Abstract:
Taken from sections of the Report:
Introduction and Project Outline
The 2000/01 MAGIP field program for the Antarctic survey season has been scoped to continue and extend the objectives of the Mapping and GIS section of the Antarctic Division in support of the ANARE mapping program (ANAREMAGIP) as well as providing survey support for other ongoing ANARE science programs.
The field component of
... the program in the Davis/ Mawson area for this season was to primarily establish ground control for existing 1:30000 photography in the Larsemann Hills. Additional tasks included updating of station summaries and the retrieval of data from the tide gauges at Law Base, Mawson and Davis Stations.
The original Antarctic Division's Brief to Surveyors is included as Appendix A of this report.
David Hurd from the Survey and Geographic Information Services Group of Hydro Tasmania and Arthur Moerke, a volunteer assistant, have been the field operatives throughout the season.
The survey program consisted of the following major areas:
* Photo control
- Larsemann Hills
* Completion of various tasks relating to the Davis tide gauge
- Installation of second tide gauge at Davis
- Downloading the existing tide gauge at Davis.
- Timed water-level measurements.
- Precise levelling connection of the tide gauge bench marks with the ARGN GPS site at Davis.
* Completion of similar tasks described for the tide gauge at Davis Base with the gauge located at Law Base.
* Lake levels within the Vestfold Hills.
* Inspection and analysis of the reader board and pole at Deep Lake.
* Providing GPS coordinates for all uncoordinated survey marks in the Vestfold Hills
Additionally other unscoped inclusions in the program included
* Update of station summary for Mawson station
* Engineering surveys at Davis, Zhongshan, Progress 2 and Law Base.
* Completion of similar tasks described for the tide gauge at Davis Base with the gauge located at Mawson station.
Discussions with Mapping Officer Henk Brolsma prior to departure (26/9/00) agreed that the Auslig Surveyors working in the area this season would utilise their equipment to complete the height connections between the tide gauge benchmarks at Davis Station and AUS99 and to complete the level run as detailed in priority 2
Similarly with the height connection to the Law Base GPS station NMS278 and AUS99 at Davis.
The scope specified that GPS locations were to be processed relevant to the base station at Casey. It was assumed that this was an error and was intended to specify AUS99 at Davis.
Later discussions with the Auslig surveyors also lead to the extension of their involvement to include the tide gauge benchmark at Law Base and the benchmark located on the peak overlooking Law Base, C1.
Recommendations
Several recommendations can be made from the experiences over the summer.
It is understood that there is a differential GPS transmitter system at Davis, which is either not functioning or is turned off. During the stay at Davis we were advised that the expeditioners last winter spent days digging to locate a series of junction boxes that required repair. A GPS unit could be provided with accuracies capable of locating the assets in a very short time. The ability to locate these buried assets could have a significant effect on station life when considering the importance of quick repairs before anything freezes. A system for all station may be worthwhile as a safety measure.
Alternatively, the establishment of a more visible control network possibly in combination with cane line locations and the basic training of one or two expeditioners in the use of a theodolite and tape, which could stay on station, may enable relatively rapid relocation of junction boxes etc.
The tide gauge location was not possible at Mawson station because of the amount of algae/vegetation that accumulated beneath the ice. Also there was significant difficulty in accessing the gauge at Law Base because the ice had broken up but not out. It was fortunate that the weather conditions provided a pond which allowed for access. Assuming that a similar level of growth was present below the ice at Law Base prior to the break up then accessing the gauges in the future should possibly be based on a balance of growth conditions and the condition of the ice.
It is recommended that all poles related to the tide gauge at Davis be repainted annually to ensure that they are readily available when boating allows.
Considering the anticipated shutting down of the old tide gauge at Davis, the establishment of the new gauge may justify a higher priority listing. The installed mounting block for the new gauge has not been painted with anti-fouling paint and because of this will continually be subjected to weed growth. Perhaps it could be arranged so that the barge at Davis could be used toinstall the new gauge and a replacement mounting block in a single operation. Possibly it could be deployed adjacent to the unused, installed block.
Some form of shore mounted interface with the tide gauges would save significant amounts of time and avoid many logistical issues in regard to boat time and organisation of drivers. Law Base does not have boats or drivers so any future access to the Law Base gauge will need to either arrange for the transportation of these resources or ensure that they are in the area before the ice breaks up.
The timed water level measurements could be made more efficiently and over a longer period with the summer deployment and retrieval of some form of GPS buoy similar to what the university has been using. Alternatively the timed water level measurements using a video camera with timed exposures may be an option.
A handheld GPS with some form of computer interface would be a great asset in the location of benchmarks in the ice-free areas. Having a list of coordinates that could be loaded into a lightweight unit would allow for rapid location of marks prior to deployment of heavy equipment or confirmation of mark identification for levelling. This should be seen as highly desirable.
As mentioned in the 98/99 report the use of a digital camera for documentation purposes should be seen as essential in the antarctic environment.
Logistically, it would seem that registration in the ASAC system ensures that expeditioners are not left off lists and that equipment and resources are more easily available. While this did not represent any immoveable barriers, some form of registration may make things easier.
It seems that the levelling in the Vestfolds is given a low priority but is an ongoing project. The number of lakes levelled varies from season to season from around seventy to three or four. While the lakes are currently levelled on an opportunistic basis a suggestion may be to either place a higher priority on completing the extensive lake list or reduce the number of lakes to be levelled so that a continuous data set may be generated. I am under the impression that there has been a thesis written on the lake levels and maybe this could be used as a guide to which lakes should be levelled annually. Possible continuously levelling lakes throughout a season may also provide indications of movement throughout the season in addition to the annual snapshot. This could be particularly relevant in regard to accessing the deep lake reader board.
The rock drill battery is incapable of holding enough charge to complete more than three drill holes. It may be worthwhile to either recondition the battery or replace it. 
