Abrupt changes in North American climate during early Holocene times

F. S. Hu (), D. Slawinski, H. E. Wright, E. Ito, R. G. Johnson, K. R. Kelts, R. F. McEwan and A. Boedigheimer
Additional contact information
F. S. Hu: University of Illinois
D. Slawinski: University of Minnesota
H. E. Wright: University of Minnesota
E. Ito: University of Minnesota
R. G. Johnson: University of Minnesota
K. R. Kelts: University of Minnesota
R. F. McEwan: University of Minnesota
A. Boedigheimer: University of Minnesota

Nature, 1999, vol. 400, issue 6743, 437-440

Abstract: Abstract Recent studies of the Greenland ice cores have offered many insights into Holocene climatic dynamics at decadal to century timescales1,2,3. Despite the abundance of continental records of Holocene climate, few have sufficient chronological control and sampling resolution to compare with the Greenland findings4. Butannually laminated sediments (varves) from lakes can provide high-resolution continental palaeoclimate data with secure chronologies. Here we present analyses of varved sediments from Deep Lake in Minnesota, USA. Trends in the stable oxygen-isotope composition of the sedimentary carbonate indicate a pronounced climate cooling from 8.9 to 8.3 kyr before present, probably characterized by increased outbreaks of polar air, decreased precipitation temperatures, and a higher fraction of the annual precipitation falling as snow. The abrupt onset of this climate reversal, over several decades, was probably caused by a reorganization of atmospheric circulation and cooling of the Arctic airmass in summer that resulted from the final collapse of the Laurentide ice near Hudson Bay and the discharge of icebergs from the Quebec and Keewatin centres into the Tyrell Sea. The timing and duration of this climate reversal suggest that it is distinct from the prominent widespread cold snap that occurred 8,200 years ago in Greenland and other regions1,5,6. No shifts in the oxygen-isotope composition of sediment carbonate occurred at 8.2 kyr before present at Deep Lake, but varve thickness increased dramatically, probably as a result of increased deposition of aeolian dust. Taken together, our data suggest that two separate regional-scale climate reversals occurred between 9,000 and 8,000 years ago, and that they were driven by different mechanisms.

Date: 1999
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/22728 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:400:y:1999:i:6743:d:10.1038_22728

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/22728

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().