Results from Sediment Trapping

Sediment traps in McMurdo Sound and Granite Harbour have been deployed by parties from Victoria University of Wellington and Rice University, Houston, Texas. Short term deployments (maximum time site occupied 61 days to date) have been successfully recovered. Long term deployments (1 year or more) have been attempted by suspending traps from ice tongues but have not been successfully recovered to this date.

Rice university assisted by K042 deployed two four trap moorings anchored from the Ferrar and Mackay Glaciers in December 1985. The traps were deployed through holes cut in the sea ice within a few metres of the glacier fronts with the intention of recovering the moorings the following season.

This season K042 were prepared to recover the two moorings, but in both instances although the anchor points were found the traps had broken out with the sea ice. The moorings would have remained intact if the sea ice breakout had not occurred at the glacier front like in 1982 at the Mackay Glacier. The probability of retrieving moorings anchored in this way is now considered unlikely after this season's experience.

These attempts show that for long term deployment to be successful, the moorings used must be unaffected by sea ice movement and breakout, and, to a lesser extent, ice tongue calving - ice berg movement. The need to measure sediment flux throughout the whole year still remains a major factor in the understanding of modern marine glacial sedimentation processes in this area and Antarctica in general.