An Analysis Comparing and Contrasting North American and Siberian Arctic Deltas, Related Shelf Troughs, Seavalleys, and Abyssal Fan Deltas.

Abstract

Multivariate statistical methodologies are used to compare and contrast 11 arctic river delta systems with 30 other delta systems from climatically diverse environments. The results indicate that: (1) arctic rivers and their deltas are systemically unique and cluster hierarchically; (2) arctic deltas are clustered as regionally dissimilar from those of other environments; (3) some North American arctic deltas are shown to be analogues of Siberian deltas; (4) arctic deltas, like those of other environments, are primarily a product of the interplay between hydrological and oceanographic processes; (5) the dominant hydrological processes are the rate of discharge and discharge peakedness and; (6) the dominant oceanographic processes are wind-induced littoral drift and haline density-driven currents. Three primary subaerial deltas are process-response related to one continental shelf secondary and three abyssal-plains tertiary subaqueous deltas. Shelf troughs and submarine canyons are identified as conduits for transporting sediment from the primary deltas to tertiary abyssal plains subaqueous deltas. A working hypothesis derived from these findings is that riverine and oceanographic current processes are responsible for transporting eroded material from the primary deltas through the troughs or submarine canyons and for forming secondary or tertiary deltas. The riverine currents are mainly responsible for the formation of the secondary delta off the mouth of the Yenisey River whereas littoral and density driven currents are the major factors in the formation of tertiary deltas. These conclusions are based on a limited amount of quantitative data and therefore the correlations between wind directions and littoral drift current directions is tenuous.