The Dry Valleys gravity survey was designed to compliment the Sea Ice gravity survey made earlier in the season and to fill gaps in the existing data measured by Bull (1962, 1964), Smithson (1971), Stern (1978) and Hicks, Bennett and Wendon (1980). A detailed gravity traverse was completed down Taylor Valley from Northwest Mountain to the sea, with stations at 1 to 3 km intervals. Gravity readings were also made at approximately 10 km spacings in the Lower Ferrar and Blue Valleys and on the Dailey Islands.

Gravity was measured with a Worden gravity meter relative to the Scott Base Gravity Ease for which absolute gravity is 982992.6 mgals Hatherton (1961). Precision of measurement is within 0.3 mgals. Heights of stations were determined barometrically relative to surveyed heights of trig stations and lake surfaces; heights are known to within ± 5 M. Where available the 1:50 000 USGS topographic maps which now cover most of the survey area were used. Terrain corrections for Hamner Zones B to D were estimated in the field and for zones E to M templates were used on the topographic maps. The total error in determination of Bouguer Anomalies is less than 2 mgals.

References

Bull, C. 1960. Gravity Observations in the Wright Valley Area, Victoria Land, Antarctica. N.Z. J. Geol. Geophys. 3: 543-52.

Bull, C., 1962. Gravity Observations in the Koettlitz Glacier Area, Southern victoria Land, Antarctica. N.Z. J. Geol. Geophys. 5: B10-19.

Hatherton, T. 1961. N.Z.D.S.I.R. Bull. 140. 117 p.

Hicks, S.R.; Bennett, O.J.; Wendon, M.J. Gravity Models of the Lower Taylor Valley, Antarctica, in press. N.Z. J. Geol. Geophys.

Stern, T., 1978. Gravity Survey of the Taylor Glacier, Victoria Land, Antarctica. Geology Department, VUW Publ. No.8.

Smithson, S.B., 1972. Gravity Interpretation in the Transantarctic Mountains near McMurdo Sound, Antarctica. Geol. Soc. of Am. Bull. 83: 3437-42.