Collaborative Research: Forty-Thousand Years of Yedoma: An investigation into the spatial heterogeneity and paleo-history of organic-rich permafrost in Alaska

合作研究的非技术特征：4万年的伊多玛(ARC 1107571)阿拉斯加富含有机物质的永久冻土的空间异质性和古史调查2011年在阿拉斯加福克斯附近挖掘了一条新的永久冻土隧道，高4米，长30米。它毗邻较老的广为人知的CRREL隧道。这条新隧道穿透了从现代到4万多年前的伊多玛(黄土或粉砂)沉积物。隧道的墙壁上美丽地暴露着一系列冰楔、热岩溶洞穴冰和古土壤，它们记录了自上一个冰河时代以来阿拉斯加中部的气候和生态历史。我们建议使用各种分析技术绘制和采样这些沉积物，包括广泛的AMS放射性碳测年，以揭示伊多玛形成期间的环境条件。我们将利用这些结果重建阿拉斯加中部地区的古气候和环境历史，在过去的4万年里，该地区足够寒冷，足以产生和支持永久冻土，但现在那里的永久冻土正在融化。预期的结果不仅将告诉我们阿拉斯加在这一关键时期的气候变化，而且还将告诉我们包括西伯利亚和加拿大在内的世界其他伊多玛地区的气候变化。这条新隧道将被用作地质学和环境工程专业学生的教室。

NON-TECHNICAL ABSTRACTforCollaborative Research: Forty-Thousand Years of Yedoma (ARC 1107571)An investigation into the spatial heterogeneity and paleo-history of organic-rich permafrost in AlaskaA new permafrost tunnel 4 m high and 30 m long was excavated near Fox, Alaska in 2011. It is adjacent to the older and widely known CRREL tunnel. The new tunnel penetrates yedoma (loess or silt) deposits ranging from modern to more than 40,000 years old. Beautifully exposed in the walls of the tunnel are a series of ice wedges, thermokarst-cave ice, and paleosols that record the climatic and ecological history of central Alaska since the last Ice Age. We propose to map and sample these sediments using a variety of analysis techniques, including extensive AMS radiocarbon dating to reveal environmental conditions during the yedoma formation. We will use the results to reconstruct the paleo-climatic and environmental history of the central Alaska region, a region that during the past 40,000 years has been cold enough to produce and support permafrost, but where now permafrost is thawing. The expected results will not only tell us about how climate has varied in Alaska during this critical period, but also in the other yedoma regions of the world which include Siberia and Canada. The new tunnel will be used as a classroom for students in geology and environmental engineering.