McMURDO SOUND SEDIMENT STUDIES (K042)
The K042 party spent a total of 9 days at Scott Base for survival training (2 days) and to prepare field and specialist seafloor sampling equipment.
Three ski trailers for toboggans were designed and built at Victoria University of Wellington. These were sent air cargo to Scott Base and reassembled in the garage during the first two days. Two trailers were dedicated for general scientific equipment including echosounder and generator and sampling equipment. The third trailer with wider skis and extended draw bar carried an 11 foot aluminium drill mast, 12" diameter ice aagers and hydrographic winch with 1200m of 5mm diameter wire cable.
This new equipment increased the speed and ease of sampling sea ice, proved the suitability of this type of toboggan operation and feasibility of new "up hole" equipment for sea floor photography in the future.
Equipment wintered in Antarctica was checked and some items that had been used for CIROS retrieved from Butter Point. The location and preparation of the equipment stored at Scott Base was time consuming. A separate secure store for our scientific equipment would greatly reduce time spent in preparations at Scott Base and help in planning future programmes.
The McMurdo Biolab was visited on two occasions to organise equipment for retrieval of the Rice University sediment traps. Dr Ted Delaca's party working in Explorers Cove (New Harbour) offered diving assistance to retrieve the traps if necessary.
Butter Point Camp was used as a base to carry out the field work in New Harbour. K042 commuted by toboggan to sampling areas at the Ferrar Glacier Snout, Mt. Barnes and "Delta 4" on the south side of Ferrar Fjord.
The sea floor was sampled in front of two large surface channels on the Ferrar Glacier Snout. The heavy drilling and sampling equipment was moved to each site and a polar tent set up to provide shelter for the day's operation. Seven closely spaced cores were obtained from these two areas, averaging 2 cores per day. The samples were returned to camp each evening together with parts of the coring equipment for cleaning and reassembly. Sampling at Mt. Barnes and Delta 4 was in water depths of less than 100m. Hard seafloor substate prevented penetration with the sphincter cover in these areas but some relatively undisturbed samples were still obtained.
Another part of the K042 programme was to retrieve sediment traps at the Ferrar Glacier (and New Harbour) and MacKay Glacier (Granite Harbour) set by Rice University (S-216) the previous season. The sediment strings were anchored to the snout of each glacier and had been deployed through a hole drilled in the sea ice at the glacier edge. We found the anchor points intact although both had undergone considerable strain and some meltout. The lines of both traps however, were broken at about the point the lines would have passed through the sea ice.page 19
It was disappointing not to be able to retrieve the traps for which we had spent time preparing, transporting drilling gear and explosives to Granite Harbour and arranging for USARP divers if necessary.
Lands and Survey surveyors provided precise location of sampling sites and the glacier edge for the Ferrar Glacier samplings. The calving crevasse in the Bowers Piedmont Glacier near Butter Point Camp was also mapped. K042 also assisted the surveyors during the measurement of control trigs along the coast and sea ice monitoring off Cape Roberts.
Two Grizzly toboggans (SM051 and SM053) were used by K042 primarily on the sea ice and generally gave few problems. SM051 and SM053 each travelled about 910 and 950 km respectively. The variator belts were changed once on SM053 and twice on SM051. The fuel filter was replaced on SM053 and had to be cleaned (only partly successful) on SM051. Only one new disposable filter was available from Scott Base. Two-stroke fuel was mixed at 35:1 in the field from bulk 44 and 12 gallon drums. Fuel was mixed in the field because some of our equipment required MOGAS only.
Toboggan SM051 was fitted with a precision odometer for surveying on the sea ice. We also installed a 12V plus via the back light to run the echosounder from the toboggan battery. We found this to be very convenient and saved carrying an extra battery specifically for the echosounder.
Daily maintenance of the toboggans included; checking gearbox oil, variator bolts and most importantly the running gear. The nyloc nuts on the running gear are liable to come loose with several days use. This can only be prevented by careful daily checks for which we used a ramp and snow pit at Butter Point.
The few mechanical problems we encountered with the toboggans are attributable to dirty fuel which appears to be a common problem for many field parties. Fuel contamination could be eliminated by:
- Providing quality fuel containers which are less likely to rust internally. Plastic containers designed specifically for petrol would be a satisfactory alternative.
- Providing drum pumps with fuel filters attached.
- Providing sufficient new in line disposable filters for the toboggans. We estimate that these filters should be changed between 300 and 500 km. The dirty filters cannot be successfully cleaned in the field.
