(Table) Specific activities of 137Cs, 90Sr and 239,240Pu in surface waters obtained during cruises BP06-BP09, Indian Ocean

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.

海洋中人为放射性核素（anthropogenic radionuclides）的主要来源之一，是1945年至1990年间美国、前苏联及其他国家主要在北半球开展核试验所产生的全球放射性沉降物。1961至1962年美、苏两国开展核试验后，1963年北半球中纬度区域的放射性沉降最为显著。
2006年至2009年间，依据俄罗斯科学院维尔纳茨基地球化学与分析化学研究所与印度地球科学部国家南极与海洋研究中心达成的合作协议，科研团队在印度洋多个海域组织开展了协同地质与地球化学调查。在此系列科考航次中，研究人员针对印度洋水体中的人为放射性核素空间分布特征展开了系统调查。本文将汇报本次调查的主要研究成果。