Geothermal heat flow studies from Ocean floor west of McMurdo

D.A. Christoffel and I. M. Calhaem

The thermal gradient probe used was constructed in the Physics workshop of Victoria University and is 6 ft long and 1 inch in diameter. It has 24 differential thermocouples extending over a length of 4.5 ft and has a built-in heater to determine thermal conductivity of the sediments it penetrates. Sea ice served as a convenient working platform and the probe was lowered through an existing hole in the ice and through a new hole that was drilled.

Unfortunately, because of hard bottom conditions, only one gradient measurement appeared to be successful. It indicated a heat flow of about 1.9 micro-calories per cm per second and is slightly above the generally accepted world average value. It is important for future work that more stations be occupied in the hope of finding-softer bottom conditions.

A Weddel Seal co-operated in providing an interesting Zoological sideline to the geophysical work. He, or she, repeatedly visited us at one of the holes, often with a fish in its mouth. On one occasion we were able to take a live fish in good condition from the seal. It weighed 651bs and was 4.9 ft long and proved to be a species. Dissostichus mawsoni that had not previously been fully described. The fish and behaviour of the seal are to be the subjects of a short paper.