Beringia

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The development of Beringia began 21,000 years ago until today

Beringia is the name for the region between Eastern Siberia and Alaska , which fell dry several times during the Pleistocene due to the decline in global sea levels and was also free of ice . The corresponding land bridge , which allowed fauna to be exchanged between the Old World and America , is also called the Bering Bridge . During the last glacial period , people lived there for several thousand years. It was only when the sea level rose that people migrated from there to the southeast, which resulted in the colonization of America .

In Whitehorse , its own museum and a small research department in the Yukon Beringia Interpretive Center deals with Beringia and the area in eastern Alaska and the Yukon, which was also ice-free during the last glacial period .

geography

Beringia was located on the site of today's Bering Strait , the northern end of the Bering Sea , and was thus between the west coast of today's Alaska ( USA ) and the east coast of today's Eastern Siberia ( Russia ). The land bridge was part of an extensive ice-free area that stretched from the Lena River in eastern Siberia to the Mackenzie River in Canada and occupied part of what is now the Arctic Ocean .

history

Until about 11,000 years ago, when the last glacial period ended and the sea level was a little more than 50 meters lower than it is today because of the continental ice masses that bound a lot of water from the oceans , was at the northern end of the Bering Sea (today's Bering Strait ) the continuous Beringia land bridge that connected America and Asia.

The woolly mammoth calf "Dima" at the place where it was found on the Kolyma in Northeast Siberia. A worker found the excellently preserved ice carcass in 1977 while mining for gold.

During the peak of the last glacial period around 20,000 years ago, the sea level was even around 125 m lower, so that a hilly landscape around 40 to 50 km wide and up to 85 km long connected the two mainlands . There a grass steppe developed with the specific characteristics of a mammoth steppe .

The first immigrants came to America via this land bridge . Back then, today's Bering Strait was a fertile grassy landscape that was populated by large animals such as mammoth , woolly rhinoceros , reindeer and musk ox . It is believed that the ancestors of the indigenous peoples of North and South America followed the huge herds and also reached the New World. In order to explain the time difference between the departure in Asia around 25,000 years ago and the arrival in America around 15,000 years ago, a long stay in the area of ​​Beringia is discussed. The reason for the delayed migration is the heavy glaciation in America and the particular suitability of Beringia for human settlement, because climatic factors resulted in tundra- like vegetation that offered trees and thus firewood.

Due to the ice advances and retreats and the associated changes in sea level over the past 140,000 years, it is likely that Beringia emerged from the floods and sank several times during this period.

Web links

Commons : Bering Bridge  - Collection of images, videos and audio files

literature

  • Frederick H. West (Ed.): American Beginnings: The Prehistory and Palaeoecology of Beringia. University of Chicago Press, 1996, ISBN 978-0-226-89399-0 .

swell

  1. with scatter of the values ​​based on various methods and indicators between 13,400 and 10,000 calibrated C-14 years for the minimum values ​​and between 13,100 and 10,800 calibrated C-14 years for the minimum values, see Martin Jakobsson, Christof Pearce, Thomas M. Cronin and 13 other authors: Post-glacial flooding of the Bering Land Bridge dated to 11 cal ka BP based on new geophysical and sediment records. In: Climate of the Past. Vol. 13, 2017, pp. 991-1005, doi: 10.5194 / cp-13-991-2017
  2. Ute Kehse: The end of Beringia. Wissenschaft.de, October 17, 2006, based on: Lloyd D. Keigwin, Jeffrey P. Donnelly, Mea S. Cook, Neal W. Driscoll, Julie Brigham-Grette: Rapid sea-level rise and Holocene climate in the Chukchi Sea. In: Geology. Vol. 34, 2006, pp. 861–864, doi: 10.1130 / G22712.1 (alternative full text access : ResearchGate )
  3. ^ A b John F. Hoffecker, Scott A. Elias, Dennis H. O'Rourke: Out of Beringia? In: Science , Vol. 343, No. 6174 (February 28, 2014) pages 979-980, doi: 10.1126 / science.1250768
  4. Aixue Hu, Gerald A. Meehl, Bette L. Otto-Bliesner, Claire Waelbroeck, Weiqing Han, Marie-France Loutre, Kurt Lambeck, Jerry X. Mitrovica, Nan Rosenbloom: Influence of Bering Strait flow and North Atlantic circulation on glacial sea -level changes. In: Nature Geoscience. Vol. 3, No. 2, 2010, pp. 118–121, doi: 10.1038 / ngeo729 (alternative full text access : ResearchGate )
  5. ^ M. Meiri, AM Lister, MJ Collins, N. Tuross, T. Goebel, S. Blockley, GD Zazula, N. Van Doorn, R. Dale Guthrie, GG Boeskorov, GF Baryshnikov, A. Sher, I. Barnes: Faunal record identifies Bering isthmus conditions as constraint to end-Pleistocene migration to the New World. In: Proceedings of the Royal Society B: Biological Sciences. Vol. 281, No. 1776, 2013, Item No. 20132167, doi: 10.1098 / rspb.2013.2167 , PMC 3871309 (free full text)