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

点击翻译按钮获取中文摘要

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.