Variability of Active-layer Thickness at Multiple Spatial Scales, North-central Alaska, U.S.A.

To examine the scales at which the maximum variability of active-layer thickness occurs within local areas, a nested sampling and analysis design was implemented in five 1-km2 areas distributed over two physiographic provinces in north-central Alaska. The primary variations of thaw depth in the low-relief terrain of the Arctic Coastal Plain province occur over distances between 100 and 300 m, and are superimposed on a trend related to the regional climatic gradient. In the Arctic Foothills province, much of the variation within the study areas occurs over horizontal distances less than 3 m, and is superimposed on mesoscale variations induced by terrain climate. To achieve maximum effectiveness, research programs concerned with sampling, interpolating, or modeling thaw depth and closely related phenomena should be designed to accommodate substantial variability at multiple spatial scales.