A regional-scale climate reconstruction of the last 4000 years from lakes in the Nebraska Sand Hills, USA

QUATERNARY SCIENCE REVIEWS

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Article

Schmieder, J.¹  Fritz, S. C.¹  Swinehart, J. B.²  Shinneman, A. L. C.¹  Wolfe, A. P.³  Miller, G.^4,5  Daniels, N.^4,5  Jacobs, K. C.¹  Grimm, E. C.⁶ 

[1] Univ Nebraska, Dept Earth & Atmospher Sci, Lincoln, NE 68588 USA

[2] Univ Nebraska, Sch Nat Resources, Lincoln, NE 68588 USA

[3] Univ Alberta, Dept Earth & Atmospher Sci, Edmonton, AB T6G 2E3, Canada

[4] Univ Colorado, Inst Arctic & Alpine Res, Boulder, CO 80309 USA

[5] Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA

[6] Res & Collect Ctr, Illinois State Museum, Springfield, IL 62703 USA

关键词: Nebraska Sand Hills;    Droughts;    Lakes;    Diatoms;    Holocene;    Great Plains;    Paleolimnology;   

DOI  :  10.1016/j.quascirev.2011.04.011

来源: Elsevier

【 摘 要 】

High-resolution paleohydrological reconstructions were carried out in five shallow lakes in the Nebraska Sand Hills across an east-west transect in order to 1) determine whether long-term droughts of the past 4000 years were spatially and temporally coherent across the region, 2) distinguish local variation in climate or hydrology from regional patterns of change, and 3) compare the paleolimnological results with the existing dune-inferred drought records. Diatom-inferred lake-level was reconstructed for all sites and compared with other regional records. Alterations between high and low lake-levels were frequent during the past 4000 years, which suggests that shifts between dry and wet periods were prevalent across the Sand Hills. Extended multi-decadal to centennial-scale droughts were more common prior to 2000 years BP, while the last two millennia were hydrologically more variable and climate conditions alternated on shorter timescales. Despite some discrepancies among the five records, the paleohydrological reconstructions refine the Holocene drought history of the Nebraska Sand Hills, particularly between similar to 2200 and 4000 cal a BP. Many of the observed drought events are contemporaneous with severe droughts documented at sites in the northern Great Plains and Rocky Mountains, lending support for the severity and regional significance of these events in western North America. (C) 2011 Elsevier Ltd. All rights reserved.

【 授权许可】

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