Antarctic-like temperature variations in the Tropical Andes recorded by glaciers and lakes during the last deglaciation

QUATERNARY SCIENCE REVIEWS

卷:247

Review

Martin, L. C. P.^1,2  Blard, P-H^1,3  Lave, J.¹  Jomelli, V^4,5  Charreau, J.¹  Condom, T.⁶  Lupker, M.⁷ 

[1] Univ Lorraine, Ctr Rech Petrograph & Geochim, CNRS, F-54000 Nancy, France

[2] Univ Oslo, Dept Geosci, POB 1047, N-0316 Oslo, Norway

[3] Univ Libre Bruxelles, Lab Glaciol, DGES IGEOS, B-1050 Brussels, Belgium

[4] Univ Paris 1 Pantheon Sorbonne, CNRS Lab Geog Phys, Meudon, France

[5] Aix Marseille Univ, CNRS IRD Coll France INRAE, UM CEREGE 34, Aix En Provence, France

[6] Univ Grenoble Alpes CNRS, Inst Geosci Environm IGE UMR, G INP, CNRS,IRD, F-5001 Grenoble, France

[7] ETH, Geol Inst, Sonneggstr 5, CH-8092 Zurich, Switzerland

关键词: Paleoclimate dynamics;    Tropical Andes;    Paleoglaciers;    Cosmogenic nuclides;    Be-10;    He-3;    Glacial geomorphology;    Last deglaciation;    Termination 1;    Continental paleotemperature and precipitation reconstruction;    Global and regional climate;   

DOI  :  10.1016/j.quascirev.2020.106542

来源: Elsevier

【 摘 要 】

The respective impacts of Northern and Southern Hemispheric climatic changes on the Tropics during the last deglaciation remain poorly understood. In the High Tropical Andes, the Antarctic Cold Reversal (ACR, 14.3-12.9 ka BP) is better represented among morainic records than the Younger Dryas (12.9-11.7 ka BP). However, in the Altiplano basin (Bolivia), two cold periods of the Northern Hemisphere (Heinrich Stadial la, 16.5-14.5 ka BP, and the Younger Dryas) are synchronous with (i) major advances or standstills of paleoglaciers and (ii) the highstands of giant paleolakes Tauca and Coipasa. Here, we present new cosmic ray exposure (CRE) ages from glacial landforms of the Bolivian Andes that formed during the last deglaciation (Termination 1). We reconstruct the equilibrium line altitudes (ELA) associated with each moraine and use them in an inverse algorithm combining paleoglaciers and paleolake budgets to derive temperature and precipitation during the last deglaciation. Our temperature reconstruction (AT relative to present day) yields a consistent regional trend of progressive warming from Delta T = -5 to -2.5 degrees C during 17-14.5 ka BP, followed by a return to colder conditions around -4 degrees C during the ACR (14.5-12.9 ka BP). The Coipasa highstand (12.9-11.8 ka BP) is coeval with another warming trend followed by AT stabilization at the onset of the Holocene (ca. 10 ka BP), around -3 degrees C. Our results suggest that, during the last deglaciation (20-10 ka BP) atmospheric temperatures in the Tropical Andes mimicked Antarctic variability, whereas precipitation over the Altiplano was driven by changes in the Northern Hemisphere. (C) 2020 Elsevier Ltd. All rights reserved.

【 授权许可】

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