Science Requirements: Replicate Coring for the Foro 3000 Drill

The Foro 3000 drill is the deep ice coring drill that will be used for ice coring at Hercules Dome, Antarctica. The IDP Science Advisory Board has identified development of replicate coring capability for the Foro 3000 drill as a high priority in the IDP Long Range Science Plan 2020-2030; the first step in the process is the establishment of the IDP Science Requirements for Replicate Coring. When the Foro 3000 drill development was under consideration, a comparison of DISC versus Foro 3000 capability and logistics (Johnson and Kippenhan, 2017) indicated that a passive design for replicate coring would be advisable. A preliminary analysis (Zeug, 2017) found that a reliable approach using a whipstock in the parent borehole is feasible for retrieving replicate cores at specified depths from the parent borehole. There may be other approaches as well, but they must also fit within the overall goal of avoiding the electronic and mechanical complexity that would accompany a steerable drilling system, which is a more costly endeavor than is feasible now. From discussions organized by IDP with iterative discussions between representatives of the ice core science and borehole logging science communities and IDP staff, the following are the science requirements for Replicate Coring Capability for the Foro 3000 drill.