Shrinking glaciers, melting permafrost, and reduced sea ice all indicate rapid contraction of the Arctic cryosphere in response to present-day climate warming, a trajectory that is expected to continue, if not accelerate. The reaction of the Arctic cryosphere to past periods of climate variation can afford insight into its present and future behavior. Here, we examine a ∼12,000 year record of glacier fluctuations and meltwater variation associated with the Renland Ice Cap, East Greenland, that extends from the early Holocene thermal optimum through the cooling of the Little Ice Age to present. Sediment records from glacially fed lakes indicate rapid early Holocene deglaciation, with ice extent likely slightly smaller than at present by ∼9500 yr BP. Glacial activity resulted in occasional deposition of rock flour in the studied lakes in the early Holocene until at least ∼7500 yr BP. Rock flour is absent for much of the period ∼7000-4000 yr BP, suggesting ice extent generally was smaller than at present. However, thin layers of blue-gray clay throughout this period may indicate millennial-scale ice expansions, with Renland Ice Cap briefly reaching extents during cold phases that may have been similar to today. Glacial sediment deposition occurred again in the late Holocene at ∼3200–3400 yr BP and was followed by a brief glacial episode at ∼1340 yr BP and then a major event beginning shortly after ∼1050 yr BP. We infer that rock flour deposition in the lakes in the last millennium corresponds with advance of Renland glaciers to their Little Ice Age positions, marked by a fresh, gray drift limit. Radiocarbon dates of in situ plant remains adjacent to the present ice cap indicate a short relatively warm period ∼500 yr ago, when ice was within its AD 2011 limit, followed by glacier readvance. The general pattern of ice fluctuations in Renland is similar to that at other ice caps in the region, but also has important differences, including the preservation of a possible mid-Holocene record at times when lower-elevation ice caps in the Scoresby Sund region may have been absent. This finding reinforces the concept that examination of multiple geographic and geomorphologic settings is necessary for a full understanding of ice variations in a region.

冰川的萎缩，永冻层的融化以及海冰的减少，都表明北极冰冻圈响应当今的气候变暖而迅速收缩，这种趋势有望持续下去，甚至不会加速。北极冰冻圈对过去气候变化时期的反应可以洞悉其当前和未来的行为。在这里，我们研究了约12,000年与东格陵兰岛Renland冰帽相关的冰川波动和融水变化的记录，该记录从全新世早期的热最佳状态一直延伸到小冰期的冷却直至现在。冰河湖泊的沉积物记录表明，全新世早期冰川融化迅速，到9500年BP时，冰层面积可能比目前略小。冰川活动导致在全新世早期至至少约7500年BP之前偶尔在所研究的湖泊中沉积岩粉。约7000-4000年BP的大部分时间都没有岩粉，这表明冰块的面积通常比目前的要小。但是，在此期间，薄薄的蓝灰色黏土层可能表明千禧年规模的冰膨胀，Renland冰帽在寒冷时期短暂地达到了可能与今天相似的程度。冰川沉积物沉积在全新世晚期约3200-3400年BP发生，随后在约1340年BP发生了短暂的冰川事件，然后在约1050 BP之后不久发生了一次重大事件。我们推断，上一千年湖中的岩粉沉积与Renland冰川向小冰河时代的发展相对应，其特征是新鲜的 灰色漂移极限。的放射性碳日期与目前的冰盖相邻的原位植物残存表明大约500年前是一个相对较暖的时期，当时冰处于其公元2011年的限制之内，其次是冰川恢复。雷兰德（Renland）的冰层波动总体模式与该地区其他冰盖相似，但也存在重要差异，包括在斯科尔斯比桑德（Scoresby Sund）地区低海拔冰盖可能保留的时候，可能保留全新世中期记录。已经缺席了。这一发现强化了这样的概念，即必须全面检查多个地理和地貌环境，才能全面了解该地区的冰变化。