Ice-core evidence for widespread Arctic glacier retreat in the Last Interglacial and the early Holocene
Ice-core evidence for widespread Arctic glacier retreat in the Last Interglacial and the early Holocene
复制标题
末次间冰期和全新世早期北极冰川广泛退缩的冰芯证据
作者：
R. Koerner;D. Fisher
早期对格陵兰、南极和加拿大北极冰帽芯的各种成分的研究（Koerner，1989）表明，在最后一次间冰期，格陵兰冰盖遭受了大规模的退缩，加拿大冰帽完全融化。从那时起，建模就帮助支持了这种解释（Cuffey和马歇尔，2000年）。稳定同位素的冰芯记录，融化分层和化学从相同的加拿大冰芯，和其他人从俄罗斯北极岛屿，斯瓦尔巴群岛和格陵兰岛的证据，更温和的，但仍然是大量的，在全新世早期撤退。在许多岩心中，代表全新世前半期的剖面的δ 18 O负值（d值）较小，融化层的百分比高于最近沉积的冰，这表明温度比今天高1.3-3.5 ℃。考虑到今天的冰川平衡略为负值，它们在全新世早期的热量最大期肯定要负得多，导致了环极冰盖的退缩。证据表明，除了Academii Nauk冰帽外，俄罗斯北极岛屿和斯瓦尔巴特群岛的冰几乎已经消失。在加拿大北极地区，较大的加拿大冰盖退缩但幸存下来。在这一热极大期之后的冷却趋势促进了俄罗斯北极岛屿和斯瓦尔巴特群岛大部分冰盖的再膨胀和新的生长。
Abstract An early study of the various components of the Greenland, Antarctic and Canadian Arctic ice-cap cores (Koerner, 1989) suggested that during the last interglacial period, the Greenland ice sheet suffered massive retreat and Canadian ice caps melted completely. Since then, modeling has helped support this interpretation (Cuffey and Marshall, 2000). Ice-core records of stable isotopes, melt layering and chemistry from the same Canadian ice cores, and others from the Russian Arctic islands, Svalbard and Greenland are presented as evidence for a more modest, but still substantial, retreat in the early Holocene. the sections representing the first half of the Holocene in many cores have less negative δ18O values (d values) and a higher percentage of melt layers than recently deposited ice, suggesting that temperatures were 1.3–3.5˚C warmer than today. Given that glacier balances are slightly negative today, they must have been substantially more negative during the early-Holocene thermal maximum, leading to retreat of the circumpolar ice caps. Evidence is presented to suggest that, with the exception of Academii Nauk ice cap, the ice in the Russian Arctic islands and Svalbard must have almost disappeared. In the Canadian Arctic, the larger Canadian ice caps retreated but survived. the cooling trend that followed this thermal maximum promoted re-expansion and new growth of most of the ice caps in the Russian Arctic islands and Svalbard.