Document DetailsIPICS Oldest Ice Core - Science Plan
|Abstract:||The international ice core community has, under the auspices of International
Partnerships in Ice Core Sciences (IPICS), defined four priority projects for the next
decade or more. One of these is to obtain the oldest possible ice core record from
Antarctica. An ice core record reaching back to or towards 1.5 Ma ago would be a
major step forward in understanding Quaternary climate, and would further our
understanding of the relationship between greenhouse gases and climate.
In order to attain the goals, it is essential to carry out a very significant preliminary
programme to provide assurance that they can be achieved. In particular, there must
be reasonable certainty that at least 1.3 Ma will be achieved, and a series of survey
and modelling steps will be required to determine suitable sites. At least two cores
will be required in order to provide replication in a regime where flow disturbance is
possible. Based on ice thickness, bedrock topography, accumulation rate and basal
temperature, the likely search region is a broad area of East Antarctica, with a region
south of Dome A provoking particular interest; other areas should also be researched.
After the current planning stage, a broad area survey and a season of shallow drilling are needed in any candidate region. This will provide enough data for a more targeted modelling effort that will provide candidate sites. Multinational consortia would be expected to form in order to tackle each candidate site. Before being confirmed as an "oldest ice" site, each candidate should undergo more detailed local survey and we would also recommend the drilling of a 300 m core to reach the last glacial maximum before heavy equipment is committed. Drilling should not pose any radical new problems, but a new drill fluid will be required, and the likely areas for drilling will be logistically very difficult. A decision will be needed on whether to do significant core processing in the field, or to have a minimal science party in the field and use a dedicated processing centre.
Such a programme will be beyond the capacity of any one nation, and we propose ways of harnessing the efforts at all stages of the project through to analysis and publication, while apportioning credit without excessive bureaucracy. Previous successful ice core projects provide a possible model. However, the details of such a scheme require much further discussion. It seems realistic to design a programme that could deliver oldest ice within about 10 years from initiation. The next step should be for the IPICS SC to agree a framework for such a programme, and to set up a formal "oldest ice" IPICS group to push the implementation of such a plan.