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Arctic Ocean sea ice drift origin derived from artificial radionuclides
P Cámara-Mor1, P Masqué, J Garcia-Orellana
1Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona, E-08193. Bellaterra, Spain. patricia.camara@uab.es
The Science of the Total Environment
|May 4, 2010
Summary
Anthropogenic radionuclides in Arctic sea-ice sediments reveal distinct geographical origins, aiding in tracking pollution sources. Cesium-137 and plutonium isotopes help identify sea ice origins from specific Arctic regions.
Area of Science:
- Environmental Science
- Radiochemistry
- Oceanography
Background:
- Nuclear activities have introduced anthropogenic radionuclides into marine environments.
- The Arctic Ocean receives contaminants from global fallout, regional fallout, nuclear reprocessing, and accidents.
- Sea ice formed on continental shelves incorporates sediments with radionuclides, transporting them across the Arctic.
Purpose of the Study:
- To analyze anthropogenic radionuclides in Arctic sea-ice sediments (SIS).
- To combine new data with existing measurements to understand radionuclide distribution.
- To identify the geographical source areas of sea ice based on radionuclide signatures.
Main Methods:
- Collected and analyzed SIS samples from five Arctic cruises.
- Measured activities of Cesium-137 (137Cs) and Plutonium isotopes (239,240Pu).
- Calculated the 240Pu/239Pu atom ratio and compared it with potential source regions and global fallout data.
Main Results:
- Geographical differences in 137Cs and 239,240Pu activities and 240Pu/239Pu ratios were observed.
- These distributions align with major Arctic sea ice drift patterns (Transpolar Drift and Beaufort Gyre).
- The 240Pu/239Pu ratio effectively distinguished ice originating from the Kara-Laptev Sea and Alaskan shelf.
Conclusions:
- Anthropogenic radionuclides in SIS can be used to determine the geographical source area of sea ice.
- While the 240Pu/239Pu ratio is a useful tracer, 137Cs and 239,240Pu activities provide complementary information when the ratio is ambiguous.
- This study enhances our understanding of contaminant transport pathways in the Arctic Ocean via sea ice.
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