Several studies have analyzed the ice margin behavior of the Quelccaya Ice Cap (QIC), Earth's largest tropical ice cap, through the Holocene. However, continuous integration of new information to produce a more cohesive history of the QIC is necessary. Here, the radiocarbon dates of 33 rooted plant specimens collected in situ along the western ice margin between 2002 and 2018 reveal the timing of its past extent as it advanced during the mid-Holocene. The most recent evaluation of collected specimens indicates that the QIC margin advanced ∼350 m down the Challpacocha Valley between 7.1 and 4.5 ka BP. Past studies of documented ice extent on the western side of the QIC based on a variety of techniques are compiled to create a more comprehensive history of the QIC's behavior throughout the Holocene. Records of documented ice extent, as well as other proxy records, indicate a climate transition ∼5–7 ka BP that created the proper environmental conditions for the expansion of the QIC. Evidence from nearby valleys indicates that the QIC behaved similarly to the documented ice extent in the Challpacocha Valley in response to Holocene climatic fluctuations. The ability to collect the plant specimens and recent analysis of satellite imagery reveals rapid retreat rates of the western outlet glaciers from 1985 to 2020, leaving the western margin of the QIC at its smallest extent since the mid-Holocene.

中文翻译：

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14 世纪植被的独特收藏揭示了秘鲁奎尔卡亚冰盖的全新世中期波动

几项研究分析了地球上最大的热带冰盖奎尔卡亚冰盖（QIC）在全新世期间的冰缘行为。然而，不断整合新信息以产生更具凝聚力的 QIC 历史是必要的。这里，2002 年至 2018 年间沿西部冰缘原位采集的 33 个有根植物样本的放射性碳测年结果揭示了其在全新世中期向前延伸的时间。对收集样本的最新评估表明，QIC 边缘在 7.1 至 4.5 ka BP 之间沿 Challpacocha 山谷推进了约 350 m。过去基于各种技术对 QIC 西侧记录的冰范围进行的研究被汇编起来，以创建 QIC 在整个全新世行为的更全面的历史。记录的冰范围记录以及其他代理记录表明，大约 5-7 ka BP 的气候转变为 QIC 的扩张创造了适当的环境条件。来自附近山谷的证据表明，QIC 的行为与查尔帕科查山谷记录的冰范围相似，以响应全新世的气候波动。收集植物标本的能力和最近对卫星图像的分析表明，从 1985 年到 2020 年，西部出口冰川的退缩速度很快，使得 QIC 的西部边缘处于自全新世中期以来的最小范围。