Eolian Deposits of Alaska

Abstract

E OLIAN deposits of Pleistocene to Recent age are recognized in all major regions of Alaska (see Fig. 1). Lack of economic incentive and of suitable base maps or air photographs have in the past precluded much detailed work on such deposits. Further, complexities produced by growth of vegetation, reworking by streams, and, particularly in areas of permafrost, by frost action and mass wasting processes, tend to mask, assimilate, modify, or remove eolian materials as they accumulate. Consequently at present only a small proportion of the eolian deposits can be shown on a map and relatively few data are available on their morphology, stratigraphy, and genesis. This paper is an attempt to summarize these data, at the request of the US. National Research Council Committee for Study of Eolian Deposits in North America.The writer has visited all the major areas of eolian deposits described here and has incorporated into the text and map his own ideas or interpretations rather than utilizing.only those of other workers. He acknowledges gratefully the unpublished information and comments received from each of the persons listed on Fig. 2, who have carried out detailed studies of the areas shown. Many ideas expressed, for which individual acknowledgment is difficult, originated with them. Special mention should be made of the valuable summaries by Clyde Wahrhaftig and David M. Hopkins, parts of which a=

A Pleistocene Sand Sea on the Alaskan Arctic Coastal Plain

“…Because the predominant ridge orientations roughly parallel the modern prevailing winds, the dunes may have formed under a wind regime similar to the present one. These large dunes are now obscured by a thin cover of younger eolian sand that includes small, stabilized longitudinal and parabolic dunes generally less than 1 km long (2). In addition, the large dunes have been extensively modified by thermokarst processes, making them difficult to detect on the ground or from aircraft.…”

Geology, Especially Geomorphology, of Northern Alaska

“…Eolian features are widespread (Black 1951a). Continuous permafrost and low relief result generally in poor drainage over large areas and in the development of striking patterned ground (Black 1952 and1963;Tedrow 1962), of thermokarst phenomena (Anderson and Hussey 1963;Black 1969), and of various ice-cored mounds (Black 1951b).…”

Modeling Wildfire-Induced Permafrost Deformation in an Alaskan Boreal Forest Using InSAR Observations

“…We assumed the soil to be fully saturated, S = 1.0. Taking porosity to be a constant value is a source of uncertainty as it is a site-specific characteristic of soil and should ideally be determined from in situ measurements at all InSAR pixels, thus we choose 0.1 of uncertainty in S. However, based on [47,48], we estimated the porosity, P, to be in a narrow range around 0.46, i.e., 0.46 ± 0.10. The uncertainty in T i 2 , thawed excess ice permafrost, equals the uncertainty of the parameter δ 2 − δ 2 .…”

“…An extensive mantle of eolian silt covers the marginal upland bordering the Yukon Flats [48]. The loess, which covers the study area, is massive well-sorted homogeneous unconsolidated tan to gray silt and sandy silt [47].…”