Recommendation of the Ice Core Working Group to the National Science Foundation on Deep Ice Core Drill Options

The Ice Core Working Group (ICWG) met on March 11-12, 2003 to discuss and recommend a deep drill design to the NSF. The ICWG had earlier presented NSF with a set of Science Requirements for deep ice core drilling, and these requirements were used by a deep drill design team to formulate four options. In brief, these options were:

Option 1. EPICA drill with minor modifications, 10.0 cm diameter
Option 2. EPICA drill with major modifications, 10.0 cm diameter
Option 3. DISC drill based on KEMS design, 10.0 cm diameter
Option 4. DISC drill based on KEMS design, 12.2 cm (nominal) diameter

RECOMMENDATION #1. The ICWG recommends Option 4 as our first choice based on our judgment that this option is most likely to meet the Science Requirements. In particular, the goal of recovering sufficient quality and quantity of core in warm ice for continuous-melter chemistry and biology studies is most likely to be met under Option 4. The ice core biological record has never been investigated in ice core studies of climate change, and acquiring sufficient ice to include biological studies opens a new area of science in polar ice coring efforts. Critical tests of abrupt climate change mechanisms that require replicate coring technology are most likely to succeed under Option 4.

RECOMMENDATION #2. As a second choice, we recommend Option 3. The Science Requirement of high-quality core in warm ice is likely to be met by this Option. The Science Requirement of replicate coring is more likely to be met by this Option than by Options 1 or 2.

RECOMMENDATION #3. Our third and last choice is Option 1. This Option will probably not meet all the Science Requirements due to difficulty recovering quality core in warm ice and problems with replicate coring.

RECOMMENDATION #4. We recommend that Option 2 be removed from further consideration, because this is essentially a new design lacking the security of a proven design but without the advantages of a totally new design.

RECOMMENDATION #5. Collecting the Inland Site core on the planned schedule is a higher priority than fully developing and testing replicate coring.

RECOMMENDATION #6. Development of short (20 m) replicate coring capability is a higher priority than long (400 m) replicate coring capability. However, note that we recommend that if Options 3 or 4 are chosen they be designed for replicate coring.