MORPHOLOGIC CHANGE IN TWO ARCTIC DELTAS.

• Main Authors: Walker,H. J., McCloy,J. M.
• Other Authors: ARCTIC INST OF NORTH AMERICA WASHINGTON D C
• Format: Text
• Language: English
• Published: 1969
• Subjects: Hydrology; Limnology and Potamology; (*DELTAS; ARCTIC REGIONS); DRAINAGE; EROSION; RIVERS; SNOW; INTERACTIONS; PERMAFROST; ICE; FLOW FIELDS; WATER; DEPOSITS; ALASKA; CANADA; COLVILLE RIVER; *GEOMORPHOLOGY; Arctic; Canada; Ice; permafrost; Alaska
• Online Access: http://www.dtic.mil/docs/citations/AD0688718; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0688718

Morphologic change in the deltas of two rivers, the Blow in northwestern Canada and the Colville in Alaska, is described and analyzed. The drainage basin of each river is confined to the Arctic Slope and is characterized by arctic conditions. Morphologic change is the result of the integration of a variety of processes some of which do not operate in temperate or tropical deltas. Although ice, like snow, is a passive agent during most of the time it is present, its erosional, transportational and depositional effectiveness may be great. However, by far the most important agent in deltaic change is flowing water which begins to operate once flow onto and over the ice is initiated. Permafrost which is present except beneath the largest lakes greatly influences erosion. Bank retreat may proceed gradually or by the sudden collapse of blocks from banks which have been undercut by as much as eight meters. Morphologic change in arctic deltas, like most other physical and biologic change in the Arctic, tends to be concentrated in a short period of time, a period of time centered around breakup. (Author) Prepared in cooperation with Louisiana State Univ., Baton Rouge. Coastal Studies Inst. and Montana Univ., Missoula. Dept. of Geography.