Similar Holocene glaciation histories in tropical South America and Africa
Similar Holocene glaciation histories in tropical South America and Africa
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DOI：
10.1130/g48059.1
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发表时间：
2021-02
期刊：
影响因子：
5.8
通讯作者：
A. Vickers;J. Shakun;B. Goehring;A. Gorin;M. Kelly;M. Jackson;A. Doughty;J. Russell
中科院分区：
文献类型：
--
作者：
A. Vickers;J. Shakun;B. Goehring;A. Gorin;M. Kelly;M. Jackson;A. Doughty;J. Russell
在过去的一个世纪里，热带冰川随着变暖而退缩，然而这些趋势在长期地质背景下的适应方式在很大程度上是不清楚的。在这里，我们根据最近暴露的基岩的14c和10Be测量数据，重建了秘鲁的Quelccaya冰盖和乌干达的Rwenzori山脉相对于今天的全新世冰川范围。这两个地点的冰范围历史相似，表明在全新世上半叶，冰通常比今天小，而在过去几千年的大部分时间里，如果不是全部的话，冰比今天大。南美洲和非洲相似的冰川历史表明，全新世晚期热带地区的大规模变暖和变冷主要驱动了冰的范围，而不是降水的区域变化。我们的结果还表明，最近的热带冰退缩在几千年的背景下是反常的。
Tropical glaciers have retreated alongside warming temperatures over the past century, yet the way in which these trends fit into a long-term geological context is largely unclear. Here, we present reconstructions of Holocene glacier extents relative to today from the Quelccaya ice cap (Peru) and the Rwenzori Mountains (Uganda) based on measurements of in situ14C and 10Be from recently exposed bedrock. Ice-extent histories are similar at both sites and suggest that ice was generally smaller than today during the first half of the Holocene and larger than today for most, if not all, of the past several millennia. The similar glaciation history in South America and Africa suggests that large-scale warming followed by cooling of the tropics during the late Holocene primarily drove ice extent, rather than regional changes in precipitation. Our results also imply that recent tropical ice retreat is anomalous in a multimillennial context.