19 MARCH 1962  -  3 MAY 1962



                    David R. Carstens            Surveyor

                    Ian Landon-Smith            Glaciologist

Assisted by all Station Personnel in turns as required and available.



In conjunction with the measurement of a series of lines with the Tellurometer in January – February 1962, levelling was commenced in March to transfer an accurate height to the inland trigonometrical stations. The work was designed on the basis of a more embracing geodetic network combined with future use for glaciological measurements. The section of the work to which this report refers is the 12 miles from Mawson Tide Gauge to a new Bench Mark established at the base of Painted Peak on the North Masson Range on which the Tellurometer Station was established.



The equipment used on this work was a Watts Autoset Level SL60.2 and two standard telescopic Sopwith Staffs. Staff bubbles and change plates were used. The change plates were manufactured at Mawson and consisted of a triangle of steel flat iron with 9 inch sides. At each corner a 11/2 inch bolt with a sharp point was fixed forming a tribrach for contact with the blue ice (encountered along the traverse) and in the centre of the plate, and on top, a suitable knob was fixed as the contact point for the staff.


Transport was by the station’s Snow Trac. The Snow Trac is a light snow vehicle, with a 55 horsepower Porsche engine, and an operating speed of 10 MPH. It was ideally suited to the work.



The method of working was designed in conjunction with the Glaciologist. A series of ablation stakes was set out at intervisible points and at approximately half mile intervals, between Mawson and the North Masson Ranges. [A diagram of the level traverse route and the staff change points is provided at Appendix A. Height values for the change points are provided at Appendix B.]


The levels were run between these stakes keeping on line by eye. Length of sights was determined by stadia. This afforded a check on total length of backsight against foresight and the sum of distances between stakes, coupled with angles read at each stake, provided a traverse fixing the position of the stakes. It is hoped that this traverse will be of use in determining the rate of ice movement along parts of this work. Previous work near part of this traverse has indicated ice movement to the order of 60 feet per year.


The levelling was carried out in sections as determined by the stakes. The vehicle would be left at a stake and the forward levels carried to the next stake. From there the check levelling was done, returning the party to the vehicle. In this way the party was never very far away from the vehicle, a safety factor when the weather can become very uncomfortable in a short time.


The stadia readings were taken only on the forward run. For the check levels pacing was used to bring change points to approximately the same position as the forward levels, thus keeping backsights and foresights balanced.


The tops of the ablation stakes, which were three to four feet out of the ice, were used as terminal points for each section; that is, as temporary bench marks. The problem in adopting a temporary bench mark is in knowing if it is going to move and if it is recognisable again. There is certainly no feature or rock that can be used and a spike or peg driven into the ice, to say twelve inches, could be made unreliable by heat absorption causing local melting around the mark. This would be highly likely should a delay in continuing the work occur.


The ablation stakes were planted on a hole drilled six feet into the ice. They are painted white to minimise heat absorption and were picked out by only nine inches of Day-Glo paint at the top of the stake. It was awkward holding the staff on top of these stakes in the wind but it did give a very definite point from which to work.


The staff-men worked in a leap-frog system. In this way the same staff remained at the change-point for foresight then backsight. This also meant that the staff-man was standing by his change-point as the instrument and the other staff were carried past. He could therefore guard the change point from being accidently bumped or, an important point as it is sometimes hard to see the white painted triangle in the snow.


Change points were located by pacing and the distances checked by the stadia readings. When backsight and foresight were not equal, this was corrected in the next step. Length of sights depended on the terrain. Generally the sights did not exceed 150 feet and the minimum was about 30 feet on the steep rise from Mawson for the first two miles.



As the work was all within 12 miles of Mawson, logistics were simple. It was found just as quick to travel from Mawson to the furthest point of the job to do a day’s work, than to camp on the job. On two occasions we stayed in the caravans (parked) at North Masson and found that by the time we prepared our own meals and attended to other work in the caravan we had less time to spend on levelling than when we drove from Mawson. The drive however is very tedious.


Early in the job, when starting techniques for the vehicle in the cold were uncertain, it was much better to return to Mawson each night. However, by the time the work was finished there was little doubt that engines could be started down to minus twenty Fahrenheit.


