Geomorphologic controls on active layer characteristics in the Alaskan Arctic and their implications for studies utilizing latitudinal temperature gradients

• Main Author: Link, Emma Grace
• Format: Text
• Language: unknown
• Published: Carleton Digital Commons 2018
• Subjects: active layer; Alaskan Arctic; carbon cycling; climate change; geomorphology; physical environment; Arctic; Climate change; north slope; permafrost; Alaska
• Online Access: https://digitalcommons.carleton.edu/comps/2015

The goal of this project is to establish how geomorphologic features affect the local periglacial environment in five sites in the Alaskan Arctic. Factors such as hydrologic regime, bedrock and soil type, slope and aspect, precipitation type and timing, and vegetation affect the stability and behavior of permafrost-affected ground. In this context, I take a critical look at site selection for a 2017-18 study by Fraterrigo et al. that investigates temperature and soil controls on plant functional characteristics and carbon cycling in the Alaskan Arctic. The five sites in their study were established along a latitudinal temperature gradient through the central interior and north slope of Alaska, and each site was thought to contain an edaphic gradient. Using geologic and ecotype maps, high-resolution imagery, and field observations, I qualitatively assess how these sites differ from each other in terms of physical characteristics such as geology, ecosystem type, and slope profile. Using soil active layer measurements and geomorphologic features measurable in high-resolution imagery, I quantitatively determine how the permafrost and soil characteristics of these sites differ. Finally, I determine whether permafrost and soil characteristics vary with stream distance and slope within each site. There is variation in soil profile and permafrost conditions between sites that is explained by temperature changes, and some that is attributable to variation in physical site characteristics, particularly in Site 3. There is no evidence of a consistent edaphic gradient with slope steepness or stream distance.