Routes and Sea Ice:
K042 followed bulldozed roads on the sea ice between Scott Base, Butter Pt and Marble Pt. We followed the surveyors inshore tracks between Marble Pt and Dunlop Island; deviating offshore to check sea ice conditions on the way to Cape Roberts and returned on the surveyors route which was quicker. Several seasons travel between Marble Pt and Cape Roberts have shown that the sea ice is generally better within 1 km page 20 of the coast. Some rough ice can be expected on the north side of Gneiss Pt around Dunlop Island, off the Debenham Glacier ice tongue and near Cape Roberts.
Ferrar Fjord this season contained about 30% rough ice up to 0.5 m high including multi-year sea ice plates and a snow cover about 100 mm thick. Travel was generally easy but slow. This is very different to the 1984-85 season when the Fjord contained very smooth ice, less than 10% rough ice without any "permanent" snow cover.
In New Harbour rough ice again occurred in the central harbour with much multi-year ice in Explorers Cove. The sea ice was generally smooth on the south side of the harbour near the Bowers Piedmont Glacier. We often travelled on the Piedmont between Butter Pt and Trig Herb when commuting into the Ferrar Fjord. This route was smooth, snow covered and without observed crevasses.
The sea ice offshore between Butter Pt and Cape Roberts was quite rough with ice block walls 3-4 m high in places. Several adjoining leads were found from Dunlop Island to Cape Roberts for travelling. However the route was circuitous in places.
The sea ice in Granite Harbour was very smooth on the south side and inner harbour. Low rough ice occurred in the central harbour and on the northern side.
Sea ice this season was about 3 m thick in Ferrar Fjord, New Harbour, 0.5 m thicker than in 1985. Sea ice in other parts of western McMurdo Sound seemed also to be thicker, and by a similar amount. The distribution of pressure ridges, rough and smooth ice, however, was similar to that observed previously.
No helo time was allocated to K042 however three flights involved K042 personnel which were charged to separate events. These flights were well coordinated by Peter Cresswell at Scott Base and enabled the planned tasks to be carried out successfully.
Scott Base → Butter Pt → Scott Base.
(Pyne and Dawkings retrieve equipment from Butter Pt. Afternoon operation only).
- Butter Pt → Seismic Drill site → Butter Pt (Pyne to photograph granite core at drill site, return with surveyors to Butter Pt. Full day operation).
Butter Pt → Cape Roberts
(MacPherson and Kelly assist survey party helo operation).
Explosives were drawn from the CIROS cache at Butter Pt to use for sediment trap recovery and other sea ice work. No explosives were used and were returned to Butter Pt.
Communication was generally good with Scott Base on HF frequencies. K042 used the morning sked which was efficiently handled from Scott Base. The Labgear radio gave no problems which was a pleasant surprise considering the age of the equipment.
UHF communication is now good on the sea ice between Cape Roberts and Scott Base. We would have preferred DBF sets for our sea ice operation particularly when we needed to communicate with other parties working with us, e.g. surveyors. It would have also enabled easier operation between our two toboggon parties while surveying and sampling.page 21
Detailed weather logs were not kept, but poor weather days are noted in the Itinerary (Appendix I). Generally the weather was cooler and windier than previous seasons at this time of the year and area. This did not stop our work but slowed down the operation of our equipment on some days.
We had hoped to observe glacier melt streams in flow, but these showed no sign of flow by December 6 and would have required at least another week of warm and sunny conditions.
Butter Pt Camp:
Butter Pt camp was used by K042 while working in the New Harbour area. Our equipment required periodic maintenance and cleaning which was easily done at Butter Pt rather than at tent camp at the sampling sites. We were also hesitant about camping in the Ferrar Fjord in light of the CIROS 2 storm the previous season. A similar storm occurred in the area this season on December 5, the day we finished work in the Fjord.
The commuting time from Butter Pt to sample sites was about an hour. We do not consider this time excessive because we were able to leave earlier from Butter Pt than a tent camp giving us more work time each day.
Cape Roberts Hut:
The Cape Roberts Hut was used by K042 and surveyors while working in the Granite Harbour area. It is a very suitable hut for messing and as a lab. There are several empty or part empty 44 gallon drums at the site. Most of these are an old (US?)-fed cache prior to 1981.
