TRANSPORT OF SUSPENDED PARTICULATE MATTER IN AN ANTARCTIC FJORD

Vertical profiles of temperature, salinity, and light attenuation were used in conjunction with underwater photography and water samples to characterize the nature and dynamics of particle transport in an Antarctic fjord. Most of the particles are sand sized (0.1-2 mm) floccules comprised of individual grains in the 5 to 50 mu m size range. The quartz silt grains are derived from basal, debris laden meltwater originating from beneath the submerged valley glacier. The meltwater buoyantly rises to form cold water interflows at mid water depths. Turbulent mixing near the seafloor also plays a role in the transport and break-up of floccules. Together the midwater cold tongues and near-bottom turbidity account for 87% of the total sediment load thus attesting to the importance of non-surface transport mechanisms in polar fjords.