Soil properties developed on the complex tundra relief of northern Alaska

Abstract

A five-year investigation of the Coastal Plain tundra in the vicinity of Barrow, Alaska, provides the basis for evaluating the variations in soils, surface relief, and near-surface lithology in a region underlain by continuous, perennially frozen ground. Analyses of 80, one-meter long soil cores showed no statistical correlation between microrelief and thaw or microrelief and moisture. A significant negative correlation was established between thaw depth and total moisture contained in the seasonally thawed soil. Seasonal thaw at the 80 points during 1962 to 1966 averaged 43, 41, 33, 36, and 37 cm for each of these years respectively. Morphological examination indicated a maximum thaw of approximately 52 cm based upon depth to ice wedges and high-ice soil. Correlation of the 5-year measured than with climatic data indicàted that wet-warm summers such as 1951 and 1954 could produce the observed thaw of 52 cm.

Chemical analyses of the soil and near-surface sediments demonstrate the freshened character of the thawed soil. A vertical depression of the chemical concentrations beneath part of the 1.5-km study transect to a depth exceeding 3 meters suggests the previous occurrence of thaw features such as a lake, Buried organic matter at the base of the active layer and in the perennially frozen ground yields radiocarbon ages of less than 2,500 to 10,500 years. The younger peat occurs over ice wedges and demonstrates a recent burial cycle assodated with wedge growth. The wide range in ages of buried peat and the general lack of textural unconformities support the theory of cryopedologic burial of the peat.