Another reason for returning to Mawson each night, and also a problem as far as speed of work was concerned, was the fact that no one person could be away from his own job for too long; and I was dependent on assistance from the personnel on the Station.


On only a couple of occasions was the same person available to work as staff-men. However as all were interested in the work, the co-operation and enthusiasm made (working method) explanations easy and I am sure the work did not suffer in accuracy through the number of staff-men involved.


As this work was done at the time of rapidly decreasing daylight, travel was done in twilight hours, thus utilising daylight for levelling. Time spent in travelling the full twelve miles usually amounted to two hours, taking into account the maintenance of the vehicle. Mileage travelled in the Snow Trac on the job was approximately 250 miles.



A great variety of weather conditions were encountered. Temperature range, of working time, was from 0°F to minus 17°F. On three days snow fell while we were working but it was no problem as it was a quite dry. These were perhaps the most satisfactory days as there was no wind. Work was continued also in drift op to two feet high. This obscured our marking stakes; but it was the wind which caused the main concern. Frostbite had to be guarded against continually. The face was the most susceptible. It seemed that when one’s face was close to an instrument or staff with the wind whistling past, frostbite was most likely to occur. We made it a practice to check each other as we moved past each time.


A blizzard mask was a good guard against frostbite but caused other problems, especially with the instrument. The warm air inside the blizzard mask channels out through the eye-hole and fogs the eyepiece very rapidly. Also one’s downward vision is almost nil which proves very awkward for booking.


It was possible to operate the Autoset with gloves on. Woollen wristlets were worn, together with one thick pair of mitts and a single thickness windproof outer glove. With walking between stations this kept one’s hands reasonably comfortable; and yet the thickness was not too great to manipulate the instrument (levelling) screws and do the booking. Body warmth was little problem wearing the normal clothing for these conditions.



After having made a start on levelling on 27 March it was realised that the two Snow Tracs on the Station were in unreliable mechanical order. Because the engineering staff were busy on other work, I decided to work on the overhaul of Snow Trac No 1 myself, under the guidance of the Senior Diesel Mechanic. This delayed the work a fortnight but it was well worth it to have a vehicle in reliable running order.


[This Snow Trac proved to be most reliable for the rest of the year, including for the major traverse to the Amery Ice Shelf in November, December and January.]


When levelling was re-commenced, the section levelled on 27 March was re-done. This was done because of the known high movement rate of the ice flow in the area and there was a possibility that the ablation stakes may have moved in height because of the glacial movement of the whole ice sheet (downhill in this case). The levels showed that this had in fact happened. One stake showed a drop of three inches. This stake was on a steep slope and the amount of drop is consistent with the rare of movement known to exist in this area, 60 feet per annum, related to the slope and the time between levelling runs, twenty-one days. Other ablation stakes in this section showed various amounts of vertical movement from half an inch to the three inches mentioned above. The furthest point compared in this manner was two miles from Mawson and was on flatter ice sheet. This point showed a fall of half an inch (0.05 feet).


Because of this ice movement it was necessary to complete the whole level traverse in as short a time as possible. Seventeen days elapsed between starting at Mawson and connecting to the rock at North Masson. Seven days of this time was lost due to bad weather.


Fortunately the weather was very co-operative during the working period. On only one day that I ventured into the field, was it impossible to work. Other times when the weather was bad coincided remarkably with vehicle breakdowns and maintenance or camp duties which I had to perform. Even the period of a fortnight which I spent on reconditioning the Snow Trac was one of continued bad weather. There were only two days in this period on which it would have been possible to do any levelling.


An important point when considering the weather, even in this twelve mile section, as that at one point it could be blowing and drifting, while a couple of miles on or back the weather is quite good. The weather at Mawson seemed to be better, always, than that on the plateau.


It was anticipated when planning this work that the katabatic wind, notable at Mawson, would delay the start of work in the morning but the afternoons would be calm. This did not prove to be the case as the wind tended to rise in the afternoons following calm mornings. It seems that the weather pattern this year is much different from anything experienced before. For instance the snow falls we have had are most unusual. It is reported that snow never falls at Mawson; but this year we have experienced a number of snow falls, with no wind blowing.


