The Yukon Delta: A Model for Deltaic Sedimentation in an Ice-Dominated Environment

Abstract

Field mapping in the Yukon delta region of western Alaska, combined with laboratory analysis of sediment and Landsat imagery, has provided insights into the role of climate and tectonics on delta ic processes on high-latitude continental sh~lves. The climatic and tectonic influences on sediment type, in combination with the role of river and sea ice in controlling patterns of sediment transport and deposition, suggest that the Yukon delta may provide a model for deltaic sedimentation in an ice-dcrninated environment.

Sediment transport in Norton Sound, Alaska

“…shows that wave and current energy is concentrated on the western margin of the delta which is exposed to the open Bering Sea and the full impact of southwesterly storm winds (Dupre and Thompson, 1979). 51 The results of our winter study strongly suggest that (1) tidal currents are the most important sediment transport agent during non-storm periods, in the summer as well as in the winter, and (2) a substantial amount of Yukon River sediment remains in the system at the close of the ice-free season.…”

Survey of River Ice Influences on Channel Bathymetry Along the Fort Peck Reach of the Missouri River, Winter 1998-1999

“…Jam formation may greatly constrict flow, causing it to discharge along an alternate, less-resistant course. Prowse (1998) and Dupre and Thompson (1979) suggested that ice-jam-induced avulsion plays a major role in shifting the distributary subchannels of river deltas.…”

Geological, geochemical, and geotechnical observations on the Bering Shelf, Alaska

“…3). As discussed by Dupre and Thompson (1979), clean sand on the Yukon Delta front is the result of wave reworking that removes the finer fraction.…”

“…Ice gouges, mixes, and deforms the substrate, and promotes current scour. Ice partially controls the geomorphology of the Yukon Delta (Dupr£ and Thompson, 1979). Sharpness of gouge morphology is highly dependent on the type of substrate being gouged.…”

“…YUKON DELTA PROCESSES o The Yukon River drains an area a little less than 900,000 km , providing a water discharge of approximately 6000 m per second and a sediment load of 70-90 million metric tons per year (Dupre and Thompson, 1979;Cacchione and Drake, 1979a). The sediment load, almost 90 % of all sediment entering the Bering Sea, is composed mainly of very fine sand and coarse silt with very little clay.…”