格陵兰岛东北部更新世中期温和湿润气候的洞穴沉积物记录

Speleothem record of mild and wet mid-Pleistocene climate in northeast Greenland.

作者信息

Moseley G E, Edwards R L, Lord N S, Spötl C, Cheng H

机构信息

Institute of Geology, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria.

Isotope Geochemistry Laboratory, School of Earth and Environmental Sciences, University of Minnesota, John T. Tate Hall, 116 Church Street SE, Minneapolis, MN 55455, USA.

出版信息

Sci Adv. 2021 Mar 24;7(13). doi: 10.1126/sciadv.abe1260. Print 2021 Mar.

DOI:10.1126/sciadv.abe1260

PMID:33762333

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7990333/

Abstract

The five interglacials before the Mid-Brunhes Event (MBE) [c.430 thousand years (ka) ago] are generally considered to be globally cooler than those post-MBE. Inhomogeneities exist regionally, however, which suggest that the Arctic was warmer than present during Marine Isotope Stage (MIS) 15a. Using the first speleothem record for the High Arctic, we investigate the climatic response of northeast Greenland between c.588 and c.549 ka ago. Our results indicate an enhanced warmth of at least +3.5°C relative to the present, leading to permafrost thaw and increased precipitation. We find that δO of precipitation was at least 3‰ higher than today and recognize two local cooling events (c.571 and c.594 ka ago) thought to be caused by freshwater forcing. Our results are important for improving understanding of the regional climatic response leading up to the MBE and specifically provide insights into the climatic response of a warmer Arctic.

摘要

布容期中事件（MBE）[约43万年前]之前的五次间冰期通常被认为全球比MBE之后的间冰期更冷。然而，区域存在不均匀性，这表明在海洋同位素阶段（MIS）15a期间北极比现在更温暖。利用高北极地区的首个洞穴石笋记录，我们研究了约58.8至54.9千年前格陵兰东北部的气候响应。我们的结果表明，相对于现在，温度至少升高了3.5°C，导致永久冻土融化和降水量增加。我们发现，降水的δO比今天至少高3‰，并识别出两次局部降温事件（约57.1和59.4千年前），认为是由淡水强迫引起的。我们的结果对于增进对MBE之前区域气候响应的理解很重要，特别是为更温暖北极的气候响应提供了见解。