Waters were sampled by first drilling through the ice and then lowering a Go-Flo bottle to the indicated depths. Retrieved samples were then spit into separate containers for analysis. Following the sampling of water, a shallow gravity corer with plastic lining was  attached to steel cable  and lowered through the ice hole and down to the lake bottom. The corer was dropped the final 3 meters. Core recovery ranged from only a few centimeters to 25 centimeters. Once recovered, the sediments were stoppered and transported vertically to Crary Laboratory at McMurdo station. Sediment was separated along several intervals of each core and sediment and pore waters were separated by centrifugation.  

 

Sediment samples were shipped to Rice University where they were freeze dried and then powdered. Iodine was volatilized from the samples using a pyrohydrolysis apparatus at 900 degrees Celsius, and the vapors were trapped in a solution of tetramethylammonium hydroxide. The trapped iodine was diluted then analyzed for stable I-127 at the ICP-MS facility of Cin-Ty Lee at Rice University. Methods for analysis are described in: Schnetger, B., and Muramatsu, Y., Determination of the halogens, with special reference to iodine, in geological and biological samples using pyrohydrolysis for preparation of inductively coupled plasma mass spectrometry and ion chromatography for measurement, Analyst, 121:1627-1631.