Lower Victoria Valley (13 Nov – 1 Dec)

1. Sample ice in modern glacial and lake environments at snout of Lower Victoria Glacier. Sample buried ice and ice cemented sediment down valley (stream) from Lower Victoria Glacier.
2. Sample several soil profiles for Atm Be-10 on top of buried ice, down valley from Lower Vic Glacier.
3. Survey profiles of meltwater channels around the Packard Glacier for a paper by Atkins and Dickinson entitled 'Landscape modification by meltwater channels at margins of cold-based glaciers'.
4. Testing of resistivity soundings/profiling over known occurrences of ground ice (both massive and ice cemented sediment).

Beacon Valley (1 – 10 Dec)

1. Sample ice in modern glacial and lake environments around Beacon Valley. Sample buried ice and ice cemented sediment in central Beacon Valley as well as one of the side valleys (University or Farnell). Also to sample the main body of ice in central Beacon Valley to look for spatial differences/variations since vertical variations are nil.
2. Sample several soil profiles for Atm Be-10 on top of the buried ice.
3. Testing of resistivity soundings/profiling over central Beacon Valley. These should follow the gravity and GPR lines of Ron Sletten.

Summary

The four members of the event spent 17 days in Lower Victoria Valley from 13 Nov to 1 Dec and 9 days in central Beacon Valley from 1 Dec to 10 Dec. Ice and permafrost samples (Table 1), resistivity soundings, and topographic profiles were completed in both of these areas. Resistivity soundings may be useful in imaging subsurface ice in Beacon Valley. However, variable conditions (thawing) on the surface of the Lower Victoria Valley caused unstable resistivity readings and these yielded ambiguous results in this area.

Method

Sampling sites were selected for the occurrence of massive relict ice. At each site, a 1.5 square metre pit was dug into the ice free soil or sediment above the relict ice. In some areas ice cemented sediment was above the relict ice. This was sampled by means of a small gasoline powered hammer drill with a diamond or carbide core bit. Once into the relatively sediment-free relict ice, a sipre auger with carbide cutters was used to core to a depth of about one metre.

Ian Graham and co-workers at GNS, Lower Hutt, will carry out the dating method using atmospheric 10Be. The procedure will be similar to that used in previous studies (Dickinson et al. 2003b; Graham et al. 1995; Graham et al. 2002). To streamline the method, we will only process the >62 micron fraction of sediment which we believe contains most of the Be.

Samples of relict ice taken at 5cm intervals down the sipre auger cores were subsampled and sent to Ron Sletten at the University of Washington for chemical and isotopic analyses (see supporting letter).

Resistivity soundings (one dimensional, vertical profile) were made in selected locations where relic ice was sampled. The results are expected to help characterize the extent and depth of the relict ice. Previous attempts by A. Hubbard (pers. comm. 2001) and H. Conway (pers. comm. 2003) to define the depth of the ice by ground penetrating radar (GPR) have yielded ambiguous results because of salts that have accumulated in the soils and ice. Apart for these two surveys, other geophysical surveys to define the depth of the ice have not been conducted in Beacon Valley.