The Ross Sea (Antarctica) is one of the most productive marine ecosystems in the Southern Ocean and supports nearly one million breeding pairs of Adélie penguins (Pygoscelis adeliae) annually. There also is a well-preserved record of abandoned penguin colonies that date from before the Last Glacial Maximum (>45,000 ¹⁴C yr B.P.) through the Holocene. Cape Irizar is a rocky cape located just south of the Drygalski Ice Tongue on the Scott Coast. In January 2016, several abandoned Adélie penguin sites and abundant surface remains of penguin bones, feathers, and carcasses that appeared to be fresh were being exposed by melting snow and were sampled for radiocarbon analysis. The results indicate the “fresh” remains are actually ancient and that three periods of occupation by Adélie penguins are represented beginning ca. 5000 calibrated calendar (cal.) yr B.P., with the last occupation ending by ca. 800 cal. yr B.P. The presence of fresh-appearing remains on the surface that are actually ancient in age suggests that only recently has snowmelt exposed previously frozen carcasses and other remains for the first time in ∼800 yr, allowing them to decay and appear fresh. Recent warming trends and historical satellite imagery (Landsat) showing decreasing snow cover on the cape since 2013 support this hypothesis. Increased δ¹³C values of penguin bone collagen further indicate a period of enhanced marine productivity during the penguin “optimum”, a warm period at 4000–2000 cal. yr B.P., perhaps related to an expansion of the Terra Nova Bay polynya with calving events of the Drygalski Ice Tongue.

中文翻译：

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南极洲罗斯海伊利扎尔角融雪揭示的古老阿德利企鹅殖民地

罗斯海（南极洲）是南部海洋中生产力最高的海洋生态系统之一，每年为近一百万对阿德利企鹅（Pygoscelis adeliae）繁殖提供支持。还有一个保存完好的废弃企鹅殖民地的记录，该记录可追溯到上次冰河最高峰（> 45,000 ^{14）之前。}Cyr BP）通过全新世。伊里萨尔角（Cape Irizar）是一个岩石海角，位于斯科特海岸（Scott Coast）的Drygalski冰舌的南边。2016年1月，几只废弃的Adélie企鹅遗址和看似新鲜的企鹅骨头，羽毛和尸体的大量表面残留物被融化的雪暴露，并进行了放射性碳分析采样。结果表明，“新鲜”的遗骸实际上是古老的，并且在大约公元3月开始代表了阿德利企鹅占领的三个时期。校准的5000日历年（cal。）yr BP，最后一个职业以ca为结尾。800卡路里 yr BP在表面上实际上是古老的新鲜残留物的存在表明，直到最近，融雪才暴露了先前冷冻的尸体和其他残留物，这是约800年以来的第一次，使它们腐烂并显得新鲜。自2013年以来，最近的变暖趋势和历史卫星图像（Landsat）证明了海角积雪的减少，支持了这一假设。δ增加企鹅骨胶原蛋白的¹³ C值进一步表明，在企鹅“最佳”时期，即4000-2000 cal的温暖时期，海洋生产力有所提高。BP，也许与Terradryski冰舌破裂的事件导致Terra Nova Bay的polynya扩张有关。