Wind was the main problem while levelling, both in regard to the instruments and bodily comfort. One most inconvenient episode, while working close into the ranges, was that a gust of wind blew away the metal change point plate which was holding the level (height) while the instrument was moving forward. The plate was fixed in the normal manner, on blue ice. The loss of this point meant re-levelling from the previous temporary bench mark, a distance of half a mile. This illustrates the necessity of having substantial temporary bench marks at reasonably small intervals, say half to one mile.


In whiteout and drift conditions it was hard to see the white painted stakes. As this was necessary for keeping on line it was quite a problem. It was desirable not to have flags on the ablation stakes because the Glaciologist was using them to measure ablation. (Flags caused stakes to lay over or even fail.) Even with flags attached the stakes sometimes could not be seen in drift. The most satisfactory solution was to leave the tripod over the rear stake, drive to the forward stake, then carefully drive back along the line towards the tripod, which could easily be seen because of its dark colouring. Levelling then followed the vehicle tracks.


In all this work one had to be wary of small crevasses. It can be most uncomfortable having one’s leg drop down a gaping hole in the surface. This did happen several times, but fortunately with no more injury than that of the dignity of the person concerned.


The Instruments

The collimation adjustment of the Autoset Level appears to alter with temperature. Error amounts to 0.01 feet per 10°F. The instrument was adjusted at 0°F at the beginning of the job. It was not re-adjusted even on a cold day when the error was 0.025 feet. Because the error was proportional to temperature change the instrument is considered by me to be quite stable, and the use of balanced backsights and foresights would balance the collimation error. Collimation checks were carried out regularly. (The readings were booked.).


A copy of the Watts Autoset manual can be viewed at this link.


The Autoset was used on a Wild T2 tripod because the instrument’s own tripod was too low and very flimsy. Although the Autoset does not require a tripod as solid as a bubble level, the more solid tripod seemed less likely to vibrate in the wind. Height was the main reason for choosing the Wild tripod.


The speed of setting up, coupled with the ability to operate all screws and knobs while wearing heavy gloves, was a huge advantage of the Autoset.

The wooden, telescopic, Sopwith Staffs tightened in the cold and the extension of extra leaves was quite an effort. This also imposes strain on the clips which suffer a sharp tug as they engage. The length of the staffs was checked while cold and found to be satisfactory.


The detached staff bubbles were fiddlesome to handle with heavy gloves. The bubble on one was broken by dropping on the ice.


The change point plates, as described on page 1 seemed satisfactory. For use on blue ice they were struck firmly onto the ground by hand and each of the three sharp points makes a small hole, which is all there is to hold the plate in position. Care has to be taken, before using the change point, that the feet are really held firm in these holes and are not sliding slightly. When working in snow cover the plate is pushed firmly in with the foot. The plate usually rests on the snow, which is wind packed and usually quite firm. The three legs serve to hold the plate laterally.


Levelling equipment in surveyor’s office at Rymill Hut Mawson. From left Autoset level on tripod, staff change plates, staff bubble and Sopwith staff.

David Carstens photo.




Permanent bench marks resulting from this section of work are:-


1.    PSM Brass Plate, 15 yards south of the door of Rymill, the Survey Office hut.

2.    PSM Brass Plate, beside the original beacon, a black painted drum, on Mawson Rock, the highest rock feature at Mawson.

3.    PSM Brass Plate, at the base of the peak on which the Tellurometer station is located in North Masson Ranges. This PSM is just above the scree line, 100feet above the ice surface of the melt lake, and is on the south-east side of the peak.


These points are more fully described in the official Station Summaries.

The datum for the survey was taken from the Mawson Tide Gauge Bench Mark, value 6.42 feet above Mean Sea Level.


This value was determined in 1955 and 1956 by Geologist Peter Crohn. The Bench Mark consists of a small pimple of rock surrounded by a concrete wall twelve inches square, approximately, and three inches high. Its position is indicated on maps of the Station.


Appended is a schedule of the time involved in completing the work.


Finally I would like to thank the O.I.C. and all the others who cooperated in this work.





June, 1963.                                                             D.R.Carstens





Retyped by D. R. Carstens, August 2015         (Computer file: Mawson to Rumdoodle Level Traverse)



Additional Notes

The performance of this levelling, in Antarctic conditions, was facilitated by the previous levelling surveys I had had done and in particular using an Autoset Level in Australia. This was valuable experience to be adapted for the locality at Mawson.


