Description
Summary:Survey report for Casey Station, 1978, by Peter Quinn. Taken from the survey report: Purpose: - To provide survey expertise for the Glaciology Traverses south of Casey. - To do survey work for the building program as required by the Antarctic Division. - To establish new control stations in the Windmill Islands. Project Summary The major survey events are summarised below. The remaining time was spent in preparations for the events and generally helping in the maintenance of the station. Commonwealth Bay 18-19 Jan, 1978 The JMR was run on Bage's Astro site for 20 huors. This site was connected to a bench-mark adjacent to Mawson's Hut: vertically by trig levelling and horizontally by a sun azimuth. Horizontal angles were read from the bench-mark to various local features. Autumn Traverse 15 March - 23 May 1978 The first traverse was under-taken chiefly as a fuel-depot establishment exercise for the spring traverse. The 1975 fuel-depots at B021, A024 and A034 were re-established. JMR observations were taken at all major stops, ice radar and accumulation and gravity observations were taken along the journey. A new JMR station, V150, was established fifty kilometres south of A034, and a strain grid placed and measured here too. Some seventy odd drums of A.T.K. were added to the depot at A034 leaving a total of one hundred and eighteen for use on the later traverse. The trip proved an excellent learning experience for the members of the party. New Site Surveys 28 May - 20 Aug (not continuous) 1978 This was a stadia survey undertaken for the Antarctic Division on a site near Casey. The contour interval was 1 metre. Control was introduced from the local network by resection. Available daylight was down to one hour at one stage so the work progressed slowly. Assistance from the station personnel was required; the normal operating team consisted of two staffmen and one booker. The stadia observations were reduced using a HP65 and spot heights plotted at 1:500 scale. The completed contour map was photographed and sent to Melbourne by a facsimile radio technique. Swain Islands Geodetic Survey 27 June to 23 August (not inclusive) 1978 and 19-21 Jan 1979. Five trig stations were established in the Swain Islands. The stations consisted of a 1.4 metre length of .05 metre steel snowpole cemented into the rock. Tellurometer measurements were made to connect the stations to each other and to the existing Casey - Wilkins network, and the fixes were strengthened by T3 theodolite measurements in the summer. Spring Traverse 6 September to 23 December 1978 This was the major event of the year - a traverse of 2300 kilometres taking 110 days. The chief purpose was to extend the IAGP network established in 1975 southward to a point which crossed the Russian Traverse line from Mirny to Dome C. Cones were placed every two kilometres south of A034, with JMR stations at intervals of fifty kilometres. Gravity readings were made at each cone, ice radar depth and barometric heights recorded continuously along the way. Strain grids were placed at V300 and V450 and tellurometer measurements of all arms and the perimeter made. The requirement for at least twenty precise passes meant a stay of forty-eight hours at JMR stations. The party consisted of two independent traverse teams so often two sets of Doppler observations were taken concurrently. To navigate an astro-compass and odometer were used enabling a dead reckoned position at any instant to be computed. As an origin for these D.R. positions each JMR station was fixed by position lines on the sun, the moon or stars.