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Report on the Eleventh Victoria University of Wellington Antarctic Expedition 1966-67: VUWAE 11

Scientific Background to Proposals

Scientific Background to Proposals

Problem No. 1

Glacial History of Ross Dependency

As a result of work on previous expeditions Wilson has worked out a glacial history of the Ross Dependency. Part of this history involves an ice sheet from the sea which entered the Taylor Valley to cover the slopes of Erebus and Terror up to 1000ft. This glaciation has been called the "Great Flood Glaciation" by earlier workers.

One explanation for this glaciation is that due to sea level lowering during the last glaciation the ice shelf became grounded and hence became part of the Continental ice sheet. If this explanation is correct one would expect the retreat to have taken place about 6000 years ago, and hence the glacial moraine would be very fresh as compared with the glacial debris in the dry valleys. Thus it is proposed to study the moraines on the slopes of Erebus which are easy to find and well described by early workers. The weathering of the granite should provide a good indication of age. It is desired to travel by motor toboggan rather than by helicopter as this will give a greater range and enables one to take one's camp with one when mapping the moraine.

Problem No. 2

Ablation measurements on the Antarctic Ice Sheet

During an earlier expedition Wilson and House developed a technique for measurement of ablation rates. It is proposed to develop this technique further and to extend the measurements to other areas on the polar ice sheet. This is the only method of making this measurement and it has never been determined at Byrd Station or at Plateau Station. No one else has the page 3 necessary technique to make the measurement. The measurements have to be made in the field as a very large number of samples are involved and contamination is a real problem. It is hoped to extend the technique to measurement of the contribution by drift to the total accumulation.

Importance of measurements: besides its own intrinsic interest - the ablation when combined together with nett accumulation (which is known) gives the gross precipitation. These figures are needed to enable one to estimate the effect on the budget of the Antarctic ice sheet on any change - such as for example the growth of an ice shelf around Antarctica, the increase in sea ice or a change in world temperature.

It is proposed that Wilson and Hendy spend four days at each of the following stations:-
  • Byrd Station
  • Pole Station
  • Plateau Station
  • and, if possible. Vostok

Problem No. 3

Ice budget of Antarctic Ice Sheet

Is the Polar Plateau going up or down or remaining constant?

Since the Antarctic Ice Shelf theory for Pleistocene Glaciations was proposed.

There has been much interest in this problem. The English are doing radio echo soundings on outlet glaciers to determine total ice budgets. The Russians and French have a strain set-up to measure the change directly.

It is proposed to tackle the problem another way and to examine points where the Polar Plateau pushes ice tongues into dry areas. Since the Polar Plateau ice contains salts and these remain behind when the ice evaporates it is possible to determine how long the ice tongue has been supplied by the Polar Plateau.

The upper Wright Glacier is an example of this situation and it is proposed that
1.A two man party go to the upper Wright Glacier area by helicopter to study this problem.
2.That a reconnaissance be made in an aircraft from the Victoria Valley and along the edge of the Polar Plateau as far south as possible looking at other critical areas.

NB. In my view, Wilson's "Problem 2" is of fundamental importance and should be given all reasonable priority, with the proviso that it is realised Vostok may be impractical.

The remainder of Wilson's programme is sound, but the degree of support requested may be unreasonable. I would welcome discussion with Mr. Thompson on this point.

page 4
12(c).It is proposed to continue and expand the project commenced with VUWAE 11. The following are the objects:
1.Measure the heat flow through the bottom of McMurdo Sound on a line extending from McMurdo Station to Brown Peninsula.
2.Measure the heat flow through the bottom of Lake Bonney.
3.Measure the heat flow through the bottom of Lake Vanda.
  • Personnel required - two.
  • Duration of projects -
    1. 4 weeks
    2. 10 days
    3. 10 days
    Total 7 weeks

Equipment

1.Heat flow probe to drive into the bottom. Three probes have been built and satisfactorily tested. However, to work through a Cipri drill hole as envisaged for (2) and (3) a new small diameter head must be constructed.
2.Electric cable and lowering wire. These items are to hand.
3.Cable reeling drums - 2 required; 1 to hand, 1 to be purchased from the Army. Cost: £8.
4.Metering blocks - 2 required; 1 to hand, 1 to be obtained.
5.Cipri ice drill?
6.One 18" chain saw for cutting large holes in the ice - to be purchased.
7.Ice tongs - 2 pairs to purchase.
8.Portable potentiometer - to hand.
9.Sheer legs: 3 aluminium pipes, probably obtainable from Scott Base.

Background

On the 1966 operation, difficulty was experienced in driving the probe into the gravel bottom encountered in McMurdo Sound. The sites tried were close to C. Armitage and strong sea currents were found. It is felt that further out in the sound conditions are likely to be more favourable. The measuring equipment itself worked well and apart from reducing the physical diameter of the probe head, no changes are required.

Support required: Transport to the Wright and Taylor Valleys; A tractor, Wan nagon and sledge for operating on the sea ice.

Dr. Wright hopes to visit the Boomerang Range. This is the subject of a separate memorandum and is not discussed here.

Yours faithfully,

R.H. CLARK Convener, V. U. W. Antarctic Research Committee