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Victoria University Antarctic Research Expedition Science and Logistics Reports 1980-81: VUWAE 25

Scientific Equipment

Scientific Equipment

No equipment was lost or damaged. However, the sphincter corer, which was an important part of the operation, did not perform satisfactorily.

The sphincter corer was designed to take a shallow (=300mm long) large diameter (=200mm) minimally disturbed core and retain the sea floor sediment-water interface intact. The main feature of the corer is a cloth sleeve (sphincter) which cuts the sediment in situ and retains the core with a nearly water-tight seal.

Two major types of problems were encountered when operating the corer. A lack of penetration was evident in some areas of the Sound where the sea floor was stoney, e.g. near Ross Island. Thick sponge mat in some areas also contributed to poor corer penetration. Extra lead weights and a short barrel option will be used to overcome the penetration problem.

The second problem was that caused by freezing sea water in the trigger mechanism. This mechanism consisted of a main pin into which was hooked a sprung detent pin. Both pins were greased and enclosed in a close-fitting steel housing. Sea water on freezing ejects brine and forms "fresh water" ice. This ice does not melt in the sea water, which has a temperature of −1.9°C. Because the trigger was enclosed, ice was not flushed out as the corer descended to the bottom. The problem should be solved by opening out the trigger so that it will be self-draining, and can be flushed either in the sea or with alcohol.

In general the other scientific equipment performed well, particularly the winch. The salinity-temperature bridge was difficult to use in the open page 44 where it was impossible to keep unfrozen the water standards used for calibration of the instrument.