Collaborative Research: Investigation of Paleoenvironment, Geomorphic Processes, and Carbon Stocks of Drained Thaw-Lake Basins, Arctic Coastal Plain, Alaska

这是威斯康星-麦迪逊大学和辛辛那提大学的主要研究人员的合作建议。大约20%的北极沿海平原被融化湖覆盖，这些融化湖是在富含冰的永久冻土层上形成的，而这一景观的更大比例也被排干的融化湖盆地所破坏，这些盆地成为有机碳作为泥炭矿床积累的场所。在2000年至2002年期间在巴罗半岛所做的工作的基础上，主要研究人员将研究融冰湖盆地的起源以及相关的地貌、生物和土壤学过程。高分辨率多光谱卫星数据将量化沿海平原湖泊和排水融湖盆地的大小频率分布，并得出其形态特征。此外，将选择干涸的湖泊盆地进行巴罗和阿特卡苏克之间的密集地面分析。pi将利用植被选择相同数量的年轻、中期、年老和古老的排水融湖盆地。探地雷达和广泛的冬季土壤取心将用于绘制下垫湖沉积物与排水后有机沉积物之间的不整合面。结合卫星影像确定面积尺度，估算40个盆地内的有机物体积，确定有机层和上部湖相沉积物中土壤碳储量。这些结果将估算出在排水盆地中封存的碳量。对碎屑湖盆沉积物上方的原位泥炭进行放射性定年，可以估计湖泊排水和湖盆形成的年代。有证据表明，这些事件可能与气候变化有关，而其他湖泊则因海岸侵蚀而干涸。利用古生态指标重建全新世海岸带平原植被和土壤对气候的时空响应。高频岩心定年法将用于得出碳积累速率、有机土壤化学和分解状态，以确定碳积累速率是否对区域气候变化作出反应，还是在更大程度上受到当地植物演替速率的影响。对融冰湖流域进行广泛的时空分析将1)加深我们对阿拉斯加北部景观中这些重要元素的基本过程的理解，2)提供景观尺度对气候变化响应的新信息，3)有助于开发和验证环境变化和碳封存的因果模型。更广泛的影响包括1)获取巴罗当地长老的传统知识，他们对最近的湖泊排水和洪水事件拥有第一手和二手信息；2)通过最近成立的nasa资助的阿拉斯加本土遥感教育项目，加强巴罗高中学生的教育；3)加强与美国其他机构的联系；4)继续通过若干国家科学基金项目为本科生提供科学培训。所有卫星图像、岩心地层学、全球定位系统样带和花粉/微化石数据将通过网站、国家冰雪数据中心档案和古环境北极科学网站公开。

This is a collaborative proposal by Principal Investigators at the Universities of Wisconsin-Madison and Cincinnati. About 20% of the Arctic Coastal Plain is covered by thaw lakes developed over ice- rich permafrost and a larger proportion of this landscape is also scarred by drained thaw-lake basins, which become sites for the accumulation of organic carbon as peat deposits. The Principal Investigators will study of the origin of thaw-lake basins and associated geomorphological, biological, and pedological processes, building on work done on the Barrow Peninsula during 2000-2002. High-resolution multispectral satellite data will quantify the size frequency distribution and derive morphometric characteristics for lakes and drained thaw-lake basins across the Coastal Plain. In addition, drained lake basins will be selected for intensive ground-based analysis between Barrow and Atqasuk. The PIs will use the vegetation to select an equal number of young, medium, old and ancient drained thaw-lake basins. Ground-penetrating radar and extensive winter soil coring will be used to map unconformities between underlying lake sediments and the post-drainage organic deposit. Combined with satellite imagery to determine the areal dimensions, the volume of organics within the 40 basins will be estimated to determine the amount of soil carbon stored in the organic layer and upper lacustrine deposits. These results will estimate the amount of carbon sequestered in drained basins. Radiometric dating of the in situ peat above the clastic lake basin sediments will estimate of the date of lake drainage and basin inception. There is evidence to suggest that these events may be related to climatic change, while other lakes have drained in response to coastal erosion. The research will use paleoecological indicators to reconstruct the spatial and temporal response of vegetation and soil to climate on the Coastal Plain during the Holocene. High-frequency core dating will be used to derive carbon accumulation rates and organic soil chemistry and state of decomposition to determine whether carbon accumulation rates respond to regional changes in climate or if they are influenced to a greater degree by local rates of plant succession. Extensive spatial and temporal analysis of thaw-lake basins will 1) add to our understanding of the basic processes responsible for these important elements of the northern Alaskan landscape, 2) provide new information on landscape-scale response to climate change, and 3) help develop and validate causative models of environmental change and carbon sequestering. Broader impacts include 1) accessing traditional knowledge of local elders in Barrow, who have primary and secondary information on recent lake drainage and flooding events; 2) enhancing education of students at the Barrow High School through the recently established NASA-funded Alaskan Native Remote Sensing Education Project; 3) strengthening links with other U.S. agencies; and 4) continuing to provide scientific training to undergraduate students through several NSF programs. All satellite imagery, core stratigraphy, Global Positioning System transects, and pollen/microfossil data will be made publicly available through web sites, archives at the National Snow and Ice Data Center, and the Paleoenvironmental Arctic Sciences web site.