Distribution and dispersal pattern of suspended particulate matter in Maxwell Bay and its tributary, Marian Cove, in the South Shetland Islands, West Antarctica

Abstract

Water property casting data (SPM and CTDT) have been obtained from ice-influenced fjords, Maxwell Bay and Marian Cove, in the South Shetland Islands, Antarctica to describe the configuration of turbid meltwater plumes in detail and to elucidate the dispersal pattern of the plumes in the areas. Of the primary sediment pathways, only ice-contact processes are unique in ice-influenced fjords. The effect of glaciofluvial discharges has been overwhelmed by the influences of subglacial discharge and ice-front melting. Fluvial discharge from side-entry glaciers that commonly end on land and/or supraglacial discharge from ice surface are, however, more responsible for the overflow plumes in Maxwell Bay and Marian Cove. Subglacial meltwater discharge, which is almost always in the form of vertically rising buoyant jets, is considered rare. Active,glaciofluvial and/or supraglacial input from Marian Cove causes most suspended particulate matter to be concentrated near the mid-point of Maxwell Bay. Thus, even though closer to fjord-head trunk glaciers, SPM concentration in Collins Bay is comparatively low, largely due to clean tidewater glaciers and absence of meltwater streams around Collins Bay. Strong bottom current flowing along the continental shelf off the South Shetland Islands may import and export sediment from the outside of Maxwell Bay, influencing the distribution of bottom sediment as well as benthic community. (C) 1998 Elsevier Science B.V. All rights reserved.