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

University Of Cincinnati Main Campus, Cincinnati OH

Investigators

Abstract

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.