Johnson-Pyrtle, A. Department of Oceanography, Texas A&M University, apyrtle@ocean.tamu.edu

 
TRANSPORT OF CS-137 INTO THE ARCTIC'S LAPTEV SEA AND THE LENA RIVER ESTUARY AS EVIDENCED BY MARINE, ESTUARINE AND LACUSTRINE SEDIMENTS
 
This study has shown that there are relatively elevated levels of Cs-137 in surface sediments located in the Arctic's Laptev Sea-Lena River estuary. Studies which were focused on the Kara Sea-Yenisey River region have reported similar results. The average Cs-137 activity in surface sediments from the Lena River estuary is 84% higher than that of the Laptev Sea marine sediments. However, unlike the Yenisey River estuary, the Lena River estuary has no known local source of Cs-137. This study has examined several possible factors that may have led to the increased radionuclide activity determined in the Laptev Sea-Lena River estuary region. Cs-137 activity and grainsize distributions were determined for all surface samples. In addition, chemical and mineralogical compositions were determined for a subset of surface and down-core samples. Cs-137 inventory values for several cores have been obtained. Analysis of marine, estuarine and lacustrine sediments indicate that the enrichment of Cs-137 in the Lena River estuary is the result of favorable environmental conditions which have lead to the retention of this radionuclide. These features include: low bottom water salinities, significant amounts of fine sized particles, substantial smectite-illite concentrations, and additional Cs-137 being introduced into this region by the Lena River.
 
Day: Thursday, Feb. 4
Time: Poster
Location: Sweeney Center
 
Code: CS63TH0256S