MIGRATION OF GLOBAL RADIOACTIVE FALLOUT TO THE ARCTIC OCEAN (ON THE EXAMPLE OF THE OB'S RIVER DRAINAGE BASIN)

• Published in: Radiation Protection Dosimetry
• Main Authors: Miroshnikov, A., Semenkov, I.
• Format: Text
• Language: English
• Published: Oxford University Press 2012
• Subjects: Paper; Arctic; Arctic Ocean; Kara Sea
• Online Access: http://rpd.oxfordjournals.org/cgi/content/short/ncs195v1; https://doi.org/10.1093/rpd/ncs195

This article provides an assessment of the impact of global fallout on 137Cs contamination in the bottom sediments of Kara Sea. The erosiveness of 10th-level river basins was estimated by landscape-geochemical and geomorphological characteristics. All 10th-level basins ( n =154) were separated into three groups: mountain, mountain-lowland and plain. Four different types of basins were identified depending on the geochemical conditions of the migration of radiocaesium in the plain and mountain-lowland. Classifications of types were carried out using the geographic information systems-based approach. The Ob River's macroarena covers 3.5 million km2. Internal drainage basins cover 23 % of the macroarena and accumulate whole radiocaesium from the global fallout. The remaining territory is transitional for the 137Cs. The field research works performed in the three plain first-level basins allow one to estimate the radiocaesium run-off. The calculations show that 7 % of 137Cs was removed from the first-level basin in arable land. Accumulation of radiocaesium in the first-level basin under undisturbed forest is 99.8 %. The research shows that 137Cs transfer from the humid basins is in the range of 6.9–25.5 TBq and for semi-humid basins 5.6–285.5 TBq. The areas of these basins cover 40 and 8 % of the Ob River's macroarena, respectively. Drainage lakes and reservoir drainage basins make up 22 % of the macroarena. Mountainous and semi-arid drainage basins cover 7 % of the macroarena.