Cosmogenic Radionuclide in Ice Cores

Below 54 m, we coordinated our sample collection with the continuous ion measurements. Although we received more than 800 melt water samples, more than 25% of these samples were not suitable for our work, either because of partial loss of solution during transport, unclear depth information, or because the sample mass was too small. We have selected over 600 samples, including some uncertainties of sample documentation that cover less than 75% of total depth of core.

Presently, chemical separation and purification of Be and Cl for all samples has been completed. 10Be AMS measurements are also nearly completed. Although Cl sample preparation has been completed, about 90% of the 36Cl measurements and Cl concentration measurements at LLNL need to be performed. Thus, the data are still preliminary and fragmental.

Each melted ice sample was passed through a 30 µm Millipore filters before chemical separation of Be and Cl. A photograph of each filter was taken and digitized for archival storage. These digitized pictures will be available for distribution to other investigators.

This material is based upon work supported by the National Science Foundation under Grant No. OPP-0126343.