2008-09 End of Season Field Reports

Physical Properties of the WAIS Divide Deep Core (I-168-M)
NSF-OPP supported
PIs: Richard Alley (Pennsylvania State University) and Kurt Cuffey (University of California-Berkeley)

Field Team:
John Fegyveresi

Season Objectives:
To characterize the physical properties of the core, gain additional useful information from observing snow pits and surface evolution, and conduct exploratory research on drilling chips to see whether information can be gained from them to help the drilling effort.

Field Season Overview:
Note: Due to the brittle nature of the ice drilled this season, it was known in advance that the number of physical properties samples that would be obtained from the deep core would be limited. Because of this fact, the first half of the field deployment was primarily dedicated to performing ice-chip studies, snow pit studies, and assisting with core-handling duties. Towards the end of the season, once drilling reached more-ductile ice, several samples were obtained and mounted.

John Fegyveresi deployed to Antarctica December 1st, handled cargo in McMurdo, and then to WAIS Divide on December 9th. During the field season, John regularly photographed ice chips produced by the drilling (10-12 images per sample, both dry and suspended in drill fluid), recorded chip characteristics, and recorded drilling parameters such as drill-shoe configuration. John logged core-break tensions for each run. During this time, John also dug two snowpits from which he took various density and isotope samples. In addition, John documented various surface and crusting observations and also assisted the science technicians with various core handling duties.

For the last 2 weeks at the WAIS Divide camp, John was able to obtain 18 physical properties samples. These samples included both horizontal and vertical sections from depths of 1340 meters through 1500 meters, at 20 meter intervals. These samples were cut, prepared, mounted, and labeled on-site. Because there was no ice leaving the camp this season, all 18 physical properties samples were placed in an ISC box and stored in the Arch basement with the ice cores. Next season, these samples will be shipped out to the NICL at the beginning of the season so that both thin sections and bubble sections can be prepared and photographed. The bubble section images that will be created from these samples (as well as those from last year's samples), will eventually be used to help model paleoclimates of West Antarctica.