Ice wedges are ubiquitous periglacial features in permafrost terrain. This study investigates the timing of ice wedge formation in the Fosheim Peninsula (Ellesmere and Axel Heiberg Islands). In this region, ice wedge polygons occupy ~50% of the landscape, the majority occurring below the marine limit in the Eureka Sound Lowlands. Numerical simulations suggest that ice wedges may crack to depths of 2.7–3.6 m following a rapid cooling of the ground over mean winter surface temperatures of −18°C to −38°C, corresponding to the depth of ice wedges in the region. The dissolved organic carbon (DOC)/Cl molar ratios suggest that the DOC in the ice wedges is sourced from snowmelt and not from leaching of the active layer. Based on 32 14CDOC measurements from 15 ice wedges, the wedges were likely developing between 9000–2500 cal yr BP. This interval also corresponds to the period of peat accumulation in the region, a proxy of increased moisture. Considering that winter air temperatures remained favorable for ice wedge growth throughout the Holocene, the timing of ice wedge formation reflects changes in snowfall. Overall, this study provides the first reconstruction of ice wedge formation from a high Arctic polar desert environment.

中文翻译：

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加拿大北极高地尤里卡海峡低地的全新世冰楔形成

冰楔是永久冻土地形中普遍存在的冰缘特征。本研究调查了福斯海姆半岛（Ellesmere 和 Axel Heiberg 群岛）冰楔形成的时间。在该地区，冰楔多边形占据了约 50% 的景观，其中大部分发生在尤里卡海峡低地的海洋界限以下。数值模拟表明，在冬季平均表面温度为 -18°C 至 -38°C 的情况下，冰楔可能会破裂至 2.7-3.6 m 的深度，这与该地区冰楔的深度相对应。溶解有机碳 (DOC)/Cl 摩尔比表明冰楔中的 DOC 来自融雪而不是来自活性层的浸出。基于 3214C文档从 15 个冰楔的测量结果来看，这些楔很可能在 9000-2500 cal yr BP 之间形成。该间隔也对应于该地区泥炭积累的时期，即水分增加的代表。考虑到整个全新世冬季气温仍然有利于冰楔的生长，冰楔形成的时间反映了降雪的变化。总体而言，这项研究首次重建了北极高地极地沙漠环境中的冰楔形成。