 years ago, 10 thousand years before the onset of the peak of the ice age.
The rise in ice sheets and the associated drop in sea levels occurred unusually quickly and at a later stage in the glacial cycle than previous theories suggested.
The study allows a different look at the timing of migration to America. Scientists noted that not only herds of horses and mammoths, but also ancient people moved to new lands along the land bridge.
The new data says that the settlement could have occurred in a later era.
In addition, the results demonstrate complex feedbacks between climate and ice cover. So, ice sheets were formed far from immediately after it got colder on Earth.
The average global sea level during the ice age was 130 meters lower than the current one.
But the actual level in specific places depended on a number of factors, in particular, the deformation of the earth’s crust under the weight of ice sheets.
The analysis of such mechanisms will be useful for assessing the state of modern glaciers and the prospects for their melting.
—
Online:
Contact us: [email protected]
Our Standards, Terms of Use: Standard Terms And Conditions.