Proposed ITASE Traverse Routes and Implementation
A preliminary plan of proposed national and multinational oversnow traverses was prepared from the national reports presented in Cambridge. The plan is shown in Figure 12. Twelve nations have proposed oversnow traverse activities for the period 1997 to 2003. The proposed traverses cover a significant part of East and West Antarctica, building on the existing coverage of glaciological traverses since the 1950's. It is proposed that firn/ice cores will be retrieved at 100 km intervals along these routes. On many of the routes continuous measurements of snow accumulation will be made using snow radar.
The proposed traverse plan is indicative only and is subject to approval at the national programme level. It is hoped that as the ITASE plan is formulated, these proposed routes can be optimised to gain the best geographic coverage.
These traverses will require good liaison with and logistic support from the Council of Managers of Antarctic Programs (COMNAP) to ensure that the appropriate level of traversing equipment is available. International collaboration is encouraged to share the burden of logistic requirements and to enhance the scientific expertise and use of national and institutional laboratories for ice core analysis. The traverses will be conducted using a variety of logistics; from the lightweight approach using twin track skidoos and sleds; to heavy plant including bulldozers and Caterpillar Challengers and large snowmobiles such as Kassborers. Some ITASE traverses are planned to be attached to inland station resupply traverses, and are considered to be `traverses of opportunity'.
Ice core recovery will nominally be conducted at 100 km intervals along ground-based sampling sites. Minimum 200-year ice core multi-variate (Tables 1 and 2) records will be retrieved requiring similar penetration depths to those specified for the sample drill sites in West Antarctica shown in Figure 6. Shallow (10-40 m) depth ice cores can be drilled and retrieved using lightweight manual (unmotorised), pipe string extendable hand augers such as the PICO auger. These augers can be extended by 2m long drill pipe extensions to depths up to 40m. Medium depth ice cores (50-200 m) are usually drilled using a cable suspended electromechanical drill, and operated from a portable generator.
Annually resolved records will be developed from a suite of dating tools (Tables 1 and 2) sampled either continuously or at discrete sub-annual intervals (eg., 8-10 samples/year). Surface sampling (fresh snow, snowpit) will be conducted at each ice core site and more frequently if needed. Atmospheric sampling will be conducted at selected ice core sites along with AWS units. Specific methods for sample collection along these traverses are presented in Appendix B of this report.