One of the main sources of anthropogenic radionuclides in the ocean is the global fallout resulting from the nuclear tests that had been conducted by the United States, the former Soviet Union, and other countries between 1945 and 1990 mainly in the Northern Hemisphere. The most extensive fallout was observed in the middle latitudes of the Northern Hemisphere in 1963 immediately after the nuclear tests of 1961-1962 conducted by the United States and the Soviet Union. In 2006-2009, under the auspices of an agreement between the Vernadsky Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences and the National Center of Antarctic and Marine Research of the Ministry of Earth Sciences of India, cooperative geological and geochemical investigations were organized in several regions of the Indian Ocean. During these expeditions, the spatial distribution of anthropogenic radionuclides was investigated in the water of the Indian Ocean. The main results of these investigations are reported in this paper.

Activities were recalculated to March 30, 2009 to account for radioactive decay.

Supplement to: Stepanets, Oleg V; Borisov, Alexander P; Ligaev, Alexander N; Travkina, A V; Solovjeva, Galina Y; Shmel'kov, Boris (2011): Distribution of anthropogenic radionuclides in the surface waters of the Indian Ocean in 2006-2009. Geochemistry International, 49(6), 618-627