The knob on the base plate was an important provide a fixed point so errors caused by the contact point of the flat base of the staff were eliminated.


Footnotes and Postscripts.

               The re-typing of this report has copied the wording, the format, punctuation and content except in a few occasions where some variations to words or abbreviations clarified the meaning. Minor correction and addition is included from reference to the original hand written report. This cross-check resulted in some improvements in the hand written report. Some additional punctuation has been added in the belief that this improved the readability of the text


               Temptation to add explanations in some places was resisted. Where it was considered an advantage some additional comment is inserted in brackets.




Appendix A


David Carstens’ 1962 level traverse route and staff change points.

Diagram prepared by Paul Wise 2018.



Appendix B

David Carstens, 1962 Level Traverse

Mawson – North Masson Range

Values of Change Points along the Traverse

Refer to Appendix A for locations of Change Points

Change Point

Height (m)


































































Monday   March 19.      Planned to commence placing of Ablation Stakes. Drift and vehicle repairs prevented start.

Worked on repairing tailpipe of Snow Trac No 2.

Tuesday   March 20.      Nightwatch duties.

Wed.   March21.            Finished Nightwatch and went to Plateau, commencing to place Ablation Stakes and read angles. With Glaciologist.

Thursday   March 22.    Placing more stakes. Slow work in drift.

Friday   March 23.         Late start. Vehicle hard to start. Took 2 hours work to start. Continued placing ablation stakes.

Saturday   March 24.     Placed and levelled two PSMs in Mawson area. (On rock).

Sunday   March 25.       Day off. Drifting.

Monday   March 26.      Drifting. Day in Office.

Tuesday   March 27.      Started levelling. (Ted Foley, Ian Landon‑Smith). Nightwatch.

Wed.   March 28.           Finished Nightwatch and prepared to continue work on levelling. Neither Snow Trac serviceable.

Thursday   March 29.    I commenced to repair Snow Trac No 1.

Friday   March 30          Worked on Snow Trac giving it a complete overhaul. Worked Saturdays and Sundays.


Tuesday   April 10.        One day on Mess duties. One day lost with Zinc oxide poisoning.

Wed.   April 11.              Collected seals using Snow Trac and did short trip to plateau.

Thursday   April 12       Assisted in taking gear to Fischer Nunatak Met Station.

Saturday   April 14.       Three trips in Snow Trac.

Sunday   April 15.          Nightwatch.

Monday    April 16.        Sleep after Nightwatch.

Tuesday   April 17.        Fresh start on levelling. Some drift.

Wed.   April 18               Continued levelling. Snowing, no wind. (Dave Wigg, Ken Tate.)

Thursday   April 19.      Levelling. No wind and snowing. (D. Wigg & C. Melvold.)

Friday   April 20.           Mess Duty. High wind and drift & also Snow Trac not available.

Saturday   April 21.       Levelling. Some wind caused frostbite. (J Freeman, J Phillips.)

Sunday   April 22.          Levelling. Half Day. Easter Day. (D. Wigg, O Ferguson.)

Monday   April 23.        No levelling done. Went out hopefully; but too much wind and drift. (J. Williams, P. Trost.)

Tuesday   April 24.        Levelling. Temp ­17°F. Light wind & drift. (J. Freeman, R. Harvey.)

Wed.   April 25.              Levelling. Fine to start with but drift increased during day. Had difficulty in navigating home. (D. Wigg, J. Branson.)

Thursday   April 26.      No work. High wind and drift. Reducing levels.

Friday   April 27.           Levelling. Drifting heavily 4 miles from North Masson where I intended to work but found conditions calm beside range. (T. Foley, K. Mc Donald.)

Saturday   April 28.       Blizzard. No Levelling.

Sunday   April 29.          Day off. Cut my finger. Two stitched inserted.

Monday   April 30.        Worked on Snow Trac. Running repairs & service.

Tuesday   May 1             Completed Snow Trac & some office work.

Wed.   May 2                  Levelling continued. Camping in caravans North Masson Ranges. (M. Single, K. McDonald, I. Landon-Smith.)

Thursday   May 3          Levelling completed. (Same Team). Weather fine but cold.


Note:-Ten days actually working in the field for levelling, after second start. That is for 12 miles route length.


                                                                                D.R. Carstens.