Volume 19, Number 1 (1992)
Articles

The Seasonal Distribution of Suspended Particles and Their Iron and Manganese Loading in a Glacial Runoff Fiord

J. P. M. Syvitski
Geological Survey of Canada, Bedford Institute of Oceanography, Dartmouth, Nova Scotia.
A. G. Lewis
Department of Oceanography, University of British Columbia, Vancouver, British Columbia.
Published March 3, 1992
How to Cite
Syvitski, J. P. M., & Lewis, A. G. (1992). The Seasonal Distribution of Suspended Particles and Their Iron and Manganese Loading in a Glacial Runoff Fiord. Geoscience Canada, 19(1). Retrieved from https://journals.lib.unb.ca/index.php/GC/article/view/3747

Abstract

Three mechanisms are responsible for the distribution of inorganic suspended particulate matter in a glacially influenced fiord such as Knight Inlet, British Columbia. The most important is the influx of sediment from rivers draining hinterland ice fields, with maximum input levels reached in the summer melt season and during the autumn period of flash floods. Sediment can also enter a fiord from the sea: 1) within the return flow of estuarine circulation that is fully developed during the late spring through early autumn, and 2) as part of deep shelf water that exchanges and flushes out the deep water of the fiord basin, particularly during the winter season. The third mechanism for sediment accumulating on the sea floor is through the action of episodic turbidity currents. These sediment gravity flows carry coarse delta-front sediments to the otherwise muddy basin floor. The relative abundance of particulate iron within the suspended sediment load directly relates to higher levels of iron in glacially derived particles issuing from river mouths at the head of the fiord. Elevated levels of particulate manganese may be a result of turbidity currents. They are observed in the water column nearest the sea floor where circulation and geochemical conditions would normally preclude their existence.