Cape Roberts Hut @ 30 November 1985:
|Mogas 1.5 × 44 gal 1 × 12 gal||78 gals (estimate)|
|DFA||80 gals (estimate)|
|Kerosene||10 gals (estimate)|
|Science equipment assorted - VUW.|
Itinerary for Sea Floor Sedimentation Studies (K042)
|November 3||Pyne, MacPherson, Kelly to Christchurch.|
|4||Pyne, MacPherson, Kelly, Dawkings on flight returned to Christchurch|
|5||Pyne, MacPherson, Kelly and Dawkings to Scott Base.|
|6||Began assembling equipment (two toboggon ski trailers completed and winch trailer begun) in garage. Calibrated odometer on Grizzly tobotton SM051.|
|7||Continued assembly and fitting of winch-drilling trailer.|
|8||Dawkings, MacPherson and Kelly on day 1 of survival course. Pyne continued preparation of equipment.|
|9||Pyne joined K042 for day 2 of survival training.|
|10||Equipment preparation in morning. Visited Biolab at McMurdo in afternoon to check on equipment for sediment trap recovery.|
|11||Equipment preparation continues.page 22|
|November 12||Field equipment checked. Pyne and Dawkings to Butter Pt (opportunity helo) to retrieve equipment stored at Butter Pt (afternoon).|
|13||Equipment preparation continues. Pyne meet with P. Cresswell (OIC) and G. Varcoe to discuss implications of calving crevasse at Butter Pt near CIROS camp.|
|14||Preparation of equipment.|
|15||Loaded sledges in morning. Left for Butter Pt in afternoon.|
|16||Maintenance checks of toboggons in the morning. Snow and weather closed in this afternoon.|
|17||Travelled to Ferrar Snout and found sediment trap mooring. Set up grid on sea ice in front of the snout for sea floor sampling. Return to Butter Pt via Explorers Cove.|
|18||Moved drilling and sampling equipment to Ferrar Glacier Snout.|
|19-21||Sea floor sampling at site 1. Five cores retrieved.|
|22||Moved sampling equipment south along snout to site 2. Recovered two cores.|
|23||MacPherson, Kelly and Dawkings worked in Ferrar Snout channel, returned sampling equipment to Butter Pt.|
|Pyne to DVSP drill site to photograph granite core and sample for Dr D. Craw (Otago University).|
|24||Pyne, Kelly, Belgrave and Winters (L & S surveyors) to Ferrar Snout to survey sampling sites and snout terminus.|
|Surveyed calving crevasse at Butter Pt in evening. MacPherson and Dawkings prepare equipment for move to Cape Roberts.|
|25||MacPherson, Kelly assisted surveyors with helo close support surveying from Trig Herb (New Harbour) to Mt Marston (Granite Harbour) finishing at Cape Roberts.|
|Pyne and Dawkings with toboggons from Butter Pt to Cape Roberts.|
|26||Surveying sea ice east of Cape Roberts. Maintenance checks of toboggons and equipment.|
|27||Party (6) to MacKay Glacier Snout to find sediment trap. Couldn't find Glacier snout anchor. Returned to Cape Roberts via New Glacier snout and Cape Geology. Very cloudy, light snow with little wind in the inner harbour.|
|28||Poor weather, tenth day at Cape Roberts.|
|29||Surveyors to Scott Base by helo in afternoon. K042 to MacKay Glacier. Found sediment trap anchor but traps again lost.|
|30||K042 Cape Roberts to Butter Pt. Six hour trip on good route. Scott Base personnel (work team and seal collectors) arrived at Butter Pt late evening.|
|December 1||Maintenance check of Toboggons with Scott Base mechanic assistance. Moved sampling equipment to sampling line at Mt Barnes. Two "Footsteps of SCott" people stayed the night at Butter Pt.|
|2||Sampled at Mt Barnes and moved equipment to south side of Ferrar Fjord at Delta 4. Footsteps people manhauled to Explorers Cove.|
|3||Snowing and windy. Stayed at Butter Pt for office day. Pyne worked on CIROS lab plan. Enquiry from Cresswell to Pyne of ice conditions for late season tractor train. Pyne confirmed good ice conditions with only problems directly off Marble Pt and sea ice transit ramp to Marble Pt airport.|
|4||Sampled at Delta 4, returned equipment to Butter Pt.|
|5||Ferrar Snout. Photographed and sampled superglacial debris. High winds and blowing snow in late afternoon and evening.|
|6||Packed up equipment and returned to Scott Base. Equipment cached for cargo train returning to Scott Base via Butter Pt. Camera electronics arrived Scott Base for testing.page 23|
|December 7||Packed equipment for return to New Zealand and winter storage at Scott Base including moving VUW equipment in hangar. Testing camera electronics but couldn't stabilise in Scott Base science lab.|
|8||Pack remaining equipment and samples. Camera still not functioning.|
|9||Pyne checked repaired Scott Base microscope parts damaged at CIROS 2 drillsite and finalised work plan for Ken Woolfe while at Scott Base. Pyne, MacPherson and Kelly return to Christchurch.|
|10||Pyne attends debrief and CIROS discussion with Jim Barker at Antarctic Division.|